末次刈割时间对科尔沁沙地苜蓿越冬率及根系营养物质含量的影响

摘要

通过以科尔沁沙地二年生紫花苜蓿(Medicago sativa)为试验材料,测定不同末次刈割时间处理条件下科尔沁沙地苜蓿根系全氮、可溶性糖、淀粉含量及翌年返青率.结果表明:随着末次刈割时间的推迟,苜蓿越冬率呈现先降低后升高的趋势,而苜蓿根系全氮及可溶性糖含量则呈现逐渐降低的趋势,根系淀粉含量则呈现出“升-降-升”的变化趋势,其中8月23日刈割处理越冬率、根系全氮及可溶性糖含量显著高于其他刈割处理(P＜0.05).%Second-year alfalfa grown in Horqin sandy land was cut at different time for the final harvest in this study.The root total nitrogen,soluble sugar,starch,and the following year green-up rate were measured.The results showed that:with the delay of the cutting time alfalfa winter survival rate decreased first and then increased,while alfalfa root total nitrogen and soluble sugar content decreased continuously.And root starch content exhibited an "up-down-up "trend.Last cutting on August 23 had significantly higher winter survival rate,root total nitrogen and soluble sugar content than other cutting time treatments (P＜0.05).