Improving soil micronutrient availability under organic farming

Salwinder Singh Dhaliwal^a , Vivek Sharma^a,et al.,

Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, India.

Abstract

Intensive agriculture has covered the way for “Green Revolution” with the use of high yielding varieties, chemical fertilizers and pesticides with sole objective of yield maximization. But in the same time, it deteriorated the soil health, macro and micronutrient deficiencies, low yields, poor quality and environmental hazards which resulted in serious health problems and disorders in animals and human beings. Globally, deficiencies of micronutrients in soils have emerged as a major limiting factor to higher crop yields and lowers the concentration of micronutrient in crops. One of the ways to cope with the problems of micronutrient deficiencies is to improve the soil micronutrient availability or uptake efficiency of plants. Micronutrient availability in soil is determined by the parent materials which is influenced by the edaphic and biological factors in soil such as pH, redox potential, soil minerals, organic matter and soil microbial activity. The improved agricultural practices such as soil organic amendments and soil water management play vital role in soil micronutrient availability. Under organic farming, soil health and nutrient availability is sustained by the addition of local organic inputs, i.e., waste, dungs, biofertilizers, crop residues, green manures followed by crop rotation system. Effective management and recycling of available on-farm wastes helps to reduce the dependency on external chemical inputs and limits the environmental pollution arising out with burning of farm wastes. In this chapter, we summarize behavior, availability and factors affecting of micronutrients availability in soils as well as detail about the different organic sources of micronutrients to improve the availability in soil.

Keywords: Micronutrient availability, Organic farming, Organic manures, Transformations and sorption, Plant and human health.