滴灌施肥对华北地区冬小麦-夏玉米作物产量及水氮利用效率的影响

Effects of Drip Irrigation Fertilization on Wheat and MaizeYields and Water-and Nitrogen-Use Efficiency in Northern China

华北地区是我国重要的粮食产区,以冬小麦(Triticumaestivum L.)和夏玉米(Zea mays L.)的集约化种植模式为主,而水资源缺乏和化肥过量投入却限制了该地区农业的可持续发展;为此,在在提高水氮利用效率和保证作物高产的同时,增加土壤氮库、推广应用水肥一体化技术很有必要。研究2015~2017年在山东桓台进行冬小麦和夏玉米滴灌施肥田间试验,探讨水分管理技术对作物产量、水分和氮肥利用效率以及对土壤氮库的影响;田间试验设漫灌和滴灌两种灌溉方法和三种氮肥用量,漫灌有0、600 kg hm-2yr-1两个施氮量处理(FN0,FN600),滴灌有0、420、600 kg hm-2yr-1三个施氮量处理(DN0、DN420和DN600)。结果表明,施肥处理间小麦和玉米产量均无显著差异,其中,较FN600,优化滴灌(DN420)处理下小麦和玉米产量分别增加5.8%和7.2%,作物地上部吸氮量增加4.6%。滴灌条件下,减氮30%后(DN420)能分别增加偏生产力(PFP)、表观氮素利用率(ANUE)、水分利用率(WUE)和灌溉利用率(IWUE)达47.4%、49.0%、3.4%和4.6%;与常规施肥处理相比,DN420能分别增加PFP、ANUE、WUE和IWUE达49.3%、52.0%、34.5%和101.9%。漫灌施肥处理导致无机氮在深层土壤(80~100 cm)的累积,增加氮素淋溶风险,滴灌施肥则会有利于氮素在表层土壤(0~40 cm)的累积,有利于作物吸收利用。经过2年试验后,表层土(0~20 cm)全氮的含量以滴灌施肥处理(DN420:1.27 g kg-1;DN600:1.28 g kg-1)最高。滴灌处理+优化施肥能增加作物产量,提高水氮利用效率,降低土壤氮素向深层土壤迁移,该措施在华北地粮食生产区推广使用,有利于集约化农业的可持续发展。

As one of the most intensified agricultural regions in China,the region of Northern China is mainly cropped with winter wheat(Triticum aestivum L.)and summer maize(Zea mays L.).Shortage of groundwater and over fertilization limit the sustainable development of intensified agriculture in Northern China.Water-saving irrigation fertilization is adopted as a sound farming practice to increase water-and nitrogen(N)-use efficiencies,crop yield and soil N pool.A field experiment was established with flood irrigation treatments(FN600,conventional N fertilizer of 600 kg hm-2 yr-1 and flood irrigation;FN0,no N fertilizer and flood irrigation)and drip irrigation treatments(DN0,no N fertilizer and drip irrigation;DN420,optimized N fertilizer of 420 kg hm-2 yr-1 and drip irrigation;DN600,600 kg hm-2 yr-1 and drip irrigation)in 2015-2017 in Huantai,Shandong,Northern China.There was no significant difference of crop yield under different fertilization treatments.Compared with FN600 treatments,the wheat and maize yields of DN420 were increased by 5.8%and 7.2%,and the N uptake amounts was increased by 4.6%.Under drip treatments,DN420(30%of N reduced)increased PFP,ANUE,WUE,and IWUE by 47.4%,49.0%,3.4%,and 4.6%compared with DN600 treatment,respectively.Compared with FN600,DN420 increased PFP,ANUE,WUE,and IWUE by49.3%,52.0%,34.5%,and 101.9%,respectively.Flood irrigation caused the high N accumulation at 80-100 cm soil depth,which increased the soil N loss,while drip irrigation caused a higher N accumulation at 0-40 cm soil layer,which contributed to higher N uptake by crop.The content of total N in surface soil(0-20 cm)was the highest in DN600 treatment(1.28 g kg-1).The drip irrigation combined with optimized fertilization increased the crop yields and the water-and fertilizer N-use efficiencies,and decreased the N accumulation at deep soil.Therefore,the optimal drip irrigation fertilization was widely recommended in the grain producing region of Northern China for sustainable agricultural development.