Boron in Soil Plant System and Its Significance in Indian Agriculture

Abstract

Boron is one of the 17 essential plant nutrients, required for normal plant growth. Its widespread deficiency in ~30% of Indian soils have been observed to affect plant growth and economic yield. Because of its mobile nature, it tends to leach down in soil layers. Boron deficiency has more specifically been observed in light-textured alluvial soils with low content of organic matter. The higher active absorptive surface area of clays restricts its leaching losses. Boron becomes available to plants upon decomposition of organic matter by soil micro-organisms after its mineralization. The soils with high content of calcium carbonate are also prone to B deficiency. Boron availability decreases with an increase in soil pH, except in saline-sodic soils. Soil application of B has been observed to more credible option owing to its considerable residual effect on succeeding crops. Considerable yield response of B application has been found in cotton, cereals, legumes, oilseeds and alfalfa and citrus fruit plants, grown in B deficient soils. Therefore, assessment of B status in soils is crucial to ensure B application in deficient soils for the long-term sustainability of soils in terms of exploring crop genetic potential. Boron is a critical nutrient from a nutritional requirement point of view as it shows second most widespread micronutrient deficiency globally after Zn.