Evaluation of silicon and gypsum amendments on growth and yield of rice in an alkali soil

Abstract

A pot culture experiment was conducted in order to check the effect of silicon (Si) and gypsum on growth and yield of rice in an alkali soil. The Si sources used were rice hull ash (RHA), diatomite (DE) and calcium silicate. These Si sources were applied in two graded levels viz., Si @ 125 and 250 kg ha-1. Gypsum was applied based on the gypsum requirement of the soil. Combined application of Si and gypsum proved to be effective in improving the growth and yield attributes of rice than the sole application of Si. Regardless of the dosage, the combination of Si as DE and RHA performed well with gypsum than CaSiO3 with gypsum which might be due to the differential reactivity of these silica materials with gypsum and with soil. Rice yield was significantly higher with the application of DE @ 250 kg Si ha-1 + gypsum @ 100% GR. Both concentration and uptake of Si also differed with regards to combinations of different Si sources with gypsum. Grain Si content uptake was significantly higher with the combined application of DE @ 250 kg Si ha-1 with gypsum @ 100% GR. On the contrary, significantly higher straw Si content and uptake was observed with the combination of RHA @ 250 kg Si ha-1 + gypsum @ 100% GR.