Nitrogen absorption and grain yield in short-term rice cultivars

Abstract

Short-term rice cultivars, "Fujihikari" and "Hanahyogo", were cultivated in both direct-seeding and transplanting methods with two levels of planting density, low and high. Rice dry weight and nitrogen uptake were measured through rice growth stages and at the mature stage yield and yield components were measured. Yielding ability when cultivated in directseeding with high planting density was the highest in Fujihikari, while yielding ability when cultivated in transplanting with high planting density was the highest in Hanahyogo. In both cultivars, rice dry weight with high planting density were higher than that with low planting density through rice growth stages. In Fujihikari, at mature stage rice dry weight when cultivated in direct-seeding with high planting density was the highest among all the cultivation methods, while in Hanahyogo at mature stage rice dry weight when cultivated in transplanting with high planting density was the highest among all the cultivation methods. In both cultivars, nitrogen uptakes with high planting density were higher than that with low planting density through rice growth stages. In Fujihikari, at mature stage the values of nitrogen uptake were almost the same without the value when cultivated in transplanting with low plant density, while in Hanahyogo the values of nitrogen uptake with high planting density were higher than the values with low planting density. It was revealed that to obtain much dry weight in early growth stage with high planting density is important in order to obtain high yield in short-term rice cultivars. In addition, it may be necessary to select the adequate cultivation method, either direct-seeding or transplanting, for each rice cultivar.