Sources and accumulation of silicon in plants of lowland rice

The low Brazilian productivity of rice is mainly because of the low soil fertility and high susceptibility to some diseases. The fertilization with silicon can be an alternative to decrease the impact of the diseases in the yield. To identify efficient silicon sources for rice, an experiment was installed in pots, using a Quartzipsamment soil, in randomized blocks. The silicon sources used were siligran and silicon, in the forms granulated and powder, in the dose of 200 mg kg-1 of Si. The curve of response to Si was established by application of a standard source (Wollastonite) in the doses of 0, 50, 100, 200, 400 mg kg-1 of Si, seeking to obtain a curve of response. The rice cultivar Rio formoso was sown and the production of dry mass of the aerial part, panicles mass, production of grains, plant tissue and soil Si content, were determined by the rice cycle. The standard source Wollastonite had linear behavior, increasing soil Si availability and its absorption by rice with the increase of the applied doses. The largest increases in the contents of Si in the aerial part, in the peel, and Si accumulated in the plant and Si in the dry total mass were produced by Wollastonite. The source that provided larger increase in the yield of grains was silicon in the powder form. The acetic acid extracted larger amount of Si of the soil than calcium chloride, overestimating the results.

Oriza sativa; calcium silicate; fertilizer