摘要:控释与稳定尿素配施，可通过双重调控作用增强对氮素的高效管理。本文以聚氨酯包膜控释尿素和新型复合型抑制剂涂覆尿素为试材，研究了二者配施条件下，调控冬小麦-夏玉米季施肥后氮素的动态迁移转化的效果，为开发高效专用肥和农业面源污染治理提供新的思路和技术手段。试验设置不施氮肥（CK）、农民习惯施用尿素[CV，冬小麦和夏玉米习惯施氮量分别为285 kg（N）·hm-2和225 kg（N）·hm-2]、优化施用尿素（OPT，冬小麦和夏玉米优化施氮量分别为199.50 kg（N）·hm-2和157.50 kg（N）·hm-2）、优化施氮量下控释尿素+普通尿素（CRF1，冬小麦和夏玉米控释氮分别占40%和30%）和2个优化施氮量下控释尿素+抑制剂涂覆尿素（CRF2，冬小麦季和夏玉米季控释氮分别占30%和20%；CRF3，冬小麦季和夏玉米季控释氮分别占50%和30%）。试验测定了氨挥发和土壤硝态氮及作物产量。结果表明：在同等施氮量条件下，与OPT相比，CRF1、CRF2和CRF3在夏玉米、冬小麦季分别显著降低累积氨挥发量24.90%~57.00%和10.20%~27.80%，CRF2、CRF3比CRF1分别显著降低33.30%~42.80%和12.20%~19.60%。施肥后土壤表层硝态氮含量升高和降低速率由快至慢依次为CV、OPT、CRF1、CRF2和CRF3。夏玉米收获期土壤剖面残留硝态氮淋失风险由大到小依次是CV、OPT、CRF1、CRF2和CRF3，而冬小麦则为CV、OPT、CRF2、CRF1和CRF3。与CV和OPT处理相比，一次性优化施氮CRF1、CRF2和CRF3处理冬小麦、夏玉米产量没有显著差异。CRF2和CRF3净收入与其他施氮处理相比略有增加，与CRF1相比在夏玉米季增加639元·hm-2和859元·hm-2，在冬小麦季降低1 196元·hm-2和增加61元·hm-2。控释氮和稳定氮为5：5（冬小麦）和3：7（夏玉米）表现效果最佳。
关键词:复合抑制剂/
涂覆工艺/
控释尿素/
氨挥发/
淋溶/
冬小麦-夏玉米/
产量
Abstract:The combined application of controlled-release and stable urea can enhance the efficiency of nitrogen management. In the present study, a combination of polyurethane-coated controlled-release urea and inhibitor-coated urea were used to study the effect of nitrogen transformation in winter wheat and summer maize. The results will provide new ideas and technical means for the development of high-efficiency fertilizer and limited non-point source pollution. The study included six treatments: no nitrogen application (control), traditional nitrogen application [CV, 285 and 225 kg(N)·hm-2 in wheat and maize, respectively], optimized nitrogen application [OPT, 199.50 and 157.50 kg(N)·hm-2 in wheat and maize, respectively], controlled-release urea + traditional urea application (CRF1, 40% and 30% controlled released nitrogen for wheat and maize, respectively), controlled-release urea + inhibitor-coated urea (CRF2, 30% and 20% controlled released nitrogen for wheat and maize, respectively), and controlled-release urea + inhibitor-coated urea (CRF3, 50% and 30% controlled released nitrogen for wheat and maize, respectively). CRF1, CRF2 and CRF3 were all the optimized nitrogen application, which significantly reduced cumulative ammonia volatilization during the summer maize and winter wheat seasons by 24.90%-57.00% and 10.20%-27.80%, respectively, compared with OPT treatment. At the same nitrogen application rate, the cumulative ammonia volatilization of CRF2 and CRF3 treatments were significantly lower than that of CRF1 treatment by 33.30%-42.80% and 12.20%-19.60% during the summer maize and winter wheat seasons, respectively. After fertilization, the rate of soil nitrate increase or decrease was greatest in CV treatment, followed by OPT, CRF1, CRF2, and CRF3 treatments. During the summer maize harvest period, the risk of residual nitrate leaching was highest in CV treatment, followed by OPT, CRF1, CRF2, and CRF3 treatments; whereas during the winter wheat season, leaching rate decreased as follows: CV, OPT, CRF2, CRF1, and CRF3. The yields of both winter wheat and summer maize under CRF1, CRF2, or CRF3 treatments were not significantly different from those of CV or OPT treatments. However, the net incomes of CRF2 and CRF3 treatments were 639 ￥·hm-2 and 859 ￥·hm-2 greater than that of CRF1 treatment during the summer maize season, whereas they were 1 196 ￥·hm-2 less and 61 ￥·hm-2 greater than that of CRF1 treatment during the winter wheat season. The favorable ratios of controlled-release nitrogen to stable nitrogen were 5:5 and 3:7 for winter wheat and summer maize, respectively, in the study area.
Key words:Composite inhibitor/
Coating process/
Controlled release urea/
Ammonia volatilization/
Leaching/
Winter wheat-summer maize/
Yield
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