Organic farming is a production system which avoids or largely excludes the use of synthetically compounded fertilizers, pesticides, growth regulators, genetically modified organisms and livestock food additives. To the maximum extent possible organic farming system rely upon crop rotations, use of crop residues, animal manures, legumes, green manures, off farm organic wastes, biofertilizers, mechanical cultivation, mineral bearing rocks and aspects of biological control to maintain soil productivity and tilth to supply plant nutrients and to control insect, weeds and other pests.
Organic methods can increase farm productivity, repair decades of environmental damage and knit small farm families into more sustainable distribution networks leading to improved food security if they organize themselves in production, certification and marketing. During last few years an increasing number of farmers have shown lack of interest in farming and the people who used to cultivate are migrating to other areas. Organic farming is one way to promote either self-sufficiency or food security. Use of massive inputs of chemical fertilizers and toxic pesticides poisons the land and water heavily. The after-effects of this are severe environmental consequences, including loss of topsoil, decrease in soil fertility, surface and ground water contamination and loss of genetic diversity.
Organic farming which is a holistic production management system that promotes and enhances agro-ecosystem health, including biodiversity, biological cycles, and soil biological activity is hence important. Many studies have shown that organic farming methods can produce even higher yields than conventional methods. Significant difference in soil health indicators such as nitrogen mineralization potential and microbial abundance and diversity, which were higher in the organic farms can also be seen. The increased soil health in organic farms also resulted in considerably lower insect and disease incidence. The emphasis on small-scale integrated farming systems has the potential to revitalize rural areas and their economies.
In organic farming, it is important to constantly work to build a healthy soil that is rich in organic matter and has all the nutrients that the plants need. Several methods viz. green manuring, addition of manures and biofertilizers etc can be used to build up soil fertility. These organic sources not only add different nutrients to the soil but also help to prevent weeds and increase soil organic matter to feed soil microorganisms. Soil with high organic matter resists soil erosion, holds water better and thus requires less irrigation. Some natural minerals that are needed by the plants to grow and to improve the soil’s consistency can also be added. Soil amendments like lime are added to adjust the soil’s pH balance. However soil amendment and water should contain minimum heavy metals. Most of the organic fertilizers used are recycled by-products from other industries that would otherwise go to waste. Farmers also make compost from animal manures and mushroom compost. Before compost can be applied to the fields, it is heated and aged for at least two months, reaching and maintaining an internal temperature of 130°-140°F to kill unwanted bacteria and weed seeds. A number of organic fertilizers / amendments and bacterial and fungal biofertilizers can be used in organic farming depending upon availability and their suitability to crop. Different available organic inputs are described below:
1. Organic manures
Commonly available and applied farm yard manure (FYM) and vermicompost etc. are generally low in nutrient content, so high application rates are needed to meet crop nutrient requirements. However, in many developing countries including India, the availability of organic manures is not sufficient for crop requirements; partly due to its extensive use of cattle dung in energy production. Green manuring with Sesbania, cowpea, green gram etc are quiet effective to improve the organic matter content of soil. However, use of green manuring has declined in last few decades due to intensive cropping and socioeconomic reasons. Considering these constraints International Federation of Organic Agriculture Movement (IFOAM) and Codex Alimentarius have approved the use of some inorganic sources of plant nutrients like rock phosphate, basic slag, rock potash etc. in organic farming systems. These substances can supply essential nutrients and may be from plant, animal, microbial or mineral origin and may undergo physical, enzymatic or microbial processes and their use does not result in unacceptable effects on produce and the environment including soil organisms.
2. Bacterial and fungal biofertilizers
Contribution of biological fixation of nitrogen on surface of earth is the highest (67.3%) among all the sources of N fixation. Following bacterial and fungal biofertilizers can be used as a component of organic farming in different crops.
In organic farming, chemical herbicides cannot be used. So weeding can be done only manually. Different cultural practices like tillage, flooding, mulching can be used to manage the weeds. Besides, biological (pathogen) method can be used to manage the loss due to weeds. When the ground is fallow, a cover crop can be planted to suppress weeds and build soil quality. Weeds growth can also be limited by using drip irrigation whenever possible, which restricts the distribution of water to the plant line.
In organic farming, the presence of pests (where and when) is anticipated in advance and accordingly the planting schedules and locations are adjusted as much as possible to avoid serious pest problems. The main strategy to combat harmful pests is to build up a population of beneficial insects, whose larvae feed off the eggs of pests. The key to building a population of beneficial insects is to establish borders (host crops) around fields planted with blends of flowering plants that the beneficial insects particularly like. Then periodically beneficial insects are released into the fields, where the host crops serve as their home base and attract more beneficial insects over time. When faced with a pest outbreak that cannot be handled by beneficial insects, the used of natural or other organically approved insecticides like neem pesticides is done. The two most important criteria for allowed organic pesticides are low toxicity to people and other animals and low persistence in the environment. These criteria are determined by the National Organic Standards.
Plant diseases are major constraints for reductions in crop yield and quality in organic and low input production systems. Proper fertility management to crops through balanced supply of macro and micronutrients and adoption of crop rotation have shown to improve the resistance of crops to certain diseases. Thus one of the biggest rewards of organic farming is healthy soil that is alive with beneficial organisms. These healthy microbes, fungi and bacteria keep the harmful bacteria and fungi that cause disease in check.
There are a few limitations with organic farming such as
In dry lands, covering over 65% cultivated area in India, application of chemical fertilizers and pesticides is always low. So these areas are at least “relatively organic” or “organic by default” and a portion of these lands can be converted easily to an organic one to provide better yields/returns. India can greatly benefit from the export of organic foods, but needs to seriously devote attention to market intelligence regarding which product to grow, where to sell, distribution channels, competition, marketing access etc. Presently, good awareness exists among farmers, researchers and policy makers about organic production but a lot more need to be done to streamline production, certification and marketing of organic produce. Uttaranchal and some other state governments have already declared their states as “Organic” state and created special Export Zones like Basmati Export Zone. A large area of North eastern states and other states may be developed as commodity based “organic” production areas. With greater political will and investment in research, extension and marketing infrastructure more of this potential could be realized. Therefore to feed the world’s hungry and poor and to ensure present and future food security right policies, increased public and private investments and technologies, knowledge and capacity building, grounded in sound ecosystem management and harmony between organic farming and food security goals are required.
Source: Article written by Shir Y.V Singh and J.P.S Dabas in Kurukshetra journal