播期和播量对不同类型小麦品种产量及氮素利用效率的影响

Effects of Sowing Time and Density on Yield and Nitrogen Utilization Efficiency of Different Wheat Varieties

在大田条件下,以大穗型品种泰农18和中穗型品种山农15为试材,分别设置三个种植密度、两个播期研究播期和播量对不同类型小麦品种产量构成因素及其氮素利用效率的影响。结果表明:两个品种花前营养器官中贮存的氮素向籽粒中的转运量、转运率和贡献率均随种植密度的增大而增大,随播期的延迟而降低。随种植密度增大,穗粒数、千粒重相应降低,单位面积穗数升高;随播期延迟穗粒数、千粒重则相应升高,单位面积穗数降低。在延迟播期和增加密度的最终影响下籽粒产量显著提高。两个品种的籽粒含氮量随播期的延迟和种植密度的增加而降低,地上部氮素积累量随播期的延迟和种植密度的增加而增加,结果氮素吸收效率和氮素利用效率同步提高。因此,通过适当延迟播期和增加种植密度可以实现籽粒产量和氮素利用效率的协同提高。本试验条件下,泰农18和山农15兼顾高产和氮素利用效率的最适宜播期为10月14日,种植密度(基本苗)分别为405.0、517.5万株/hm2。

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 contribu-tion 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 spike and 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 utiliza- tion efficiency increased synchronously. Therefore, grain yield and nitrogen utilization efficiency could in- crease synergistically by delaying sowing time and increasing sowing density appropriately. Under the experi-mental 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 × 10^4 and 517.5 × 10^4 plants per hectare for Tainong 18 and Shannong 15 respectively.