Effects Of The Amount Of Nitrogen And Density On Yield,Quality And N-absorbing Utilization Efficiency Of Rice "Fengyouxiangzhan"

Effects of the amount of nitrogen and density on yield , quality and n-absorbing utilization efficiency of rice " Fengyouxiangzhan" were studied in the farm of Agricultural Institute of Yangzhou University with a medium indica hybrid rice Fen youxiangzhan as material in 2002-2003. The main results showed as follow:1. Under the sandy loam wirh middle fertility, grain yield could be over 650/mu when amount of nitrogen was 15 kg/mu and plant density was within 1.0-2.0 X 104 hills/mu or amount of nitrogen was 20 kg/mu and plant density was within 1.0 X 104 hills/mu. Among them, a tiptop yield could be attained. Milling quality was improved and the chalkiness, gel consistency and amylose content was decreased and the protein content was increased with increasing of amount of nitrogen. Head milled was highest and when plant density was 1.0 104 hills/mu, and the percentage of chalkiness was low when plant density was within 1.0-104 hills/mu. Gel consistency was increased with increasing of plant density and effect of plant density to amylose content and the protein content was little. Nitrogen utilization efficiency was tiptop when amount of nitrogen was 15 kg/mu or 20 kg/mu which was beneficial to consistency among super high yield, good quality and high efficiency. The combination that amount of nitrogen was 15 kg/mu and plant density was 1.0 104hills/mu was optimum.2. With increasing of leaf age when N was addressed, the yield of the treatments of N14 and N15 was highest. Head milled rice were increased with increasing of leaf age when N was addressed. The percentage of chalkiness and the degree of chalkiness were decreased obviously in N16 and N17. Amylase content was decreased and the protein content was increased with increasing of leaf age when N was addressed. The N utilization efficiency of the treatments of N14-. N15 is higher than others. With a view toyields, quality and N utilization, yield of the treatment of N14, N15 were high but quality of them is general. Quality of the treatment of N16 was good, but yield of it was declined.3. Under the sandy loam with an middle fertility and planting density of 1.0 104hills/mu, grain yield of the treatment that amount of nitrogen was 10 kg/mu with planting 1 seedling per hole was high as that of CK which amount of nitrogen was 15 kg/mu with planting 2 seedling per hole. The gel consistency was improved with plant density increased. The degree of chalkiness was low when planting 2 seedling per hole. Nitrogen utilization efficiency in the period of rice growth and apparent productivity of treatment that were higher than that of CK. Treatment that amount of nitrogen was 10 kg/mu with planting 2 seedling per hole was optimum which guaranteed high yield, good quality, high N utilization efficiency and low environmental pollution.4. To get high yield, different soil need different amount of nitrogen fertilizer. On sand soil (the yield was 286.33 kg/mu without nitrogen fertilizer) , the tiptop yield of 594.75 kg/mu could be obtained when amount of nitrogen was 20kg/mu. On clay soil (the yield was 335.7 kg/mu without nitrogen fertilizer) , the tiptop yield of 625.69 kg/mu could be obtained when amount of nitrogen was 15 kg/mu. Under the same nitrogen level, yield on the clay soil was higher than that of the sand soil. Amylase content and the gel consistency of rice on sand soil was lower and the protein was higher than that on clay soil. Effects of amount of nitrogen to rice quality were same on two types of soil. Milling quality was improved and percentage of chalkiness, degree of chalkiness, gel consistency and amylase content were decreased and protein content was increased with increasing of amount of nitrogen. N utilization efficiency on clay soil was higher than sand soil under different amount of nitrogen. N utilization efficiency was tiptop when amount of nitrogen was 20 kg/mu on sand soil but that was tiptop when amount of nitrogen was 15 kg/mu on clay soil.