biodiversity strategy action plan – west bengal

BIODIVERSITY STRATEGY ACTION PLAN – WEST BENGAL Agricultural Ecosystems

8. SOIL BIODIVERSITY

Biodiversity is the abundance of variability existing among living organisms – be it plants, animals, microorganisms or the whole ecosystem of which they are a part. Progress of industrial civilisation, rapid growth of human population and excessive exploitation of earth’s resources have led to dwindling of earth’s biodiversity. Biodiversity programmes up till now are mostly centred on plants, animals and insects, with little attention given to microorganisms, in general, and soil microorganisms in particular. Soil biodiversity is largely due to soil biotic community comprising various micro and macro organisms. The described microbial phenomenon and range of diversity of microorganisms in soil are perhaps only a fraction of biodiversity present in soils of the world (Kennedy and Smith, 1995). The difficulties in cataloguing the full range of soil microbial diversity lies in the construction of culture media suitable for growth of each species and strain that occur in soil. At the present level of expertise, only less than 1.0% of soil microbes can be cultured (Pace, 1997)

Soil is a natural habitat of diverse groups of organisms ranging from tiny bacteria to large earthworm. This diversity is indispensable for sustainability in production system on the one hand and maintenance of soil health on the other. The accelerating over-exploitation of soil due to intensification of agriculture resulting in habitat destruction and chemical pollution and overall ecological crisis created by man have threatened the existing biodiversity of soil, in other words the whole life supporting system of soil.Diversity within the soil organisms maintains the sustainability and productivity of the soil ecosystem. The high species diversity may be instrumental in cycling and recycling of nutrients and energy and thereby achieving the stability of the soil ecosystem. The diverse group of soil organisms is not only pivotal in nutrients availability but also in maintaining different trophic relationships among the existing soil population. There is a definite relationship among the soil organisms – synergistic, antagonistic or neutral - in a well-managed agro-ecosystem. Soil flora, particularly fungi by their enormous mycelial hyphae entangle the soil particles and improve soil aggregation, which in turn improves soil aeration, infiltration and root elongation. Rhizosphere microorganisms, particularly plant growth-promoting rhizobacteria (PGPR) by their release of growth promoting substances help the crops to sustain even in

stress conditions. Vesicular-arbuscular mycorrhizal fungi by their elaborating phosphate acquisition and moisture conservation system help the establishment of plants in degraded ecosystem. A diverse group of soil microorganisms are endowed with the capacity of detoxication of wide range of unwanted and unnatural compounds called xenobiotics which agricultural soil receives enormously every season in the form of pesticides. Microbial oxidation sometimes modifies the oxidation state of some heavy metals received from city compost, sewage-sludge and thereby convert them to less toxic state. Soil biota thus perform a myriad of activities beneficial to human beings.

The state of West Bengal has a unique geographical setting in terms of agro-climatic conditions. The hilly mountain and Terai region in the north, alluvial tract in the middle, red and lateritic zone in the west and coastal saline zone in the south with wide range of soils gives a diversification in agro-ecosystem. The diversity of soil organisms may increase or decrease due to occurrence of different landforms that constitute various ecological niches for different communities. The soil distribution in West Bengal has been given in Colour Plate III and for area of broad classes/association of soils in different districts see Annexure IX.

Information regarding the occurrence and distribution of diverse groups of soil organisms under different agro-ecosystem of West Bengal is not comprehensive. Most of our present knowledge has accumulated from studies conducted with specific organisms or individual groups of organisms. Scientific efforts to elucidate interconnections or interactions among organisms and their activities which are responsible for operation of soil ecosystems are also little. However, some information regarding the quantitative and qualitative composition of soil flora and fauna are available which may highlight mainly the organism load under different agro-ecological conditions of the state.

The relative abundance of soil microflora primarily depends on the moisture, pH and organic matter content of soil. In general, the soils of Nadia, which represent the new alluvial zone, rear maximum bacterial and actinomycetal diversity owing to slightly alkaline reaction (pH 7.7) favourable for their development (Table XL). On

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Agricultural Ecosystems BIODIVERSITY STRATEGY ACTION PLAN – WEST BENGAL

the other hand, saline soils representative of coastal zone support minimum diversity of those organisms due to high osmotic potential and some adverse ionic effects.

Lateritic soil, representative of red lateritic zone, however, is enriched with fungal diversity (Mukherjee et al., 1999). In acid soils of northern districts of West Bengal actinomycetal diversity is relatively less owing to unfavourable pH condition. Although rhizobial diversity under acid soil is high but their symbiotic effectiveness is low (Table XLI) and hence pulse cultivation in acid soil is restricted to some extent. Reports (De, 1954) suggest that Azotobacter is not universally present in the acid soil; pH may be the limiting factor for their sustenance in this soil. Beijerinckia have, however, been observed in some acid soils. Information indicates that more than 50% of rice soil of West Bengal, in spite of having favourable pH, does not harbour Azotobacter. Even in those soils where Azotobacter is present, the number is generally small (Bhattacharya, 1958) as also their species richness (Table XLII), the population of A. Chroococcum being the single dominant species. A. indicum, which is later renamed as A. Beijerinckia is very scarce. In rice ecosystem photosynthetic heterocysts bearing cyanobacterial appearance is a unique phenomena. Reports (Saha, 1979) suggest that the majority of the cyanobacterial abundance in alluvial soil of West Bengal is restricted to the family Nostocaceae, with Nostoc, Anabaena and Cylindrospermum being by far the most frequently observed genera. The other dominant genera are Calothrix, Mastigocladus and Scytonema found in some alluvial soils (Table XLIII). Under acid soils, Nostoc and Anabaena may be found because they are seen to have tolerance to a wider range of pH (5.0 to 10.5) and to be ubiquitous in all regions in varying proportions. Plant parasitic nematodes infestation is gaining importance under rice based cropping system. Nematode diversity increases if nematode susceptible crops are included in cropping system (Mukherjee and Khan, 2000) (Table XLIV and XLV).

The component of biodiversity of soils whether being beneficial or harmful, undergoes a quick shift upon perturbations or anthropogenic activities like management practices including intensive land clearing, tillage, puddling, monoculture, use of fertilisers, pesticides, sewage-sludge and inoculation of exotic highly competitive organisms etc. Hassink et al (1991) showed the rhizospheric community was affected most by management practices. Alternative management practices such as minimum tillage or no tillage, crop rotation, organic matter application, integrated nutrient –

pest management, mulching, agro-forestry system improved and preserved soil biodiversity when compared with the previous detrimental practices.

West Bengal has a vast area of land where rice-rice system is followed. Excessive ploughing and laddering during puddling destroy structural stability leading to compaction and hardpan formation under such system. Diffusion of air to such soil is restricted. A distinct microbial shift is obvious. Aerobic flora and fauna disappear while facultative and obligate anaerobes proliferate. Fungal flora falls dramatically whereas microaerophilic Azospirillum population predominates and strict aerobes like Azotobacter mostly disappear. Photosynthetic blue-green algae with lot of diversity appear profusely in such puddled rice soil (Table XLIII).

In red-lateritic, coastal saline and acidic alluvial zones of West Bengal monocropping is usually practiced. Under such system the total carbohydrate fraction of soil organic carbon (SOC) is exhausted compared to that of native (barren) soil resulting in reduction of macroaggregates, the habitat of microbial population. Thus soil structure is modified or in extreme cases destroyed. This habitat destruction under monocropping leads to poor microbial diversity. Continuous monocropping encourages less variability among the microbes around the rhizosphere due to less variation in rhizodeposition. On the other hand, monocrop helps to build up root associated pathogenic organisms. Whereas, crop rotation with suitable crops increases soil organic matter, balances uptake of nutrients, diversifies rhizodepositions and breaks the root associated pathogenic incidence.

Although a balanced fertilisation at field dose is not harmful to soil organisms, but nature of fertiliser used dictates how it influences the soil biodiversity. For example, there are evidences that long-term application of (NH4)2SO4 develops acidity in the soil. On the other hand use of NaNO3 on long-term basis results in deterioration of soil stability and soil structure by dispersing the clay colloids. Thus fertiliser application causes alteration in soil condition in respect to microbial growth and development. On the other hand, fertiliser by its ionic effects and osmotic pressure reduces microbial diversity. Generally speaking, where fertiliser application increases plant growth, the effect on soil macrofauna, notably earthworm, is also favourable (Fraser, 1994). However, earthworms are very sensitive to soil pH, so that the repeated addition of ammonia-based fertilisers to poorly buffered soils may be harmful to earthworms.

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Nitrogeneous fertilisers at field dose increase active protozoa population (Griffiths, 1990) but high levels of nitrogenous fertiliser (120 kg/ha) reduces the same. There are several reports of decreased nematodes diversity after application of ammonium-based fertiliser. Fertiliser consumption in West Bengal is high when compared to our national figure. Such high application of fertiliser may have shifted population dynamics of different soil biota. However, no information is available in this respect.

Soil biology remains in an equilibrium state. This equilibrium is disturbed when an exogenous material like pesticides is introduced (Alexander, 1977). There are some pesticides, which have o effect on microbial diversity (Bollag and Liu, 1990) while others exert deleterious effect on micro-organisms (Das and Mukherjee, 2000; Mukherjee et al., 200). In an alluvial soil of West Bengal under rice ecosystem insecticides like hexachlorocyclohexane (HCH), phorate, carbofuran and fenbalerate, in general, significantly increased total bacteria, fungi, actinomycetes and phosphate solubilisers. While the effect of carbofuran on the diversity of nitrogen fixing bacteria was not significant (Das and Kukherjee, 1995) (Table XLVI). Insecticides, in general did not bring about much quantitative change in the microbial community in the rice rhizosphere. Among the organisms studied Azotobacter disappeared under the influence of phorate and fenvalerate while Diplococcus and Lactobacillus appeared under phorate and fenvalerate, respectively (Table XLVII). Among the actinomycetes diversity. Streptomyces were highly stimulated while those of Nocardia and Micromonospora were reduced (Table XLVII).

When pesticides are applied to soils in very high concentrations, microbial composition significantly changes. Indiscriminate pesticides application causes a tremendous reduction in earthworm population. Although single application of pesticides have shown minimal affect on soil biological properties, it may be more important to consider the effect of repeated application over many years. West Bengal is a state of high cropping intensity. In the north tea is the main commercial crop, which receives wide range of pesticides. In the south field and horticultural crops receive variety of pesticides. Farmers very often indiscriminately use pesticides that may create soil and environmental pollution leading to destruction of non-target beneficial microbial pool.

The effect of most of herbicides on soil flora is more or less temporal at recommended dose. But blanket

application of herbicides can upset the microbial ecology in soil and change the useful flora.

Inoculated organisms, if competitive enough, sometimes alter the microbial composition of native soils. Introduced organisms may be synergistic, antagonistic or neutral. Consequently, the native flora may be accelerated, retarded or remain static. Reports (Saha, 2000) suggest that ginger rhizome inoculation with Azotobacter and Bacillus alone or in combination enhance the bacteria, fungi and actinomycetes, N-fixing bacteria and P-solubilisers in zinger rhizosphere. More interesting was that combined inoculation of Azotobacter and Bacillus significantly suppressed the soft-rot of ginger by reducing the fungal propagules of Fusarium and Phthium.

Organic matter and its quality tremendously modify the composition of soil flora and fauna. Reports (Saha et al., 1993, 1995) suggest that organic matter application (@ 0.5% w/w) significantly increases various groups of microorganisms in alluvial soils. Among the organic matter berseem straw enriches the soil with huge number of bacteria, fungi, actinomycetes, N-fixers, P-solubilisers and S-oxidisers (Table XLVIII). Organic matter upon their decomposition releases phenols, aldehydes, fatty acids, sulphides etc. that may depress plant parasitic nematodes biodiversity. On the other hand, the diversity of bacteria and protozoa feeding nematodes flourishes upon the addition of organic matter in soil.

Soil invertebrates are an integral part of soil biodiversity. They affect soil structure; alter patterns of microbial activity and influence soil organic matter dynamics and nutrient cycling. Among the soil invertebrates, nematodes, termites and earthworms are considered important from agricultural point of view. Cultivation of virgin soil significantly reduces the total nematodes population. Decreased nematode diversity is a common feature of cultivated soils (Yeates and Bird, 1994) and increasing cultivation commonly increases losses of diversity (Boag, 1988). Earthworms in soil engulf large number of nematodes along with soil, which get killed inside the earthworm gut. Thus, abundance of nematode is regulated naturally. Free-living nematodes feed on bacteria, fungi and algae and thereby regulate the diversity and abundance of those organisms in soil (Ingham et al., 1985).

From prehistoric era earthworm is considered as the friend of farmer as they improve the soil fertility by their casting. But successive tillage operations particularly

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mechanical disruptions of soil by tractor and mould board plough disturb their growth. Excessive use of agrochemicals like pesticide and fertilisers in general, and ammonia based fertiliser, in particular reduces their number in cultivated soil. Recent evidences suggest that earthworm population in long-term fertiliser experiment plots is almost non-existent. Insufficient use of organic matter is one of the causes of reduction of earthworm population in cultivated soil. Earthworm essentially increases microbial diversity in surrounding soil by their castings. Ponomareva (1953) stated that there is an increase of actinomycetes, pigmented bacteria and other acteria of Bacillus cereus group in earthworm excreta. Earthworm stimulates the growth of N-fixers and Azotobacter in drilosphere by stabilising the pH of soil by supplying CaCO3 from their calciferous glands.

Deforestation and fragmentation are the common phenomenon in the northern and southern districts of West Bengal and these operations lead to extinction of symbiotic microbes that are host specific and have poor dispersal ability. Some evidence suggests that symbiotic VA-mycorrhizal fungi and N-fixing bacteria are often adapted to a narrow range of environmental conditions.

Disturbance such as deforestation and over grazing alter the soil environment so drastically that mycorrhizal fungi from the neighbouring forest are no longer capable of colonizing and surviving. Certain macro basidiomycetes sp. very common in forest soil are more venerable to disturbance than micro fungi. Canopy opening, acid rains etc. cause changes in Basidiomycetes community composition and reduction in species richness. These subsequently result in decline in fungi vorus snail in forest ecosystem.

West Bengal has a vast soil biological resource base. To protect its soil biodiversity government should formulate an action plan in consultation with scientific and rural community. As soil is the most basic natural resource for human sustainability, research is required at an accelerated space to understand the significance of soil biodiversity and their changes in soil ecosystem with the changes in management practices. There is also a necessity to understand the forces that regulate soil biodiversity and whether a definite level of biodiversity needs to be maintained in soil to sustain soil health and its resilience.

Table XL : Variability in microbial population in some soils of West Bengal

Soil type Bacterial population(cfu x 105/g soil)

Actinomycetespopulation

(cfu x 105/g soil)

Fungi population(cfu x 104/g soil)

Alluvial soil 96.0 84.6 3.4

Lateritic 76.2 30.5 19.0

Saline Soil 62.5 20.0 3.5

Table XLI: Representative symbiotic effectiveness of native rhizobial strains in soils of different districts of W.B.

District Block ChickpeaRhizobia

LentilRhizobia

PeaRhizobia

LathyrusRhizobia

Nadia Krishnagar-IRanaghat-I

CC

DD

CC

--

Beldanga-IBhagabangola-II

BB

BB

C-

--

Murshidabad Farakka B B - -

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Lalgola B B C -West Dinajpur Bansihari

KusmarganjGangarampurIslampur

BBBB

BBBB

CCBB

ADAD

Malda BamangolaEnglish BazarKharba-IIRotua-II

BBBB

BBBB

-B--

B-BB

A – very poor, B – poor, C – medium, D – high

Table XLII : Population of Azotobacter in soils of different regions of West Bengal.

Location pH Azotobacter (No. / g soil)Serampore 6.0 650Bardhaman 6.6 150Swarupnagar 6.8 100Tamluk 6.9 2000Konnagar 7.0 50Kharampur 7.3 300Baruipur 7.3 2500Jadupur 7.4 700Belur 7.7 InnumerableChakmir 7.9 1800Baduria - 50Beldanga - 150

Table XLIII : Heterocyst bearing N-fixing spp. of Blue-Green Algae found in different rice growing soils of W.B.

Location/Family Nagarukhra Haringhata Kalyani Narayanpur ChakdahRivulariaceae - Calothrix

Membranacea,Calothrix sp.

- - -

Nostacaceae Cylindrospermummuscicola,C. licheniforme,Anabaena sp.Nostoc sp.

NostocMuscorum,Nostoc sp.,C.Muscicola,Anabaena sp.

C. michailovskoense,C. muscicola,CylindrospermumSp., AnabaenaSpiroides, Anabaena sp.,Nostoc sp.

AnabaenaVariabilis,Anabaena sp.

AnabaenaOrientalis, A. oscillarioides,Anabaena sp.,C. muscicola

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Scytonemataceae CamptylonemopsisLahorensis

- - - Scytonoma sp.

Microchaetaceae Microchaete sp - - - MicrochaeteLoktakensis,Microchaete sp.

Stigonemataceae - - - Hapalisiphon fontinalis

-

Mastigocladaceae - - - MastigocladusLaminosus

-

Table XLIV : Phytoparasitic nematode biodiversity in rice based cropping system in W.B. at different

agroclimatic zones

Agroclimatic region

Cropping system Stage of sampling

Population density of different nematode species / 250 cc soil(1) (2) (3) (4) (5) (6)

GangeticNew alluvium

Rice-Jute-Rice Tillering(Rice)

163 170 185 94 - 560

Red and lateritic Rice-Wheat PanicleInitiation(Rice)

171 - - - 114 869

Gangetic old alluvium

Rice-Rice Tillering(Rice)

165 - 215 - - 946

Table XLV : Phytoparasitic nematode biodiversity in West Bengal under different cropping systems

Cropping system Population density of different nematode species / 200 cc soil(1) (2) (3) (4) (5) (6) (7)

Rice-Rice-Greenmanure 45 - 38 22 15 - 395Rice-Mustard-Ladies finger 31 - 24 6 - - 543Rice-Potato-Sesame 29 25 18 41 - 15 668Rice-Potato-Groundnut 11 4 29 38 - 15 603Rice-Rice-Rice 18 10 11 11 - - 355Rice-Potato-Rice 27 70 48 - - 21 749Rice-Wheat-Jute - 220 17 18 - 9 636Rice-Cabbage-Rice 58 - 16 18 - 6 508Rice-Mustard 36 - 32 28 - 5 647

1. Hirschmanniella oryzae, 2. Meloidogyne sp., 3. Hoplolaimus sp., 4. Helicotylenchus sp., 5. Pratylenchus sp., 6. Tylenchorhynelous sp., 7. Saprozoic nematodes

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Table XLVI: Effect of insecticides on the diversity of microflora in a rice field soil.

Treatment Bacterial population

(cfu x 105/g soil)

Actinomycetes population

(cfu x 105/g soil)


N-fixing bacterial population

(cfu x 104/g soil)

P-solubilising organisms (cfu x

105/g soil)Initial At

60dInitial At

60dInitial At

60dInitial At

60dInitial At

60dControl 121 101 13 63 60HCH 174 144 13 69 95

Phorate 102 153 75 132 8 14 40 68 44 86Carbofuran 129 106 10 60 70Fenvalerate 116 137 11 61 88

Table XLVII: Effect of insecticides on the occurrence of predominant genera of micro-organisms in rice field soils

Micro-organism No. of isolates Treatment

Control

HCH Phorate Carbofuran Fenvalerate

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BacteriaBacillus sp.MicrococcusPseudomonasStaphylococcusCorynebacteriumProteusAzotobacterDiplococcusLactobacillusErysipelothrix

45878101000

49973011000

481132130101

441046311001

52743100120

ActinomycetesStreptomyces sp.Nacardia sp.Micromonospora sp.

35296

50191

43234

47203

44242

FungiAspergillus sp.Penicillium sp.Fusarium sp.Trichoderma sp.Rhizopus sp.Helminthosporium sp.

272313340

261026323

1919101480

241819630

241525320

Table XLVIII : Effect of different organic matter on microbial diversity in soils.

Treatment Bacterial population

(cfu x 106/g soil)

Actinomycetes population

(cfu x 105/g soil)


N-fixer (cfu x 105/g soil)

P-solubiliser(cfu x 106/g soil)

S-oxidiser(cfu x 105/g soil)

Control 22 26 75 77 23 5

Berseem Straw 67 97 95 150 51 13

Bagasse 59 70 109 109 35 11

Paddy Straw 40 65 88 108 37 10

IX. Ca 76 84 94 130 46 15

X. Ces 85 84 102 131 42 24

XI. Ipo 59 101 109 105 35 25

Strategy

There are certain broad-based overall strategies for addressing problems of soil biodiversity.

Ÿ Evolving better soil management techniques and putting an end to manipulating soil morphology for high value crops like tea.

Ÿ Encourage R&D in soil bio-diversity.

Ÿ Encourage soil testing before growing season on a regular basis.

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Ÿ Thrust on soil care by farmers.

Action Plan

Ÿ Device sample soil-testing and regeneration

mechanisms by use of biological indicators. Earthworm culture using indigenous species may be useful as a first step.Suggested actors: Agricultural Department, Government of West Bengal, Soil-scientists (State govt/ ICAR institutes located in the state), Entomologists/ plant pathologists, Farmers who are ready to experiment on their fields, WBCADC, NGOs and Panchayat Institutions. Time frame: 5 years.

Ÿ Participatory meetings to be organised with local

bodies in the process of soil status report-yearly review.Suggested actors: Agriculture department, People from the administrative arena of the state like Block Development Officers/ agriculture development

officer, Agricultural officers in the Banks specially in the rural sector, Representatives of local bodies, NGOs, Panchayat. Time frame: Yearly

Ÿ Composting requires to be practised on a much

larger scale. Suggested actors : Agricultural extension services, Panchayats. Time frame : One year.

Ÿ Soil and water conservation.

Suggested actors : WBCADC, Kalyani Krishi Vigyan Kendra, Forest Department. Time frame : One year.

Ÿ Alteration of cropping pattern.

Suggested actors : Agriculture Department, Agricultural Universities, Kalyani Krishi Vigyan Kendra. Time frame : One year.

.

9. AGRICULTURAL ECOSYSTEMS

In about a hundred years (1856 to 1949) because of excessive use of fertilisers on a pasture in England, number of species of native plants were reduced from 49 to 3. Widespread use of chemicals based agriculture that was the norm in England then, continues to be the norm in most states in our country even today. West Bengal is no exception, despite the setbacks in terms of loss of variety, which has affected the entire spectrum of crops grown. A

recent study of diminishing crop varieties in West Bengal, commissioned by the Department of Environment, shows declining trends in availability of many native varieties especially in rice. In a separate project also commissioned by the Department of Environment in 2000, phenomenal rise in inorganic fertiliser application rate has been observed along with declining yield and soil health.

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The traditional farmers, who are globally known to be the only repository of varietal diversity of seeds are hardly left with very many incentives to carry on with their practices which are increasingly losing out to the persistent advocacy and monetary promise of modern agriculture. To match this loss of diversity, the formal centers of seed preservation (rice/ oil etc.) have shown a drastic fall in the number they are now maintaining in the State.

While the defaulting industries which are releasing polluted waste, can be apprehended by the Pollution Control Board/ Department of Environment and be punished for non-compliance of the provisions of the Environmental Protection Act, there is no legislative or regulatory provision for non-point sources of pollution in our country. Very often, the agricultural fields, are non-point sources of pollution, as they drain a large amount of unutilised chemicals and toxins. The Department of Environment or for that matter the State Pollution Control Board does not have any tangible instrument to regulate the overuse of agrochemicals. This will have to be read with the plight of very aggressive marketing of agro-chemicals by the corporate quarters that do not hesitate to buy decisions in their favour to promote sale. This situation is hardly enviable for those who care for nature and conservation of biodiversity. It is also well known now that the ‘protected area’ approach is losing its significance more and more as the primary method of managing biodiversity. It will be in the non-forest areas where the major thrust for biodiversity management programme will have to be positioned in future. Understandably, the agricultural fields will be the most significant land use area where the future of biodiversity management will have to meet the most formidable challenge. This is true for West Bengal and is also true for the country as a whole.

Agriculture is by far the most extensively practised activity in West Bengal. Ecological history of agricultural biodiversity tends to separate the time into three sections: pre-independence, diversity when the Green Revolution was on, and biodiversity now.

The completely rain-fed, organic and single-cropped pattern of the pre-independence period went through a complete overhaul during the days of the Green Revolution, when improved varieties, synthetic, inorganic inputs and mechanised techniques took over slowly but surely. This was due to a single important consideration – yield, at remunerative prices. This, however meant a lot of changes in the agro-biodiversity of the entire landscape of West Bengal, and a massive change in its land-use pattern. This also led to a gradual to rapid change in gene pool and varietal base, which became narrower with time.

This chapter takes a look at the status of biodiversity and its decline in West Bengal, and suggests appropriate measures to conserve variety. There is a special note on weeds found in the different agro-climatic zones, which are a very important component of wild biodiversity. Horticulture being of prime importance and having immense potential, has been dealt with elaborately, with separate statement on biodiversity status, current initiatives and future conservation measures required.

In addition, there are two success stories of good conservation initiatives – one in the area of biofertilisers and the other on reviving biodiversity of a Medinipur wasteland by the Rural Development Centre, Kharagpur.

Since tea is an important commercial crop in West Bengal, its problem has been treated separately, in accordance with the feedback from the people in separate meetings held in North-Bengal.

Agro-climatic zones

Introduction

West Bengal is the only State in India which extends from the snowy peaks of the World’s loftiest mountain, the Himalaya in the North to the Bay of Bengal in the South. Although not very large in itself, its location in respect of land and water and varied topography induces diverse climatic conditions. The South facing slopes of the Himalayas receive very heavy rainfall in some places exceeding 5,000 mm, whereas in some areas of the relatively drier western districts of the State the average annual rainfall marginally exceeds 1,200

mm. The western districts of the State suffer from frequent ‘heat wave’ in summer months when maximum temperature frequently goes upto 45oC or even beyond, whereas the northern hilly region comes under the grip of intense cold during winter when the minimum temperature often drops below freezing point. The coastal areas of the State experience fierce cyclonic storms during pre-monsoon and post-monsoon months. Droughts of different intensity are common in some areas while floods have become almost a regular phenomena in others.

The distribution of precipitation, temperature, humidity, cloudiness also register marked variations from one

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season to the other. During the monsoon cloudy sky moderately high temperature, high humidity and rainfall are almost of regular occurrence whereas a rainy day is rare in winter when clear sky, bright sunshine and low temperature become usual features. During transitional periods the weather is variable from day to day but during monsoon the condition of any one day is a fair sample of the season. Apart from the above regional and seasonal variations in the climatic elements and weather phenomena, some areas have some definite climatic trend also.

All the above variations of climatic conditions coupled with soil are well reflected in the natural vegetation of the land, which includes numerous varieties of species beginning with mangrove along the coastal belt to

purely temperate flora over the Himalayas. Various aspects of agricultural activity, cropping pattern, productivity and occurrence of posts and diseases are also in tune with the above. Management of water, soil and land are also conditioned by climatic variations in the State.

The agro-climatic regions of West Bengal have been shown in Colour Plate IV.

Seasonal Diversity

Depending on homogeneity of weather condition the year in West Bengal may broadly be divided into the following four seasons :

SEASON PERIOD BROADLY CORRES PONDING AGRICULTURAL OR CROP SEASON

1) Cold weather season or winter December – February Rabi2) Hot weather season or summer March – May Pre-kharif3) Southwest monsoon or Rainy June – September Kharif4) Retreating monsoon or ‘Hemanta’ October – November Maturity and harvesting of kharif and field

preparation and sowing of Rabi crops

Compiled for present publication

Cold Weather Season or Winter

Weather of the winter season is characterised by low temperature, clear skies, inclined but bright sunshine, light, variable northerly wind which is dry and chilly. Fog frequently occur where and when the humidity is high. In the coastal areas sea fog frequently invade inland.It is the season of low temperature. January is the coldest month in the brief winter season lasting from December to February. The mean daily temperature of the winter season varies from a little over 21oC along the coastal belt of the south to 16oC in the northern margin of the plains of Darjiling and Jalpaiguri in the north. In the hills temperature decreases rapidly with increasing elevation. Minimum temperature over the plains of North Bengal often drops up to 4 to 5oC and over the Gangetic West Bengal 6 oC - 7oC following the passage of the Western disturbances.

This is the driest season of the year which contributes 1.1 to 3.6 % of the total annual rainfall of different districts and the amount varies from 21.6 mm at Tapan to 121.7 mm at Gorubathan in the Sub-Himalayan West Bengal and 32.2 mm at Memari-II to 69.9 mm at Taldangra in Gangetic West Bengal.

Hot Weather Season or Summer

The summer is proceeded by a somewhat insignificant spring season which is rather a period of transition between the winter and the summer. It is a period of extreme heat which gradually increases day by day, reaching the maximum in May. During the season the western plateau fringe becomes the hottest place where the average temperature lies above 30oC. To the east it is slightly lower and along the coastal belt it is also low due to the moderating affect of the sea. To the north the average summer temperature gradually decreases from 28oC in Maldah to 20oC up to margins of the hills. May is the hottest month everywhere when the average daily maximum temperature lies above 38oC along the Western part. Maximum temperature frequently exceeds 40oC specially in the western districts during April and May.

West Bengal receives 6% to 18% of the total annual rainfall during the season. The main source of rainfall during the season is from the well known ‘Norwesters’. The amount of rainfall gradually increases along with the progress of the season. Average summer rain in the

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State varies from 95 mm at Para in Purulia to 680 mm at Gorubathan in Darjiling. Cultivation of Jute, Aus Paddy, summer pulses, oilseeds and vegetables in the State depend largely on the distribution of summer rain.

South-West Monsoon or Rainy Season The southwest monsoon is the principal feature in the climate of West Bengal as well as the main denominator of the prosperity of the State and its agro-economy.

This season is characterised by uniform temperature with minimum diurnal range almost throughout the entire tenure of the season. Average temperature of the season over the State from the coastal belt up to the plains of Jalpaiguri and Koch Bihar varies from 28oC to 29oC.

This is the well-known rainy season in the State which contributes 73 to 81 % of total annual rainfall of different districts within 48 to 88 rainy days. The amount of rainfall varies from 970 mm at Burabazar in Purulia to 3914 mm at Gorubathan in Darjiling.

By the second week of June the whole of West Bengal comes under the influence of the Bay of Bengal branch of the monsoon current. The monsoon is a period of general rain with intervals of comparatively dry weather. The districtwise figure of normal rainfall in West Bengal has been shown in Annexure X.

Retreating Monsoon or ‘Hemanto’

The season of retreating monsoon is a period of transition between the warm rainy monsoon and the dry cool winter. The change begins in the early October after the withdrawal of monsoon and is usually completed by the end of November.

The clear autumn weather following the termination of the monsoon rains is accompanied by a rapid fall of temperature. Minimum temperature drops more steadily than the maximum, creating a larger diurnal range. The mean temperature of October is about 2oC lower than the mean temperature of September but the change from October to November is still larger.

The monsoon withdraws from West Bengal after some intermittent action in the first half of October. Rainfall gradually ceases to occur over most part of the State except the coastal areas, where the amount of cyclonic rain is fairly high. This season shares with 5oC to 10oC of the average annual rainfall of different districts which

varies from 80 mm to 290 mm in different parts of the State.

The sky becomes gradually clear with some white patches of floating cumulus clouds. This is the season of cyclones specially in the coastal belt. During cyclonic storms and depressions the sky remains overcast with low cloud which persists for days together along with gusty winds and rain specially in the coastal areas.

The nights start becoming cooler as the days’ heat is radiated out fast through the clear, night skies. There is much dew in the morning which is caused by sudden drop in temperature at night.

Regional Diversity;

The State has been divided into 6 agro-climatic zones as follows :

Northern Hill Zone

Terai-Tista Alluvial zone

Gangetic Alluvial zone

Vindhyan Alluvial zone

Undulating Red and Lateritic zone and

Coastal saline zone

There is no doubt that the above classification is primarily based on soil and terrain but the zones differ among themselves by the variation in climate and weather characteristics.

Northern Hill Zone

This region occupies only 2.8 % of the total area of the State extending over 8 agricultural blocks in Darjiling, Kalimpong and Kurseong Sub-division of Darjiling district. Although the average annual rainfall of this zone is 3045 mm it varies widely depending on the location of a place with respect to height and slope. Gorubathan located on the south facing slope in Kalimpong sub-division receives average annual rainfall of 5007.8 mm, Pulbazar on the other hand records 1895.4 mm average annual rainfall due to its location on the leeward side. Temperature also varies widely due to variation in height. Annual average precipitation is much higher than the potential evapotranspiration

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and the span of growing season (when precipitation exceeds half the potential evapotranspiration) is large which varies from 200 to 280 days. This zone covers two distinct climatic regions – (a) Super humid montane southern slope and (b) Humid montane northern slope.

Terai-Tista Alluvial Zone

This zone occupies 14 % of the total land area and extends over 31 agricultural blocks covering whole of Jalpaiguri and Koch Bihar, parts of Siliguri sub-division of Darjiling and Islampur Sub-division of Uttar Dinajpur. Amount of rainfall increases from about 1600 mm at Karandighi in the south to 4035 mm at Kumargram in the north. Annual average precipitation exceeds by more than 1000 to 2000 mm over the average potential evapotranspiration and the length of growing season varies from 180 to 220 days. This zone embraces two climatic zones viz: Super humid Terai and Humid interior.

Gangetic Alluvial Zone

This zone occupies 19.7 % total area of the State covering 92 agricultural blocks of 9 agricultural districts from Uttar Dinajpur to South 24-Parganas mainly to the east of river Hugli in South Bengal. Average annual rainfall of the zone is 1494 mm which varies from 1265 mm to 1858 mm within the zone. Average annual precipitation is almost equal to the potential evapotranspiration in its central part but exceeds to its northern and southern part. Length of growing season varies from 160 to a little above 180 days. This zone includes parts of Humid interior, Semi humid north and south and Sub-humid east.

Vindhyan Alluvial Zone

The Vindhyan Alluvial zone also extends in a north-south direction to the west of river Hugli and occupies 14.4 % total area of the State covering 67 agricultural blocks spread over 10 agricultural districts. This zone receives an average annual rainfall of 1472 mm which varies from 1244 mm to 1955 mm over its different parts. Average annual precipitation in general is almost equal to or slightly less than the potential evapotranspiration. Length of growing season is around 160 days and this zone includes three climatic zones like Semi Humid north, Semi Humid south and parts of Sub-Humid west.Undulating Red And Lateritic Zone

This zone occupies 32 % of the total land area covering 84 agricultural blocks spread over 6 agricultural districts mainly along the western part. This zone receives an average annual rainfall of 1413 mm which varies between 1219 mm and 1644 mm over its different parts. This is the zone where the average annual precipitation is less than the average annual potential evapotranspiration. Here the growing season is around 140 days and this zone broadly corresponds the remaining part of the Sub-Humid west climatic zone.Coastal Saline Zone

This region occupies 17.1 % of the total land area covering 53 agricultural blocks of 4 agricultural districts all along the coastal belt. Average annual rainfall of this zone is 1743 mm which varies from 1535 mm to 1919 mm over its different parts. Average annual precipitation exceeds by more than 200 mm over the average annual potential evapotranspiration. Here the length of growing period varies from 160 to 180 days. This zone broadly corresponds with the Humid coastal climatic region of the State.

Land Use Pattern

According to the report on Status of Agriculture in West Bengal, 2000, net cultivated area in West Bengal is about 54.71 lakh hectares. Total number of cultivators is 65.47 lakh and per cultivator availability of net sown area comes to about 0.85 hectare. Due to continuous division and fragmentation of cultivated land, larger capital investment for development in the agriculture sector is gradually becoming less remunerative. A striking feature of the state agriculture is that 72% of the cultivated land is in the hands of small and marginal farmers who

account for more than 93% of farming community. About 61% of the geographical area (88.75 lakh hectare) is available for agriculture, of which about 95 per cent is actually under agricultural use and 5% is uncultivable wasteland including current fallow. Approximately 13.4 per cent of the land area has forest cover.

Agro-climatic zone wise land use statistics of West Bengal is presented in Table XLIX.

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Table XLIX : Land Use Statistics ( area in ha ) 1999 -2000, West BengalZo

ne

Repo

rting

area

Fore

star

ea

Area

Unde

r non

-ag

ricul

tura

l

Barre

n an

d un

cultu

rabl

el

Perm

anen

tp

past

ures

and

othe

r

Land

und

er

misc

. tre

eG

rove

s no

t

Cultu

rabl

eW

aste

Land

Fallo

w La

nd

Oth

er T

han

Curre

nt

Curre

nt

fallo

w

Net a

rea

sown

Northern Hill

Terai-TeestaAlluvial

GangeticAlluvial

VindhyanAlluvial

Coastal Saline

Undulating Red& Lateritic

241543

1216367

1714530

1247216

1484944

2784432

113401

196130

2227

14933

427520

437741

13333

186529

418085

244689

234262

534310

4504

4783

2246

1094

1344

13757

1216

336

155

180

131

3186

1797

20545

13368

5581

10435

24750

1615

1595

4218

6671

1609

26491

4874

1893

654

2015

2309

22516

4622

17958

24409

6359

9021

145928

96181

786598

1249168

965694

798313

1575753

Total 8689032 1191952 1631208 27728 5204 76476 42199 34261 208297 5471707

Source: Status Of Agriculture in West Bengal, 2000

Recent (1999-2000) information of cultivable area, net cropped, gross cropped area (hectare) and cropping intensity (per cent) of the state are presented in Table L.

Table L : Cultivable area, net cropped area, gross cropped area & cropping intensity of West Bengal, 1999-2000

DistrictCultivable

Area(ha)

Net croppedArea(ha)

Gross croppedArea(ha)

CroppingIntensity(Per cent)

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Darjiling

Jalpaiguri

Coochbehar

Dinajpur ( N )

Dinajpur ( S )

Maldah

Murshidabad

Nadia

24-Pgs (N)

24-Pgs (S)

Haora

Hugli

Burdwan

Birbhum

Bankura

Puruliya

Medinipur (W)

Medinipur (E)

166871

346063

260492

270701

196185

304252

423948

320935

268263

403849

93706

230249

477343

342399

397731

438406

516572

374975

147986

333158

246121

260538

192390

281281

417997

309329

262043

387610

88085

225712

456751

330619

349590

328133

485648

368716

173672

510923

498569

486432

298258

440127

879055

769126

548090

571845

181660

495856

872844

515514

523165

361237

792259

626731

117

153

203

187

155

156

210

249

209

148

206

220

191

156

150

110

163

170

West Bengal 5832940 5471707 9545363 174 Source: Estimatesof Area & Production of Principal Crops in West Bengal, Directorate of Agriculture, Govt. of West Bengal, 1999-2000

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In the preceding decades, the land-pattern in our State had drastically changed. Almost entire arable land has been brought under the cultivation of Cash-crops and also under Multiple-cropping. As a result, area of traditional pasture-land has almost vanished. Our state is fodder deficient. Against an annual requirement of 92.6 thousand M/T only 18.78 thousand M/T of green-Fodder is produced. Land available for fodder cultivation in west Bengal is only 1.18%. Considering all these aspects, Animal Resources Development Department has decided to give emphasis on establishment/revival/strengthening of pasture land as a means to combat the situation at least to some extent. The Department proposes to adopt from current financial year Silvi Pasture system in waste and degraded land.

Crop Production

Rice, wheat and pulses constitute the major foodgrain crops of the state, while varieties of oilseeds, potato, jute and sugarcane are other important agricultural crops. Among horticultural crops, vegetables, fruits and flowers occupy important position.

Diversity at crop and varietal levels in agriculture

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Background information

Diversity in agriculture has been a matter of concern for some time now. More so, when scores of high yielding and hybrid varieties of different crops have entered the field, slowly replacing the old indigenous types. While replacement of old poor yielding indigenous types in the different crops, particularly food crops, was imperative in view of deficiency in food crop production, with it several ill effects are also being observed due to lack of judicious management of these highly productive varieties. Hence along with appropriate management, conservation of old indigenous types is also required so that future breeders utilise the valuable source offered by the indigenous types developed after enduring the stress of natural selection over ages.

Agricultural diversity has to be considered from two angles: (1) crop diversity, and (2) varietal diversity. It has to be assessed first what was the spectrum of diversity earlier and what is it now.A cut off point needs to be fixed which from a realistic view was taken to be the independence of the country.

With this objective in view a project “Studies of the Diminishing Species Diversity in Agriculture in West Bengal“ was commissioned by the Department of Environment. As a result of the studies conducted, a somewhat acceptable picture of the status of crop and varietal diversity existing in the state during pre-Independence period and after Independence has emerged. The study required extensive survey in the districts covering all the blocks. But that extensive survey could not be undertaken due to the limited scope under the project.

Methodology

While the districts were not sampled, blocks had to be sampled restricting it into three per district. Then again the villages under each sampled block had to be sampled on the basis of high, medium and low land situations for cultivation of crops. However, the number of villages sampled was not fixed, it varied from district to district.

It was seen that rummaging through the old records available in the district agricultural offices, very scanty information was available for the pre-independence period, so old farmers with mental alertness were selected in each village sampled. The villages were visited and the old farmers were interrogated with assistance from the relatively younger villagers who could remember what crops and varieties used to be cultivated during the pre-Independence period. The information emanating from the interrogation was collected and compiled. The main difficulty was with rice as there were so many indigenous and improved indigenous varieties under cultivation that the farmers could not remember a great many of them. In crops however there was no difficulty as in most cases only non-descript indigenous types were under cultivation. Hence for rice the records kept at the Rice Research Station, Chinsura were consulted and information available recorded.

Availing this opportunity of interrogating the farmers other questions were also asked, which were:

Reaction of the farmers towards the high yielding and hybrid varieties,Views of the farmers regarding requirement and use of chemical fertilisers, pesticides, and irrigation water, as well as trend of using organic manure,Farmer’s views about essentiality of applying organic manures in conjunction with chemical fertilisers and the way this can be made available to them.

Questions about other related topics were also asked and the farmers’ views recorded.

Results of investigations

The results of the studies made are dealt in two parts. The first part relates to the information collected on the status of crop and varietal diversities during pre- and post-Independence periods. The second part is about the farmers’ reactions to the questions asked other than those about crop and varietal diversity.

(A) Status of crop and varietal diversity during the two periods under consideration

1. Number of crops cultivated during pre-Independence period was by and large as it is now.

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2. Number of indigenous varieties, particularly in rice was remarkably higher earlier than it is now.

3. The indigenous rice varieties now are restricted to such areas only for which high yielding varieties are not available. In all medium, medium-low and partly high land where irrigation water has been made available, only HYV or hybrid varieties are cultivated.

4. Thus while during pre-Independence period 1015 indigenous and improved indigenous varieties were in cultivation, at present only 255 are in the field. These numbers however, are not absolute as the survey work could not be conducted as extensively as it was necessary. At present it is estimated that the indigenous and improved indigenous varieties together occupy 30 per cent of the total kharif area while the remaining 70 per cent is occupied by the HYVs and hybrid varieties taken together. Besides, 100 per cent of the boro rice area is covered only by short duration HYVs.

5. In other crops of importance like pulses, oilseeds, sugarcane, potato, jute etc., while in the pre-Independence period mostly non-descript local varieties were in cultivation, there has been a sea of change after Independence. Wherever available, the crops are all of better yielding varieties developed either within the state or introduced from other states

6. Following an urge to produce more, catchy varieties have been introduced from neighbouring countries, ignoring the advice of the Department of Agriculture. Saket-4 variety of rice is a case in point. This variety was introduced by the farmers of the districts adjoining Bangladesh. Being highly susceptible to blast disease this variety caused havoc in the field. However, there are also other examples of introduction of beneficial varieties at the initiative of the farmers. China Boro from Bangladesh is extensively cultivated in Koch Bihar and Jalpaiguri districts. This has not inflicted any damage on the farmer’s production level.

7. A bold seeded mustard variety Varuna was planted by the farmers. Its cultivation had to be discontinued later as this variety needed some special management that the farmers could not afford.

8. A scented variety of mung i.e. Sonamung is going to be lost as being poor in productivity and highly susceptible to yellow mosaic virus, this variety has been pushed to a backseat. The germplasm of this variety is a treasure in the germplasm stock at the disposal of the entire country as it is perhaps the only mung variety endowed with a characteristic scent.

9. The short duration indigenous toria, part of the natural diversity in its centre of origin – the foothills of the Himalayas – is facing extinction due to the urge of the farmers for higher productivity in rapeseed, Brassica campestris and subsequent adoption of yellow sarson in its place.

10. Sabui and Babui grass used particularly by the tribals living in the driver parts of the state are slowly disappearing . The grasses were used for making rope and other articles of household utility. They no longer find favour with the tribals after synthetic fibre made rope are available in the market. The rope made out of these grasses were considered to be handier and stable than ropes made of jute, sunhemp, mesta etc. Further, the growing of these grasses does not require any special cultivational practice.

11. Gangajali variety of wheat, a durum wheat, known to withstand moisture stress in the soils, is hardly visible after the HYVs of wheat have invaded the cultivated arena. This precious genotype is getting lost.

(B) Farmer’s reactions

1. High yielding varieties particularly rice, require greater use of chemical fertilisers, irrigation water and pesticides. Indiscriminate use of chemical fertilisers and pesticides is causing disturbance in environment and soil health.

2. Out of an urge to produce more, the practice of using organic manures is being overlooked. Further, as the rural bovine population is gradually decreasing, the availability of cowdung manure is also on the wane. Tractors and power tillers are now available on hire for which land preparation has become easier and quicker. Though tilling of soil by bullock driven plough is cheaper, small farmers do not favour the upkeep of bullocks due to high cost of cattle feed and non-availability of pasture.

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3. Further, due to fuel scarcity in rural areas whatever cowdung is produced is all burnt. This has added to the problem of availability of farm yard manure (FYM).

4. Farmer’s feel the problem can be addressed to a substantial extent if the drive for rural composting is revived. The farm refuse, cowdung, poultry litter, and the huge tonnage of weeds removed from the field to keep the cultivated land clean can be used for preparing compost.

5. Farmers are well aware of the essentiality of using organic manure in conjunction with chemical fertilisers to get the best result.

6. The disappearance of agriculturally beneficial creatures like toads, frogs, earthworms, small fishes in the rice fields etc was related to the non-judicious use of pesticides, ignoring the recommended dose and frequency of application. The loss of small fish is felt very gravely by the farmers as these used to provide food to the poor farming community.

7. Farmers were of the view that indiscriminate use of pesticides has led to the disappearance of the beneficial insects, allowing harmful insects to multiply and spread in the crop fields.

8. Note: This is not fully acceptable as the view that new insects have appeared with the destruction of beneficial insects is not true. The insects commonly found now existed earlier also. They have flourished due to intensive cropping.

9. Introduction of high yielding varieties has changed the rural social character and has been instrumental in providing more employment to the rural agricultural labourers. Further, higher production being the need of the day to keep pace with the steady growth of population, a compromise has to be reached.

10. Modern agricultural technology has provided solutions to many problems. Short duration varieties have made it possible to take up intensive cropping system.

11. Land shaping techniques followed in South 24 Parganas have enabled the farmers to convert the chronically mono-cropped areas to at least double cropped, that too with vegetables, raising the economic level of the farmer. Similarly, soil amendment techniques in the highly acid soil areas of the state has enabled the farmers to grow crops of choice and need.

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Action Plans suggested

This may be discussed in two parts, one relating to conservation of genetic wealth and the other on the steps to take according to the farmers’ views and related matters.

(A) Conservation of genetic wealth available in indigenous material

1. Indigenous rice varieties that are not found in the field, should be conserved. Before starting the conservation process a fresh and extensive survey has to be conducted. This will take into account the existing varieties still cultivated in the remote areas where modern agricultural technology has not yet percolated or due to economic reasons high yielding varieties cannot be grown. These materials should be collected and added to the repository, after checking the list of already available genetic wealth which are being maintained.Actor: Department of Agriculture, Govt of West BengalTime frame: (i) Survey- 3 years (ii) Collection and conservation - 5 years

2. Earlier a large number of scented indigenous and improved indigenous varieties of rice used to be grown. Presently, very few of them are in the field, presumably due to their poor yielding ability. All such scented varieties are to be conserved.It is necessary to check whether the characteristic scent will be retained if these scented varieties are conserved in an area other than where it used to be grown. One example will amply demonstrate this concern. Tulai Parigi, a scented variety of South Dinajpur, does not express its scented character even in the nearby district of Murshidabad. Under such circumstances, location-based repositories are to be established.Actor: Department of Agriculture Time frame: 5 years

3. Sonamung, a scented indigenous variety of mung should be collected and conserved as it is the only scented mung in the country. Sonamung also does not express its characteristic scent in places other than where it is grown at present viz. specific areas in the districts of Malda and Nadia. Hence location-based repositories are to be established.

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Actor: Department of Agriculture Time frame: 3 years

4. Naturally occurring diversity of toria, Brassica campestris, found in its centre of origin near the foothills of the Himalayas, has to be conserved by collecting the available material and maintaining in the relevant research centre.Actor: Department of Agriculture Time frame: 3 years

5. Mash and Biri Kalai used to be extensively cultivated earlier. With the availability of better yielding erect and photo-insensitive types, these have been pushed to back seat. These indigenous types are endowed with capability of growing in adverse climatic conditions and the seeds have a high content of oligosaccarhide that is useful for preparation of some split pulse products so popular with the consumers. These types require to be conserved.Actor: Department of Agriculture Time frame: 3 years

6. Mashiam Kalai in hills is a very hardy and stable pulse for hilly areas where very few other kinds of pulses can be grown due to high acidic content of soils. Other crops are slowly replacing this pulse and it is not unlikely that in future this crop may lose its identity. This indigenous crop variety should be conserved.Actor: Bidhan Chandra Krishi Viswavidyalaya Research Centre, Kalimpong and Department of Agriculture Time frame: 2 years

7. A wild maize type was located in Darjiling and Sikkim hills in the 60s by the Indian Agricultural Research Institute (IARI). This was considered to be one of the progenitors of cultivated maize and was found to possess some useful characters worthy of being incorporated into the cultivated maize. The seeds may be collected and conserved.Actor: Bidhan Chandra Krishi Viswavidyalaya Research Centre, Kalimpong and Department of Agriculture Time frame: 3 years

8. A durum wheat variety Gangajali, capable of growing well under rainfed condition and having excellent chapati-making quality used to be grown in Malda. With the availability of HYVs of wheat this variety finds no place at present excepting in the fields of some interested farmers. This variety requires to be conserved. Actor: Department of Agriculture Time frame: 2 years

Actions to be taken according to farmers’ views and related matters

1. Special drive to develop rural composting using farm and household refuse, cowdung, and weeds removed from the cultivated land, coupled with restoration of the practice of growing green manure crops with short duration legumes like mung, cowpea and others.Actor: Department of Agriculture Time frame: 2 years

2. Growing of Azola in village tanks and ponds for subsequent application in the field.Actor: Department of Agriculture and relevant non-government organisations (NGOs)Time frame: 5 years

3. Drive to extensively use bio-fertilisers with special stress on B.G.A. Actors: Department of Agriculture, Bidhan Chandra Krishi Viswavidyalaya (BCKV) and relevant NGOs Time frame: 5 years and should be regular programme

4. Application of effective strains of Brady Rhizobium to pulse crops, particularly when a pulse crop is intended to be taken in an area where earlier no such pulse crop was grown. Effective nodulating strains require to be given.Actors: Department of Agriculture, Bidhan Chandra Krishi Viswavidyalaya (BCKV)Time frame: 2 years

5. Sabui and Babui grass plants to be conserved Actors: Department of AgricultureTime frame: 1 year)

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6. The seed size of Benoy, a rapeseed variety popular amongst the farmers, is found to have deteriorated. Seed size improvement programme requires to be taken up immediately by utilising the natural variability in the plants.Actors: Department of AgricultureTime frame: 6 to 7 years)

7. Farmers may be trained about the vermiculture technique developed at BCKV and followed by some NGOs. This will add organic matter as well as earthworms to the soil, to supplement use of organic manures.Actors: Department of Agriculture and BCKV Time frame: 3-4 years

8. Balanced farming was advocated by the Department of Agriculture quite some time ago. Such balanced farming will involve use of use of organic manures, green manures, bio-fertilisers like BGA, Azotobacter, Brady Rhizobium, phosphate solubilising bacteria etc. as well as chemical fertilisers. By this the efficacy of N, P, K intake as well as soil health will improve. Actors: Department of AgricultureTime frame: it should be a continuous process

9. In view of the possible bad effects of high doses of chemical fertilisers and pesticides beyond the recommended levels, farmers must be educated about the Integrated Pest Management techniques to keep pest attacks at bay.Actor: Department of Agriculture Time frame: This should be a continuous process till the farmers are educated

10. Soil testing facilities should be expanded from the present level, by establishing mobile testing laboratories. This way, the farmers themselves will learn how to minimise the use of chemical fertilisers.Actor: Department of AgricultureTime frame: This should be a continuous process

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The Challenge of Conserving Horticultural Biodiversity in West Bengal

I. Introduction:

Commercial horticulture in West Bengal started as an extension of home-gardens. Nawabs, Zamindars, kings and the wealthy people promoted gardening with indigenous and exotic collections as a symbol of nobility. Home gardens and subsistence horticulture have been a continued programme among communities since time immemorial. Vegetables and fruits for home consumption are supplied from such gardens only in remote areas having no organised market. Home gardens and subsistence horticulture have been a continued programme among communities since time immemorial. Vegetables and fruits for home consumption are supplied from such gardens only in remote areas having no organised market. Many of the new species and varieties of fruits, vegetables, flowers have been introduced from other countries. For example, papaya came to India from Central America, pineapples from Brazil, tomato from Peru or Mexico. Some of the crops came with voyagers and some others with travellers and invaders. Scientists, farmers and institutions introduced and evolved a large number of varieties of horticultural crops in course of time by selection from natural sources, breeding or from exotic sources. Consequently, the varietal treasure was very rich in colour, flavour, taste and all other quality attributes.

Many of the introduced varieties existed in cultivation for a short period and were replaced by better ones after some time. There exists a continuous process in commercial horticulture. With increase in population, pressure on land multiplied, search for higher yielding types intensified, and thus old varieties even with excellent rare qualities were slowly pushed out by new high yielding varieties. Apart from human interventions, there were other biotic and abiotic stresses acting on the system like pests, diseases, environmental hazards etc. Wide variability in many crops like mango, citrus, banana, some of the flowers, etc. was due to existence of a large number of wild relatives in India and nearby countries.There are many horticultural crop species. Fruits, vegetables, flowers, spices, plantation crops, medicinal and aromatic plants are generally in the fold of horticulture. However, some plantation crops like tea, coffee, rubber and cocoa are dealt with separately for their great industrial and commercial importance. Multiplicity of varieties in each of the said crop species has added to the complexity of the issue.

Conservation of all existing and dwindling genotypes is a gigantic task.

Fruits and vegetables, known as protective foods, are strongly recommended in daily diet for health care because these are rich sources of essential constituents like minerals, vitamins, enzymes, etc. in addition to carbohydrates, fats and proteins. Ever since the early human beings started gathering roots and fruits from forests at the dawn of civilisation, these crops became inseparably bonded with culture and customs of mankind especially in India. These were used in religious offerings, in social gatherings, parties and also as valuable gifts. Spice crops had been in use not only for adding taste and flavour to foods but also to preserve for future use. Spice was a precious trade item to early voyagers from Europe. Flowers were used in every household not only for decoration and beautification but also for various religious performances, from birth until death. Relationship of medicinal plants with mankind needs no mention.

Horticultural crops, apart from supplying nutrition, satisfy demand for taste, flavour, aesthetic beauty etc. This is possible because of existence of innumerable varieties. In other words, an important basic issue in utility of horticultural crops is in the existence of wide diversity in quality, colour, flavour, taste, etc. Loss in diversity reduces ability to satisfy in general. Some varieties were introduced and some others occurred as a consequence of natural phenomena. In course of time the varieties were distributed and then flourished in preferred agro-climatic zones.

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Analysis of ongoing development programmes is necessary to find the gaps. Most of the programmes aim at distribution of seeds, plants, equipment and other materials for introducing or popularising a few varieties selected centrally. There is hardly any scope of participation of farmers in planning. Peoples’ participation alongwith decentralised planning is, on the other hand, considered as the appropriate course of action for a sustained programme for conservation of biodiversity in horticulture.

It has been stated under the action plan that general awareness among public and people’s participation are essential for preserving the diversity in horticulture. Under alternative action plans, one of them is “Viswavidyalays will involve NGOs, local bodies, voluntary organisations (VOs) and other associations of the area”. In the institutional structure envisaged for conservation of biodiversity, a zonal biodiversity conservation centre, an organisation of the people, NGOs and the government has been conceived. This organisation may be set up at zonal or dictrict level.

Under the specific project proposal with reference to horticulture (Annexure XI), an amount of Rs 10 lakh has been shown as cost of awareness campaign.

Conservation of biodiversity is a global issue extending across all ecosystems and habitats. Developed countries owe an ecological debt to the developing countries and industrially prosperous areas within a country owe a similar debt to those in ecologically handicapped areas. The people at large should be made to understand the concept through training, publicity, meetings and media reports.

In West Bengal 62.9% of the total geographical area is sown which is much above the national average. Finding new area for cropping to feed the expanding population is becoming more and more difficult. Therefore, increasing crop productivity by popularising high yielding varieties and hybrids is the most predominant strategy in almost all the development programmes. Hence, the diverse varietal base is gradually narrowing. But at the same time the demand for quality is increasing. Biotic and biotic stresses coupled with human intervention are continuously changing the scenario of biodiversity in horticulture. Overemphasis on a few genotypes may lead the farmers to a disastrous situation in future.

Conserving biodiversity against this backdrop is thus a challenging task.

The study of the biodiversity in horticultural crops in the state of West Bengal will include identifying reasons for loss, if any, the impact of the loss and suggesting measures for conserving the biodiversity.

II. Agro-climate and agriculture:

As stated earlier, West Bengal is divided into three agro-climatic regions and six agro-climatic zones. A brief account of important zones in relation to horticulture is given below. Area and production of horticultural crops in the state have been presented in Annexure XII & XIII. i. Hill zone:

Three hill subdivisions of Darjiling district constitute this zone. High rainfall (3212 mm), cool humid climate, sloppy land, brown forest soil, rich in undecomposed organic matter, light texture, acidic reaction are characteristic features of this area. Soil is subjected to heavy erosion. The pH ranges between 4.2 and 5.8.

Excellent quality mandarin orange grows on about 2000 ha at a height below 2000 m. Cabbages, cauliflower, radish, peas and beans, tomato, cucumbers, potato, chow chow are important vegetables. Orchids, gladioli and bulbous flowers grow luxuriantly. Many ornamental and foliage plants, cacti and succulents are also grown in numerous nurseries. Many playhouses have been erected in Kalimpong area for commercial floriculture. Production of vegetable seeds, flower seeds and bulbs has been taken up by many. Ginger and large cardamom are the two spices grown in this area. Some plants of plum, peach and pear are grown in small home-gardens. The hill region has special importance in the horticultural scenario of the state. Tea is of great importance in the economy of the area. Eastern Himalayas is a rich source of medicinal plants. There are two plantations of cinchona and dioscorea under the Pharmaceuticals and Phytochemicals Corporation of the Govt. of West Bengal.

ii Terai Zone

The districts of Jalpaiguri and Coochbehar and the northern fringe of Uttar Dinajpur district may be

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included in this zone. Normal rainfall is as high as 4136 mm in Jalpaiguri and 3193 mm in Coochbehar. This terrain has characteristic light acidic soil, turbulent rivers and waterways. Predominant soil type is sandy loam. It is subjected to high rate of soil erosion from sloppy land as well as flush floods. In general soil fertility status is low. The pH of soil ranges between 4.2 and 6.5.Tea is the most important plantation crop. Pineapple grows on 9 to 10 thousand ha. The area supplies 28% of pineapples produced in the whole country. Jackfruit, lemon, mangoes, guava, coconut, arecanut and banana are grown in small orchards or home-gardens. Major vegetables are tomato, cabbage, cauliflower, brinjal, cucumber, lady’s finger, pumpkin, colocasia, amaranthus, beans, sponge gourd, ridge gourd etc. Ginger, turmeric, chili, minor seed spices like black cumin, coriander are also cultivated. Marigold, Chinarose, season flowers may be seen growing in small plots and home-gardens. Tea planters introduced many crops in this area. A number of medicinal plants grow in this region. Citronella and lemon grass are also found in terai region.

iii Alluvial Zone

The alluvial zone extends from Uttar Dinajpur to South 24 Parganas and includes both Ganga alluvium and Vindya alluvium soils. In this vast plain rainfall is about 1500 mm and climate moderate.

Ganga alluvium soils contain high proportion of fine sand, silt and clay loam in low situations. The soil in general is neutral in reaction. But Vindya alluvium soil is coarse in upland but fine in medium and low land. It is slightly acidic, pH 5.0 to 7.0.Mango is the predominant fruit crop of this zone distributed mainly in the deep alluvial soils on the two sides of the river Ganges and the Bhagirathi. Banana is the next important crop. Papaya, litchi, guava, limes, lemon and coconut are other fruit crops. Potato, brinjal, lady’s finger, cucurbit vegetables, (cucumber, pumpkin, ridge gourd, snake gourd, sponge gourd, palwal etc.) colocasia, leafy vegetables, tomato, cabbage, cauliflower, sweet pepper, peas and beans, radish, are major vegetables widely grown in different parts of this region. Hugli, Midnapur and Barddhamandistricts together contribute 2/3rd of potatoes of the state. Chili, turmeric, ginger, minor seed spices are also cultivated. Commercial cultivation of flowers is popular in parts of Midnapur,

Nadia, Haora and North 24 Parganas districts. Ornamental and fruit plants are produced in nurseries near Kolkata in this zone. Medicinal plants occur in forests, homesteads, tankbanks, odd plots, bushes, roadsides and borders of crop fields in this zone. In each of the major crops a large number of varieties are available. Wide variations are found in colour, size, quality, and form as well as in other characteristics of the crops in this zone.

iv Western Lateritic Zone

The districts of Puruliya, Bankura, Birbhum, western parts of Midnapur are included within this zone. Total area is about 10 lakh ha and rainfall around 1400 mm. A comparatively dry hot climate prevails during summer season when the temperature shoots upto 42°C or more and desiccating wind blows in mid-day time.

The terrain is undulated and subject to erosion of soil through innumerable waterways. Soil is mild acidic with low nutrient content. Iron and aluminium oxides are found in surface and subsurface of eroded soil. In many places the upland situations are uncultivated and gravelly. A huge area is marked as cultivable waste. Organic matter, nitrogen and micronutrient content are generally low in upland horticultural areas.

The area does not grow much of fruit crops. ‘Deshi’ date palm and palmyra palm are found in abundance. Guava, papaya, citrus fruits, ber, Jackfruit grow in home-gardens and small orchards. ‘Kendu’ is found in this zone only. Cucurbit vegetable especially, cucumber, ridge gourd and pumkin are cultivated in large areas. Brinjal, peas, radish, cabbage, cauliflower, tomato, lady’s finger, colocasia, amaranthus are other important vegetables. Potato is cultivated in all the districts. Sweet potato, ‘Shank Alllu’, ‘Mete Alu’, different types of beans are also grown. Commercial cultivation of flowers is not common. However, rose gardens are coming up with promise. Many medicinal plant species are found in crop fields, bushes, forest areas, tank banks and homesteads. Among spices chilli and coriander are grown.

v Coastal Zone

A stretch of 11.42 lakh ha coastal zone lies in Midnapur (East), South 24 Parganas and Haora districts. Annual rainfall in this area is 1750 mm on

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average and the monthly mean relative humidity varies between 68 and 82%. Mean maximum and minimum temperatures are 28.2 to 34C and 16 to 26C. Thus the climate is milder.

The soil is alluvial, partly saline with alkali patches. The pH is between 7.0 and 8.5. About 86% is clay loam to heavy clay and the rest sandy loam to loam. Nearly 60% of the cropped area is low and only 10% is in high situation. Soil salinity is very high in dry seasons. Coconut, sapota and cashew are the most important fruit crops. Date palm being highly salt tolerant is found all over the area. Cucurbit vegetables like watermelon, luffa, sponge gourd, palwal, cucumber, etc. are cultivated traditionally. Tomato, brinjal, lady’s finger, leafy vegetables are also grown. Chilli is the most important commercial spice crop of the region. Different varieties like Sagar Sundari, Bullet etc. occupy a huge area of about 28 thousand ha in South 24 Parganas only. Flowers like marigold, jasmine, hibiscus, tube rose, etc. are grown in small plots near homesteads. Nursery is an important business in this region especially in South 24 Parganas. There are more than 200 to 300 small and large nurseries producing fruit and ornamental plants.

III. Current knowledge of biodiversity in horticulture

Horticultural crops, unlike food grains, cannot directly address the world hunger Issues but can contribute to reduce risks of many fatal diseases in addition to providing nutrition. Consequently, until self-sufficiency in food grains was achieved in the country, horticulture had to wait in the sidelines. Significant stress on horticulture in the agricultural production plan could be noticed since

seventh five-year plan. Instead of regular survey, knowledge on area and production of horticultural crops was mostly based on notional estimates, market arrivals, trade channel reports etc. Excepting potato no other horticultural crop feature in the regular survey reports. Area and production of horticultural crops in West Bengal have been shown in Annexures XII & XIII.

Nevertheless, horticultural crops have been contributing upto 18% of the total income from agriculture while occupying less than 10% of the gross cropped area. Income per unit area from these crops is more. Many of the horticultural crops have well known areas of concentration. In such areas huge employment is generated in harvest season for handling, packing, storage, transport and retailing. Since most of the produce is highly perishable and the harvest seasons are short, growers, traders, transporters are all very active during the seasons for marketing and distribution.

Demand for quality from consumers changes with time. So is the demand from traders, transporters and retailers. The farmers also keep on changing varieties. In the process of welcoming new types for immediate gains, many old varieties get lost unnoticed. But no one has been categorically entrusted with the responsibility of conservation of genotypes. The warnings and suggestions from scientists or institutes have failed to initiate comprehensive action plan in this direction.

Most of the fruit and vegetable crops are highly cross-pollinated and so a lot of variations are found in the form of cultivars or strains/ecotypes. Multiplicity of varieties in each crop has added to the complexity of the scenario. Table LI represents an account of varieties of different crop species grown in West Bengal. But this is not exhaustive.

Table LI : Multiplicity of horticultural crops and varieties

CropDivisions

Crops grown in West Bengal Approx. number of commonvarieties/hybrids under

cultivation (not exhaustive)1 2 3

Fruits mango, banana, guava, pineapple, sapota Papaya, litchi, mandarin, orange, limes, lemon, pummelo, jackfruit, and around 40 other minor fruits

mango – above 150banana – about 25guava - 8pineapple – 6litchi – 7Others together – Above 200(Total number of varieties of minor fruits not known)

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CropDivisions

Crops grown in West Bengal Approx. number of commonvarieties/hybrids under

cultivation (not exhaustive)Plantationcrops

Coconut, cashew, arecanut coconut – 5cashew – (Not ascertained)areca – 3

Vegetables potato, brinjal, lady’s finger, cucumber, cabbage, cauliflower, tomato, peas, beans, radish, carrot, beet, spinach, basella, pumkin, luffa, sponge gourd, ash gourd, palwal, kankrol, amaranth, cowpea taro, elephant foot and another 30 vegetables

potato – 2brinjal – 25lady’s finger – 15cucumber – 1 1cabbage – 18cauliflower – 22tomato – 17Total number of varieties of the remaning 30 could not be ascertained.

Spices Chili, ginger, turmeric and large cardamom , coriander, black cumin, fenugreek

Chili-21Ginger-2Others- A few

Flowers rose, tuberose, jasmine, marigold, gladiolus, lilium, dahlia, chrysanthemum and all other season flowers, hibiscus, narium tabarnaemontana and other flowering plants

Innumerable varieties of rose, season flowers, chrysanthemum, hibiscus etc. are grown.

Shrubs and ornamentalplants

Huge number of trees, shrubs, creepers, climbers, cacti, succulants and houseplants are maintained in nurseries

There are many varieties in each group of ornamental plants

The number of varieties mentioned in Table LI above is not exhaustive. However, the wideness of the varietal diversity is understandable. Even a clone within a cultivar or an ecotype is an important genetic material. Detailed description of each specific component is out of scope of this paper. The State Agricultural University, research stations and govt. farms maintain many varieties. Farmers and nurseries are rich sources of information.

In the last 50 years there has been reduction in the number of commercial food crops. Modernised agriculture requires uniformity of genetic composition of domesticated plants which has resulted in erosion and narrowing of genetic base. Reduced diversity renders crops less adaptable to new stresses like flood` draught, pests and disease. Future generation may blame us for lack of responsibility and foresight.

It cannot be conclusively stated how many of these species/ varieties are indigenous to West Bengal. However, some of the mango varieties, around 50-60 in number, have been developed and grown only in West Bengal. Same is the case with several banana and litchi varieties, and some minor fruits and vegetables which are found in West Bengal only. It cannot be stated that any of the cultivated species is threatened a of today. But most of the open pollinated varieties of vegetables have been pushed almost out of the field by high-yielding, hybrid types.For example, varieties like Sioux, Moneymaker, Monitoba, Marglobe etc of open pollinated tomatoes have been replaced totally by a host of hybrid tomatoes from different companies. Same is the case with traditional cabbage varieties. The area under local banana varieties like Kanthali, Martaman etc are being gradually squeezed out and Cavendish varieties are aggressively occupying these areas.

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(List of species and common varieties of some fruit and plantation crops, vegetable varieties and flower and ornamental plants have been shon in Annexure XIV, Annexure XV & Annexure XVI respectively.)

PROBLEMS RELATING TO HORTICULTURAL BIODIVERSITY

After domestication of horticultural plant species, the varietal base widened by human intervention in the manner described under the diagram below.

Accelerated food production is inescapable

due to rapid increase in population. In fact tremendous success in

food production has also contributed to the growth of pupulation. Need for quick gains in quantity prompted overdependence on an increasingly narrowing gene pool. On the other hand varied genetic resource contributes to the genesis of many new traits. However, it may be mentioned that diverse germplasm is not always preferred in the traditional breeding in anticipation of transfer of negative traits in hybrids which may be difficult to eliminate.

The forces that decide sustainability of a variety are too many. The major ones are adaptibility to the soil and climate, tolerance to pests and diseases, quality including keeping quality, consumer preference etc. The strongest force is however return per unit area. Human initiatives are not fully balanced in making adjustment for all possible implications from introduction of a new variety or a technology. Therefore, search for a better and more versatile variety continues. Consequently, rapid changes are noticed in varietal scenario. Farmers are strongly attached to traditional systems of cultivation and varieties. But higher income per unit area being the driving force in the choice of a variety they are to accept new promising ones.

The

assignment of food security for the expanding population from fixed land resource prompts dependance on varietal replacements and overreliance on a few high yielders. The challenge of conserving diversity originates in the backdrop of expanding population pressure, diminishing holding size, rapid urbanisation etc. The diverse base tends to narrow down under pressures from these burning issues and a few high yielding varieties and hybrids agressively push out many others with special qualities. Consequently, many genotypes are lost unnoticed. Major factors affecting biodiversity in horticulture in West Bengal may be listed as follows.

(i) Increasing population and reducing land holding size: High yield potentiality of some of the varieties and hybrids has narrowed down the wide varietal base.

(ii) Disease and pest tolerance of several varieties and hybrids: Some resistant varieties replaced susceptible ones. Martaman variety of banana, susceptible to sigatoka disease, has been replaced by Giant Governor in some areas.

(iii) Better quality and market demand of certain accepted types: Sugar Baby watermelon yielding family size fruits replaced Shipper, which is a very large fruited variety.

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Introduction from various sources

Selection from natural habitat, chance seedlings

Breeding ofNew varieties

Appearance of a new variety

Trials, demonstrations restricted cultivation

Pests and disease pressure

Soil and climate suitability

Productivity and production cost

Variety sustains or replaced

Quality demand from traders and

consumers


(iv) High keeping quality: A few selected types which can be stored longer or transported to distant city markets are gaining more areas . Hybrid tomatoes are good example.

(v) Advantages in cultivation: Absence of spine of Giant Kew pineapples, dwarf stature of some of the fruit varieties, uniformity of hybrid cabbages, adaptability to adverse climate like high temperature, high or low soil moisture etc. are some of the qualities which made several fruit and vegetable varieties/hybrids more popular.

(vi) Extension of irrigation facilities: In unirrigated areas larger number of varieties are cultivated traditionally but irrigated plots are occupied by a few high income generating types only.

(vii) Govt. policies: Govt. policies are framed at present primarily to ensure higher per capita availability, i.e. higher production from unit area, and not to ensure conservation of diverse quality attributes. Seeds of highly productive varieties and hybrids are distributed. The farmers hardly have any say in such centrally administered decisions. Such programmes are prone to be disbalanced. In the event of a severe biotic or abiotic stress threatening sustainability of a crop or farming system, a large gene pool will be needed for scientific selection of the appropriate type. Farmers’ participation in deciding the programmes might be a better course.

(viii) Introduction of exotic varieties and hybrids: In recent years as a result of liberalisation of seed import policy many varieties and hybrids of horticultural crops are being easily imported by various agencies. This has strongly threatened sustenance of a number of indigenous varieties.

(ix) Development programmes: Roadsides, crop fields, bushes, odd plots, tank banks etc. are the natural habitats of innumerable species and varieties of flowers, medicinal and aromatic plants. Many of the forest areas are known to have conserved speciies and varieties of horticultural importance like minor fruits, minor root vegetables etc. from time immemorial. But development programmes like roads, industries, institutions, housing, irregation projects, etc. destroy such habitats and destroy the resources without making alternative arrangements for ex-situ conservation.

(x) Natural resources: Collection of food and herbs from natural habitats, had been supporting human life since the dawn of civilisation. Many of these species and varieties were gradually domesticated and cultivated. Others continued to remain in their habitats and were collected in need by knowledgeable persons of local communities. Medicinal plants, some root vegetables, flowers especially orchids are examples. Among aborigins in different parts of the world, where collection of root vegetables and hunting were the main activities for sourcing of food, a rule prevailed that an area visited once will not be exploited in next six months during which period it will regenerate all resources. With more and more modernisation of village life and demise of old timers the communities got detached from much knowledge based on experience. In some cases overexploitation resulted in loss of types. Some valuable orchids are difficult to find in their natural habitats.

Changes in social customs: Slow changes in social customs, religious performances, ethical and moral perceptions of the people have also contributed to the loss of biodiversity. A busket of rare varieties of excellent quality mangoes is not a commonly used gift package now a days. Instead of Kanthali, other varieties of banana are also finding place in religious rites.

Fertiliser consumption in West Bengal was 7.32 lakh MT in 1992-93 which increased to 13.50 lakh MT (estimated) in 2000-01. Pesticide application per ha increased from 0.47 kg AI in 1990-91 to 0.50 kg AI in 1997-98 on gross cropped area. Incidence of cancer, mental retardation, neurological disorders in Kasargod district of Kerala, neighbouring cashew plantations where aerial spray of endosulfan is done frequently to control tea mosquito in cashew, has recently raised serious alarm among people of the area.

A few varieties are aggressively occupying the fields and many others with special qualities are being wiped out. Introduction of these new varieties and hybrids have brought in application of underground water, fertilisers and pesticides in very high quantities. Hybrid vegetables, potato, cavendish, banana receive high inputs. Continuous application of such inputs is initiating adverse effect on soil health and evolution of resistant strains of pathogens. Race for immediate gains by these methods may compel the production system to confront a disastrous situation in near future. A large gene pool at hand will be essential in such an event.

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MAJOR STAKEHOLDERS

Every individual is a stakeholder in the matter of conservation of biodiversity. The government of a welfare state has the responsibility to conserve the environment and hence the genotypes within the same. But this is a very hard task especially in a Third World country besieged with an exploding population. Policy makers as well as the administrators have to contribute a lot. Participation of all individuals, groups of individuals like Non Govt Organisations (NGO), voluntary organisations (VO), clubs, associations, cooperative bodies etc. is necessary. It calls for a general awareness campaign. Such a peoples’ movement may be supported or supplemented by laws and administrative orders. The scientists in the research institutes and universities are to give guidance for framing the laws and orders.

The current understanding of the biodiversity of the stakeholders require replenishment from discussions, seminars and in-depth studies. Different communities, the farming groups, the traders, packers, transporters, industrialists and corporate bodies are not fully aware that they can contribute towards conservation of the genetic resources. A change or a loss can affect all of the beneficiaries who act as a part in the chain of operations from production to consumption. Some important organisations like Agri-Horticultural Society, Rose Society, Floriculture Associations, nurserymen are custodians of many horticultural varieties. These societies and similar other bodies can play very important role in this movement.

ONGOING INITIATIVES

The ongoing schemes are mainly from the Central Govt., State Govt., National Horticulture Board, Commodity Boards for coconut, cashew, spices, etc. Each government farm and research station maintains many varieties. The govt also distributes quality seeds and planting materials of proven varieties as well as new varieties and hybrids. NGOs, associations and societies or peoples organisations also participates in such programmes. The nurseries maintain and distribute planting materials and seeds of many horticultural plants. These actions are without any coordination from biodiversity conservation point of view. It is necessary to integrate all such initiatives to conserve the genetic resources.

The magnitude of the task of conserving the diversity is so vast that ongoing programmes can hardly touch the

fringe of the problem. Moreover, ex-situ stocks become genetically more or less static since these are not subject to stresses for evolution of new types. In spite of much weaknesses such varietal and clonal collections are very important. A more important initiative will be conserving spices and varieties in situ in collaboration with farmers, land owners, NGOs, various associations and societies and voluntary organisations.

Food crops like fruits and vegetables receive more attention followed by the plantation crops. Spices are in low priority area. Flowers and ornamental plants as well as medicinal plants are outside the focal area of the initiatives mentioned above. This should also be given due importance as far as practicable in the programmes of distribution of seeds and plants and conservation of diversity.

GAP ANALYSIS

Gaps in the ongoing initiatives are too many of which a few are mentioned hereafter.

Gaps in informationBefore any positive step is taken for conservation of biodiversity in horticulture in a region the foremost requirement is a bench mark survey in the ecosystem. Unfortunately, no such comprehensive study report, statewise or regionwise, exists. Information is available from old villagers, scientists working in a region, NGOs and the people engaged in production and trade of

horticultural crops. Gaps in information can be reduced by systematic and scientific documentation of all inputs related to varietal diversity available from knowledgeable persons and institutes. Old timers, who received the knowledge through oral communications from ancestors are also reducing in number. Some such information are already lost.

(ii) Lacunae in the linkages between horticulture and biodiversity

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Not only the health and prosperity but survival of human race on earth is dependant on the contribution from innumerable plant and animal species. Diversity is the biggest tool for maintaining a state of natural balance in the environment congenial for existence of all living beings. The components of horticulture are also integral part of this system. Fruits, vegetables, plantation crops and spices, being replete with vitamins, antioxidants, minerals and unknown nutriceuticals not only provide nutrition but reduce risks of many diseases and abnormality. Flowers, ornamental plants provide aesthetic beauty. Medicinal plants distributed all over in the surroundings protect men and animals from diseases. Horticulture has not been attached due priority as a part of the life and prosperity supporting biodiversity. The major crops receive some attention but the minor crops and species remain unnoticed. But each component, stated above, should have its place in the biodiversity in totality.

(iii) Gaps in vision

Food availability for the rapidly increasing population has been the biggest concern absorbing full attention of all stakeholders. Immediate gains from overdependence on a narrowed down varietal diversity was an inescapable measure. Seeds and planting materials of high yielding varieties/hybrids are multiplied and distributed through various programmes like minikits etc. Majority of varieties cannot be considered in this programme. Again, beneficiaries are not the choosers. The policy adopted centrally is generally implemented. In the process, a large proportion of the gene pool remain out of notice. A genotype of strawberry, Frageria virginiana ssp.glauca clone having day neutrality character has revolutionised California strawberry industry. The trait is said to be worth 80 million $ per year. Hence it is not only the immediate gain which should be in view.

(iv) Gaps in policy and legal structure

Horticultural crop production plan does not address the problem of conserving biodiversity in its totality. Identification of threatened species or varieties, monitoring extent of exploitation, regulating varietal collections are not adequately covered under the present legal framework or administrative orders in force. There is scope for reviewing in the greater interest of sustaining horticultural development. Instead of creating infrastructural facilities the stress of the horticultural crop production policy was on the distribution of seeds and various other inputs at subsidy or free of cost. This may bring immediate gains but induce negative growth. However, in recent years stress on creating infrastructure to support production and marketing is being noticed.

(v) Gaps in institutional and human capacity

Human capacity is limited for various reasons and so is the capacity of institutions. But the task of conserving biodiversity is voluminous because of multipolicity of species and varieties. Even the variation at clonal level is an important issue. This unlimited resource cannot be conserved with the limited capacity of the institutions working in isolation. A good number of research stations under the control of the state govt. and the State Agricultural University are doing excellent job of maintaining many germplasms. The objective of such programme is not to preserve the available biodiversity in totality but to keep some of the selected types of special merit in collection. This attempt may be considered as a supplimentary one. Comprehensive plan for conserving all the germplasms, involving every citizen in one way or other, will perhaps generate better results.

ACTION PLAN ENVISAGED

Preparation of an action plan should be preceded by a clear understanding of the issues and problems related to the biodiversity in horticulture in West Bengal. This may be enumerated as below.

Components of horticulture have not been duly noted as integral parts of the biodiversity in totality supporting the life cycle in an ecosystem and enhancing prosperity of inhabitants.

Multiplicity of species and varieties have added to the complexity of the problem. But none can be ignored since each of the genotypes is a potential contributor.

No systematic documentation of the available genotypes has been made so far.

Inadequacy of knowledge is a serious bottleneck. Even the sources of knowledge are not sufficient and gradually reducing

Attempts made for conserving varieties in research stations, educational institutes etc. are much less than requirement. The objective is also different.

There is limitation in human or institutional capacity in this respect considering the volume of work.

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The challenge can perhaps be met if the people’s participation, i.e. involvement of all stakeholders including NGOs, VOs, institutions, etc. are achieved.

Creation of infrastructural facilities should receive overriding priority instead of subsidised distribution of a few inputs.

Farmers’ views should also be considered during planning for horticulture development in an area.

The sole objective of the action plan is to conserve the biodiversity wealth in horticulture as comprehensively as possible. Based on the discussions on gap analysis and the issues identified above several actions may be suggested as follows.

Policy intervention

There is no denial of the hard fact that production of horticultural crops from the fixed land resource should increase at a much faster rate than that of population. New varieties and technologies are to be introduced in place of traditional types. But instead of ignoring the local germplasms altogether these should be conserved in a research station, a reserve area or in a germplasm bank. Collection of orchids, rare medicinal plants or such other species from natural sources should be intervened with effective orders to prevent overexploitation. Institutes entrusted with the task of conserving biodiversity will advise the administrative authorities to frame such orders.

Distribution of plants, seeds and inputs to enhance production by introduction of new varieties/hybrids, expansion of area, reduction of loss due to pests and diseases or improvement of existing orchards, constitute the ongoing govt. programmes. Experienced farmers, associations, NGOs, etc. working in villages may be given opportunity in selection of programmes. Their views should be analysed, or alternatively planning should be from the grassroot level. Steps are to be initiated one year ahead of target season. Such policy decisions are likely to save some of the diversities.

Farmer-led R&D

Farmer-led research and development is an area that has not received adequate thinking and has not gained currency among the powers that be. But farmer-led R&D

is definitely a distinct step in empowerment. However, farmer-led R&D cannot develop without being guided by competent scientists. Food security issue and very small holding size are the two major problems that can frustrate such a programme. Where these problems do not exist, farmer-led R&D may be possible under the able guidance of a competent scientist under an apex body. Specially, progressive farmers may be useful for experimentation that is essential for research and development.

People’s participation in the biodiversity conservation programme

It is important to understand that the action plans that have been conceived as part of the discussions require to be in the form of projects. The biodiversity wealth is distributed in every nook and corner of West Bengal. Fallow land, canal banks, borders of crop fields, forest fringe areas, wastelands and similar other places, mostly highland areas, are the storehouses of valuable biodiversity in addition to regular crop fields and gardens.

In order to preserve the wealth distributed in such a manner, people’s groups in the local areas are to be vigilant. Beginning from the zonal/district biodiversity conservation centres, there should be organisations like NGOs, VOs, local clubs, even schools and colleges, social welfare groups right up to the village level. It s not a difficult proposition in the era of organised Panchayati Raj. What is required is a very strong campaign and training programme, coupled with some financial assistance. The apex body can organise such units at every level and disseminate the messages from the scientists in charge up to the grassroot level.

It may be necessary to prepare a detailed working plan by a separate competent organisation/ personnel for implementation.

Not only the working groups, but all the stakeholders, including the consumers should also be aware about the biodiversity issues.

Actions to conserve biodiversity

The function of conserving biodiversity is a kind of research work on one hand and a form of movement with people’s participation on the other. It must be considered that ex-situ collections tend to be genetically static. These are not subjected to pests, pathogens, abiotic stresses and other selective agents which result in

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continued evolution of new traits and characters. The process of conserving genetic resourses should be multidimentional and comprehensive to allow preservation as well as continued evolution of new characters.

1. A central institute under the technical control of the State Agricultural University will be primarily responsible to coordinate functions of all related agencies and to conserve biodiversity in horticulture in the state.

2. An organisation may be set up in each district involving NGOs and VOs and a few distinguished people of the district to implement biodiversity conservation plan. This district level functionary will act under the guidance of the central institute. It will create general awareness among the different classes of people. It will also keep contacts with owners of land, bushes, tankbanks and monitor exploitation of species and varieties available. It will try to conserve germplasms in situ. If a species or variety has fear of being lost it will be sent for conservation in reserve experimental farms. Instead of a separate organisation working in isolation for different biodiversity components one such body may be set up in the district for all subjects.

Each district organisation will prepare an inventory of horticultural species and varieties available in different corners. NGOs and VOs will conduct the survey under the supervision of a scientist from a related discipline available within the district itself or selected from the central institute.

In one or two govt. farms or University research centres in each district some areas will be allotted for conserving the species and varieties. A technologist working in the farm will be in charge of such ex- situ conservation plots.

The central institute will be equipped with a laboratory for cryogenic storage of seeds, plant tissues, pollen grains etc. It will also have a farm for conservation of one set of species and varieties kept in the district farms. The laboratory and farm will conserve the indigenous types only and not the exotic ones. These actions will elevate the status of horticultural biodiversity to a much higher level and at the same time enhance its linkage with the national biodiversity.

3. Setting up of the institutions, involving organisations, sensitisation of the people and stakeholders¸ establishment of laboratory, allotment of land in identified farms can be completed in a period of 3-5 years. Preparation of a Detailed Project Report is out of scope of this theme paper. An indicative estimate of expenditure has been presented in Annexure XI.

The estimated fixed cost for implementation will be Rs 350 lakhs and annual expenditure in the project will be to the tune of Rs.100 lakhs as detailed in Annexure XI. Cost can be minimised if an alternative action plan is followed.

4. Women farmers should be taken into confidence for every agricultural programme extending from control over seeds right up to credit supply. On a small scale, home garden/kitchen garden can be an important part of the horticultural production plan where participation of women, children and even students can be a very effective approach in conserving horticultural biodiversity.Actors – Women farmers, housewives etcTimeframe – Ongoing

.Alternative Action Plan

An alternative action plan which will be less costly is stated below:

Ÿ Bidhan Chandra Krishi Viswavidyalay may be designated as the apex body entrusted with the work of conservation of biodiversity. Uttar Banga Krishi Vishwavidyalay will take up the programmes in North Bengal.

Ÿ One or two farms in each agro-climatic zone will have some reserved area for conservation of indigenous germplasms available in the respective zone. One type will be conserved in one farm only.

Ÿ A compendium containing the description of varieties of each zone will be compiled and published by the Vishwavidyalays.

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Ÿ Vishwavidyalays will involve NGOs, Local bodies, Voluntary Organisations and other associations of the areas.

Ÿ The staff of the farms will monitor ex-situ conservation and coordinate in – situ conservation.

Ÿ Additional staff and fund required by the Universities may be made available for implementing the programme.

Ÿ Loss in biodiversity as a consequence of natural stresses or human intervention is a continued

phenomenon with long lasting effects. Reduction of this loss and conserving the entire genetic resources is also a continuous and huge task requiring thorough planning and adequate investments.

.WEED DIVERSITY

Within the scope of “National Biodiversity Strategy and Action Plan (NBSAP), weeds belong to the Group of Wild Species and Varieties and also Agricultural Ecosystems. They are an important component of agro-biodiversity, and have vital links with the socio-economic life of West Bengal. They are used for edible value, in folk medicine (both internal and external use), as fodder, thatching materials, rope-making, broom making, refrigeration, stitching material for sal leaves, composting, as insecticides, paper making and very importantly as soil binders. Because of their diverse use, they deserve special attention in terms of status description according to agro-climatic zones.

West Bengal has six agro-climatic zones. The following is a description of the agro-climatic zones of West Bengal and common weed species in agricultural crop fields of different zones:

Zone – I

Hill Regions of North

Tea Gardens – Imperata Cylindrica Mikania scandeusPineapple crop – Stellaria sp,. Dry meria sp, and Cyperus rotundusDirect seeded rice and maize crop fields – Cyperus rotundus, Digitaria sp., Lindernia, Echinochloa colona (Shamaghas)Potato crop fields – Chenopodium album (Balhka), Cyperus rotundus (motha), Anagallis arvensis.

Zone – II

Terai - Tista Alluvial of North

In maize crop fields (kharif) – Echinochloa colona (Shamaghas), Digitaria sp., Cyperus rotundus (motha), Cynodon daetylon (Durba ghas)

In direct seeded rice (Aus paddy) – Echinochloa colona (Shama ghash), Cynodon Daetylon (Durba ghas), Digera arvenses, Digitaris sp.

In transplanted rice (Amon) – Echinochloa crussgalli, Digitaria sanguinals, Fimbristyllis sp., Marsilea qudrofida

In Jute crop – Cyperus rotundus, Echinochloa colona, Dactyloctenium aegyptium, Corchorus acutangulas (wild jute).

In wheat crop (Rabi season) – Chenopoduum album, Anagallis arvensis, polygonum sp.

In oilseeds crops (Mustard, Niger) – Argemone mexicana, Chenopodium album

In potato crop – Chenopodium album, Anagallis arvensis, Cyperus rotundus

Zone – III

Vindhya alluvial region

In transplanted rice – Echinochloa crussgalli, Digitaria sp., Ludwigia parviflora, Ammania sp., Fimbristyllis sp., Scirpus sp., Monochoria vaginalis, Sagiltari sagittifolia

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Jute – Cyperus rotundus (Motha), Echinochloa colona, Digera arvensis, Eleusine indica

Sugarcane – Ageratum conyzoides, Echinochloa colona, Trianthema portulacastrum, Cyperus rotundus

Zone – IV

Lateritic Region of the West Birbhum, Bankura, Puruliya and parts of Medinipur

Direct seeded rice – Cyperus rotundus, Echinochloa colona, Digitaria sp., Eleusine indica.

Transplanted rice – Echinochloa crusgalli, Digitaria sp., Monochoria vaginalis, Sagitaria sagittifolia, Fimbristyllis sp., Scirpus sp., Marsilea quadrifida (Shusni), Ludwigra parviflora, Ammania baccifera

Wheat – Chenopodium album, Anagalis arvensis (Krishna neel), Sperfula arvensis (Gajra), Polygonum sp.l, Cyperus rotundus, Cynodun dactylon, Amarathus viridis.

Sugarcane – Echinochloa colona, Cyperus rotundus, Ageratum conyzoides, Convotvulus arvensis (Hiran Khuri), Trianthema portulacastrum, Cynodon dactylon, Euphobia hirta, Phyllanthus niruri, Euphorbia pilulifore, Eleusine India, Daelyloctenium aegyptium

Zone – V

Coastal Region of 24-Parganas and Medinipur

Rice fields – Chara zeylanica (Rustna), Nitella eriocaulon, Hydrodictyon sp., Cyperus iria (Annual motha), Scirpus sp.

Chillis vegetables, sugarbeet (Rabi season) – Ecliptra alba, Echinochloa colona, Cyperus rotundus

Indiscriminate use of herbicides and widely grown high yielding varieties are creating shifts in weed flora, and there has come to think about the alternative use of weeds without destroying them completely by chemical means.

Action Plan

1. A fresh survey needs to be done on both status of weeds and shifts in their pattern of occurrence, considering the changes in pattern of land use. Actors: Bidhan Chandra Krishi Vidyalaya, Uttar Banga Krishi Vidyalaya, Krishi Vigyan Kendras.Timeframe: 1 year.

2. Agricultural policy should have a specific section dealing with weedsActor: Agriculture dept.Timeframe: Immediate.

TEA INDUSTRY IN NORTH BENGAL VERSUS BIODIVERSITY

In North Bengal, particularly in the districts Darjiling and Jalpaiguri, the cause of man animal conflict and destruction of large tracts of forest cover has a very unlikely root. It is the tea industry which is responsible for all these. The industry generated a sizeable chunk of unemployed population during the recession years. A large section of this population occupied forest land and started cultivation. This finally led to growing of scattered settlements which expanded in size and increased in number over time creating the present problem of settlements and rights in protected forest areas. The unplanned and ill-conceived importing of coolie labour from all parts also led to ethnic tensions, which are still being felt today. Some of these conflicts have taken a

militant turn of late, making forest protection and development increasingly difficult.

The onset of large scale tea cultivation in North Bengal was not only responsible for the conversion of land for tea production but was also the root cause behind generation of this excessive population pressure in and around the adjoining wilderness zones abound with floral and faunal diversity. The Forest areas which harbour a wide variety of animal life, were partially converted to cultivated patches of land and the remaining portions left to be exploited for fuelwood, food, fodder and timber. This not only decimated the animal population but also devastated or degraded some rich habitats of North Bengal leading to the extinction of certain species. Gross

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change in North Bengal landscape for cultivation of tea is largely liable for the fragmentation of Duars forest and thus destruction of North Bengal forest corridors.

The tea industry today can perhaps be held responsible for affecting biodiversity of North Bengal in three different ways:

Ÿ Through excessive use of synthetic pesticides which is harmful to floral and faunal diversity.

Ÿ Through illegal encroachment.

Ÿ Indirectly putting immense pressure on the adjacent forest areas for livelihood of the labour population or excess population generating from the labour community.

Contrarily, the recent thrust given by some of the tea estates to develop organic farming and also forest and nature preserving models as attempted to be achieved in Makaibari Tea Estate (Dutt, 2000) are not generally detrimental to biodiversity. In the NBSAP Consultation Meet held at Siliguri on September 11, 2001 and on 5-6 January, 2002, the concern regarding the ongoing damage to biodiversity caused by the tea garden activities featured repeatedly. Most of the NGO representatives present at the meeting expressed serious concern about the issue and unanimously demanded some immediate action to assess and to impose control over the situation.

The major points raised by the participants on tea gardens issues were as follows:

Ÿ Excessive quantity of chemical pesticides being used in tea gardens. Apparently such extensive use of pesticide is causing irreparable and indiscriminate damage to the insect community. Also these chemicals are coming into the streams flowing through the tea gardens and then to the river system of the area, causing damage primarily to the aquatic diversity and in turn the overall diversity of North Bengal. These pesticides have already caused havoc to the fish fauna of the area. In some places such contaminated stream water are entering and flowing through major National Parks and Wildlife Sanctuaries. But almost no scientific research has been done on the subject. NGOs alleged that working on this subject within the tea gardens will not be possible unless the study is carried out by the administration. According to them, the tea estate administration will never supply real figures on the

use of pesticides, neither they will allow any organisation to work freely on this particular issue. One of the NGO representatives claimed that 74 chemicals are being used in tea gardens for different purposes, including pesticides. But the impacts of those chemicals on the surrounding natural system is not known. The tea estate management does not provide proper training to the workers regarding use of pesticides. Apparently insignificant regular practices like washing of used pesticide containers in the streams might cause severe damage to the surrounding ecosystem, which can easily be avoided. Uncontrolled use of synthetic pesticides in tea gardens apparently takes place in some tea estates, as labourers get payment for spraying pesticide on per litre basis. Such a practise leads to further excessive spraying. Though these might seem trivial points, but the total practice of pesticide application in tea gardens should be scientifically scrutinised. [ In this context another point that can be mentioned, though not discussed in the Consultation Meet, is that ‘According to Mr. Ghosh Hazra, Director of the Tea Research Centre, Kurseong, the topsoil of Darjiling is disappearing due to increased erosion. The erosion is attributed to regular application of weedicide (from weeds) that grow around tea bushes. These chemicals not only kill the weed but also strike at the root, thus loosening the soil in the process. This explains the increasing number of landslides in the past few years.(Dutt, 2000)]

Ÿ Excessive pressure from tea estate labourers causing severe damage to the adjoining forest areas. Tea estate laborers collect huge quantity of fireweed, their cattle graze in the forest in great number, their requirements for NTFP and also timber are met from the nearby forest and so on. There are certain measures to reduce exploitation of forest patches, but malpractice and corruption take the lead and worsen the situation. For example, as alleged by one of the NGO representatives, in some gardens, labourers are supposed to receive lakri or fuelwood worth Rs 200/- from local contractors against a slip issued to them by the tea estate management. Contractors buy the slip from the labourers at much lower prices without giving them anything. The labourers as usual collect their required quantity of fuelwood from adjacent forests. Contractors are selling away the supply. Again, in most of the areas tea estate labourers are

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incidentally crime prone and show much inclination towards involving themselves in activities like illegal tree felling and poaching, even militant action. The population is rising at a considerably high rate. The unemployed youths from the labourer community indulge in all sorts of destructive activities and due to the proximity to forest areas most of these actions are damaging to the surrounding ecosystem.

Ÿ Illegal encroachment activities to the forest land by the tea estate administration have been alleged by some NGOs. Such encroachments can be traced without much difficulty and can be tackled firmly by the state administration.

Gap Analysis

If the alleged problems are carefully looked at, it can be said that proper relevant information is very much lacking. No proper scientific study has been carried out to assess the real impact of the use of pesticides in tea gardens on the flora and fauna of the surrounding ecosystems. For instance some NGO representative alleged that bee keeping is being encouraged to generate alternative income for the North Bengal forest fringe villagers, but ironically the bees are occasionally dying in swarms due to indiscriminate use of pesticides. In reality, there is no supporting evidence from any scientific institution to corroborate this statement. Same is the case with the accusation that the fish fauna suffered heavy damage from pesticides coming into the streams flowing out of tea gardens. Since evidence and supporting research findings are missing, it is extremely difficult to draw any action plan to reduce the problems. Scientific information is lacking on average quantity, composition and contamination factors of pesticides or other chemicals in use.On the socio-economic side much hard work is needed to solve the multifaceted problems of tea estate labourers. For this, the NGOs, tea estate management and the government departments must act in unison. But lack of proper coordination can be felt everywhere in the field. One point must be kept in mind that the tea industry is providing substantial amount of foreign exchange and

thus only scientific management can improve the situation. Necessary restrictions should better be imposed keeping the production level intact.

Suggested Action Plans

Ÿ Extensive scientific research on the impact of pesticide and weedicide application in tea gardens on the flora, fauna and total ecological system of the adjoining areas. The research survey should cover sample areas in the hills as well as plains, and study carefully the seasonal variation in level of impact. [ Actors: Government Departments preferably Dept.of Environment and Dept. of Forest jointly in collaboration with research institutes like the Bose Institute and Indian Institute of Chemical Biology; University of North Bengal; University of Calcutta and local NGOs. Expected Time Frame : 3 years. ]

Ÿ Extensive research and development regarding application of bio-farming in tea gardens. [ Actors: Government Departments preferably Dept.of Agriculture jointly in collaboration with research and education institutes like the Bidhan Chandra Krishi Viswavidyalaya, Tea Research Institute, Universities, and R & D wings of big tea companies. Expected Time Frame : Immediate and ongoing. ]

Ÿ Arrangement for alternative fuel source for the tea estate labourers. Developing alternative income source and special welfare measures for unemployed family members of tea estate labourers. [Actors: Tea estate management, government departments, research institutes, universities and local NGOs. Expected Time Frame: Ongoing ]

Ÿ Assessment of the participatory management model of Makaibari Tea Estate and if found to be effective, publicity and adoption of the same model for other tea estate areas. [ Actors: For assessment Government Departments preferably Dept.of Environment and Dept. of Forest jointly. Expected Time Frame : Immediate. ]

CASE STUDIES

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1) Wasteland development: Case study of acid lateritic uplands of West Bengal

About half of India’s landmass is estimated as degraded and is thus subjected to the process of transformation into wasteland. Since arable land is gradually declining and agricultural sector is under tremendous pressure for extension of land, wasting of this vast wasteland should be prevented. Although there are possibilities of meeting a part of our huge energy deficit from other conventional and non-conventional sources, the major part of this demand will have to be met from fuel wood sources only. This necessitates rapid and large-scale reforestation and afforestation of wastelands through appropriate reclamation measures.

Since the recent past an unprecedented level of awareness has been created throughout the country to improve the conditions of wastelands as a vital natural resource. Greening the wasteland is not only a prior concern in our planning but also a focal area of study and work of many voluntary organization and individuals. It has been realised that the presence of wastelands injurious to the land, environment and economy. Hence there is a felt-need for developing them as a natural resource for guaranteeing income and employment for millions of rural poor on the one hand and for maintaining ecological balance in the countryside on the other.

Presence of wasteland and/or degraded land is a threat to the productive lands also. The productive lands, adjacent to the wastelands are easily affected by the degradation process and turn into wastelands, if appropriate conversation measures are not adopted. Presence of wasteland and process of degradation cannot be admitted for several environmental reasons. Many other hazards like reduction in atmospheric moisture, increased siltation in reservoirs, rise in incidence of flooding, increasing in soil salinity, pollution of water and air, wild life depletion, decline in land productivity etc. inevitably occur. Moreover, barrenness means visual pollution also.

The need for land use planning in wastelands appears as inescapable, if one analyses the changing land uses in our country over time. Reclamation of barren land, degradation of existing land uses in our country over time. Reclamation of barren land, degradation of existing arable land transformation of agricultural land to non-agricultural uses are going simultaneously over the years. Large areas of wastelands, which were once reclaimed, have often gone back to the state of degraded

land. In fact, the emphasis was given to reclaim and conserve statistically larger target areas as fast as possible rather than qualitatively changing them into permanently cultured areas as a long-term sustainable measure. Indiscriminate plantation of certain species has been the most common prescriptions for wasteland development in major part of the country. Factors of wasteland formation, its use potentiality, existence of activities in and around the wastelands, possibilities of biotic encroachment and need for legal control on use of wastelands are some issues which have not been given due consideration in the process of wasteland planning. The result of these shortcomings have been the reclamation of wasteland on the one hand and degradation of larger areas on the other. This calls for prescribing appropriate measures for wastelands at micro-level commensurate with land potential and infrastructure available and hence formulating policy outlines for control and regulation of the wastelands.

The strategy for wasteland development has varied considerably depending mainly upon the socio-economic status/background of the target users beneficiaries, since the level of development and economic return depend very much on the initial investment potential, management capability and interest in such a risk prone venture. However, appropriate technological support is a must for the venture, irrespective of socio-economic considerations. Accordingly, the following three models of wasteland development have been conceived by the Rural Development Centre of IIT Kharagpur, with special reference to undulating acid lateritic uplands of South –Western part of West Bengal.

a) Community organisation for wasteland development:

This programme involves participation of socio-economically backward small and marginal land holders who have been allotted with parcels of vested lands which are degraded to the extent that does not permit any viable agricultural practice. Those lands are available in scattered small plots without any irrigation resource within their reach. In this effort, physical consolidation of land is not possible though technological conformity is always feasible through technological conformity is always feasible through participatory approach to development.

The acid lateritic soils are considered to be handicapped with its very slow depth of surface soil, low organic matter, low CEC, Ca, Mg, P, Zn, etc. and high Fe, Mn,

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and AP content of soil responsible for poor growth and meager yield of crops. Hence such marginal lands owned mostly by marginal people remain fallow year after year and thus get further degraded.

Keeping these problems in view, attempts have been made at the outset to organise such marginal land holders to form a group who could be imparted with knowledge through training and demonstration on the following areas:Land shaping, soil treatment and water conservation methodsSelection of appropriate crops and cropping system to substitute the traditional cultivation practices .Introduction and sustainable cultivation of crop like medicinal plants, horticultural crops, aromatic grasses, sabai etc. besides plants providing fuel and fodder requirements.Processing and marketing of cash crops for value addition and income generation.Promoting integrated farming system involving improved goatery, duckery, piggery etc. along with production of agricultural and horticultural crops.

Implementation of the programme has been in progress since March, 1996 in about 10 villages of Nayagram block of Medinipur district.

Wasteland development through largescale commercial cultivation:

The programme demands scientific and technical expertise for efficient use of lands which lay barren and unproductive for years, through creation of infrastructure and adoption of innovative cropping practice. However such a venture calls for progressive entrepreneurs, capable of taking risk of high investments on one hand and on the other, efficient enough to foster high level management. On the social front, it aims at employment of the land dependent deprived class of people living around the sites of such farming lands.

This centre has made voluntary efforts towards transfer of technology and prepared the master plan for developing a piece of 150-acre lot owned by a private entrepreneur. The salient features of the programme are as follows:

Development of 150 acres of contiguous patch of wasteland characterized by undulating topography with shallow layer gravelly surface soil including exposure of lateritic soil at places.

Land shaping and fencing for protection for biotic intervention.Creation of irrigation facilities by constructing a deep tube well with capacity to cover more than 100 acres under dry land annual crops including agro-forestry.The plan of cropping system includes major perennial forest and horticultural plantation viz. teak, white sandal, papaya, mango, guava, anona, amloki, drumstick, ber, banana, coconut etc. Agro-forestry test cropping model included a very short duration (3 to 4 months) intercrop with perennial species viz., teak/ sandalwood + watermelon/ cucumber, mango + amorphophalus (ol) /brinjal, drumstick + groundnut, etc.

Complete coverage of soil surface with the canopy of watermelon or cucumber in teak plantation served as an effective vegetative mesh resulting in better growth of teak plants.

The intensive cropping schedule of a number of short duration vegetable crops like amaranthus, spinach, capsicum, brinjal, cucumber, radish, onion, pea, bitter guard, lady’s finger etc. which have been grown as sequence and inter-crops. A host of first hand information has been generated. One among these is inter-cropping of amorphophilus with short duration cash crops like green grass or sesamum. Currently, attempts have also been made for raising seedlings of high value ornamental plants. The future plan includes cultivation of medicinal plants like Isabgul and export quality bold seeded peanuts.Required guidance was provided for maintaining soil fertility at this level for sustainable production of perennials and annuals. This involve intensive use of cattle manure which were made available from surrounding villages. Besides use of lime, appropriate mix of micro-nutrient and major nutrient based fertilisers were used. Besides, effort have been made in a limited way for fresh water aquaculture including composite fish culture and prawn culture.

This venture provided round the year employment for about 100 people of three surrounding villages, and this had a visible impact on their general health irrespective of male and female workers. This exercise generated a good number cropping systems/ packages which could be replicated in similar ecological niche besides catering to different socio-economic classes.

Wasteland development in community land or clustered land of individuals by forming SHG:

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The third model concerns the contiguous patch of land owned by a good number of villages where both physical and technological consolidation is possible. In Jhargram Block, an area of about 70 acres which was vested to Govt. and later distributed to about 130 Lodha families is being considered for development in this manner. Land is characterized by the domination of large patches of red laterite wasteland, which are put to fragmented use by the inhabitants who are mostly tribals. The composition of tribals and non-tribals is 88% and 12% respectively. The extremely primitive state of the art results in a meagre subsistence for the people. For the present study a 68.6 acre tract of wasteland has been considered and a section of the tribal population has been identified as the target group for adoption and implementation of the improved utilization model. The choice of project area was done with the help of local leaders.

The approach here has been participatory and technological achievements and experiences of the first model could be maid replicable here though with certain limited options. In fact, major considerations included comparatively low but affordable inputs, less risks and quick returns. The farmers need intensive training in groups and marketing of products need to be given priority. Participation of the farmers has been assured through formation of the Self Help Group (SHG) and operationalising technological consolidation for the purpose of planning and farming.

This approach to wasteland development is in its initial implementation stage. However the activities that have been initiated are: organisation and orientation of tribals towards acceptance of the new technology and participation in the institutional framework which is expected to smoothen the functional and operational aspects. However, in this current approach a lot more has to be done to prove it to be an established model. But the general enthusiasm and motivation that have been induced among the local people through repeated contacts and meetings, have laid the foundation for a systematic intervention for sustainable wasteland development.

2) Case study – Use of biofertilisers in West Bengal: A success story The agriculture output of West Bengal has been steadily increasing. In the state, the total foodgrain production in 2000-2001 was 144.82 lakh tones, and in the 2001-2002 fiscal the target production was set to 171.87 tonnes. Thus we are expected to achieve self-sufficiency in food grains in very near future.

Despite this rosy statistics, a little investigation and interaction with our farming community always reveal the prevailing despair in our agriculture sector. The present fertiliser application rate is about 117.8 kg/hectare 2000-2001 which is significantly higher than the national average of 87.56 Kg per ha. But, for a 1.85 times increase in food grain production during the period – 1975-98, our state had to increase its fertiliser consumption by 9.5 times1.

Paddy is the principal crop of this state. The paddy growers of our state are facing an acute problem: low crop yield and ever-increasing production cost. Three main crops of paddy are grown in the state through the year: Aus during summer, Aman in the monsoons and Boro in winter. In 1996-97 the total area under Aus production in the state was 461,000 hectares and the yield was 1,600 kg a hectare. The Aman crop on 4.2 million hectares yielded 2,000 kg a hectare. Boro cultivation accounted for 1.05 million hectares and the yield was 3,119 kg a hectare or around 800 kg a bigha. (One bigha is conventionally equal to 33 decimal.)

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Boro paddy is one of the most important cash crop of our state and the present increase in foodgrain production can be attributed to the expansion of Boro area only, but, at present, the yield of Boro came down to just 600 kg per bigha in many places, and the cost of production is rising every year.

Boro cultivation is dependent more on irrigation, which means more electricity and higher cost because the electricity tariff has gone up. The costs of all essential inputs of cultivation, too, have gone up according to farmers. Last year the cost of cultivation of one bigha land was roughly about Rs 1,680, but this year it is not less than Rs 2,200.The cost of chemical fertilisers, pesticides and insecticides, too, have mounted from Rs 400 on an average for one bigha to Rs 600, Above all, the labour cost has increased 11 times in the last 15 years. Most hard-pressed among the farmers are those who do not themselves till the soil, but are dependent on labourers. Just a year ago the labour cost component of the total production cost for a bigha was Rs 695. Now it is Rs 865.

Alongwith increase in production cost, there is a concomitant fall in the price of paddy this year. Even in the leanest of seasons, the paddy price remained near Rs 5.00 per kg – which is often insufficient for realisation of the production cost. The potato sector has also experienced similar setback.

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Thus the rural agro-economy has recently entered into a vicious circle, which can be schematically represented as follows.

Small and marginal farmers who have small holdings dominate the farming community of our state. This community raises high yielding variety crops, but they can not afford the costly chemical fertilisers in recommended doses. Raising of nutrient hungry high yielding variety with inadequate nutrient supply often seriously depletes soil fertility. On the other hand, in case of farmers who have large holdings and practice high input intensive commercial farming, indiscriminate and unbalanced fertiliser use has resulted in deep-seated adverse changes in soil structure and productivity.

Use of chemical inputs in agriculture has a very significant environmental implication also. It not only disturbs the sustainability of our agriculture by destroying

the natural productivity of our soil but also affects the quality of the air we breathe, the water we drink and the food we eat.

Groundwater contamination is an irreversible act that will deprive future generations of one of life's basic resources. Apart from direct contamination with many hazardous nitrates and pesticide residues, the chemical inputs and the exploitative agriculture also indirectly imposed threat of arsenic contamination in a large part of our state. Expansion of cultivable area by installation of groundwater irrigation system made our crops depend more on irrigation as there were heavy chemical inputs. This caused heavy groundwater removal and release of arsenic in it.

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Indiscriminate use of chemical inputs

Motivation to increase yield with a shortsighted outlook

Susceptibility to pest and diseases

Enhanced use of plant protection chemicals Loss of soil productivity Stagnation/loss of yield

Application of more chemical fertiliser to compensate the yield loss

Increase in input cost

Fall in production


Tea, which is one of the most important crops in North Bengal and a major exportable agricultural produce has also suffered setback due to high dependence on chemical inputs. The yield and quality has fallen, and high pesticide residues in tea has reduced its exportability.

Biofertilisers have long been identified as one of the major tools for sustainable agriculture, but their potential for rescuing our agriculture from this malady of high input of inorganic fertilisers could not be exploited in this state due to lack of awareness about it among the farming community. In this prevailing scenario, West Bengal Forest Development Corporation Limited in collaboration with Nitrofix Laboratories, undertook a project to produce and market biofertilisers under the brand name Azophos and Rhizophos. The objective of this project was (1)

development of suitable biofertilisers for agriculture, forestry, tea and sericulture sector of our state, (2) production and distribution of quality biofertilisers (3) continuous research and development to monitor the adverse effects of high chemical input agriculture and development of location specific biofertiliser-based agronomic practices for different crops.

The joint venture was formally launched in June 1996 and the unit began their constant endeavour of awareness building in different levels. Government and non-government extension agencies, farmers’ associations. Local three-tier panchayat administration – all were motivated to join in this movement. The unit organised numerous demonstration trials in government farms and farmers fields with different crops in different districts with its own resources. The results of the demonstration trials were found to be very promising. Some of the results of the trials are presented here :

Source : Azophos and Rhizophos – The Wonder Biofertilisers for Sustainable Agriculture – Information Brochure published by West Bengal Forest Development Corporation Ltd.

The Department of Agriculture of our state recognised the movement and issued a circular to all the department staff to co-operate in popularising the biofertiliser in our state. Recently, in September, 2001, in a fresh circular, the Department of Agriculture

instructed all their departmental staff to include the biofertilisers produced by the joint venture unit in their recommendations for all crops and to consider the biofertilisers as an essential input for various Centre and state funded projects. Accordingly, biofertilisers

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Location - Bankura State Seed Farm

Duration - August-'96 to December- '96 Rice variety - IR 36

ControlFull N

300

400

500

600

700

514

611 610

Yie

ld in

Kg/

Big

ha

Half N + Azophos

Location - Moynaguri Adaptive Research Farm

200

300

400

500

600

331

515483

Duration - August-'96 to December- '96 Rice variety - IR 36

Control Half N + Azophos

Full N

EFFECT OF AZOPHOS APPLICATION ON KHARIF RICE

6450

With Chemical fertilizersWith Azophos + 1/2 chemical fertilizers

3500

4000

4500

5000

5500

6000

6500

7000

4500

Duration - July - November, 1997

Farmers name- Sri Nilkantha Mahato

Location - Village - Bongabari,

P.O. - Vivekananda Nagar, Purulia

Yield in Kg/ha


produced by this organisation has been successfully used in National Watershed Development Project of different districts.

Department of Environment of Government of West Bengal has helped this organisation to strengthen its production facility for catering to the enhanced demand created in different sectors of our state.At present the joint venture unit selected the districts of Jalpaiguri, Coochbehar, Burdwan, Birbhum, Bankura and Medinipur as thrust areas and began wide scale demonstration and promotion efforts there.

The results of the demonstrations in potato in a major potato growing area Near Joypur, Bankura was found to be impressive. The farmers reported a net saving of Rs 400.00 per bigha on fertiliser cost when biofertilisers are used to supplement chemical fertilisers. Moreover there was an enhancement of yield to the tune of about 10 to 15%. The farmers reported less pest and disease infestation in the biofertiliser treated plots. In the plots receiving only chemical fertiliser, often rooting of seed potato was reported in that area this year, but no farmer using biofertilisers experienced that setback. Farmers also have grown very good winter vegetables, particularly onion, using biofertilisers in that belt.

Barddhamanis one of the districts which practices high chemical input agriculture for a long time. Sometimes even 2000 Kgs of NPK is applied per hectare annually in some multicropped plots. At the time of conducting the trials in farmers’ fields in Burdwan, the farmers could not believe that such small amount of chemical

inputs in combination with biofertilisers would be able to produce yield comparable to the plots receiving very heavy inorganic fertilisers, but the results of the field demonstrations really surprised them.

The betel-vine farmers of South 24 Parganas received biofertilisers with great enthusiasm. They found, in addition to increase in leaf yield, the plants become resistant to most of the damaging diseases after biofertiliser application. Thus, the farmers could do away with pesticide application altogether in the plots applied with biofertiliser. This not only cut back the production cost, but enhanced the crop quality also.

The tobacco farmers of Coochbehar, winter vegetable and potato farmers of Jalpaiguri, Nadia and Murshidabad, rice growers of Medinipur who have used this biofertiliser are all convinced about the effect of biofertilisers and gradually a steady demand is being generated among them. In 1999-2000, this sector consumed about 7.9 tonnes of biofertiliser produced by the joint venture, whereas in 2000-2001 the consumption rose to about 15 tonnes.

The Dept. of Forests entrusted the work of standardising the application methodology of biofertiliser application on forestry species to the unit under an IDA sponsored project. Under this project, numerous field trials were organised and documented. The effect of biofertilisers in raising health seedlings in different nurseries of Forest Dept. was demonstrated. Some representative results are shown in the next page:

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0.00

38.80

Duration of experiment - 120 days

10.00

ArabariBeliatoreSalugara

20.00

48.00

23.50

31.9

Anon. (1998) Final Report - Consultancy Project on Application of Biofertilisers and Mycorrhiza in Forestry, W.B. Forestry Project sponsored by IDA

29.60

Effect of Rhizophos application on Sisoo

Plant height in cm

36.8

Jhargram

13.0

Salugara

Azophos + 1/2N + 3/4P

17.3

19.9 22.2

0.0

60.00

5.0

50.00

10.0

40.00

15.0

30.00

20.0

Salugara25.0

Full NPK

Full NPK

Rhizophos + 1/2 N+ 3/4 P

1.8

3.2

2.0

2.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Jhargram

Plant height in cm Collar diameter in mm

Duration of experiment - 120 days

Effect of Azophos application on Sal

Anon. (1998) Final Report - Consultancy Project on Application of Biofertilisers and Mycorrhiza in Forestry, W.B. Forestry Project sponsored by IDA


The forest divisions are now important buyers of biofertilisers and the forestry sector consumed 11 tonnes of Azophos/Rhizophos in the last fiscal year. Apart from using in their nurseries, Forest Department also distributes these biofertilisers to the members of the Forest Protection Committees of the Joint Forest Managenent Programme to encourage environment friendly agriculture in forest fringe areas.

Swiss Agency for Development and Co-operation – an international NGO also sanctioned a project for developing a organic input based nutrient management technology for mulberry farming for the sericulture sector of our state. Under this project, a number of field trials were organised in the districts of Jalpaiguri, Maldah, Birbhum and Bankura, both in Government Sericulture farms and in farmers’ fields. In all these trials, biofertiliser was found to support very good leaf yield with a concomitant 50% and 25% decrease in inorganic nitrogen and phosphate application respectively.

The silkworm fed with leaves from plots applied with biofertilisers grew well and produced superior silk. Thus the potential of biofertilisers in the sericulture sector was amply proved. Now Azophos is regularly used in State Sericulture Farms and a large community of farmers in the traditional sericulture zones have been gradually adopting this biofertiliser as an essential input for their mulberry farming. The sericulture sector of our state consumed nearly 8 tonnes of this biofertiliser in 2000-2001.

Recently the Joint Venture Unit has been awarded with another project by SDC for dissemination of the standardised technology of biofertiliser aplication in mulberry farming in the districts of Murshidabad, Nadia, Burdwan, Uttar Dinajpur and Medinipur along with the districts already covered.

Tea is one of the major commercial crop of our state and this sector alone governs the economy of northern districts of West Bengal. Tea is a major consumer of fertiliser in our state. The entire tea sector of North-East has consumed about 20,000 tonnes of NPK last year. Recently many tea garden suffered a drastic fall of yield despite manifold enhancement in input

consumption. Actually this is

a repercussion of short-term benefit-oriented outlook of the tea sector. The tea crop responds quickly to the application of inorganic nitrogenous fertilisers. The foliage appears quickly and the number of leaves increases with each dose of chemical fertiliser application. But excessive chemical fertiliser application made the soil less productive by destroying the natural productivity. High pesticide application has made the plants more disease prone and necessitates intensive pesticide application. The quality of tea has fallen and often the tea leaves have been harbouring harmful pesticide residues. Such contamination makes the tea thoroughly unfit for marketing, especially in international markets. The tea gardens are generally situated in the most environmentally fragile area of North Bengal forests. The forests are now are under threat of environmental pollution caused by fertilisers and pesticides used in tea gardens. The sloping landscape of tea gardens make the soils extremely vulnerable to erosion loss and chemical fertilisers only aggravates the problem by rapidly destroying the organic matter in the soil. This is often the major cause of tea area loss in recent floods.

To combat the environmental hazards caused by the tea gardens, as well as to ensure the sustainability of the tea

151

Effect of Azophos Application on Mulberry leaf yield – Malda District

96

115

9197

115126 128

86

109

133

100 105

133142

163

95

60

80

100

120

140

160

180

Samayun AliSaifuddin Dilar

Abul Hossain

Lalmoha-mmad Biswas

Abdul Majid

Wahedul Haque

Hafijul AlamEntaj Ali

Fre

sh le

af y

ield

in g

/sq.

ft

Full NPK50% N,75% P, Full K + Organic manure @ 10t/ha+Azophos


sector and maintain the economic stability in tea areas, West Bengal Forest Development Corporation Ltd. initiated promotion of use of biofertilisers in that area through its local divisions. A number of demonstration trials were conducted and awareness building programmes organised in different places in Japlaiguri and Darjiling districts. The result of biofertiliser application in tea was found to be good .

More than 38 tea gardens have used this biofertiliser and consumed total of 10 tonnes Azophos/Rhizophos in 2000-2001 fiscal year.

Thus the future of biofertilisers in West Bengal

seems immensely encouraging. The need of the hour

is wide scale awareness building among the actual

users. The joint venture unit does not have enough

resources for undertaking very large-scale promotion

of their biofertilisers. Thus a concerted effort from

all concerned extension agencies in this regard is an

immediate necessity to keep the movement alive.

152

biodiversity strategy action plan – west bengal

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