Building Healthy Soils Organically

K.Raghavendra Rao

 When I decided to leave a cushy and comfortable job in Delhi to come South and settle down in a ‘palli’ (the term for village in the south Indian language, Telugu), I knew I’d be in for a few surprises. My idea was to start organic farming from scratch on a barren patch of land and make a living from it! I knew it would be a difficult and time consuming process and entail a lot of hard work, but somehow I felt that it could be done. In spite of being a first generation farmer, I was confident of making it a successful venture. Looking back, I can’t explain my confidence; maybe it was because I was armed with the theoretical knowledge – a Masters in Ecology – and considerable practical experience in soil and moisture conservation, afforestation and in growing vegetables and fruit. Agriculture, after all is applied Ecology.

Some known ‘truths’

For those of us who have grown up in cities, soil is a bunch of dirt on the ground. It is something that has to be washed off our clothes, swept off the floor and wiped off our TV screens and refrigerators.  For me as a farmer, however, soil is a lot more than that. Soil, a major constituent of our planet is the mother of us all – plants, animals and humans. It gives us our sustenance and provides us resources to build our shelters. It is the substrate for plants and is the thin top layer on which we do agriculture and produce our food. It is not inert – every square meter swarms with millions upon millions of bacteria and other microorganisms. Potentially the organic material that’s in the soil or the raw materials that you deposit there – fallen leaves, grass clippings, kitchen waste, agricultural residues, animal manure, and so forth- contains essential elements that plants can use in their own growth. Unfortunately, these elements are tied up in such a way that our crops – agricultural, horticultural and commercial – cannot make immediate use of them.  Fortunately, for our plants, the soil bacteria rip into such dead material in the soil, breaking it down and converting it into forms that plants can use and build with.

The ambient temperature, the amount of air available, the soil moisture and the nature of the organic material itself determine how fast the soil bacteria act. When the soil is warm and has the right level of moisture, both the bacteria in the soil and bacterial action increase tremendously. When you add fresh organic material, the bacteria immediately attack it, breaking it down into food for our crops. The bacterial organisms themselves need nitrogen to take care of their growing needs. And if you don’t have nitrogen in the material that you put into the field or your garden, the bacteria will be constrained to steal it from the crop or vegetables that you’re trying to grow. As farmers or gardeners we don’t want to see that happen.

In order to be healthy and vigorous, plants need appropriate soil conditions and certain nutrients – sixteen of them, to be precise – besides air, water and sunlight. Among them are three major nutrients: Nitrogen (N), Phosphorous (P) and Potassium (K) and a number of minor nutrients. The absence of even one of these nutrients can make a difference to the overall health and yield from the plant.

The path I took – Learning by doing – Going step by step

My experiments in farming started in June 2003. Before that I treated the entire patch of land as a “nano” watershed and did a lot of soil and moisture conservation work so as to ensure that not even a drop of water would flow off the land. This, I believe is the foundation on which a sustainable agriculture enterprise has to be built. The actual vegetable cultivation which forms the basis of my confidence and experience was done on a little less than 1.75 acres (7000 sq.m).

Initial investments included digging a bore well, obtaining an electrical connection, laying out the pipelines, installing a drip irrigation system, land levelling and dozing and establishing field bunds along the boundaries. Since I was starting from scratch, theses expenses were necessary but for persons who have been farming for generations all these are available in greater or lesser measure and do not need large capital investment.

The first thing I did on the farm was to mark out contours and make trenches cum bunds to harvest rain water which is a very precious resource in the drought prone area where my land was. The field boundaries were stablized vegetatively with various species of locally occurring grasses. Lemon grass which has a good economic value can also be used. Several other tree, shrub and herb species can be grown along the bunds to provide wind-break effects, bio-mass production and habitat creation.

Nurturing diversity

The second activity was to procure saplings of a diverse variety of nitrogen fixing and multi-purpose herbs, shrubs and trees. These were integrated into the agricultural landscape as field boundary plantations, windbreaks, vegetative stabilization for bunds and micro-climate amelioration elements. In addition, tree saplings which have grown for a few years can serve as live trellises to support  trailing vegetables (gourds, beans, leafy vegetables, etc.), thereby freeing up space and utilizing the vertical dimension to increase yield.

Planting around the boundary of the farm provides – according to the terminology of permaculture (permanent agriculture) – the advantage of one element fulfilling several functions. A hedge of herbs, shrubs and trees along the perimeter of the land serves as a barrier or a “live fence”. Based on the choice of species, the fence (element) also serves several other functions – as windbreak, a habitat for birds, reptiles and small animals, a forage area for bees and birds, a zone for fuelwood, timber, fruit production, and nitrogen fixation. Through leaf fall, it also acts as a stable and steady production zone for a fair amount of organic matter. Also, trees with deep root systems within agricultural landscapes serve as “nutrient pumps” to “mine” lower horizons of bedrock. The roots in their quest for water and nutrients bring valuable minerals to the soil surface by way of leaf fall. When the leaves decompose by the action of bacteria, these minerals are released for use by crops.

A close observation of the plants growing in a particular agro-ecological system provides valuable insights into the species that can be chosen for producing  organic material to improve soil quality. Drought hardy nitrogen-fixers, which produce large quantities of biomass are the first choice. Species like Albizzia lebbek, Albizzia amara, Glyricidia sepium, Sesbania sesban, Sesbania grandiflora, Enterolobium saman, Cajanus cajan, Leucaena leucocephala, Pongamia pinnata, Erythrina sp., Cassia sp., Dalbergia sissoo, Pithecollobium dulce, Acacia auriculiformis, Acacia nilotica, Crotolaria sp. and ground covers like Macroptilium atropurpureum, Mucuna puriens, Dolichos lablab, Centroscema pubescens and Clitorea ternatea are some that can be used. In addition, Annona squamosa, Azadirachta indica, Melia azadirach, Holoptelia integrifolia, Wrightia tinctoria, Holarrhina antidysenterica, Bambusa sp., Muntingia calabura produce copious amounts of leaf litter which can easily be collected and composted.

Building organic matter in the soils

The next big effort was to incorporate enough organic matter into the soil. The old axiom of organic farming is basically sound advice: When in doubt, add more organic matter. This can be in the form of compost, humus, or raw organic matter.

Since the soil was quite depleted and the plan was to grow vegetables, in the first season I applied about 8 tonnes of poultry manure collected from a deep litter broiler operation. This was incorporated into the area of 7000 sq. m. using a tractor with plough attachment. The only other amendment was vermicompost mixed with oil cakes (neem, castor, pongam) and biofertilizers which used to be provided as a basal dressing at the root zone of each individual plant. This was at intervals of about three to four weeks depending on the stage of growth – vegetative or reproductive. I also used granite dust, a valuable source of potash, which is abundantly available in my area.  In addition, to provide the diverse nutrition required for plants, I added the following organic ingredients: compost, well rotted manure, bone-meal, wood-ash and fish emulsion.

A drip irrigation system ensured that water was used judiciously and applied directly at the root zone of the plants. The weed biomass that was put as mulch around the plants coupled with moisture from the drip holes, provided a food source and habitat for earthworms which were found in abundance where ever I dug! Weed growth between the drip lines in the rainy season was chopped with a nylon-cord trimmer and used as mulch. So the “weeds” actually served as a perennial source of much needed organic matter / mulch which covered the soil, prevented excessive evaporation and served as food for soil microorganisms.

 A compost pile was made to break down organic material. This pile lets the initial bacterial decomposition take place outside the soil. Then, when the material is turned into the soil, the nutrients are in a form that the plants can use immediately. The slow metabolic transformation of organic waste by soil micro organisms into the good friable humus and rich, brown, fertile, tilthy material that is so familiar to organic farmers, takes time (weeks to months) and human effort.

After the harvest, crop residues were converted into compost and incorporated into the soil again in the place where the plants had grown before. Thus the quality of the soil continually improved.

Integrating animals

 Another parallel activity is to integrate animals – small and large ruminants and domesticated birds – into the farming system. These animals (elements) by their inherent nature perform several functions – they convert biomass into milk, meat and poultry products, produce dung which is a valuable “innoculant” for composting, a soil ameliorant, a “bio-energy” source, and a substrate for “vermi-compost” production.

Domesticated birds like chicken and ducks provide pest and weed control in addition to meat and eggs. Wild animals and birds provide for free, pest control, pollination and seed dispersal services, and help to maintain the balance in nature by ensuring that pest populations don’t build up to dangerous levels and cause damage to our crops.

Since no plant protection chemicals are used, pollinator activity was very high on the farm leading to good fruit set. A variety of birds and garden lizards contribute to pest control during the day.  At night, toads, frogs, bats, owls and geckos help to control all forms of pests. With a well designed system, one can have 24X7 pest control!

Returns from the farm

The farm was a “certified organic” operation – more than 17 species of vegetables were grown during any cropping season taking care to maintain diversity and following crop rotation. Needless to say, very exhaustive records were kept regarding any agricultural operation carried out. This meticulous recording of operations is also mandatory for any organic operation. This small vegetable growing operation was managed by two persons (including myself) with casual labour (2men and 3-4 women), as required, to help.

During the peak harvest time product worth Rs. 10-14K was supplied each week to Spencers in Trivandrum. The harvest would last from six to twelve weeks. Since the planting was done to have peak productivity at all times, careful staggered planting and planning was very essential. I have recorded yields of 2.5 to 5 Kg/ sq.meter, which translates into 10 – 20 tonnes/acre! The net profit after deducting all expenses on labour materials, etc, would be in the range of 5-7K/week.

Imagination is the key

The lack of greenery and the absence of trees in today’s farms, does not augur well for the future of agriculture. No one tells farmers of the important role that trees play in the health and productivity of their farming systems. As a general principle, the goal of every farmer should be to have enough organic matter growing on the farm. This can be achieved with a little bit of imaginative thinking and a small investment of time and labour.

With directed efforts it is still possible to build the life in soils which are depleted and degraded. Even if a farm has been intensive in the use of chemicals over a long period of time, you can convert it into an organic farming system relying on inputs produced from within the farm.  Reintroducing microbial bio-fertlilizers and bio-pesticides such as Rhizobium sp., Azospirillum, Azotobacter, Phosphate Solubilizing Bacteria, VAM, Beauvaria bassiana, Verticillium, Trichoderma, Pseudomonas, etc. does a lot to build natural productivity and keep pests and diseases at bay. If the right environment and appropriate conditions are provided and use of chemical fertilizers and sprays are stopped, these microorganisms will remain and multiply in the agroecosystem ensuring healthy and bountiful yields on a long-term basis.

All it requires to convert unproductive land into a bountiful oasis is lots of hard work, dedication, commitment and a deep respect for nature our teacher. The more one walks around in their farm, the more you know what works and what doesn’t.

As the Chinese proverb says: “the best fertilizer (for the soil) is the footsteps of the gardener”.


K. Raghavendra Rao, CEO, GREEN Foundation, Bangalore.



The Postage Stamp Garden Book. Duane Newcomb. Bantam Books.

Designing and maintaining your edible landscape – Naturally. Robert Kourik. Metmorphic Press.

Permaculture: A Designers’ Manual. Bill Mollison. DDS and Permaculture India.

Secrets of the soil. Peter Tompkins and Christopher Bird. Rupa.

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