Effects of powdered rice chaff application on Si and N absorption, lodging resistance and yield in rice plants (Oryza sativa L.)

Abstract

Rice chaff, a major by-product of rice cultivation, is generally known for its high content of Si. Pot and small field plot (concrete plot) experiments were conducted to ascertain the effects of rice chaff in powdered form (Cp) and normal rice chaff (Ch) with or without bio-decomposer application on lodging resistance, yield, Si and N absorption of rice (Oryza sativa L. ev. Hatsushimo). The results showed that the absorption of Si by plants could be promoted by Cp supplied together with a bio-decomposer, although the N content in plants was not increased. In the concrete plot experiment, lodging resistance was improved by Cp applied under a lightly-fertilized condition due to the high breaking strength and strong bending stress caused by the high Si content in the plants. Cp application tended to increase under a lightly-fertilized condition, but decreased the yield under a heavily-fertilized condition. It was suggested hat Cp application is effective on rice growth under a lightly-fertilized condition, and that Cp may be useful as an alternative of inorganic Si fertilizer and contribute to a sustainable Si recycle system in rice cultivation.