在陇东半湿润区采用完全组合设计进行了大豆全膜微垄沟播种植密度田间试验，结果表明，密度的增大可促进大豆提早成熟，不利于提高单株分枝数和荚长增加，降低百粒重。在试验设计范围内，行距对产量的影响显著，株距对产量的影响明显。在试验区条件下，全膜微垄沟播大豆的最佳种植密度为130 183株/hm2时，产量最高，为1 696.5 kg/hm2。适宜种植密度为142 857.1株/hm2(行距为50 cm，株距为14 cm)，产量为1 664.5 kg/hm2。

In eastern part of Gansu province， a field experiment is carried out to determine the effects of plant density on yield of soybean under whole field surface plastic mulching and Micro-ridge-furrow planting. The result shows that， as the plant density of soybean increase， the soybean matured earlier， and the branching number per plant and length of pod are negatively influenced， as well as the weight of 100 grain is significantly decreased. In this experiment， the effect of distance between lines and distance between plants on yield of soybean are significant. The optimum plant density of soybean for whole field surface plastic mulching and Micro-ridge-furrow planting is 130 183 /hm2， and the highest yield is 1 696.5 kg/hm2. Another suitable plant density is 142 857.1 /hm2， in this situation， the distance between lines and plants is 50 cm and 14 cm respectively， the yield is 1 664.5 kg/hm2.

S565.1