Basic Slag as a Liming Material to Ameliorate Soil Acidity in Alfisols of Sub-tropical India

Crop production on acid soils can be improved greatly by adjusting the pH to near neutrality. While soil acidity is commonly corrected by calcite, there is evidence that use of basic slag as an amendment can increase the pH of acid soils. The effect of calcite and basic slag (CaSiO ) with different doses on soil acidity, 3 nutrient availability and grain yield was determined in the experiments. Fourteen field experiments were conducted during the rabi season of 2003-2004 and 2004-2005 in Alfisolsof Midnapur West and Purulia districts of West Bengal, INDIA. Besides liming materials, locally available organic resources e.g. farmyard manure (FYM) and poultry manure (PM) were also used along with basic slag to increase its efficacy. The treatments used were as follows: No lime, 1/5 LR (basic slag), 1/5 LR (calcite), 1/10 LR (basic slag), 1/10 LR (calcite), th th th th 1/5 LR (basic slag + FYM @ 5t/ha) and 1/5 LR (basic slag + PM @ 3t/ha). Results showed that both th th calcite and basic slag increased the grain yield of wheat. They were effective when applied @ 1/5 LR dose th than 1/10 LR. On an average, calcite and basic slag caused an increase in grain yield to the extent of 21.9 and th 31.0% over the no lime treatment, respectively. Results also showed that increase in the yield of wheat was more with basic slag 1/5 LR than with calcite. Incorporation of organic sources of nutrients particularly FYM and th PM caused a further increase in yield, the magnitude being 56.2 and 60.2% respectively over the no lim e treatment. Results of straw yield also showed the similar trend of change. Uptake of N and P by wheat plants showed that liming caused significant increases in their uptake. There was no significant increase in concentration of K with lime application. Organic matter addition enhanced the uptake of the nutrient elements viz., N, P and K. Results of the analysis of residual soil showed that total acidity, exchange acidity and hydrolytic acidity recorded a decrease upon liming.