尿素配施添加剂NAM对三江平原白浆土氮素转化和玉米产量的影响

通过田间小区试验,研究了尿素配施肥料添加剂NAM(由脲酶抑制剂和硝化抑制剂等成分组成)对三江平原白浆土氮素转化、玉米产量以及氮肥利用率的影响,以期为肥料添加剂NAM的进一步推广应用提供理论依据。研究结果表明,与常规施氮处理相比,等氮量配施NAM处理使土壤NH4+-N在较长时间内维持较高的水平,并显著提高了作物后期的土壤总有效氮供应水平,从而使作物吸氮量增加了6.8%,增产3.1%;减氮20%配施NAM处理维持了土壤NH4+-N总体供应水平和作物后期的土壤总有效氮供应,从而使作物吸氮量及产量与常规施氮处理保持相当;减氮40%配施NAM处理由于过多降低了施氮水平,致使在作物生长前期土壤供氮量明显不足,进而降低了作物吸氮量及产量。尿素配施NAM较单施尿素提高氮肥利用率4.9～8.0个百分点。在等氮和适当减氮条件下,肥料添加剂NAM适用于三江平原白浆土-玉米体系,有利于农业可持续发展。

Soil nitrogen transformation and corn yield as affected by combination of urea and fertilizer additive NAM in Sanjiang Plain of China

NAM is a kind of fertilizer additive made of the urease inhibitor,nitrification inhibitor and other components.This paper reported the effects of urea combined with NAM on soil nitrogen(N)transformation and corn yield and fertilizer N use efficiency in Sanjiang Plain of China.Compared with the N1 treatment,the N1+NAM treatment significantly increased soil NH+4-N content across the corn growing season and total available N content at the corn later season,and thus elevated corn N uptake(6.8%)and grain yield(3.1%);the 80%N1+NAM treatment remained constant soil NH+4-N content across the season and total available N content at the later season,and therefore resulted in unchanged corn N uptake and grain yield;The 60%N1+NAM treatment caused the significant decline of soil N supply especially at the earlier season due to the over reduction of urea rate,and in turn decreased N uptake by corn and grain yield.Urea N recovery rate was significantly enhanced by 4.9 to 8.0 percentage point under the combination of urea and NAM than the urea alone.Our findings indicated that NAM application was an effective option for promoting agricultural sustainability in corn systems of Sanjiang Plain of China.