Nutrient management in organic crop products

DJ Rajkhowa
India has achieved significant progress in agri- cultural production during the last five decades due to green revolution. The food grain production increased from 51 tonnes in 1950-51 to 108 million tonnes during 1970-71, 211 million tonnes during 2000-01 and a record food grain production of 230 million tonnes during 2006-07. However, the intensive modern agriculture for the past five decades has led to several environmental and health issues.
Decline and deterioration of natural resources emerged as a serious concern for the sustainability of agricultural production. The yield stagnation, decline in soil fertility and deficiency of secondary and micro-nutrients, lowering of water table, loss of bio-diversity, loss of soil organic carbon (SOC), increase in pests and disease problems, food and feed contamination due to indiscriminate use of pesticides, development of pests resistance and decline in factor productivity are some of the negative effects of green revolution technologies. The decline in soil productivity in terms of nutritional disorders, micro- nutrient deficiencies, poor soil physical condition, salinity, alkalinity, poor soil biological activity and the out break of pests and diseases are posing serious threat to our food security and livelihood supporting systems. In view of this organic farming is emerging as an alternative to the chemical oriented intensive agriculture.
Organic Farming -the concept
Various definitions of organic farming have been put forwarded by USDA, FAO, IFOAM etc. As per the definition given by USDA 1980-Organic farming is a production system which avoids or largely excludes the use of synthetic fertilizers, pesticides, growth regulators and livestock feed additives. Organic farming systems rely on crop rotations crop residues, animal manures, legumes, green manures, off-farm organic wastes and aspects of biological pest control to maintain soil productivity and tilth, to supply plant nutrients and to control insects, weeds and other pests.
For practical purpose the simplest definition can be “Optimum use of local resources for getting sustainable agriculture production without harming bio-physical and social environment as well as regenerative capacity of resources” (Faroda et al., 2008).
This implies non-use of external inputs that may harm environment like fertilizers, pesticides etc. Organic farming is a holistic production system that has the advantage of efficient use and recycling of locally available resources. Organic agriculture does not imply the simple replacement of synthetic fertilizers and other chemicals with organic inputs and biologi- cally active formulations. Instead, it envisages a comprehensive management approach to improve the productivity of soil. In a healthy soil, the biotic and abiotic components covering organic matter including soil life mineral particles, soil air and water exist in a dynamic equilibrium and regulate the ecosystem processes in mutual harmony by complementing and supplementing each other.
Organic farming relies on crop rotations, crop residues, animal manures, legumes, green manures, off farm organic wastes and aspects of biological and cultural pest control to maintain soil productivity and tilth, to supply plant nutrients and to control insects, weeds and other pets. With increasing health consciousness and concern for environment, organic farming system as been drawing attention al over the world. Demand for organic products, especially in developed countries has been increasing by leaps and bounds.
Principles of organic farming
The main principles of organic farming are: to produce high quality food in sufficient quantity, to interact in a constructive and life enhancing way with natural systems and cycles, to consider the social and ecological impact of the organic production and processing systems, to enhance biological cycles within the farming system, flora and fauna, plants and animals, to maintain and increase long term soil fertility, to protect and healthy use of water resources, to use as far as possible renewable resources in locally organized production systems, to minimize all forms of pollution, processing, and distribution chain which is both socially justifiable and ecologically responsible. (To be contd)