EFFECT OF APPLIED LIME AND BORON ON THE AVAILABILITY OF NUTRIENTS IN AN ACID SOIL.

Productivity of resources on acid soils occupying one fourth of the total area in India is abysmally low. Lime is applied to such soils with the primary objective of increasing the productivity of crops by enhancing the availability of native and applied plant nutrients. Greenhouse pot experiments and laboratory experiments were conducted to evaluate the effects of lime and boron (B) on the availability of nutrients in soils and their uptake by plants. The application of lime enhanced the available nitrogen (N,), phosphorus (P), calcium (Ca), magnesium (Mg), sulfur (S), and zinc (Zn) content in soils, which was reflected in their uptake by sunflower (Helianthus annus). On the contrary, availability of copper (Cu), iron (Fe), and manganese (Mn) in soil was reduced due to liming. Sunflower responded very well in terms of dry matter yield to B application to the extent of 175% and 188% under 1 and 2 mg kg−1applied levels of B, respectively. Dry matter yield of sunflower was reduced to the tune of 29.2 and 42.7% under 2/3 and 1 lime requirement (LR), respectively, over control. Lime application at 1/3 LR with 2 mg kg−1of applied B emerged as an optimum combination in acid soils. [ABSTRACT FROM PUBLISHER]