控释掺混肥对麦玉轮作体系农田温室气体排放和硝态氮残留的影响

    Effects of controlled-release blended fertilizers on greenhouse gas emissions and nitrate residue in wheat-maize rotation system

    • 摘要: 为阐明控释肥对冬小麦-夏玉米轮作体系作物产量、温室气体排放和硝态氮残留的影响,该研究以郑单958(夏玉米)和济麦22(冬小麦)为供试材料,设不施氮对照(CK)、常规施氮(FFP)、优化施氮(OPT)、含30%控释尿素的控释掺混肥(夏玉米)和含50%控释尿素的控释掺混肥(冬小麦)(CRBF1)、含50%控释尿素的控释掺混肥(夏玉米)和含70%控释尿素的控释掺混肥(冬小麦)(CRBF2)共5个处理,对比分析了不同处理的冬小麦、夏玉米及周年产量、温室气体排放和土壤硝态氮残留的差异。结果表明,施氮可显著提高麦玉轮作系统单季和周年作物产量(P<0.05)。与FFP相比,CRBF1和CRBF2处理的夏玉米、冬小麦和周年产量分别提高了1.4%~3.0%、1.9%~3.4%和1.6%~3.1%(P>0.05)。施氮显著增加了麦玉轮作体系的土壤N2O和CO2的周年排放(P<0.05)。CRBF1和CRBF2处理的土壤N2O周年排放总量较FFP处理显著降低了27.7%~34.6%(P <0.05)。施氮显著增加了麦玉轮作体系的周年全球增温潜势(GWP)(P<0.05)。CRBF1和CRBF2处理的周年GWP较FFP处理降低了4.2%和5.7%,其中CRBF2处理差异显著(P<0.05)。施氮降低了麦玉轮作体系的周年温室气体排放强度(GHGI)。CRBF1和CRBF2处理的周年GHGI较FFP处理降低了5.6%~8.6%(P>0.05)。与FFP相比,CRBF1和CRBF2处理的100~200 cm土层硝态氮残留降低30.6%~34.3%(P<0.05),减少了硝态氮淋失风险。综上所述,控释掺混肥在稳定作物产量、减少温室气体排放和土壤硝态氮残留方面具有积极作用,研究结果可为麦玉轮作体系的轻简高效氮肥管理提供数据支持和理论支撑。

       

      Abstract: Ever-increasing nitrogen fertilizers have posed extreme pressure on the environment for the winter wheat-summer maize rotation system in the North China Plain. Controlled-release fertilizer can be expected to serve as the nutrient-efficient and environment-friendly approach. The available nutrients are applied at controlled rates or concentration levels required for the crop growth in the soil while maintaining the nutrients for a longer period. The controlled-release fertilizers can be considered as an effective measure to improve crop yield and nitrogen use efficiency. This study aims to explore the impacts of one-time fertilization of controlled-release blended fertilizer on the crop yield, greenhouse gas emissions (GHGs) and nitrate residues in the winter wheat-summer maize rotation system. A field experiment was conducted with the summer maize cultivar of Zhengdan 958 and the winter wheat cultivar of Jimai 22. Five treatments were performed on both winter wheat and summer maize, including no nitrogen control (CK), farmers' conventional nitrogen application (FFP), optimized nitrogen application (OPT), CRU1 (the blending ratios of coated urea and traditional urea on winter wheat and summer maize were 5:5 and 3:7, respectively), and CRU2 (the blending ratios of coated urea and traditional urea on winter wheat and summer maize were 7:3 and 5:5, respectively). A comparison was then made on the yield, GHGs, and soil nitrate nitrogen residues among different treatments. The results showed that the nitrogen application significantly improved the single-season and annual crop yield in the wheat-maize rotation system (P<0.05). CRU1 and CRU2 treatments increased the summer maize, winter wheat, and annual yields by 1.4%-3.0%, 1.9%-3.4%, and 1.6%-3.1%, respectively (P>0.05), compared with FFP. Nitrogen application also significantly increased the annual emissions of soil N2O and CO2 in the wheat-maize rotation system (P<0.05). The annual accumulation of N2O emissions from soil treated with CRBF1 and CRBF2 was significantly reduced by 27.7%-34.6%, compared with FFP treatment (P<0.05). The nitrogen also increased the annual global warming potential (GWP) of the wheat-maize rotation system (P<0.05). The annual GWP of CRBF1 and CRBF2 treatments decreased by 4.2% and 5.7%, respectively, compared with FFP treatment. There was a significant difference in the CRBF2 treatment (P<0.05). The application of nitrogen reduced the annual greenhouse gas emission intensity (GHGI) of the wheat-maize rotation system. The annual GHGI of CRBF1and CRBF2 treatments decreased by 5.6% to 8.6%, respectively, compared with FFP treatments (P>0.05). CRBF1 and CRBF2 treatments were also reduced by 30.6%-34.3% (P<0.05) for the nitrate nitrogen residues in the 100-200 cm soil layer, indicating the lower risk of nitrate nitrogen leaching. In summary, the controlled-release blended fertilizer can be expected to reduce the GHGs and soil nitrate nitrogen residues for the high crop yield. The finding can provide the data and theoretical support for the highly efficient application of nitrogen fertilizer in the winter wheat-summer maize rotation system.

       

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