Biofertilizer: the opportunities and constraints

Dr. Chaveevan Leaungvutiviroj

Land Development Department

Ministry of Agriculture and Cooperatives

4

3 Term of biofertilizer

1 Introduction

2 Concept of biofertilizer

LDD biofertilizer product

Outline of the presentation

5 Constraints in biofertilizer technology

The potential negative environmental impact of the large scale use of

chemical fertilizers together with their increase cost has prompted a

number of scientists worldwide to seriously consider the possibility of at

least partially replacing to chemical fertilizers with bacterial inoculants.

Introduction

Biofertilizer can help increasing crop yield without causing the damage

associated with chemical fertilizer.

Supporting Thai government policy “National organic agriculture” including

strategic plan to reduce unit cost of crop production and food safety.

Utilization of biofertilizer is both economical and environmental friendly”.

Conventional agriculture production in Thailand

need more application of chemical fertilizer to

accelerate plant’s growth including utilization

herbicides, insecticides and fungicide for

eradicating weed, pests and disease.

The amount and value of imported chemical fertilizer during 2007-2012

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The amount of imported pesticide during 2008-2012

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Herbicide Insecticide Fungicide other

Problem of chemical agriculture

Directly affect the health of farmers and consumers

Adverse impact to the soil properties

Cause the contamination in agricultural products

and environment

Hardening and crusting of soils

Soil aggregate by organic matter and root

The perspective of biofertilizer came into existence discovery of many

beneficial microorganisms in the rhizosphere through capable of decompose

plant residue and organic materials, nitrogen fixation, P and K solubilization,

mobilization and micronutrient transformation in the soil, produce plant

growth hormone and antibiotic like substance.

Concept of biofertilizer

Synthesize humus, Mineralize organic

N, S, P

Symbiotic and asymbiotic N2 fixation Phosphorus solubilizer

Biological control

Role beneficial

Make availability of nutrients. Replace 25-30% chemical fertilizer, especially

regarding N and P

Improve fertilizer use efficiency. Supplement chemical fertilizers.

Produce growth promoting substances More root proliferations, promotes germination,

flowering, fruiting and ripening in plants, increase

crop yield by 20-30%

Secrete antibiotic like substances against Suppress soil borne pathogen, reduce to use

pesticides

Make the root rhizosphere more lively. More biotic and abiotic stress tolerance.

Less residual effect, no adverse effect on

plant growth and soil fertility

Sustain soil health, non-pollutants, eco-friendly

Role and beneficial of biofertilizer

Biofertilizers are defined as preparations containing living cells or latent cells

of efficient strains of microorganisms that help crop plants’ uptake of nutrients

by their interactions in the rhizosphere when applied through seed or soil.

They accelerate certain microbial processes in the soil which augment the

extent of availability of nutrients in a form easily assimilated by plants.

Term of biofertilizer

Biofertilizers are not fertilizers. Fertilizers directly increase soil fertility by adding

nutrients. Biofertilizers are microorganisms that enrich the nutrient quality of soil

through the processes of fixing atmospheric nitrogen, solubilizing phosphorus,

stimulating plant growth through synthesis of growth promoting substances.

No. Groups Examples

N2 fixing Biofertilizers

1 Symbiotic Rhizobium, Frankia, Anabaena azollae

2 Free-living Azotobacter, Clostridium, Beijerinkia, Anabaena, Nostoc, 3 Associative Symbiotic Azospirillum lipoferum

P Solubilizing Biofertilizers

1 Bacteria Bacillus megaterium var. phosphaticum, Bacillus circulans,

Pseudomonas sp.

2 Fungi Penicillium sp, Aspergillus sp.

P Mobilizing Biofertilizers

1 Arbuscular mycorrhiza Glomus sp., Gigaspora sp., Acaulospora sp., Scutellospora sp. &

Sclerocystis sp.

2 Ectomycorrhiza Laccaria sp., Pisolithus sp., Boletus sp., Amanita sp.

Potassium & Silicate Biofertilizer

1 Bacteria Bacillus mucilaginosus, Bacillus edaphicus

Plant Growth Promoting Rhizobacteria

1 Bacteria Pseudomonas fluorescens, Azospirillum brasilense, Acetobacter sp.,

Different types of biofertilizers

Rhizobia can infect the legume hosts and induce root or stem nodules. They

reduce molecular nitrogen to ammonia which is reality utilized by the plant to

produce valuable proteins, vitamins and other nitrogen containing compounds.

Symbiotic N2 fixer Rhizobium

Host legumes Rhizobium Species N2 fixed (kg/ha/yr)

Peas R. leguminosarum 62-132

Soybean R. japonicum 57-94

Lupines R. lupine orinthopus 150-169

Alfafa, Sweetclover R. melliloti 100-150

Beans R. phaseoli 80-110

Clover R. trifolii 104-160

Cowpeas, Groundnut R. species 84-105

Estimated average rates of biological N2 fixation by Rhizobium in different crops

Associative symbiotic on roots of grass and similar types of plants fix nitrogen

20-40 kg N/ha/yr in the rhizosphere of non-leguminous plants such as cereals,

millets, oilseeds etc. It also benefits host plants by supplying growth hormones

and vitamins to enhance biomass-root system and uptake plant nutrient.

Azospirillum

Non-symbiotic N2 fixing bacteria

Well known free living nitrogen fixing aerobic bacteria is used as biofertilizer

for all non leguminous plants especially cereals (rice, maize, sorghum), cotton,

vegetables etc. Azotobacter are abundant in the rhizosphere region, quantity of

N2 fixatin in the range of 40-60 kg N/ha/yr. Lack of soil organic matter is a

limiting factor for the proliferation of Azotobaceter in soil.

Azotobacter

Scanning electron micrograph demonstrating

the colonization of wheat roots by strains of

Azospirillium. A bacterial inoculant that acts

as a phytostimulator.

Azospirillum induces the proliferation of

plant root hairs which can result in improved

nutrient uptake.

Free-living N2 fixation is an important group of aquatic organisms,

mostly found in wet and marshy condition, only used for

rice cultivation and do not survive in acidic condition.

Cyanobacteria (blue green algae: BGA)

Algae biofertilizer

Azolla is a free-floating aquatic fern that found on water

surface having cyanobacterial symbiont Anabaena azollae

in their leaves. It fixes nitrogen 40-80 kg N/ha use as green

manure in paddy field because of large biomass.

BGA associated with Azolla

PSM are a group of microbes capable of solubilizing inorganic phosphorus

from insoluble sources such as rock phosphate. In alkaline and acidic soils,

the availability of phosphorus is low. These microbes reverse this process by

secrete organic acids to dissolve bound phosphate in soil.

Phosphate solubilizing microorganisms (PSM)

Bacteria are capable of degrading silicate minerals to provide plants with K and

silicon. During the metabolism of microbes several organic acids are produced

and these have a dual role in silicate weathering.

Potassium & Silicate solubilizing bacteria

Treated by living bacteria,

rough in surface

Treated by dead bacteria,

smooth in surface

Scanning electronic photograph of feldspar treated by bacteria under continuous shaking flask experiment

Source: Hebei academy of science

Found cells on surface of mineral splinters

in which bacteria predominate on feldspars

AMF are found to be associated with a majority of agricultural crops. AMF have been associated with increased plant growth and enhanced accumulation of plant nutrients, mainly P, Zn & S through greater soil exploitation by mycorrhizal hyphae. Maximum root colonization and sporulation occurs in soil with low phosphorus content. Moreover AMF help plant tolerate disease, nematode and adverse environmental stress (drought resistance).

Arbuscular mycorrhiza fungi (AMF)

Type of mycorrhizal fungi penetrates the cortical cells of the roots of vascular plant.

Non-mycorrhiza Mycorrhiza

The group of bacteria colonize roots or rhizosphere soil. These PGPR are

referred to as biostimulants and phytohormones production (indole-acetic

acid, cytokinins, gibberellin and vitamin) to promotes seed germination, initial

vigor of plants to resist disease and tolerate drought condition.

Plant Growth Promoting Rhizobacteria (PGPR)

Therefore, application of bio-fertilizer are considered as a promising alternative way for

mineral fertilizers, bio-control and supports an effective tool for decreasing agricultural costs

including responsible for developing organic, green and non-polluted agriculture.

Specific purpose

Biotechnology Innovation

Microbial activators

Compost Bio-extract

Biocontrol Bio-fertilizer and

Pilot plant set up in Head Quarter of Land Development Department

LDD biofertilizer products are microbial inoculants supported on carriers

Improve soil properties

Increase soil fertility,

Produce plant hormone

Control plant diseases

Microbial activator Super LDD 9 Increasing available phosphorus in acid soil and acid sulfate soil

Microbial activator LDD 11 Increasing biomass of

green manure

Biofertilizer LDD 12 Increasing N, P, K,

plant hormone

Microbial activator LDD 3 Control plant pathogen (root & foot rot disease)

LDD biofertilizer products

Microbial activator Super LDD 9

This activator consisted of phosphate solubilizing microorganisms

to release P particularly in acidic or acid sulfate soil (pH< 4) from

unavailable form (inorganic phosphorus complex or phosphorus

fixed by Al and Fe) to available form for increase phosphate solubility

H2PO4-

HPO42-

H2PO4-

HPO42-

Al+-P

Fe+-P

Fe+-P

Al+-P

Al+-P

Fe+-P

Al+-P

Miroorganisms produce organic acid

Available form

Fe3+ Fe3+

Citric acid + iron (trivalent cation) iron citrate (chelateed iron)

Green manure is one kind of organic fertilizer. Legume crops usually are

planted before cash crops two months and incorporated into soil to increase

organic matter and plant nutrients especially, increase nitrogen content.

Legume green manures are utilized in Thailand such as Sesbania sp.,

Crotalaria sp., Canavalia sp., Vigna sp. and Cajanus sp.

Green manure

Microorganism LDD 11 promoting growth of green manure

Sesbania rostrata Crotalaria juncea

Symbiotic nitrogen fixing bacteria (Rhizobium sp.) specify to each kind of green manure. Promote growth and increase the biomass - Sesbania rostrata (lowland area, salt tolerant) - Crotalaria juncea (upland area, drought tolerant)

LDD 11 (African Doncha) LDD 11 (Sunhemp)

Bio-fertilizer LDD 12

A group of effective microorganisms can produce nutrient element

or convert insoluble of inorganic compounds to soluble form to

increase soil fertility especially N, P, K and produce plant growth

hormone to enhance plant growth.

Free living nitrogen fixing bacteria:

Azotobacter tropicalis

Phosphate solubilizing bacteria:

Burkholderia unamae

Potassium solubilizing bacteria:

Bacillus subtilis

Auxin producing bacteria:

Azotobacter chroococcum

compost 300 kg

rice bran 3 kg

bio-fertilizer PD 12 (1 package) 100 g

Ingredient for propagation biofertilizer LDD 12