Effects Of Amount Of Nitrogen And Planting Density On Yield And Quality Of Japonica Rice D46 In The Chengdu Plain

To calculate the effects of nitrogen and planting densities on agronomic traits, material accumulation and translocation, nitrogen uptake and utilization, yield and quality of rice, we carried out the experiment by using two split block design and japonica rice variety D46 (Chengxing) as the test material. In which planting densities (25cm×20cm,25cm×15cm,25cm×10cm, row spacing×line spacing) and nitrogen content (0,150,225 and 300kg/hm2, pure nitrogen). The results are as follows:1. Effects of planting density, nitrogen and planting density xnitrogen on rice yield had a significant impact. Planting density 25cm×15cm has the highest yield, and significantly higher than 25cmx20cm and 25cm×10cm. The effective panicles, number of flowers per panicle, number of grains per panicle, seed setting rate and yield were increased significantly with the increase of nitrogen within the scope of 0-225kg/hm2 range. However, the yield was decreased because of the decline of number of spikelet per panicle and number of real grains per panicle with nitrogen 300kg/hm2 range. In two factor interactions, the yield was highest with planting density 25cm×15cm and 225kg/hm range, followed by planting density 25cm×20cm and 225kg/hm2 range.2. Planting density and nitrogen on rice quality have a different degree of influence, and with greatest influence on nitrogen. Planting density 25cm×15cm has the highest quality, and better than 25cmx20cm and 25cm×10cm. The process quality improved, chalky rate increased, chalkiness decreased, cooking and eating quality decreased and protein content increased with the increase of nitrogen within the scope of 0-225kg/hm2 range, and grain quality declined with 300kg/hm2. In two factor interactions, the quality was best with planting density 25cmx20cm and 115-225kg/hm2 range.3. Effects of planting density and nitrogen on tillers and chlorophyll content are opposite. The tillers and chlorophyll content decreased with the increase of planting density, while the tillers and chlorophyll content showed the opposite with the increase of nitrogen and which were highest with planting density 25 cm×20cm and 300kg/hm2 range. In two factors interactions, the tillers and chlorophyll content attenuate deepened with the increase of the both factors.4. Effects of planting density, nitrogen and planting density×nitrogen on dry matter accumulation and translocation had a significant impact. The dry matter weight increased with the increased of nitrogen levels, especially under the combination of nitrogen 225kg/hm2 range and planting density 25cm×15cm. When both of nitrogen and density increased, the dry matter distribution of stem-sheaths and leaves increased accordingly, conversely, the dry matter distribution of ears showed the opposite condition. The dry matter translocation of stem-sheaths and leaves was highest with planting density 25cm×15cm. The dry matter translocation of stem-sheaths and leaves increased with the increase of nitrogen within the scope of 0-225kg/hm2 range and decreased with 300 kg/hm2.5. Effects of planting density, nitrogen and planting density x nitrogen on nitrogen accumulation and translocation had a significant impact. Nitrogen accumulation, nitrogen translocation of stem-sheaths and leaves and nitrogen translocation contribution rate increased with planting density 25cm×15cm. Nitrogen accumulation, nitrogen distribution of stem-sheaths and leaves increased, nitrogen distribution of panicle decreased with increased of nitrogen, nitrogen translocation of stem-sheaths and leaves and nitrogen translocation contribution rate with 225kg/hm2 range. Planting density and nitrogen on nitrogen on dry matter productivity, nitrogen production efficiency, nitrogen harvest index and nitrogen partial productivity have a different degree of influence, with greatest influence on nitrogen, and decreased with the increasing of nitrogen. Effects of planting density x nitrogen on nitrogen harvest index had a significant impact, nitrogen harvest index declined significantly with the increasing of the both factors planting density and nitrogen. There was beneficial for improvement yield, processing quality and nutrient quality with the decreasing of nitrogen uptake and utilization, which reducing the appearance quality and eating quality of rice.