Dolomite as an Effective Soil Ameliorant for Managing Soil Acidity, Micronutrient Availability and Rice Yield in Coastal Soil

Abstract

Soil acidity coupled with iron toxicity is an important limiting factor for growing rice in coastal soils. A field experiment was conducted to evaluate the effectiveness of non conventional sources of calcium for the management of soil acidity and improvement of nutrient availability and growth of rice under coastal sandy conditions. The experiment was conducted following a randomized block design consisting of nine treatments: conventional practice followed by farmers (control), application of lime at recommended rate based on Kerala Agricultural University Package of Practices 2016, and different concentrations (100% and 125% calcium equivalent) of dolomite, gypsum, and calcium silicate. It was found that soil amelioration with calcium-based amendments applied in two splits at tillering and panicle initiation stage recorded considerable effects on the chemical characteristics of the soil, availability of nutrients and performance of crops. The application of dolomite at 125% of calcium equivalent was found to be effective in increasing the availability of micronutrients such as Mn, Zn, Cu, and B, while minimizing iron and aluminium toxicity. The liming treatments were beneficial in promoting growth and production parameters of rice plants. The best value for grain yield (5345.00 kg ha⁻¹) and straw yield (18248.67 kg ha⁻¹) was obtained from the application of dolomite at 125% of calcium equivalent.