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close this book Environmentally sound technologies for women in agriculture
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View the document Multipurpose trees and shrubs

Organic farming

 

Organic farming

Deadly

Pesticides are dangerous to human health: 22,000 people die in developing countries each year from pesticide poisoning.

High dosages of fertilizers and liberal use of synthetic pesticides can pollute water, air, and soil. Pests can develop resistance to pesticides and previously unimportant pests can emerge

The health of the soil is also adversely affected. Certain micronutrients such as zinc, copper, and iron can become deficient in the soil over a period of time. As a result, it becomes increasingly difficult for farmers to sustain high yields year after year.

How can we face this critical dilemma of consistently obtaining high crop yields without polluting soil, air, and water, and without depleting soil fertility? The answer perhaps lies

In organic farming.

What is organic farming?

The aim of organic farming is to increase productivity with minimum reliance on chemicals, while at the same time conserving resources. It is a rediscovery of the practices of our ancestors, but with a modern and scientific outlook. It nurtures the soil rather than just a particular crop.

The use of synthetic chemicals is minimized (to the level of bare necessity). There is a greater reliance on conservation and use of all resources available on the farm, including animal, human, and plant wastes.

The goal of organic farming is to achieve stability without sacrificing high production and without polluting water, soil, and air.

It requires a multidimensional approach emolovina many practices.


Ecosystem integrated complex

Integrated nutrient management

- Use minimum tillage practices to conserve soil organic matter and biotic life including earthworms.

- Convert all available biomass on the farm into compost rather than burning or otherwise wasting it. (See Compost-making and Vermicomposting.)

- Add at least 2-3 tonnes of compost per hectare annually. The ideal is 10 tonnes per hectare.

- Apply green manure to the fields after every second or third year. For instance, prunings from gliricidia or other leguminous trees planted on bunds can be incorporated in the rice fields at the time of puddling. This can reduce or eliminate the need for artificial fertilizers.

Incorporate leguminous plant material into the soil.

- Make up soil deficiencies, if any, (on a soil test basis) by applying minerals such as rock phosphate, gypsum, and pyrites.

- Manage weeds using nonchemical methods, rather than trying to eradicate weeds. (See Nonchemical methods of weed control.)

- Leave the weeds taken out of the fields to form a mulch and to decompose in the soil itself Or use them for making compost.

- Adopt suitable crop rotations, mixed cropping and intercropping, instead of growing one and the same crop year after year. This uses soil layers, space, and sunlight differently..

- Include legumes in the rotation; inoculate them with rhizobium culture.


Incorporate leguminous plant material into the soil

Integrated pest and disease management

Organic farming uses various practices to manage the pest population at a safe level (one that does not cause economic injury) rather than completely destroying them using synthetic chemicals.

These practices include the following:

- Invert the soil after harvesting a crop to expose pests.

- Clean bunds and channels of grasses which harbour pests.

- Grow pest-tolerant varieties.

- Sow the crops at the right time.

- Sow healthy seeds.

- Increase the seed rate so that uprooting insectand disease-infected plants later does not affect optimum plant populations.

- Hand-pick and destroy egg masses, gregarious larvae, caterpillars, and adult beetles.

- Use light traps.

- Apply sticky grease bands on fruit trees to stop insects from crawling up the trunk.

- Release insect parasites and predators, and apply biological control agents such as Bacillus thurigensis.

- When pesticides are used, restrict these to a few mainly plant-based pesticides: neem, karanj products, derris (also known as rotenone), and pyrethrum


Integrated pest and disease management

Integrated soil and water management

Apply irrigation water efficiently to avoid wasting water and controlling soil erosion and loss of nutrients through runoff and leaching. For this:

- Irrigate your crops only when needed, use only the required amount of water. For instance, fields can be divided into small sections which can be irrigated separately.

- Do not apply excess water at any one time. Avoid leaching soil nutrients beyond the root zone.

- Keep your fields levelled.

- Consider constructing prefabricated concrete channels to avoid water seepage and leaching of nutrients.

- Harvest water by constructing bunds, channels, and tanks to store water for future use.

- Conserve water in the soil by using mulch, cultivating along the contour, and breaking the soil crust to slow the evaporation of water from the surface.


Integrated soil and water management

Contributors/Sources: Dr. V. N. Shroff, Mr. C. V. Sheshadri, Ms. Chitra Gandhi, Dr. W. R. Deshpande, and Dr. Jagdish Singh

 

Compost making

Turn organic waste into compost for improved soil fertility and sustained crop production.

What is composting?

Composting is a big-chemical process in which micro-organisms decompose organic waste matter-crop residue, kitchen wastes, cowdung, urine-into a soil-improving product called compost.

The final product is a uniform, black mass of rotten, nutrient rich manure.

Advantages of adding compost to soil

Compost:

- supplies nutrients.

- improves microbial activity, which helps release soil nutrients for use by plants.

- checks pollution from manure heaps and leaching of urine into the soil.

- reduces the need for chemical fertilizers which are costly and potentially damaging to the environment.

- increases the amount of organic carbon and nitrogen, improving physical properties of soil and allowing higher response to chemical fertilizers and higher crop yields.

- improves soil structure, improving drainage and making tillage easier.

- increases the water-holding capacity of soil.

- helps check wind erosion by improving soil structure.

Selection of site for composting

Your compost pit should be:

- easy to inspect.

- built on higher ground to avoid waterlogging.

- near the cattle shed and a source of water.

- located away from the road to avoid contamination by lead and other toxic metals which, in turn, could contaminate food crops affecting the health of humans and livestock.

Caution

Compost and farmyard manure are major sources of weed seeds. Weed seeds withstand partial decomposition, therefore, put only fully decomposed compost and farmyard manure on your fields.

Three methods for making compost

Indore method

Raw materials for composting

Plant residues-Mix plant residues, weeds, sugarcane tops, leaves, grass, wood ash, bran, etc. Chop and crush hard woody material

Dung-Collect dung and bedding of farm animals, including the urine-soaked mud from animal sheds.

Wood ash-Wood ash reduces compost acidity and adds potassium.

Water and air-Both are necessary for bacterial and fungal activity.

Size of the compost pit

Width 2 to 2.75 m

Depth 0.75 to 1 m (not more than 1 m)

Length 3 m or more as required.

Method of filling the pit

1 Spread raw material evenly in the pit in layers 7 cm thick.

2 Add a layer of wood ash (if available) along with urine and mud.

3 Next spread a 5-cm layer of bedding with cattle dung and soil. Sprinkle with water until moist.

4 Continue adding layers until the material is 30 cm above ground level. Apply water. The heap will shrink as it decomposes.

5 Turn over the heap three times. Moisten with water each time.


To aerate, dig out the compost . . .


And then put it back in the pit.

Turning

Decomposition needs proper mixing as well as circulation of water and air. You can ensure this by turning over the material three times:

First turning 10-15 days after filling the pit.

Second turning 15 days later.

Third fuming after 2 months.

At the third turning, you can take it out of the pit and put it back in. This helps the bacteria to take nitrogen out of the air. In regions of heavy rainfall, compost pits should be covered by a shed. Compost-making should be discontinued between June and September.

Bangalore method

Raw material Same as for the Indore method.

Size of the pit

Width 2 m

Depth 1 m

Length 6 m

Method of filling the pit

1 Spread a 1 5-cm layer of farm refuse on the bottom of the pit and moisten this with water.

2 Follow this with a 5-cm layer of cattle dung and urine soaked mud.

3 Next apply a 2. 5- to 5-cm layer of soil.

4 Repeat the process until the heap is about 0.5 m above ground level.

The material decomposes within 8 to 9 months and the finished product is ready for use.

Nadep method (above ground)

Raw materials Waste organic material-about 1,500 kg. Cattle dung-90 to 100 kg (8-10 baskets) Dry-sieved soil-1,750 kg (120 baskets). Urine-soaked soil is most effective. Remove glass, stones, plastic, and other nondecomposable substances. Water-Enough to keep the pit moist.


Nadep method (above ground)

Tank construction

Build a rectangular tank (3 m long, 2 m wide and I m high) made of brick walls and floor with mud mortar. Leave holes in the tank walls for aeration (about four holes along each side wall and two holes in each end wall). Plaster the inner walls and the bottom of the tank with a mud and cow-dung mixture.

Method of filling

First layer-15-cm compact layer of plant waste material.

Second layer-Cow-dung slurry: about 4 kg of cow dung mixed with 10 buckets of water (drench thoroughly).

Third layer-Add a 2-cm layer of fine, sieved soil (60 to 65 kg).

Keep adding layers in this way until the material is heaped 15 cm above the lip of the tank. Add another 7-cm layer of fine soil on top of the heap. Seal the tank with cow-dung plaster.

For best results

- Build a temporary shed of thatch and bamboo to shield your compost tank from direct sunlight and rain.

- After three to four months, digestion (composting) is complete. Do not disturb the pit during this crucial period.

- Compost is dark and has a pleasant smell. Sieve this compost through a thick mesh and it is ready to use.

Contributor/Source: Dr. V. N. Shnoff and Dr. Jagdish Singh

 

Vermi-composting

What is vermi-composting?

Vermi-composting is the process by which earthworms convert organic waste into fertile manure. With a little knowledge of earthworms and an investment of time and some inexpensive materials, you can fertilize your garden with rich vermicompost.

Living composters

Earthworms live in the soil, mixing it, making it porous as they help decompose soil organic matter. Earthworm casts are the excrete of earthworms. These casts contain five times the nitrogen of ordinary soil, seven times the phosphorus, eleven times the potash, two times the calcium and magnesium, and eight times the actinomycetes (useful bacteria).

Earthworms:

- feed on soil and soil organic matter and convert it to compost, making the soil rich in nutrients.

- encourage growth of useful micro-organisms, which also make soil rich.

- aerate and pulverise soil.

- are natural tillers of the soil.

- make soil porous, improving drainage.

- increase the water-holding capacity of soil.

- produce enzymes, hormones, vitamins, and antibiotics, thereby increasing immunity of plants against some pests.

Advantages of vermi-compost over other fertilizers

- Low cost to produce

- Easy to use

- Not harmful to useful soil organisms

- Converts organic matter to useful plant food

- Source of income


Advantages of vermi-compost over other fertilizers

Earthworms suitable for vermi-composting There are two types of earthworm:

Surface feeders convert waste matter into humus. Surface feeders are needed for vermi-composting. Certain species introduced from Africa are very efficient humus producers. They can be bought from companies which produce vermicompost. Some important species: Eisenia foetida, Eudrilus eugivae, Perionyx excavates, Lumbricus rubellus.

Deep feeder move soil and humus around and aerate the soil. Most Indian earthworm species are deep-feeders and are not suitable for vermi-composting.

Materials required for vermi-composting For a 10-sq-m plot:

- Dry organic matter-200-300 kg

- Decomposed farmyard manure 300-400 kg

- Organic wastes-700-800 kg

- Earthworms-10,000

- Water-ready supply

Method of preparation

1 Erect a shed 5 m wide and 12 m long.

2 Under the roof of this shed, build a long, thin rectangular (1 m wide and 10 m long) bed of organic matter 15 cm deep.

3 On top of this, spread a layer of decomposed manure or biogas slurry 15 cm deep.

4 Moisten the bed with water and leave it for 48 hours.

5 Place earthworms uniformly at the rate of 1,000 per sq m on the top layer.


Raised bed

6 Spread a 20-cm layer of organic wastes, litter, etc., over the earthworms.

7 Cover with gunny cloth and sprinkle water regularly to keep the plot wet. During summer months, you might have to sprinkle water twice a day.

8 Turn the material after 30 days, cover it again with gunny cloth and keep it moist.

9 The whole material is converted to humus, called vermicompost, in 65-70 days.

10 You can build a second bed next to the first. Use the earthworms from the first bed to repeat the process. Two beds of this type will produce about 1 tonne of vermicompost every 3 months.


Cover and keep moist.


Turn after 30 days.


Replace cover and keep moist.

Application of vermi-compost

Field-2. 5 tonnes per hectare

Pots-50 grams per pot

Trees-apply vermi-compost at the rate of 100-200 g per tree, or place 100-200 worms around the tree trunk.

Reproduction

Under ideal conditions, earthworms multiply 20 to 25 times in

65-70 days. Use a sieve to separate the vermi-compost from the earthworms.

Use the earthworms to repeat the above process to make vermi compost throughout the year.

Keep moist

- Surface-feeding earthworms can survive only if the surface soil is kept moist. This can be done with drip irrigation. (See

Efficient use of irrigation water.)

- Where surface soil dries out, apply vermicompost each year at the beginning of the rainy season.

Developing an earthworm population

You can develop an earthworm population by placing earthworms or worm casts in the soil. After this, it is not necessary to apply vermi-compost; simply apply organic matter which the worms will convert into compost.

Maintenance

Take care to maintain an optimum number of earthworms in your fields. Their population is adversely affected by:

- use of chemical fertilizers.

- use of certain pesticides against soil-borne pests.

- inappropriate cultivation techniques, like use of rotary cultivators.

- acidification of soil.

- insufficient organic matter in the soil.

Earthworms are your friends. Protect them and nurture them in your fields. Adding vermi-compost and reducing the application of inorganic fertilizers will increase populations of deepburrowing earthworms, which turn over and aerate the soil.

Contributors: Dr. W.R. Deshpande, Dr. Chitra Srivastara and Dr. Jagdish Singh

 

Bio-inoculants

Bio-inoculants are living organisms containing strains of specific bacteria, fungi, or algae which:

- take nitrogen from the air and make it available to plants- reducing the need for nitrogen fertilizer.

- make inorganic phosphate and micronutrients soluble and available to plants.

- collect and store available nutrients.

- enhance plant uptake of phosphorus and zinc.

- provide physical barriers against pathogens.

- stimulate plant growth.

- decompose organic residues.

Biological nitrogen-fixation

Atmospheric nitrogen is taken from the air-or "fixed"-by micro-organisms which live on some leguminous and non leguminous plants.

Rhizobium

These bacteria live in nodules on the roots of legumes. Legume seeds can be inoculated to encourage the growth of nitrogen fixing nodules.

Rhizobia:

- meet 80 to 90 percent of the nitrogen requirements of legume crops.

- increase production of legume crone.

- benefit successive crops.

- minimize the chance of crop failure.

- increase soil fertility.

- are cost effective.

- are pollution free.


Nodules on a legume plant

About 200 g of good quality rhizobium culture is enough to

An, treat 12-15 kg of seed. There are specific cultures for different crops. You can buy rhizobium inoculant from agricultural extension centres, agricultural universities, private dealers, and the National Biofertilizer Development Centre, Ghaziabad, Uttar Pradesh.

Azotobacter and Azospirillum

These bacteria fix atmospheric nitrogen in cereal crops. Azotobacter produce antifungal compounds against many plant pathogens and control nematode diseases. Azospirillum increase germination and improve vigour of young plants. One kg of seed needs 5 g of inoculant. This will fix 30 kg/ha of nitrogen per year.

Blue-green algae

Blue-green algae can fix 25-30 kg/ha of nitrogen per year. A paddy crop needs 10 kg/ha of algal powder, available from the National Biofertilizer Development Centre. Algal powder is not required after 3-4 years of continuous use in the field.

Blue-green algae in a paddy crop:

- produces 25-30 kg nitrogen (equivalent to 55-65 kg urea) per ha, and enhances yield 10 to 12 percent.

- is cost effective and pollution free.

- provides more oxygen to paddy roots.

- benefits the next crop.

Algae production

1 Prepare shallow trays (2 m x I m x 20 cm) of galvanized iron sheet. The size can be increased if more material is to be produced.

2 Spread 8-10 kg of soil and mix well with 200 g of super phosphate.

3 Add water to the trays (5 to 15 cm deep) depending on the rate of evaporation. The soil should be about neutral. If it is acidic, add lime.

4 After the soil has settled, sprinkle the algal culture on the surface of the standing water. Keep the trays in the open air, in direct sunlight.

5 Growth of the algae will be rapid in the hot summer months and in about 7 to 10 days they will form a thick mat. If the daily rate of evaporation is high, add water regularly. When the algal growth becomes sufficiently thick, stop watering.

Azolla

Azolla is a floating fresh water fern. It grows in stagnant water. The fern forms a green mat over the water surface. It readily decomposes to ammonia which is available to rice plants. Apply 10 kg of powdered, dry azolla fern per hectare.

Application Seed treatment-Rhizoblum and Azotobacter Top dressing-Rhizoblum, Azotobacter, PSM Crops Legumes-Rhizablum + PSM Cereal-Azotobacter + PSM Legumes mixed with nonlegumes-Rhizoblum + Azotobacter + PSM

For more information contact the National Biofertilizer Development Centre, CGO Complex 11, Ghaziabad Uttar Pradesh 201002, India.

Mycorrhiza

Mycorrhiza are fungi which live in association with the roots of crops. The fungi stimulate plant growth, help the plants use phosphate, and protect the plants from disease. One kg of crop seed needs 7-10 g of inoculant, available from Mycology and Plant Pathology Division, Indian Agricultural Research Institute, and the Department of Botany, Delhi University.

PSM

Phosphate solubilising micro-organisms (PSM) convert soil phosphorus into forms that plants can use. To use PSM, mix 3 kg of PSM, 50 kg of farmyard manure, and the crop seed. Drill them together.

Methods of application

Bio-inoculants can be used two ways: as seed treatment and as top dressing in the soil.


Seed treatment

Moisten the seed and sprinkle the inoculum at a rate of 5-10 g per kg of moist seed. Mix thoroughly and dry in the shade for an hour. Sow the inoculated seed immediately.

Top dressing

For legumes, mix 1.5 kg rhizobium or 0.5 kg Azotobacter or 3 kg PSM in 50 kg of farmyard manure or compost. Top dress.

For cereals and millets, use 2 kg of PSM.

Broadcasting

Mix 3 kg of PSM with 100 kg of farmyard manure and broadcast the granular mixture. Can be broadcast in a standing crop seed treatment

Source: Dr. W. R. Deshpande

 

Multipurpose trees and shrubs

Selection criteria

Select tree species and varieties that have these features:

- Adaptability to local climatic conditions

- Multiple uses high demand and value of the produce

- Fast growth, short time to harvest

- Vigorous regrowth after cutting

- Nitrogen-fixing ability

- Ability to improve soil

- Compatible with ground vegetation

- Easy management

Fuel and fodder collection is hard, time-consuming work for farm women. Multipurpose trees, grown on the farm in an organized manner, can significantly improve farm incomes by providing food, fodder, fuelwood, timber, gum, and building and fence poles, while reducing drudgery for farm women.

Trees consume carbon dioxide and release vital oxygen, maintain cool weather, increase rainfall, and protect soil from erosion and loss of productivity.

Trees on farm land

Suitable multipurpose trees can be incorporated on farm lands for a variety of uses.

Mainly protective

Windbreaks and shelter belts

In places where wind erosion is severe, like arid and desert areas, wind breaks and shelter belts of trees, such as Israeli babul, can reduce erosion.

Live hedges

Species, like vilayati babul and brij babul, can be grown as hedges around fields. They can serve as animal barriers, reduce soil erosion, and provide fodder, timber, and fuelwood.


Trees have many uses.

Soil conservation

Species, like desi babul, ardu, and shisham, are reported to be good soil binders and help conserve soil.

Mainly productive

Boundary planting

Many tree species, such as eucalyptus, can be grown around farm boundaries for additional returns without adversely affecting crop yields. Care must be taken in site selection to avoid crop shading. Tree roots should be pruned by digging a trench along the crop boundary.

Agri-silvipasture, agri-horticulture

Forest trees, like shisham, anjan, subabul, and fruit trees, like aonla, guava, mulberry, and ber, can be introduced at suitable spacings in agricultural systems to stabilize the farm system and provide additional returns.

Silvipasture, hortipasture

As above, many of the same forest and fruit trees can be introduced in pastures and grasslands.

Home gardens

In humid regions, a mixture of many trees and shrubs in a multitier system can be profitable and ecologically sustainable.

Alley cropping

Hedges of subabul and gliricidia can be grown 8-10 m apart. Crops can be planted between the hedges. The hedges should be pruned regularly and the prunings used as mulch or fodder.

Multipurpose woodlots

Multipurpose trees, like babul, desi siris, shisham, eucalyptus, sesbania, subabul, ber, casuarina, neem, and kathal, can be planted on community bunds for fuelwood, charcoal, timber, poles, medicine, gum, pulp, and fodder.

Contributors: Dr. Punjab Singh and Dr. R S. Chillar