减氮增密对水稻产量及稻米食味品质的影响OA

The elite rice variety Ezhong 5 was used to study the coordinated effects of nitrogen fertiliz-er and planting density on the yield formation and taste quality of rice.8 treatments of nitrogen fertilizer con-sisted of the nitrogen application level and the ratio of fertilizer for base,tiller,and spikes including T1(0 kg/hm2),T2(50 kg/hm2,7∶3∶0),T3(50 kg/hm2,5∶3∶2),T4(100 kg/hm2,7∶3∶0),T5(100 kg/hm2,5∶3∶2),T6(100 kg/hm2,4∶2∶4),T7(200 kg/hm2,7∶3∶0),T8(200 kg/hm2,5∶3∶2)were set up under 3 densities including D1(3.7×105 holes/hm2),D2(3.0×105 holes/hm2),and D3(2.6×105 holes/hm2).A 2-year field experiment was conducted to study the effects of reducing nitrogen and in-creasing planting density on the population quality,yield and taste quality of rice.The results showed that T4D3 reduced the high-efficiency leaf area index and canopy radiation interception rate and T4D1 optimized the population structure to alleviate the negative effect of reducing nitrogen on the utilization of light energy resources in terms of population quality.Reducing nitrogen decreased the number of grains per spike,but in-creasing planting density effectively compensated for the yield loss caused by reducing nitrogen via increas-ing the number of effective spikes(with an increase of 9.14%-16.65%)to achieve stable yield in terms of yield.The number of effective spikes of T4D1 was significantly increased by 15.70%compared with that of T4D2,with an increase in yield of 19.72%.In terms of taste quality,the content of protein in grain was syn-ergistically reduced by reducing nitrogen,increasing planting density,and reducing the proportion of fertiliz-er for spikes at the late stage of growth and development.The taste value of rice was significantly improved,with an increase ranging from 13.39%to 14.33%.It is indicated that reducing nitrogen and increasing plant-ing density,while reducing the proportion of fertilizer for spikes at the late stage of growth and development(less than 20%)can synergistically improve the yield and taste quality of elite rice.