控失尿素减施及不同配比对夏玉米产量及氮肥效率的影响

添加纳米矿物类控失剂的控失尿素可通过吸附作用,减少施入土壤后的氮素损失,明确该控失尿素施用量、与常规尿素合理配比在夏玉米上的效应,可为夏玉米一次性施肥、氮肥减施增效提供依据。在不同产量水平(高、中、低产田)土壤上,通过田间试验研究常规尿素(纯氮210 kg hm^–2)、控失尿素常量及减施(减量10%,即纯氮189 kg hm^–2;减量20%,即纯氮168kghm^–2)、控失尿素与常规尿素配施(配比分别为7∶3、5∶5和3∶7)对夏玉米产量、地上部生物量、养分积累量、光合特性及氮肥利用效率的影响。结果表明,氮肥施用可显著提高夏玉米产量,常量控失尿素施用下夏玉米增产率达22.96%～27.55%,在高、中产田上产量较常规尿素有显著提升。与常量控失尿素相比,控失尿素减施10%和20%通过提升穗粒数使得高、中产田夏玉米产量不降低,控失尿素减施20%处理下高产田氮肥利用率高达41.60%。控失尿素与常规尿素7∶3配施下的氮素积累量与常量控失尿素处理无显著差异,高产田和中产田夏玉米产量、秸秆干物重均未显著降低,同时可显著提高低产田夏...

Reduced application and different combined applications of loss-control urea on summer maize yield and fertilizer efficiency improvement

Loss-control urea with nanometer mineral loss control agent added during production period could reduce the loss of nitrogen(N)through adsorption.Figuring out the application rate of loss-control urea and the appropriate rate with conventional urea could provide evidences for summer maize one-time fertilization,N fertilizer reduction,and use efficiency improvement.Under different yield level soil conditions,field experiment was arranged to investigate the effects of different N fertilizer man-agements on summer maize yield,aboveground biomass,nutrient accumulation,photosynthetic characteristic,and N utilization efficiency.Treatments of conventional urea(N at 210 kg hm^-2),loss-control urea(full dose with N at 210 kg hm^-2,10%reduction with N at 189 kg hm^-2,and 20%reduction with N at 168 kg hm^-2),and different combined proportions of loss-control urea and conventional urea(at 7:3,5:5,and 3:7)were carried out.The results revealed that N fertilizer application could significantly in-crease the yield of summer maize and the full-dose loss-control urea treatments increased the yield by 22.96%-27.55%,compared with that under conventional urea application at high-and middle-yield soil conditions.The application of loss-control urea at 10%and 20%reduction sustained the summer maize yield at high-and middle-yield soil condition with improved grains per ear,compared with full-dose loss-control urea application.The N fertilizer utilization efficiency under loss-control urea at 20%reduction treatment at high-yield soil condition reached 41.60%.N accumulation was comparable with full-dose loss-control urea ap-plication under proportions of loss-control urea and conventional urea at 7:3 application.Meanwhile,this treatment could sustain the yield and straw biomass at high-and middle-yield level soil and significantly increased the yield and straw biomass at low-yield field.In conclusion,one-time application of loss-control urea with N at 210 kg hm-2 could significantly improve the yield of summer maize and N efficiency of the fertilizer utilization.The application of loss-control urea with 20%reduction could sustain the summer maize yield with significantly improved N utilization efficiency at high-and middle-yield soil conditions,which was the suitable N fertilizer application for high-and middle-yield field.Loss-control urea and conventional urea at 7:3 application was suitable for N fertilizer application for low-yield field.