中文摘要：

田间试验条件下,研究5个播种量（7.5-37.5 kg/hm^2）对紫云英（Astragalus sinicus L.）种子产量及其构成因素的影响。结果表明,紫云英鲜草产量和种子产量与播种量呈抛物线关系,均随播种量增加先升高后降低,在播种量22.5 kg/hm^2时最大。根据种子产量与播种量效应函数,在节约用种原则下,推荐江汉平原稻区紫云英种子高产播种量为15-24 kg/hm^2。紫云英种子产量与鲜草产量呈正相关。随着播种量增加,紫云英群体密度增加,株高、茎基部直径、单株重、单株一级分枝数、一级分枝花序数显著降低,每有效花序结荚数、每荚粒数和千粒重受影响较小。单位面积一级分枝数和花序数随着播种量增加先升高后降低,与种子产量显著正相关,是影响种子产量的关键因子。

英文摘要：

Effects of different seeding rate（7.5-37.5 kg / hm^2） on the seed yield and yield components of Chinese milk vetch were studied in a field experiment. The results showed that the fresh grass yield in full-blossom stage and seed yield of Chinese milk vetch firstly increased and then decreased with the increase of seeding rate, which showed as a parabola pattern reached the peak in the seeding rate of 22.5 kg / hm^2. The optimum seeding rate to achieve high Chinese milk vetch seed yield was 15-24 kg / hm^2 in rice producing area in Jianghan Plain according to the parabola function and saving seeding rate.The plant density increased with increasing seeding rate, however, plant height, diameter of the stem base, weight per plant, number of first branch per plant and its number of racemes branch decreased, and the number of pods per effective raceme, the number of seeds per pod and 1 000-grain weight remain stable throughout. As seeding rate increased, both first branch and racemes in unit area raised first and then declined. They were the major factors controlling seed yield which positively correlated with seed yield.