西藏拉萨河谷地区紫花苜蓿的刈割管理

Cutting management of Medicago sativa in the Lhasa river valley,Tibet

通过对西藏拉萨河谷地区紫花苜蓿的刈割试验,构建了拉萨河谷地区紫花苜蓿刈割生长动态模型,并分析了刈割次数对紫花苜蓿干鲜草积累量、刈割高度、干鲜比、营养成分的影响。分析结果表明,紫花苜蓿在西藏拉萨河谷地区具有很大的发展潜力,在管理措施保障条件下,紫花苜蓿刈割1次的干草年积累量可达1 645g/m2,刈割2次达2 128g/m2,刈割3次达2 201g/m2;多次刈割可提高紫花苜蓿鲜草年积累量90%以上,而对干草年积累量提高约55%;同时,建议拉萨河谷地区紫花苜蓿宜采用分枝期一年刈割3次的刈割方案,分别于5月下旬、7月中旬和9月初实施,可获得干草积累量最大,草产品质量最好的紫花苜蓿干草。

Through systematic research of the cutting areas in the Lhasa river valley,dynamic models of Medicago sativa growth were structured to simulate and forecast the accumulation of dry matter and fresh forage of M.sativa in different cutting schemes.The effects of cutting times on accumulation of dry matter and fresh forage,height,dry weight/fresh weight ratio,nutrient component of M.sativa were studied and different cutting schemes were developed to suit different objectives.Cutting three times a year at branching for M.sativa pasture gave the maximum dry matter and best quality of M.sativa hay in the Lhasa river valley.