长期翻压绿肥对提高灌漠土土壤肥力和作物产量的贡献

Contribution of long-term application of green manure to soil fertility and crop yield in irrigated desert soil

【目的】研究河西绿洲灌区灌漠土长期施用绿肥培肥土壤和作物增产的机理。【方法】灌漠土培肥武威长期定位试验始于1988年,种植制度为小麦/玉米间作,供试绿肥为箭筈豌豆。选择绿肥磷肥配施(GP)、绿肥氮磷配施[1/2 (G+N) P]、氮磷配施(NP)、空白对照(CK) 4个处理,调查了作物产量和产量构成因素;2018年取0—20 cm耕层土壤样品,测定pH、有机质和养分含量。【结果】GP和1/2 (G+N) P处理均显著提高了灌漠土土壤肥力和作物产量。与试验初始值相比,GP、1/2 (G+N) P处理土壤有机质31年后分别增加了68.8%、56.6%,全氮分别增加了75.8%、56.3%,全钾分别增加了16.1%、18.0%,而全磷分别降低了20.3%、27.8%;与NP处理相比,GP和1/2 (G+N) P处理土壤有机质分别增加了29.0%、19.6%,全氮分别增加了43.3%、27.4%,全磷分别增加了18.4%、7.2%,全钾分别增加了1.7%、3.3%。GP和1/2 (G+N) P处理的小麦产量与NP处理差异显著,分别较NP处理增加305 kg/hm^(2)、248 kg/hm^(2),增幅分别为8.0%、6.5%。NP和1/2 (G+N)P处理的玉米产量与GP处理差异显著,分别较GP处理增加1538 kg/hm^(2)、1503 kg/hm^(2),增幅分别为20.3%、19.8%。小麦/玉米间作体系下,GP、1/2 (G+N) P处理的31年肥料贡献率(FCR)平均分别为0.53、0.59,变异系数(CV)分别为0.23、0.20,可持续性指数(SYI)分别为0.54、0.62。【结论】绿肥与氮磷化肥配施均能持续显著提高土壤有机质、全氮、全钾含量,提高肥料贡献率及作物产量稳定性和可持续性。小麦、玉米产量与土壤全磷和有效磷含量显著相关。因此,采用适宜绿肥用量和增加氮磷化肥用量的绿肥化肥配施方式,是甘肃河西绿洲灌区灌漠土上小麦玉米生产经济和生态效益双赢的施肥方式。

【Objectives】The contribution of long-term application of green manure to soil fertility and crop yield of irrigated desert soil in Hexi oasis irrigation area was assessed.【Methods】Long-term fertilization experiment in irrigated desert soil of Wuwei started in 1988.The cropping system was wheat/maize intercropping,and the green manure was common vetch.Four treatments were included in the study,green manure combined with phosphorus(GP),green manure combined with nitrogen and phosphorus [1/2(G + N)P],nitrogen and phosphorus(NP),and blank(control,CK).Soil samples of 0 – 20 cm topsoil were taken in2018,and pH,organic matter and nutrient contents were determined.【Results】GP and 1/2(G+N) P treatments significantly increased soil fertility and crop yield of irrigated desert soil.Compared with the initial value of the experiment,GP and 1/2(G + N) P treatments increased soil organic matter by 68.8 % and 56.6 %,increased total nitrogen by 75.8% and 56.3 %,increased total potassium by 16.1 % and 18.0 %,and decreased total phosphorus by 20.3 % and 27.8 %.Compared with NP treatment,GP and 1/2(G + N) P treatment increased soil organic matter by 29.0 % and 19.6 %,total nitrogen by 43.3 % and 27.4 %,total phosphorus by 18.4 % and 7.2 %,and total potassium by 1.7 % and 3.3 %.The wheat yields of GP and 1/2(G + N) P treatments were 8.0 % and 6.5 %higher than that of NP treatment,respectively.The maize yields of NP and 1/2(G + N) P treatments were 20.3 %and 19.8 % higher than that of GP treatment,respectively.The average 31-year fertilizer contribution rates(FCR)of GP and 1/2(G + N) P treatments were 0.53 and 0.59,respectively,the coefficients of variation(CV) were 0.23and 0.20,respectively,and the sustainability indexes(SYI) were 0.54 and 0.62,respectively.【Conclusions】Combined application of green manure and nitrogen and phosphorus fertilizers can continuously improve soil organic matter,total nitrogen and total potassium content,fertilizer contribution rate,crop yield stability and sustainability.The yields of wheat and maize are significantly correlated with soil total phosphorus and available phosphorus.Therefore,it is a win-win fertilization method for the economic and ecological benefits of wheat and maize production on the irrigated desert soil in Hexi Oasis Irrigation District of Gansu Province to adopt the combined application of green manure and chemical fertilizers.