聚天门冬氨酸螯合氮肥减量基施对东北春玉米的增效机制

2016年和2017年在中国农业科学院作物科学研究所吉林公主岭试验站(43°29'55'N,124°48'43'E),以中单909为材料,设置常规氮素(CN)和PASP螯合氮素(PASP-N)的不同施肥量全基施处理,探讨东北春玉米PASP螯合氮素减量全基施的增效机制。结果表明,相比CN,PASP-N在总施氮量减少1/3的条件下,玉米增产0.9%～3.0%,穗长增加0.5%～2.9%,灌浆中期叶面积指数增大18.5%～22.3%,秃尖长降低13.8%～46.7%,株高及穗位高分别降低1.5%～2.5%和0.7%～8.4%。PASP-N处理下,花期玉米功能叶硝酸还原酶(NR)活性降低1.4%～19.8%,花后30 d穗位叶谷氨酰胺合成酶(GS)活性提高18.5%～33.1%,花后20 d穗位叶谷草转氨酶(GOT)活性增高0.8%～6.4%。多项式曲线模拟结果表明, PASP-N和CN处理全基施最佳氮用量分别为185.3 kg hm~(–2)和219.1 kg hm~(–2), PASP-N比CN少施氮肥33.8kg hm~(–2), PASP-N产量比CN高108.9 kg hm~(–2)。氮肥偏生产力、氮肥农学效率、氮肥表观利用率和氮肥生理效率分别比常规氮素处理增加51.3%～54.4%、2.9%～104.2%、28.9%～126.6%和48.0%～405.2%。因此, PASP螯合氮肥能促进东北春玉米籽粒灌浆中后期氮素代谢,提高玉米氮肥利用效率。

Increasing spring maize yield by basic application of PASP chelating nitrogen fertilizer in northeast China

The randomized block field experiments were conducted using maize variety of Zhongdan 909 with different nitrogen treatments of polyaspartic acid chelating nitrogen fertilizer (PASP-N) and commonly used nitrogen fertilizer (CN) in Gongzhuling Experimental Station (43o29°55°°N, 124o48°43°°E) in Jilin province in 2016 and 2017. The PASP-N increased maize yield, ear length and leaf area index (LAI) by 0.9%-3.0%, 0.5%-2.9%, and 18.5%-22.3% respectively, and decreased bare top length, plant height and ear height by 13.8%-46.7%, 1.5%-2.5%, and 0.7%-8.4%, respectively, compared with CN. Moreover, PASP-N significantly influenced activity of enzymes related to nitrogen metabolism: nitrate reductase (NR) activity decreased by 1.4%-19.8% at anthesis stage, glutamine synthetase (GS) activity increased by 18.5%-33.1% at 30 days after anthesis, and glutamic oxalacetic transaminase (GOT) activity increased by 0.8%-6.4% at 20 days after anthesis. The total nitrogen inputs of PASP-N and CN for the highest maize yield were 185.3 kg ha ^-1 and 219.1 kg ha ^-1, respectively, with 108.9 kg ha ^-1 higher in PASP-N treatment than in CN treatment. Nitrogen fertilizer partial productivity, agronomic efficiency, apparent utilization and physiological efficiency of nitrogen fertilizer in PASP-N treatment increased by 51.3%-54.4%, 2.9%-104.2%, 28.9%-126.6%, and 48.0%-405.2%, respectively, compared with these in CN treatments. In conclusion, PASP could enhance nitrogen metabolism during middle and late grain-filling stage, resulting in increased yield and nitrogen use efficiency in maize.