Boron dynamics in red loam soil amended with different organic fertilizers

Abstract

Boron is an essential micronutrient which is required in trace amount by the crop plants for their growth and development. There is a widespread deficiency of B in Indian soils and it has emerged as the second most deficient micronutrient after zinc. As its requirement is less, the deficiency can be corrected with the application of organic manures to a certain extent. The boron present in the soil exists in different chemical forms. The different fractions of B in the soil are readily soluble (Rs-B), specifically adsorbed (Spa-B), oxide bound (Ox-B), organically bound (Org-B) and residual B (Res-B). All these fractions together form the total B (T-B) content in the soil. As application of organic manures had a positive influence on the B availability, an incubation study was conducted for period of 24 weeks to analyze the release pattern of B and their dynamics in red loam soil amended with different organic fertilizers. The availability of B in the soil was mainly influenced by the dynamics of B fractions in the soil. Addition of organic amendments enhanced the readily available and specifically adsorbed B fractions in the soil and thereby increased B availability. The highest availability was from fortified thermochemical organic fertilizer (F-TOF) amended soil. It was mainly due to their higher B content than other organic fertilizers. The study of B dynamics in the soil provides a clear idea on its availability as well as the potential B reserve in the soil.