黄土旱塬施氮模式对春玉米产量和水肥利用效率的影响

Effects of nitrogen fertilization regime on crop yield and water and fertilizer use efficiency in spring maize field on the semiarid Loess Plateau

通过3a田间试验,研究了不同施肥模式对春玉米产量、耗水量、水分利用效率及氮肥利用效率的影响。试验于2013年4月至2015年9月,在中国科学院长武黄土高原农业生态试验站进行,供试作物为春玉米,半覆膜种植。试验共设不施氮对照(CK)、传统施氮(TR)、减量施氮(DR)、缓控释肥(SR)4个处理,定期测定玉米产量、土壤剖面含水量等指标。结果表明:3a试验期间,与TR相比,DR、SR在施氮量减少25%的条件下,春玉米产量无显著差异。TR、DR、SR处理下的春玉米产量分别为13 416.2、13 270.1、13 063.0kg hm-2。施氮显著影响作物水分利用效率,CK、TR、DR、SR处理的水分利用效率值分别为12.6%、24.7%、28.3%、28.8%,DR、SR处理较TR处理,显著增加了土壤水分利用效率,其增幅分别为14.0%、16.0%。CK、TR、DR、SR处理的耗水量依次为376.3、547.4、469.6、452.1mm,与TR相比,DR、SR处理显著降低了土壤耗水量,其降幅分别为14.2%、17.4%。DR、SR处理在连续3a施氮量减少25%的同时,不仅保证了春玉米产量、氮肥利用效率、地上部生物量不降低,而且减少了土壤耗水量,增加了土壤水分利用效率。因此,在土壤干旱贫瘠的黄土高原地区,减少肥料施用量和施用缓控释肥是一种科学合理的施肥管理方式。

Effects of different fertilization regimes on crop yield,water consumption,nitrogen fertilizer and water use efficiency were investigated in spring maize field through a three-year field experiment.The experiment was conducted at the State Key Agro-Ecological Experimental Station of Chinese Academy of Sciences during April,2013 to September,2015,with the spring maize being researched under partially-mulched treatment.Four treatments were considered,including control(CK)、conventional N fertilization rate(TR)、reduced nitrogen fertilization、controlled release fertilization,to periodically determine the crop yield,soil water content within profile,etc.Result showed that crop yield of the spring maize showed no significant difference at DR and SR as compared to that at TR.The crop yield were 13 416.2,13 270.1,13 063.0 kg hm-2 respectively at TR,DR and SR treatments.The water use efficiency were 12.6%,24.7%,28.3% and 28.8% at CK,TR,DR and SR treatments,which was significantly affected by the nitrogen fertilization regimes.Specifically,it was significantly increased by 14.0%and 16.0%at DR and SR treatments when compared to that of TR.The water consumption were 376.3,547.4,469.6 and 452.1 mm at CK,TR,DR and SR treatments,respectively.Compared with TR,the water consumption was significantly reduced at DR and SR,with decrease of 14.2%and17.4%.although the nitrogen fertilization have been reduced by 25%,the DR and SR treatments not only maintained the crop yield,nitrogen use efficiency and aboveground biomass,but also decreased the soil water consumption and increased soil water use efficiency.Therefore,the application of reduced nitrogen fertilization and controlled release fertilization were scientific and efficient fertilization in the semiarid and barren Loess Plateau.