Assessment of the complex relationship of boron fractions with available soil nutrient status as influenced by boron fertilization in cauliflower

Abstract

Present investigation was conducted at Horticultural Experimental Farm, Assam Agricultural University, Jorhat during the year 2015-16 to assess the impact of boron fertilization on the dynamics of boron fractions and its relationship with available nutrients in soil under cauliflower–cowpea- okra cropping sequence in an Inceptisol of North East India. Five levels of boron were applied (0, 0.5, 1.0, 1.5 & 2.0 kg ha-1) along with recommended dose of NPK fertilizer once in both the years only in cauliflower to assess the direct effect of boron fertilization in soil while cowpea and okra were grown as a test crop to study the concomitant residual effects of boron fertilization in cauliflower crop. Different physio-chemical properties were found to increase with increasing levels of boron and application of 2 kg B ha-1. It was also found prominent in augmenting the highest content of different fractions of boron during crop period. Status of available nitrogen, phosphorus and potassium in soil were also found highest with application of 2 kg B ha-1 for all the three crops in the sequence. A highly significant positive correlation between the different boron fractions and available nutrients in soil were recorded. While in case of soil chemical properties also, excepting free Fe2O3 and Al2O3 were found highly correlated.