Vol. 9, Issue 3 (2020)

Among micronutrients, B deficiency is wide spread throughout India. Factor such as pH, texture, organic matter, temperature, moisture content and plant species influence B adsorption, and thereby, plant B uptake. Coarse textured soils prone to leaching as a result of excessive rainfall in humid climate are generally associated with B deficiency. Boron is retained in soils by adsorption onto minerals and humic particles and by forming insoluble Total boron content in Indian soils has been reported to varying from 3.80 to 630 mg kg-1 and available boron from 0.04 to 7.40 mg kg-1. It is imperative that application of Zn and B containing fertilizers are needed to exploit the production potential of crops under cropping systems and also to mitigate the deficiencies of these nutrients. Addition of S + Zn + B in balanced fertilization schedule increased N, P and K utilization efficiency which highlights the role of micronutrients in increasing macronutrient use efficiency. Since, maize and black gram are the two important crops which are preferred much for its nutritional quality; the present study “Relative changes in Boron fractions in black gram rhizosphere” was contemplated with two objectives: 1) To find out the suitable source, dose and method of boron for black gram, and 2) To study the changes in relative boron fractionation under black gram rhizosphere.

To achieve the present objectives a field experiment was conducted with Greek gram var. IPU2-43 in factorial randomized block design with three sources, four doses and two methods of application of boron replicated thrice at Bihar Agricultural College Farm of BAU, Sabour during the year 2018-19. Three sources were: S1: Borax, S2: Solubor and S3: Boric acid; Doses: D1: 0.5 kg ha-1, D2: 1.0 kg ha-1, D3: 1.5 kg ha-1, D4: 2.0 kg ha-1and methods: soil and foliar application.

Based on the findings of field experiment it can be concluded that the application of graded doses of boron enhanced the growth and yield as well as concentration and uptake of boron. Therefore, addition of boron fertilizer made more boron nutrient available to the black gram crop. The study of different forms of boron in soil also indicated that most of the soil boron was found in the form of residual boron. The trend of the boron forms in soil was found as residual B > organically bound boron > Oxide bound boron > readily soluble boron > specifically adsorbed boron.