宽幅播种条件下基本苗密度对小麦耗水特性和籽粒产量的影响

Effects of Basic Seedling Density on Water Consumption Characteristics and Grain Yield of Wheat under Wide Sowing

研究宽幅播种条件下不同基本苗密度处理的小麦全生育期耗水特性及籽粒产量特性,明确提高小麦水分利用效率和籽粒产量的最佳基本苗密度。于田间试验条件下,设置4个基本苗密度处理,即每公顷密度90万株(D1)、180万株(D2)、270万株(D3)、360万株(D4),测定其小麦生育期间各土层土壤贮水消耗量、小麦耗水来源及其占总耗水量的比例、各生育阶段耗水量、耗水模系数、日耗水量、籽粒产量及水分利用效率。结果表明:①土壤贮水消耗量及总耗水量均为D4>D3>D2、D1,140~160、160~180、180~200 cm土层土壤贮水消耗量D2处理显著高于D1、D3、D4。②拔节至开花期的阶段耗水量、耗水模系数D2处理均显著高于其它处理,日耗水量D2处理与D3、D4无显著差异,但显著高于D1。③土壤水利用效率、降水利用效率、水分利用效率及籽粒产量D2处理均显著高于D1、D3和D4。表明,在宽幅播种条件下,每公顷密度180万株的D2处理是降低小麦农田总耗水量、提高籽粒产量和水分利用效率的最佳基本苗密度。

The characteristics of water consumption during the whole growth period and grain yield of wheat with different basic seedling densities were studied under wide sowing conditions to determine the optimum basic seedling densities for increasing water use efficiency and grain yield.Under field test conditions,four basic seedling density treatments were set as 90×10^4 plants·hm^-2(D1),180×10^4 plants·hm^-2(D2),270×10^4 plants·hm^-2(D3),360×10^4 plants·hm^-2(D4),and the soil water consumption in different soil layers,sources of wheat water consumption and its proportion in total water consumption,water consumption at each growth stage,water consumption modulus,daily water consumption,grain yield and water use efficiency during wheat growth were analyzed.The results were as follows.①The soil water consumption and total water consumption were both as D4>D3>D2 and D1,and the soil water consumption in the soil layers of 140~160 cm,160~180 cm and 180~200 cm was higher under D2 treatment compared to D1,D3 and D4 treatments.②The water consumption and water consumption modulus of D2 treatment at the stages from jointing to flowering were significantly higher than those of the other treatments.The daily water consumption of D2 treatment was not significantly different from that of D3 and D4 treatments,but significantly higher than that of D1 treatment.③The soil water use efficiency,precipitation use efficiency,water use efficiency and grain yield of D2 treatment were significantly higher than those of D1,D3 and D4 treatments.All the results showed that under wide sowing conditions,the D2 treatment of 180×10^4 plants·hm^-2 was the best basic seedling density to reduce total water consumption of wheat farmland and increase grain yield and water use efficiency.