【摘要】 连续8年的施肥试验结果表明,在青海草地施用磷肥和氮肥的效应随不同草地生态类型而变化,也随不同禾本科牧草种类而变化;禾草增产量(yi)与施氮水平(x)的数量关系符合yi=x/(a+bx)或yi=x/(a+bxc)方程;单施氮和单施磷对牧草品质具有不同的影响;磷作种肥在播种时一次施入,氮作追肥在分蘖期施入土层6 cm时肥效最高。更多还原

【Abstract】 8 year’s continuous fertilizer application experiments in Qinghai grassland showed that the effect of N and P fertilizer application varied either with different grassland eco-types or different grass types.The mathematic relationship between the yield increase amount of grass and N fertilizer amount could be expressed as equations yi=x/(a+bx) or yi=x/(a+bxc).Solo N and solo P fertilizer application differently affected forage quality.P and N application as sowing and dressing respectively with 6 cm depth into earth the optimum effect was obtained.更多还原