Incubation Studies to Find Out the Transformation of Different Fractions of Boron

An incubation study was conducted in the laboratory of College of Agriculture, Central Agricultural University, Manipur, India, to know the transformation of applied Boron (B) in soils at field capacity. Soil samples was collected periodically at 0, 30, 60 and 90 days after incubation (DAI) and analyzed for different fractions of B. The experiment was carried out under completely randomized block design (CRD). Altogether there were 6 treatment replicated thrice namely, T0= Control, T1= 0.5 mg B kg-1 soil, T2= 1 mg B kg-1 soil, T3= 1.5 mg B kg-1 soil, T4= 2 mg B kg-1 soil and T5= 2.5 mg B kg-1 soil. From the incubation experiment, it was inferred that with applied B, the organically bound B fraction was higher next to residual form when compared to other forms of B. At 30 days of incubation, different fractions of B showed an increasing trend for added levels of B compared to control due to recently applied B into the soil solution. However, at 60 and 90 days different fractions of B in the soil started decreasing due the fact that boron entered into tightly bound state within the soil. In general, B fertilization increased the availability of B content in soil and hence increased its availability to the crop. The sequence of the content of different fractions of B in an acid soils of Imphal-West district was readily soluble-B>organically bound-B>oxide bound-B> specifically adsorbed-B> residual-B.