基施硒肥对紫花苜蓿草产量及农艺性状的影响

采用田间试验，研究在氮、磷、钾及微量元素充分供应情况下，基施不同量硒肥对紫花苜蓿(Medicago sativa)不同生育期草产量及农艺性状的影响。结果表明，施硒可不同程度地提高紫花苜蓿不同生育期草产量、干物质积累速率、株高和叶茎比。基施0.45 kg·hm-2硒的紫花苜蓿在分枝期、现蕾期和初花期,其草产量、株高和叶茎比方面均表现最佳，草产量分别比未施硒提高32.67%、24.78%和37.93%，株高分别比未施硒提高10.01%、14.00%和10.51%。叶茎比分别比未施硒提高6.43%、8.00%和12.80%。而干物质积累在分枝期、现蕾期和初花期分别以0.45、1.05和0.75 kg·hm-2处理积累速率最高。未施硒处理生长高峰出现在现蕾期，初花期有所下降，但施硒处理均进入生长高峰，积累速率继续上升。

Effects of base selenium on the herbage yield and agronomic characteristics of alfalfa at different growth stages

A field experiment was conducted to determine the effects of different levels of selenium on the herbage yield and agronomic characteristics of alfalfa at different growth stages.The results of this study showed that application of selenium increased the herbage yield,accumulation rate of dry matter,plant height and leaf/steam at different growth stages to some extent.The 0.45 kg·ha-1 selenium had the highest herbage yield,accumulation rate of dry matter and plant height at the branching stage,bud stage and early flowering stage,in which the herbage yield increased by 32.67%,24.78% and 37.93%,respectively,and the plant height increased by 10.01%,14.00% and 10.51%,respectively,and the leaf/steam increased by 6.43%,8.00% and 12.80%,respectively.The accumulation rate of dry matter with application of 0.45,1.05 and 0.75 kg·ha-1 selenium was the highest at the branching stage,bud stage and early flowering stage,respectively.The growth peak of alfalfa without selenium fertilization was found at the bud stage and its accumulation rate of dry matter decreased at the early flowering stage,but the alfalfa with selenium fertilization continued to grow.