“黑土型”退化草地人工植被施肥试验研究

Studies of fertilizer application on the artificialy vegetated "Black soil type" degenerated grassland

采用四因素二次通用回归旋转设计，以产草量为标准对“黑土型”退化草地上人工植被的施肥时间和氮磷钾的用量进行2年定位试验，建立牧草产量函数模型。结果表明，单因素增产效应为施肥当年：氮肥〉磷肥〉钾肥〉施肥时间；第2年：氮肥〉磷肥〉施肥时间〉钾肥。确定“黑土型”退化草地上人工植被的施肥组合方案为施肥时间在分蘖～7月上甸、N：75～130kg／hm^2、P2O5：50．0～112．5kg／hm^2、少施或不施钾肥，可取得较高的产量和经济效益。同时，为获得较高牧草产量，以每2年施肥1次为好。

Adopting a quadratic regression rotation design with forage yield as the standard, the effects of fertilization time and nitrogen （N）, phosphorus （P）, and potassium fertilizer （K） on the artificially vegetated ＂Black soil type＂ degenerated grassland was studied in a two year field trial. Regression models of yield were developed. The effects of single factors were N〉P〉K〉 fertilization time in the same year and N〉P〉 fertilization time 〉 K in the second year. A suitable combined programme for fertilizer applications were N. 75--130 kg/hm^2, P2O5：50.0-112. 5 kg/hm^2 from tillering to the first ten days of July, with no or little potassium fertilizer. Fertilizing once every two years could give higher yields and better economic efficiency.