Effect of different levels of gypsum application on soil characteristics and growth and yield of rice (Oryza sativa L.)

Summary A field experiment was conducted to compare the efficacy of application of different fractions of gypsum requirement (0, 20, 40, 60, 80 and 100%) for reclaiming alkali lands for rice cultivation. The experiment was initiated in the year 1971 and the effect of treatments was observed for three consecutive years (upto 1973) in terms of rice growth and yield and also the chemical characteristics of the soil. Economics of rice production was also worked out for different treatments.Results obtained revealed that a fairly good crop of rice with a small profit margin could be raised in the first year itself, by applying 20% of the gypsum requirement. Higher levels of gypsum proved economical only during subsequent years. Application of gypsum beyond 80% of the requirement was of no avail. Soil pH declined in all the treatments with its magnitude dilating with increased gypsum application. Electrical conductivity was also brought down with rice cultivation, irrespective of the quantum of gypsum.