苜蓿田狗尾草生态经济阈值模型的初步研究

A STUDY ON THE ECOLOGIC-ECONOMIC THRESHOLD MODEL OF SETARIA VIRIDIS(L) BEAUV.IN ALFALFA FIELDS

试验结果指出了苜蓿产量损失率与狗尾草密度之间的关系,建立了狗尾草生态经济阈值模型。计算结果表明,当杂草密度低于生态经济阈值时,不需要除杂,因此,明确杂草的生态经济阈值—杂草造成的净损失等于预防这种损失所耗费的成本时的杂草种群的大小,这对经济除杂,改良环境和维持人工草地生态平衡,具有重要的意义。

The relationship between the density of Setaria viridis(L) Beauv.and the loss rate of Medicago sativa L. yield was studied.The Setaria Viridis ecologic—economic threshold model was established.The calculated re- suits showed the weed needn't control when its density was below the threshold.