REVIEW OF LITERATURE

CHAPTER IV

REVIEW OF LITERATURE

Salinity and sodicity in mils and ground water have become major

mvimnmcntal issues due to the introduction of GRA in coastal anas and in fact an

major obstacles to increase crop production worldwide (Shannos 1984). The existing

salinity and sodicity problems in crop production will become worse due to rapidly

growing human population in many countries and the increasing w m over the

limited water mums, which arr forcing farmers to use poor quality water for

irrigation ( k g et al.. 2002).

The strntegies to overcome salinity problem in crop production include both

development of management options (Shannon, 1997) and genetic impmvement of

salinity tolffanct in existing varieties (Epstcin el d., 1980). The latter option is difficult

for poor fanners as they cannot afford to buy costly genetically engineered seeds.

Besides, the gemtically alterrd gmn p l m is a threat to the indigenous Agro-

biodiversity and has c a d several Ecological and Socio-Economic problems although

the use of same managanent options can ameliorate yield reduction uoder salinity

stress, implementation is 0 t h limited because of cost ad availability of good quality

water mourccs(Epstcin er d . 1980 and Zcng cr d., 2002). k f o r e . the need for

LElSA Apecological technologies to improve the salt tol- in rice plant is

of immarsc imporwce and is expected to incnssc bsmatcdly in the fimue wshra

1999 Md Zmg t t d . 2002).

In spite of the recent interest, the available literature on organic amendments

and LEISA besbd Agrc~cologic.1 system of rice intensification (SRI) in relation to

crop growth, soil health, crop quality, economics and management of pests and diseases

pertaining to rice in salt affscted mas sn scattered and th is m single

comprehensive review. The available litcratute can be conveniently subdivided into the

following groups.

4.1. Effect of d i t y on rice

4.1.1. Effect of salinity on rice, wU nutricot cooteat and up take

Rice is a medium tolerant crop to salinity (Gupta and Yadav, 1986); however

with increasing salinity of irrigation water delayed g e m i d o n in a dm soil (Girdhar,

1988) and decrrasc the gmnination percentage and seedling growth and the severity is

much more in sensitive fultivars (Ahmad el d., 1990). Salinity tolerance a! seedling

stage does not always cornlate with tolerance at the reproductive phase (Tripathy and

Kar, 1995).

It is now well established that salinity affects the soil nutrient content and

uptake (Zaman et d , 1995; Tripathy and Kar 1995; Aicb et d., 1997) and soil 1 water

salinity hss adverse impacts on growth and yield of rice (Ahmed er al.. 1989; Girdhar,

1988; El-Agmdi and Aboul-El-Sod 1990, Hussain el d.,1991; Flowers et d.. 1991;

Khan er 01.. 1992: Zaman et al., 1995; Aich el 01.. 1997; Rajesh kumar and Bajwa

1997).

4.1.2. EUwl olulinity on Na to K ratio ia rice plant

The @on of cations in the rice plant could be owsidered as a basis for salt

tolerance and the varieties have been classified on the besi of such cation proportions

in the plant. Tripathy and Kar (1995) nported that tbe rice cultivars which are less

tolerant to salinity had NaK ratio at higher salinity than tolerant cultivars. The salt

tokrant rice varieties have some mechanisms to restrict tbe uptake of excess N a

Girdhar (1988) reported that increase in salinity level of irrigation water

increased the NaK ratio. Ihe ratio of Na to K in rice varieties had positive relation with

salinity and negative relation with yield unda saline water irrigation. Thus, the stress of

salinity on yield an bc @aed from NaK ratio in plants during maximum tillering

and panicle initiation stage (Ahmed el a/., 1989; El-Agrodi and Abou-El-Soud,1990).

4.2. Eflect 01 poor gallily o l i n i l p h water on soil properties

43.1. Soil physical p r o p d m

nK soil physical environment is mainly controlled by soil texture and ~JUI~UR

which in turn modify the various physical, physicochemical processes that occur in the

soil, soil d o n , soil tanpmtm, mineralization, oxidation, reduction, biological

nitrugen fixation ctc, Irrigating the soil with saline water deteriorates the soil physical

condition depeoding on the concentration of ions prcsu~t in tbe inigation water

(Somani, 19%).

The consbquenc+ of incnrsed bulk density is the duction in the porosity

which makeg the pmeation of mots very difficult. Besides, tbe infiltration rate is

W y reduced (Singh d S h 1970; Joshi and Dhir. 1991).

The dtrreascd hydraulic conductivity due to irrigation with Na ' rich watm

was nported by La1 (1970), Sharma and M d (1981) and Khandelwal (1986)

whereas it increased with inrrease in the on of orha salts such as sulphate,

carborrrte of calcium (La1 and Sin& 1974; Agrawal et al., 2002). The impact of sodic

water may also vary with the clay content, the dareasc king more conspicuou in

clayey soil than in medium and light texaatd soils (Sharma and Mondal, 1981).

42.2. Sod cbcarkd p r o p d m

Under saline c n d c n 4 the comtmtion of ions in the soil solution increase

beyond the conaneation of root sap thmby causing dihnbance in the absorption

mechanism due to increase in the osmotic potential. Hence, the direct impact of

salinization starts with the increase in the osmotic potential of soil solution, which

hampm tbe cmp growth (Agrawal el d , 2002).

Irrigation with saline water increase the EC of the soil wbmas the irrigation

with sodic water may lead to sodic soils with higher pH and ESP. Under such

situations, wtvrrin salinity and lor sodicity is increased due to poor quality irrigation

water, tbe soil fnblity is gnatly affected, though the irrigation watas & not have any

d i m role to play on the nuhicnt mechanism (except the impsct of Na' on the

precipitation of pbospbonu in sodic soils), the d t a n t changes in fertility of the soil is

mainly due to its impsct on the different nactions involved in soil solution and on the

c o n e of uamilable forms of into available fonns (Sharma and Moodal, 1981).

4.23. Soil microbiologicll panmeten

The impact of poor quality water irrigation on soil microbiological population is

many fold. The first impact on the physical environment, which when is not favorable

may not support c d n group of microbes but may help in the dominance of certain

other groups. For example, m b e s dominate under the normal environment and

anaerobes dominate under impediig drainage condition thereby completely modifying

the biochemical reaction in the soil. Similarly, the nitrifying bacteria, nitrogen fucing

&a, p h o s p h o ~ ~ solubilizm, sulphate oxidizers and other beneficial microbes

which are involved in the decomposition reaction are active only under neutral pH

environment. Hence, imgation with sodic water modifies all these biochemical

reactions (Thomas and Shantaram, 1984; Azam eta/., 1985).

43. Managemet of poor qualily idgation water

The success of saline or sodic irrigation projects for increasing productivity

mainly depends upon the efficient control of salt-water balance within the root zone and

the addition of specific system of management. Besides, when poor quality water has to

be 4 specific management practices must be followed. One of the management

practices for managing the irrigation w m having high salts is the application of

organic m t s l i e FYM, g m n manure, compost and green leaf manure (Sekhon

and Bajwa 1993 and Minahas el d., 1995).

Organic mcndmmts have been found to be beneficial to crop yield under

various severe conditions including salinity I alkalinity (Poonia and Bhumbla, 1974).

Organic mmures inatrsed their water holding capacity aad improved the physical

propertics (Bismia and Khosla, 1971; Sarkar el al., 1973) of the soil and facilitating the

air and water availability to plants and increasing the yield (Mohit and Shingte, 1981;

Wyopadhyay and Bandyopadhyay, 19E4). It bas been reported that organic manures

provide better nutritional environment (Prasad and Singh, 1980; Singh et al., 1980;

Sinha el al., 1981), facilitating better growth and yield of crops.

43.1. Farmyard manun (FYM)

43.1.1 SOU pr0pct-h

Several workm have established the multidimensional role of FYM, ranging

from building up of organic matter, maintaining favorable soil physical properties and

balanced supply of nutrients (Prihar and Sandhu, 1987; Reganold et al.. 1987; Hen&

et of., 1992; Panda 1995; Meelq 1996; !hkmnm, 1999, Mahgwarappa et d., 1999).

Sudhakar (2000). Chandmhan (2002) and Praveena (2005) reported that application

of FYM to the salt affected soils improves the physical properties of the soil such as

porosity and water holding capacity.

A d n g to Rasad and Singh (1 980), continuous use of FYM for a period of

20 years improved the organic carbon content of acidic red loam soil and also soil N

content (see also: Kanwar and Prihar, 1982; Gaur et al.. 1984; Srivastava, 1985;

Sommcrfeldt et d., 1988; Singh et a/., 1988; Sud er al.. 1990; Patiram and Singh, 1993:

Manickam, 1993; Jagadcsh el d., 1994; Mishra and S h m 1997; Sd~ih1998;

Thakur et d., 1999, K a t h el d.. 2002).

The bemficial effect of organic manure addition in increasing the available 'N'

a t e a t in the soil wss nported by Shgb et al. (1980) and Omal et al. (1981). Higher

available nitrogen content of sail under FYM addition could be due to favorable

microbial Pctivity and enhanced biomess addition to the soil besides the improved soil

physical properties (Muthwel el d., 1990; Jain et al., 1995; Sathe& 1998).

7be residual fertility in tams of organic carbon and available plqhorous

hcmsed under blue green algae and FYM with and without inorganic f e r t i l i (Rathort

el al., 1995; Trivedi et a1.,1995). S- (2000) observed that incorporation of FYM

improved the phosphorous status of soil through slow decomposition of FYM.

Chellamutbu et ol. (1988), Math et al. (1998), Sanlraranan (1999) and Khatik ad

Dikshik (2001) reported that application of FYM to the salt affected soils increased the

availability of potassium (12.80 per cent).

Prassd and Singh (1980). Swarup (1987) and R q m a b n and Selvaseeh (1997)

reporrad dmt macro and miau n u t k t availability was iacreased conddersMy by the

application of FYM. Subamanian et d. (2000) opined that the inclusion of organic

manures v u . FYM and Sesbmrio oculecafa in the fertilizer schedule not only imrrased

the yield but also improved the soil moisture storage.

43.13. Sell Mdegkd p u u e t e n

The effect of organic amedwnts on suppression of soil borne pathogens has

baa aPpbuiacd by s e v d workers (Kanariyan and Rad, 1981 ; Kundu and Nandi,

1985; Rao er ol., 1988 and K h j a er al.. 1991). Wobds and Schuman (1986) found

that microbial biomass increased linearly with soil organic matter concentration.

Combined application of FYM and vamicompost k e a d the soil microbial

population. The organic manure produced more microbial biomass than inorganic and

incmd tbe proportion of labile carbon (5.5 per cent) and nihgen (8.5 per cent) by

directly stimulating the activity of the microorganisms (Maheswamppa el al., 1999 and

Menhi La1 el d., 2002).

43.13. Nutrient upbke

Varma and Bhagat (1993) found that the incorporation of FYM increased

significantly the N, P, and K contents in grain and stmw of rice. The addition of FYM

had a cumulative effect on n h e n t uptake by rice (Brar el d., 1995; Kamalakumari and

Singaram. 1996; Hegde. 1996; Sathesh 1998; Marimuthu and Wahab, 1998; Nagarajan

eta!, 2000).

4.3.1.4. Growth, yield componenb of rice

In salt a f f d soils receiving saline I sodic irrigation under a rice-wheat-maize

sy- incorporation of FYM improve the crop yield (1 1.50 per centXGaur, 1991,

Sekhon end Wwa, 1993). In rice - wheat rotation with sodic water irrigated on sandy

loam soils for evaluating the nspoosc of applied FYM and gypsMliadicatedthat

addition of FYM s i g n i h t l y in@ (8-184) rice yield (Minhes et d.. 1995;

!ja&mm, 1999, Gupta er d., 1995; S i et d.,1996, Narayana Reddy er d.. 2001;

Ravffnr, 2005).

4.4. Grscll wur lag

Olan manuring is a practice of tuning green biomass in the soil to improve

physical, p h y s i w h d c a l as well as biological properties suitable for plant growth. It

is a collvenient means to firmish higher amount of nihagen to the beneficiary crops.

Sankanmen (1999) and Ravema (2005) also reported that application of green manuns

to the salt affected soils improved the physi-cal properties of the soil and

increased the yield of rice (1 2.50 per cent) receiving continuous poor quality inigation.

Sesbania aculeata (daincha - vem.) as gram manure crop has wider acceptance

among all green crops and it occupies prime p k in India from early times

(Domnergucs 1982). Sarsdhamani el d. (1989) reported that daincha accelerates the

rate of nclamation, besides increasing the productivity status of the soil. Seshnia

aculeata accumulated the higher amount of biomass (26.3 t ha 'I) followed by Sesbmtia

rosbufa (24.9 t ha ") but in tenns of N contribution, both were comparable contributing

145 and 146 kg ha -' respectively (Siddeswaran, 1992; Pandian and Rani Penrmal,

1994; Matiwade and Shcelavantar. 1994; Bindre and Thakur, 1995).

4.4.1. W fsrttWy

The utility of green manures for incmsing soil productivity has been

noognizcd h early times in some rice growing countlie$ pticularly China, India

and countrim of Notth-East Asia (Singh, 1984). Hussain el d.(1991) nported that

application of gr#a mnure in sllt a f f d soils like Sesbunia significantly imxeasad

thcsoil fdity(seealS0: DcDatb1.1991; Bedcaretd., 1995;Mishraefd., 1996).

4.4.2. Soil pr~pc-

S e s ~ ocvleata impmved soil rrhucture by virtue of high aggregate stability and

avoidance of soil &@&tion problans such 8s crushing and mmpction (Dm 1998). In

salt affected soils w iv ing saline 1 sodic irrigation under a rice-wheat-maize system,

incorporation of g m manure improves the soil physical properties (Sekhon and

Bajwa, 1993 and Kalidurai, 1998). Yadvinder et a/. (1994) also found that green

manuring application increased the organic carbon content by 20 per cent over control.

Similar improvemmts wen reported by So- et al. (19%), Bhan and Sushil

Kumar (19%). S i d d e m a m (1992). Singh et d (1 999); Kumar el al. (1999). Thakur el d

(19993, end Paaanayak el d (2001).

Grrm manm could increase soil N, and available P205 in the soil, maintain and

m e w soil organic matter and improves soil structure and physical characteristics

(Yash-pal et d., 1995). Hundal (1985) fowl that in waterlogged soils, green manures

i n c m the availability of P through the mechanism of duction, chelation and

favourable changes in soil pH.

An increase in the concentration of P, K, Mg, Ca. Fe and Mn dw to the addition

of grwn manures was r e p o d by Mcdhi and Datta (1993). Mappaona et d. (1995) and

Vig el ol. (1997.

Orsen manuring has increased K availability (Chaphale and Badole, 1999).

Duhsn and I M a b d ~ Singh (2000) and Singh er d.(2001) reported that application of

grsen tnenun improved thc availability of N, P, and K content in soil.

4.4.4. NPK uptake

H i g h accumulation of organic matter and N was o b e d by the incorporation of

65 days old Sesbmda ~RCII manure (Bhardwaj and Dev, 1985). Thangaraj and Kannaiyan

(1990) reported that N uptake in rice grain and straw was significantly higher with

Sesbania aculeata. Similar observation were also made by Duhm and Mahendra Singh

(1994), Nooye and IXidhts (19%). Nair and Gupta (I%), Stdin et al. (1999) and

Paitanayak et al.(2001) in rice -rice cropping system.

4.4.5. Effect of green manuring on growth and yield component of rice

The plant height, number of tillers, LA1 and DMP increased due to green

manuring (Muneendra Naidu, 1981; Maskina el al., 1985; Takahashi et a1.,1986).

Several workers have indicated that in salt affected soils, receiving saline 1 sodic

irrigation under a ricewheat-maize system, incorporation of green manure improves

the crop yield ( e.g. Morris et a l . 1984; Roy et al.. 1987; Ladha et a1..1989; Singh et

a/., 1990; Sharma and Kuhd, 1993; Sekhon and Bajwa, 1993; Budhar, 1994; Rao and

Mootthy. 1994; k k a r et a!.. 1995; Jayachandran and Veerabadaran,l996;

Somasundm et d , 19%; Rangaswamy et al., 1997; Subbalakhmi et a/., 1999,

Rajmthinam and Balasubramaniyan. 1999, Bayan, 2000; Sudhakar, 2000:

Rajmthinam, 2002).

4.5. Paarlupvya

45.1. Medmgud M y

In Sanskrit, Panchagavya means thc blend of five products obtained h m cow

(811 these five products am individually called 'Gavya' aad mlleaively ticrmed as

'Panchaguvya'). It contains ghtc, milk, curd, dung and urine obtained from a cow.

Whm suitably mixed, f d rad used, it would have positive inflwme on living

orgaaisms. The positive influence may be due to depmsion f d during the

clockwise and anti clockwise s h h g of Panchagavya stock solution, which might have

facilitated cosmic ray link (Sundarnraman et al., 2001 and Natarajan, 2002). Cosmic

energy, when made to pa99 through a living system, removed the imbalances in terms

of physical, chemical, biological and physiological aspects and harmonized the basic

elnacnts, which revitalize the growth pmccss.

In 1950, Martin of USA made a liquid catalyst (living water) from lactating

cow, using dung, sea wata and yeast and it wss claimed that it was capable of greening

dtgradcd land (Vivekanandan et a l , 1998). Panchagavya-3, acts both as fertilizer and

biopestici& @@:llw.cowindia or^ acassed on 21.1 1.2005). Panchagavya has got

reverence in the scripts of Vedas (divine scripts of Indian wisdom) and Vrbhywedo

(Vrbha m t ~ s plant and apveda maurs M t h system). The texts on Vrb-da

arc systnnatiLations of tbc practices that the farmers followed at field level, plrtctd in a

theontical fiamcwodc and it &find certPin plant growth stimulants; among than

Panchagavya was an important one that enhanced the biological efficiency of crop

plants and the quality of h i t s and vegetables (Natsrajan, 2002).

P a h k and Ram (2002) reported that Rishi Xiishi, a system of traditional

agricuhun pndiocd in Mahmhtra is using Amrit p i @repand by mixing 20 kg cow

dun& 0.125 kg butter, 0.50 kg honey, 0.25 kg ghac) and kept o m night to treat Kcds

Imd for sprying on field crops to maintain sail fatility and crop yield Rwal

Community Action Centn, Kodumudi, Tamil Nadu, cxpcrimcnted with Pancbagavya

by dcbing it with fifteen mon o q d c materials and W y wmmnded the

addition of tender wcmut water, s u g a m ~ juice and t4mana fruits to add the potency

@*as 2002).

45.2. Con~tilncatr of Panchrprvya

N ~ K (1999) reported that cow dung hed bcea used by Kautilya (321-296 BC),

Varahemihirs (505-587 AD). Sump& (1000 AD) and Someshwara Dcva (1 126 AD) in

ancient history. It wntaincd undigested fibn, cpitbelial cells, pigments and salts, rich in

nitrogen, phosphorus, potassium, sulfur, m i m n ~ t s , i n t e h d bacterh and mucous.

And also, w w dung (Gomay) was rich in bactab, fungi and o h mictobial organisms.

Singh (1996) lccorded that w w dung is composed 82 pa cent of water and 18 per cent

ofsolidmatter(minaslsO.1 paca1t,psh2.4pscm$~rrmranr 14.6pacenfCaand

Mg0.4paolt,S~O.O5perccnt, Silica 1.5perwnfN0.5percmf P0.2percentand

K 0.5 per cent).

Reddy (1998) reported that ww's urine (Gomoonu) was rich in urea and amd

both as a nutrient as well as a hormone. Cow's urine bad 91 per cent wata and 9 per

cent solid matter (minerals 1.4, ash 2.0, organic manun 6.0, Ca and Mg 0.15, S@ 0.1 5.

silica 0.01, N 1.0. P h.rcor and K 1.35 per a t ) . Urine also contained uric acid and

hippuric in large quantities a l o q with otha minds mattas like NaCI, sY1pbm

of CJ and M& polassirrm hippus@ dc. ( S i 1996). This may be ascribed to smral

na#nu such as fodder, b d quality, age, sex, lactation, halth etc., tho@ w

publicrtioasmappatlyMihbkonthesetopics.

Cow's milk also had been used by fanners in ancient times and reported to be

an cxccllmt sticker and spreader (Casein); a good medium for saprophytic bac6xia and

v i m inhibitor @me, 1999). According to Varahamihira (Brahat Sarnhita, 505-587

AD) the gareral practice of sowing seeds involved soaking them in milk for ten days,

taking out daily with h a smearing with ghae, rolling many times in cow dung before

the seeds are sown in a soil. Tney p w and bloomed wbeo sprinkled with milk and

water (Deshpande and Menon, 1995). Milk contained protein, fat, carbohydrate, amino

acid, calcium, hydrogen, lactic acid and also L4Ctobacillus bacterium. Many

microorganisms could fennent either five or six carbon sugars, but the Laclobacillus

bacterium could fennent both (Linda Mc Graw, 1999). Vrkshayurveda of

Cbavundaraya (Lokopakanun, 1025 AD), which deals with agriculture and botany,

described the use of milk that changed the flower colour and enhanced the h i t taste

(Shenoy et al.. 2000).

Cow's curd is rich in microbes (Lrrctobocillus) that are responsible for

fermentation (Chandha, 1996). Nene (1999) reported that cow's ghee had been used in

ancient and medieval times (Ksutilya 321.2% BC and Someshwara Deve 1126AD)

for managing seedling health. The contained vitamin A, vitamin B, calcium, fat

etc. and also it is rich in glycosides, which protected cut wounds h m infection.

Foliar spray of coconut water as growth hormone imrrased the biomass and

yield by 200 pa cent over control as nported by Marnaril and Lopez (1 997). lmmesed

chlorophyll content with application of coconut water was due to i n d cytokinin

content which in turn in& the chlorophyll mtent and photosynthetic activity for

longer period (Kalarani, 199 1 ).

4.53. Microba usocisted with Panchyrvyr

Soiaiappan (2002) found that in Panchnpvya, proven bio fertilizers such as

Arospirillum (10'4, Asotobacter (loP), Phosphobacteria (10') and Pseudomonas (lo6)

war found besides krobucillus. Ammonia and nitrite o x i d i i are found to colonize

the leaves and i n d the ammonia uptake and total N supply of spruce trees

( P a p er d, 2002). Tbe c d e e m of Pseudomom was found to enhance the

growth of garden pea seeds as c o w to control incubated with distilled water since

it contained LAA and GA3 (Mahalingam and Skla, 2003).

4.5.4. Infloencc of Paochagrvyr on growth, yield and pod@ of crop

la jesmine, spraying two rounds of Pancbagavya 3.0 per cent, one before the

flower initiation and another during bud 4ming phase ensured continuous flowering.

Pan&gavya impoved soil health and produaivity @ m , ~ h v w v . ~ ~ ~ i n b i r ~ aa.ssed on

21.1 1.2005). Panchagavya sprayed on chillies poduoed dark leaves snd new growth

within 10 dnys (Subhashini et d.. 2001). Morwver Panchagavya sprayed on 25 DAS and

40 DAS advancad the paddy harvest by 10 days (Vivekanandan. 1999 and Yadav,

2004). Panchsgavya spray advanced the days to first flowering and 50 per cent

flowering in annual moringa (W& 2001; Shann$ 2002; Beaulah et al., 2002) and

doubled tbe fruit yield besides giving nsiscllacc to pest and diseases (Vivd.9Daadan,

1999).

Studies on the effect of Panchagavya on gefininetion and growth of New

Zeelaad spiaacb (Tetragonia tetragonoides) showed that, Panchagavya foliar spray on

I@, 2@, 30h, 40* and 5om DAP alone gave 18 per cent highet yield over the

conventional method (Natarajan, 1999). A treatment combination of Panchagavya +

vermicompost on h h bean variety Ooty - 2 registered 36 percent higher pod yield

than conventional methods (Selvaraj, 2003; Selvaraj et al., 2003; Selvaraj et a1.,2003b).

Somasundaram el al. (2004) reported that 3 pncent Panchagavya was the ideal

concmtmtion for foliar spray on green grim variety CO-4. They also slated tbat foliar

application of Panchagavya at the rate of 3 p n t on 15, 25,40 and 50 DAS with no

in organics was the effective low cost technology in trrms of grain yield in the

production of grem gram.

Emily (2003) observed that in Withania somnifera (L.) DMa, the plant height,

plant spread, number of laterals, number of leaves plant-', frrsh and dry weight of

shoot, number of hrbm plmtnt'', frrsb and dry weight of tubm, harvest index, leaf area,

leaf area index, relative water content, total chlwophyll content highest dry maner

production and total alkaloid contmt were irmeasad significantly due to spraying

4 pr cent Panchagavya

Kaairnozhi (2003) carried out an experiment to stsndardiP organic production

package for Coleusforsbhlii Briq. Results indicated that plant height, plant spread,

number of 1- number of leaves plPatt', fnsh and dry weight of shoot, number of

t u b plaot", frtsb and dry weight of tubas, barvest index, leaf am, leaf area index.

relative water con* total chlorophyll contmt, highest dry mama poduction ad total

W o i d content incrrrsed due to 4 pcr cent spray of Pmdmgavya.

Sridhar (2003) carried out an experiment to study the effect of bio-regulators

on black nightshade (Solarnun nigruml.). From the results, it was evident that

Panchagavya at 4 per cent recorded highest plant g~~wtb, number of leaves, leaf area,

leaf and stem dry might, dry matter productioq LAI, SLW, NAR and CGR, leaf k s h

and dry weight, fruit fresh and dry weight, single plant yield, yield per hectare, leaf and

fruit solesodinc, &ic acid and TSS wntcnts.

Panchagavya spray @ 1.0 per cent reduced the flower drop, increased fruit s ix ,

retained frrshness and enhanced taste, prevented fruit drop in peach trees h m green

worms attack in Hosakerc village of Karnataka (httD:llwww.nreencomeweecom

accessed on 25.1 1.2005) and 2.0 per cent was effective in cnhanciag the growth and yield

of rice (Vivelranandan 1999 and Yadav, 2004).

The key feature of Panchagavya was its efficacy to restore the yield level of all

crops during the transitory period from the very fbt year O J a t a r a j ~ 2002). This can

be used as a key driving factor for popularizing the doption of Penchagavya when

farmers are switching over from continuous practice of GRA to organic cultivation,

since thc major bottkneck is the reduced yield during the transition period (Natarajm.

2002 and Selvaraj er d.. 2003b).

ASS E m of PucL.pvyr 011 pat ud distrra

Raldy and PIldmodsya (1995) obsaved that Panchagavya controlled the wilt of

bnw Soid dnachcd with Panchqavya slwy @ 10 .O p a ccnt successllly

controlled the wilt of tomato (Mishra 2002) and it was found to be superior to

wbmduh in &wing (he plant disclrs indoc and k m s i i the vigour of the plant

and fruit yield of tomato (Reddy and Padmodaya, 1996). Panchagavya was found to

activste soil and to protect plants fmm diseases (Shenoy et d., 2000). Panchagavya

spray rscordcd the least population of cutworms, which resulted in higher yield in

potato (Sclvanj, 2003).

4.6. The Synkm of Rice lnte~ifiation (SRI)

The SRI developed in Madagascar bas been reported to increase the grain yield

of rice substantially (Uphoff, 2001). This system is c o w of a package of agronomic

meawm that should be applied s i m u l ~ u s l y to realize a yield increare. The

components of SRI include the uu of young seedlings, a single seedling per hill, wide

spacing of transplanted d i n g $ limited irrigation, aerated soil conditions by fnquent

di* of the soil, and the use of compost ~ttD:/lciifad.comlI.edu/~mdex.htm[

sccessbd on 22.1 1.2005). The Comparison of SRI with conventional practices is

presented in Table 4.1 (Thiyagarajan er al., 2002 and Uphoff, 2003).

4.6.1. Cmtimg 1 Bdter Sdl Envirooment for Rice

Olher SRI practices have their main effect on the soil environment for rice. Probably

the mosl radical SRI dcpamtre fm common practice is to keep paddy fields moist but

not continuously flooded during the rice plants' vegetative growth phase. This

contributes to th growth of larger roots in aerobic soil environments, or conversely, it

avoids the inhibition and dcgenctation of root growth under hypoxic conditions. In

continuously flooded soil. 75% of rice plant roots mnain in the top 6 cm of soil at 28

OAT (Kirfr and Soliw. 1997) and they never grow as deeply as pospible if the soil has

aot deprived of oxygen.

Tabla4.l. Compariron d S R I with conventional prrrtiea

CULTURAL , PRAmCES

Age of transplanted -duP

Number of Kbdlj.g per hill

Spacing of -dhg

Water manapmest

Weed control

Fertilizer ~ P P ~ W

Source: Modified adopted

CONVENTION& I GRA

3-4 weeks, or sometimes more

3-4, and sometimes more

Dense planting: 10-20 crn apan in rows; 50- 100 plants/m2.

15 x (Kmvi )

20 x l Ocm (Samba)

Continuous flooding, 10-20 cm depth, thmugh the entire growing period

Mostly through flooding; manual or chemical weed control as needed. Herbicide application. 3 DAT, 25 - 30 DAS hand meding

Application of NPK fertilizers as rccommendcd

CULTIVATION TYPE

SRI

Younger seedlings: 8-12 days, gmmlly not more than 15 days

Fewer seedlings: 1; sometimes 2 if soil conditions less good

Wider, sparser spacing: 25 X 25 cm to 35 X 35 cm, in square pattmn, 16 to 91m2; with best soil, up to 50 X 50 cm, may have only 4 1 m2

Keep soil from being continuously saturated during vegetative growth period, minimum water applications to maintain soil moistme, or alternating floodingdrying; shallow flooding 0-3 cm) during reproductive period

Weedii with simple mechanical 'totating hoe,' starting 10-1 2 DAT; recommend up to four times, done also for soil aeration

Application of compost recommended, not required; best put on preceding crop

from Thiyagarsjan, 2002 and Uphoff, 2003.

Research on the physiological effects of SRI methods on the rice plant done at

tbe China National Rice R a e m h Institute found that mt dry weight was 45% grater

for SRI plants compared to the same variety conventioaally grown, and roots extended

10-15 cm deeper (Kirk, 2001; Kmmckcr et a/., 1999, Tm et al., 2002). Altemtely

flooding and draining such fields can reduce Fe toxicity and A1 saturatio~ whereas

alternate wetting and drying of soil can increase both biological N fixation and P

solubilization, as discussed below. Water management can thus produce benefits that

are equivalent to the application of inorganic fertilizer.

The edge effect' is a matter partly of having more tillers and rwts growing into

unoccupied space; but increased exposure to solar radiation is probably an important

factor. When plants an densely spaced, the upper parts of the canopy shade the lower

parts and ducc photosynthetic potential (Uphoff, 2003). The total number of grains

plant" (and .hill") went frum 1431 to 6158; percent of empty grains dropped h m

19.4% to 13.9°/0, and percent of broken rice gmhs when milled went down h m 9.37%

to 2.93% (Thiyagarajan er d., 2 0 2 and Uphoff, 2003). These results indicate that witb

c l w a spacing, light intensity is less than requid to support photosynthesis, with lower

leaves in the canopy king ' subsidid by the photosynthetic activity of upper leaves.

4.6.2.2. Root Fuctiodng

Root pulling resistance (RPR) per clump is more than double for SRI plants.

and since SRI clumps m single plants whenas conventionally grown as well as

improved practice rice is grown with 3 or more plants per hill, the per plant resistance is

at least 6 times greater (Thiyagarajan el d.,2002; Wsng et d., 2002; Uphoe 2003).

Such physiological diffennces can help to explain the recorded incmws in SRI yield.

But the differences themselves need to be mplaiacd in terms of specific SRI practices.

4.633. Soil Nutrient Availability

Tbere are a number of ways, documented in the literatun, by which the supply

of nutrients to the rice plant wuld be enhanced by SRI practices, including through the

mycelial networks of mycorrhizal fungi that 'infect' plant roots (Thiyclgarajan el al., 2002

and Uphoff, 2003).

4.6.2.4. Tbc Birch Effect (flwb of N mioenltEltion)

This is the name given to the flush of N mineralization that occurs after

rewetting dry soil first documented by Birch (1958). This intensive @way of N

mineralization which increases N availability has not received much attention for its

implications for lowland rice production. Several factors contribute to this N flush. A

significant proportion of soil microorganisms, many aerobic and others anaerobic, can

die during drying and rewetting. The mineralization of dead microbial cells by the

remaining micro flora c a w pail of the observed N flu& (Mruumoto el d., 1987 and

Gijsnan et d.,1997). The youthful stab of the microbial populations that develop after

nwming CM also enhance N mineralization, according to Bircb (1958) and Cabrera

(1993). A regime of flooding and bying paddy soils could thus produot more N than is

lost from lurhing and volatilization (UphoK 2003).

4.635. Biological Nitrogen Fition (BNF)

SRI watn msnagement practices and the recommended weeding with a 'mtathg

hoe' would contribute to the juxtaposition of aerobic vis-A-vis saturatad soil. The

cmca~tmtions of the nitrogen-fixing bacteria AzospirilIm in the roots of rice plants

was higher (35 per cent) in the compost applied SRI field (Raobcl iq 2000,

Randriamiharisoa, 2002; Randriamiharisua and Uphoff, 2003).

4.6.2.6. Mycorrbiul AMoeutions

'Ibc soil aeration that is prmnoted by SRI methods is beneficial for the growth

of aerobic microbes including particularly m y w M fungi. M y c o h a e enhance the

variety as well as the quantity of nutrients that become available to the plant. Most

terresrrial plants depend on or benefit from the 'infection' of their roots by e c t o W or

endorhid (vesicular-arbwular) fungi. These send out vast, hard to imagine lengths of

thread like hyphae into the soil, with 50 meten or more of filaments in a single

teaspoon full. Mywrrhizal fungi absorb N, P and K as well as Q S, Fe, Mn, Cu, Zn

and other nutrients as m l l as water from the soil, translocating these to the plants in

whose roots the fungi have established themselves (Sieveding, 1991; Martin et al.,

2001 and UphoK, 2003)

163.7. Crop protection Ig i . l t we&, peata and d i : m integrated approach

Water management methods that avoid standing water during the vegetative

growth phase, as in SRI, may contribute to a reduced r i a yellow mottle virus incidence

(Uphoff, 2003). Thus, interactions betmen well adapted cultivars, the local biophysical

micmcnvironment and agronomic practices (sading dale, plPnt density, fertilizer use,

trsp crops and/or intercrop, ctc.), will to a large extent determine the opportunities for

weeds, pests and diseases to evolve and nach epidemic pro&ons. Judicious

agronomic management therefore can conhibute substantially through pest, discase and

webd control to enhance yields. Because of the many interachg factors involved,

integrated crop protection presents considerable scope for new research that should lead

to lowoost solutions for resoupcopoor farmers (Stoop et al., 2002; Uphoff, 2003).

4.7. Peopk'r prrHeiprtion in arlnnl raource rnraqmcnt through h n r f e r of

technology (TOT)

in recent y m the notion of sustainable development has emerged as a reaction

to the highly tcchnologid and centralized processes that have governed thinking on

development, the g m n revolution being a clmic example. The process of rmstainable

development envisages that people should not merely participate, but be in charge of

their own development. Some initiatives in India have grappled succffsfully with this

complex proms, and different models of people driven development have emerged

(Uphoff. 2001).

On-fann participatory restarcb following a farming-systems approach would be

quircd to validate the p t i d relevance and risks of SRI prectices, before any

attempts en made to promote their integRtion into specific production systems. The

findings uadrrscorc the importance of integrated and interdiscipliaary research,

c o m b i stmkgic and doptin (on-farm participatory) approaches tbat explore and

link bio-physical and socioaconomic firtors in crop production. Such approaches

would pamit to dock currently untapped production p o t d a i s of rice and other

major cereal grain crop, without mtra costs to fannns or to the emtirauaent (Stoop et

d., 2002). T&c system of rice intmdkdon (SRI) hrs been proposed as an integrated

nod agm ecologically souad appmch to rice cultivation It waa mainly dmlopcd

thro* participatory on-frrm nsearcb conducted in hbhgasw, but its duat ion is

ongoing in Asia as well (Uphoff. 2005)

In the pagf the prevailing "~huology bumfern appmches such as the T&V

(training and visit) system have focused on a routine, sequential hamfcr process

through stMiardized manmeddioas. Such a transfer strategy is suitable mainly for

large, uniform and favorable agricultural lueas tbai arc increasingly occupied by large-

scale, machaniLed f a m . For highly diverse and location-specific agricultural systems,

this is neither an efficient nor aa effective approecb (Ktnnar, 2002; Law and Mazcus,

2003; Scbeyvem and Stony, 2003).

Applying knowledge-intmsive SRI principles will require rather ikdamcntal

changes in the strategies for nwl &wlopmeot and extension. It will demand flexible

systems, based on "fanner-leadng", in addition to subject- and pmblan-specific

training. This will require additional skills fiom the m f e r agents and knowledge

brokers, including facilitating capabilities and @cipatory leaming approaches. With

wh skills naensioa w b could encourage i n f d farmer expaimentation and

reinforce annmunication within rural communities (Uphoff, 2003).

A s&iking feature san in fiam studies all ova the world is that in spite of very

s i m i l a t n s o u r c e c n d o m n c a t s , t h c r r l m o R c n h u g e d i ~ i n y i e l d s e n d ~ ~ ~ ~ m i c

performance between farms (Mulrhejee, 2002; Gosling and Edwards, 2003).

Diffennccs in education, knowledge sad past experiences among farmers an largely

nspnsible for this disparity. Collaboration between local h e r organizations and the

exteasion service m y seek to capitalize on this sitution by mobilizing certain farmers

in a combined training and communication process organiz+d at village level and

through e type of "farmer field schools". Only through such approaches can the general

educational level of d communities be raised progressively, enabling small farmers

themselves to c o p with the large, location-specific diversity in their production

systems. An attempt to test and introduce such an approach is underway in Guinea

(Conakry) through a joint effort by the national research and extension orgaaizations

(Gaskell. 2000; IFAD. 2002; Dcnsmnbe. 2003; Mikkelsm, 2005).

In view of the gnat dimity in rice production system that operate unde~

varied local biophysical and socio-eumornic conditions, SRI methods will not be

applicable invariably everywhar. Each s i t d o n will quire research and validation of

the various SRI components. Therefore, on-farm pwticipatq rrscarch will be q u i d

to introduce site-specific adaptdolls and to expose fmm and extension agents to the

SRI perspectives (Stoop cr a/.. 2002).