青海高寒草甸施氮肥增产效应浅析

Effects of nitrogen on the grass yield of Qinghai alpine meadow

采用氮肥施用量的单因子试验研究了施用氮肥对高寒草甸的增产效应。结果表明,就2年累积增产效应而言,施氮量为150 kg/hm2时,每公斤尿素可获得地上总生物量的最大增产量为19.22 kg,而当施氮量为225 kg/hm2时,禾本科牧草可以获得单位尿素的最大增产量为17.48 kg。综合考虑草地总盖度、草地总生物量、优良牧草生物量及优良牧草分盖度的增加,认为天然高寒草甸草地的最佳施氮量为150 kg/hm2,2年累积可增加地上总生物量2 883 kg/hm2鲜草,增加禾本科牧草地上生物量1 770 kg/hm2鲜草。

The experiment was carried out with a single-factor trail on fertilizer amount （urea, with 46% on amount on the grass yield of alpine pasture. The result showed that nitrogen fertilizer may significantly increase two year＇s yield. The total aboveground biomass mostly increased 19.22 kg from each kg urea with applied amount of 150 kg/hm^2 urea, while aboveground biomass of grasses mostly increased yield 17.48 kg/kg urea with 225 kg/hm^2 applied amount. Considering the total coverage, the total aboveground biomass , species biomass and coverage of fine herbage of alpine grassland, the best manure amount for natural alpine meadow is 150 kg/hm^2 , which can increase the total fresh aboveground biomass 2 883 kg/hm^2 or 1 770 kg/hm^2 fresh grasses yield.