玉米对尿素减量与复合氮肥增效剂配施的响应

RESPONSE OF MAIZE TO REDUCED UREA APPLICATION COMBINED WITH COMPOUND NITROGEN FERTILIZER SYNERGISTS

用^15N-尿素进行盆栽和田间试验（盆栽试验尿素标准用量为120mg／盆，田间试验尿素标准用量为157．5kg／hm^2），研究了复合氮肥增效剂用量、尿素减量与复合氮肥增效剂配施对玉米生长、籽粒产量和氮素吸收利用的影响。结果表明。适量（施氮量的20％～60％）的复合氮肥增效剂能显著促进玉米幼苗生长发育。氮素减量5％～15％时配施复合氮肥增效剂对玉米生长和含氮量影响不显著，^15N和吸氮总量与不施增效剂的处理相当或有所提高。除尿素减量30％处理外，其余各尿素减量配施复合氮肥增效剂的处理，玉米氮素利用率比不施增效剂的处理提高5．6％～7．3％，尿素减量5％～50％配施复合氮肥增效剂，玉米氮素表观利用率提高7．7％～17．0％。在大田条件下，尿素氮减少5％～15％（即减少施氮7．8～23．7kg／hm^2）配施复合氮肥增效剂不影响玉米的单季产量，玉米植株吸氮总量、氮素净吸收量、氮肥生理效率和农学效率与不施增效剂的处理相当或增加，氮素表现利用率提高14.8％～15．2％。尿素减量达30％时，配施复合氮肥增效剂对玉米植株生长和氮素吸收利用明显不利。尿素与20％施氮量的复合氮肥增效剂配施，不影响玉米植株生长和单季产量，能提高玉米氮素利用率，节省氮肥投入达15％。

Pot and field experiments were conducted to study the response to application rate of urea labeled with ^15 N combined with compound nitrogen fertilizer synergists in the growth, yield, uptake and utilization rate of urea of maize, In pot experiment, the standard urea application rate is 120mg/perpot; in field experiment, the standard urea application rate is 157.5kg/hm^2. Maize with ^15 N-lurea. The results showed that the growth of maize seedling was obviously promoted with appropriate dosage of compound nitrogen fertilizer synergists （20% ～ 60% of N）. The teatments of urea application rate reduced by 5% - 15% and added compound nitrogen fertilizer synergists, the growth and nitrogen content of maize were not significat changed, and the total ^15N uptake and nitrogen uptake by maize were the same as CK2 or increased a little. Nitrogen use efficiency of other treatments increased by 5.6 % - 7.3 % comparing with CK, except the treatment of urea application rate reduced by 30%. The apparent utilization rate of nitrogen was enhanced by 7.7% - 17.0%. Under the field condition, maize yield, total uptake, net uptake, physiological rate and agronomic use efficiency of nitrogen were the same as CK or increased. The apparent utilization rate of nitrogen was enhanced by 14.8% - 15.2% treated with urea reduced by 5% - 15%（7.8 ～23.7kg/hm^2） and added with compound nitrogen fertilizer synergists, it was not helpful for the growth and nitrogen utilization rate of maize when urea reduced by 30 % and combined with compound nitrogen fertilizer synergists. As a result, treated with urea decreased by 15 % and combined with appropriate dosage of compound nitrogen fertilizer synergists （20% of urea）, the growth and yield of maize had litter effect and higher the uptake and utilization of nitrogen.