Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Sci Total Environ. 2021 Nov 25;797:149038. doi: 10.1016/j.scitotenv.2021.149038. Epub 2021 Jul 14.
Nitrogen (N) application and salinity are key factors influencing crop yield and net economic benefit in coastal saline-alkali soils. Integrated analysis and optimization of the benefits of wheat-corn cropping under different nitrogen applications in saline soils could provide lay the scientific basis for sustainable development of agriculture in coastal farmlands. A total of 571 pair-reviewed literature data on two-factor cross-over trials, involving soil salinity and nitrogen application, were integratively analyzed. Based on multi-objective optimization of crop yield, agronomic and net economic benefits, and soil nitrate residue in coastal saline-alkali soils, area-specific nitrogen application strategies were developed. The results showed that increasing the N application rate under 1.8-2.9‰ salinity can increase crop yield and economic benefits. The net economic benefit of crops was negative under 3.5‰ salinity. Above that threshold of 3.5‰, it is not suitable for planting food crops. Consequently, it is necessary to strengthen the management of saline-alkali soils. While the application rate of 2.78 × 10 kg N in winter wheat/summer corn cropping ensured environmental protection, farmers preferred 3.08 × 10 kg of nitrogen dose. These were respectively 40.4% and 33.9% lower than the traditional dose and with relatively higher benefits too.
氮（N）的施加和盐度是影响沿海盐碱地作物产量和净经济效益的关键因素。综合分析盐碱地不同施氮量下小麦-玉米轮作的效益，可以为沿海农田农业的可持续发展提供科学依据。对涉及土壤盐分和氮施用量的 571 对双因素交叉试验的文献数据进行了综合分析。基于多目标优化作物产量、农学和净经济效益以及土壤硝酸盐残留，制定了适用于特定区域的氮施用量策略。结果表明，在 1.8-2.9‰盐度下增加氮施用量可以提高作物产量和经济效益。在 3.5‰盐度下，作物的净经济效益为负。超过 3.5‰的阈值，不适合种植粮食作物。因此，有必要加强对盐碱地的管理。在冬小麦/夏玉米轮作中，2.78×10kg N 的施用量既保证了环境保护，又符合农民的喜好。与传统施肥量相比，这分别降低了 40.4%和 33.9%，且具有相对更高的效益。
