播种量对紫云英生长及物质养分积累的影响

大田试验条件下研究了不同播种量对紫云英(Astragalus sinicus L.)生长及物质养分积累的影响。试验设7 个处理, 播种量为7.5~52.5 kg·hm^-2。试验结果表明, 随播种量增加, 紫云英出苗数显著增加, 单株分枝数、单株复叶数和单株重均呈下降趋势。紫云英鲜草产量随播种量增加而增加, 播种量为7.5~30.0 kg·hm^-2 范围内增产幅度较大, 而播种量>30.0 kg·hm^-2 时, 若继续增加播种量则增产幅度减小。紫云英种子产量随播种量的增加呈先升高后降低的趋势, 播种量为15.0 kg·hm^-2 时种子产量最高。播种量对紫云英养分含量影响较小,但显著影响养分积累量, C、N、P、K、Ca、Mg、Fe、Mn、Cu、Zn 积累量均随播种量增加而增加。紫云英翻压做绿肥的适宜播种量为30.0 kg·hm^-2, 而若以收获种子为目的则播种量以15.0 kg·hm^-2 为宜。

Effect of seeding rate on growth and nutrient accumulation of Chinese milk vetch

A field trial was conducted to study the effect of seeding rate on the growth, fresh yield and nutrient accumulation of Chinese milk vetch (Astragalus sinicus L.). The trial included 7 seeding rate treatments ranging from 7.5 to 52.5 kg·hm^-2. The results showed that the number of emerged seedling increased with increasing seeding rate. However, number of branch and compound leaf, weight for per plant decreased with increasing seeding rate. Fresh yield also increased with increasing seeding rate. Significant differences were noted in fresh yield under seeding rate of 7.5~30.0 kg·hm^-2. Once seeding rate above 30.0 kg·hm^-2, however, no significant difference existed among the treatments. Seed yield initially increased with increasing seeding rate up to 15.0 kg·hm^-2, and then decreased with increasing seeding rate. Seeding rate had no significant influence on nutrient content, but greatly influenced nutrient accumulation. The accumulation of C, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn significantly increased with increasing seeding rate. It was therefore concluded that the most suitable seeding rate was 30.0 kg·hm^-2 for green manure turnover, and 15.0 kg·hm^-2 for seed production.