Influence of Several Doses of Nitrogen Fertilizer on Rice Taste and Grain Yield

Abstract

In this research, two different types of nitrogen fertilizer application were examined. They were supplied uniformly at basal dressing, then with several doses at topdressing (Type 1) and several doses at basal dressing, and then uniformly at topdressing (Type 2). These were applied to investigate variations of rice taste and its properties, vegetation growth and grain yield, depending on the amount of nitrogen fertilizer and other correlations. The variation of the amount of protein at Type 1 was larger than that of Type 2. However, there was only a 4% coefficient variation, even with several doses. The correlations between the amounts of amylose, protein and the amount of nitrogen fertilizer at topdressing were 0.741 and 0.730, respectively. With vegetation growth data, it might be possible to estimate amounts of amylose and protein and rice taste using the SPAD value at the ripening stage, plant length at the heading stage, the variation of SPAD value between panicle initiation and ripening, and the variation of plant length between panicle initiation and the heading stage. Correlations between the amount of amylose, protein, rice taste, amount of nitrogen fertilizer and, grain yield of Type 1 were 0.733, 0.717, -0.764 and 0.710, respectively. With this research, it might be possible to control the amounts of amylose and protein, rice taste and grain yield, using variable rate fertilizer applications.