Study on soil nitrogen balance of spring maize continuous cropping in semi-arid area of Jilin Province | 吉林省半干旱地区春玉米连作体系氮素平衡研究

Chinese. 为吉林省半干旱地区春玉米科学施用氮肥提供指导。2004~2005年，在吉林省西部半干旱地区进行2年田间试验，研究不同施肥方式（推荐施肥、农民习惯施肥、一次性施肥）对玉米产量、吸氮量及氮素效率的影响，同时对该地区土壤氮素平衡与运转情况进行评价。一次性施肥处理受年际间降雨量影响较大，易产生后期植株脱氮现象，玉米产量及氮肥利用率年际间不稳定；农民习惯施肥处理基肥施用量过高，造成氮肥表观利用率降低；一次性施肥处理和农民习惯施肥处理下，氮肥表观残留率较高，达到了50%左右；这2种施肥方式下，0~90 cm土层土壤残留Nmin分别为201和278 kg/hm2，会对地下水体产生潜在威胁。推荐施肥处理下，玉米产量、生物量和吸氮量均较稳定，同时氮素利用率（REN）、氮素生理利用率（PEN）、氮素农学利用率（AEN）、氮素偏生产力（PFPN）均较高；在两季玉米连作后，0~90 cm土层土壤残留硝态氮为128.5 kg/hm2，可以在环境友好的前提下获得较高的产量。在吉林省西部半干旱地区，一次性施肥与农民习惯施肥会导致土壤中无机氮高残留，使氮素损失增加，对该地区的生态环境造成一定威胁，而推荐施肥是较合理的施肥方式。

English. The study was done to guide nirtogen fertilization of spring maize in semi-arid area of west of Jilin Province. Two-year field experiments in semi-arid area of west of Jilin province were carried out to study the effect of different fertilization modes on maize yield, nitrogen uptake and nitrogen efficiency. Meanwhile the soil nirtogen balance and translocation were also evaluated. The results showed that single-dose application was influenced by annual rainfall amount, and the denitrification was subject to appear, yield and nitrogen efficiency were unstable. The basal fertilizer of traditional application was too high, which caused apparent decline of nitrogen utilization. The apparent residual rates of nitrogen fertilizer were up to 50 percents with single dose application and traditional application. The residual nitrogen in soil layer from surface to 90 cm were 201 kg/hm2 and 278 kg/hm2, which was a potential threat to the safety of ground water. The yield biomass and nitrogen uptake were stable with fertilizer recommendation treatment and nitrogen apparent recovery efficiency (REN), Physiological Use Efficiency (PEN), agronomic efficiency (AEN) and partial factor productivity (PFPN) were all high. After continuous double cropping, residual nitrogen in soil layer from surface to 90 cm was 128.5 kg/hm2, and a higher yield can be obtained under the condition of environmental-friendly. Single-dose and traditional application result in high residual nitrogen in soil layer and increase nitrogen loss. Fertilizer recommendation is reasonable.