Chapter 3 - Soil fertility management in organic farming

Abstract

Soil fertility maintenance is one of the pivotal benefits of the organic farming systems. Management of the soil fertility under organic farming system has many concerns. Soil organic carbon is playing the key role in maintaining the soil fertility. Continuous losses of organic matter due to rapid turnover concerning climatic, anthropogenic as well as management practices create serious concern in the modern-day agriculture. Land cultivation without adding of organic inputs, results in depletion of total carbon content. On the other hand, addition of organic amendments to the soil is a better way to improve microbial biomass C and mineralizable C. Nutrient cycling in the systems under organic farming another important aspect of improving the soil fertility. It is the movement of nutrients within and between the various biotic or abiotic components in the global environment. These nutrients can either be obtained from their mineral or atmospheric sources or recycled from their organic forms by conversion into the ionic form, promoting uptake by plants and ultimately this return to the atmosphere or soil. Nutrient cycling is initiated and carried out by a great number of soil microorganisms; and these microbial activities have the requirement of organic substrate. Thus, maintenance of soil fertility under organic farming systems concerns about management of soil organic carbon, nutrient recycling in the system, management of the biological activities in the soil along with the in-depth knowledge of the factors of loss of organic matter, soil fertility loss and renewal etc. This chapter is mainly highlighting all these concerns.