Effects of Sowing Time and Density on Yield and Nitrogen Utilization Efficiency of Different Wheat Varieties
Using Tainong 18 and Shannong 15 as materials,the effects of sowing time and density on yield components and nitrogen utilization efficiency of different wheat varieties were studied with 3 planting densities and 2 sowing times under field condition.The transporting quantity,transporting rate and contribution rate of stored nitrogen in vegetative organs before flowering to grains of 2 varieties both increased with the increase of sowing density and decreased with the delay of sowing time.The grains per spikeand 1 000-grain weight decreased while spike number per unit increased with the increase of sowing density; the grains per spike and 1 000-grain weight increased while spike number per unit decreased with the delay of sowing time.And the grain yield increased significantly under the final effects of delayed sowing time and increased sowing density.Grain nitrogen content and nitrogen accumulation in aerial part of 2 varieties decreased and increased respectively with the delay of sowing time and the increase of sowing density.Nitrogen absorption and utilization efficiency increased synchronously.Therefore,grain yield and nitrogen utilization efficiency could increase synergistically by delaying sowing time and increasing sowing density appropriately.Under the experimental condition,considering both high yield and nitrogen utilization efficiency,the optimum sowing time was October 14th and the optimum sowing density (basical seedling) was 405.0 × 104 and 517.5 × 104 plants per hectare for Tainong 18 and Shannong 15 respectively.
国家科技期刊平台
NSTL
万方数据
维普
