摘要:氮淋溶是氮素损失的主要途径之一, 土壤硝态氮通过淋溶进入水体会造成人体中毒和水体富营养化, 对人体健康和生态环境产生严重危害。为探明我国冬小麦-夏玉米轮作体系化肥施氮量、作物种类和监测方法等因素对硝态氮淋溶量的影响, 利用中国知网期刊全文数据库(CNKI)和Web of Science核心合集英文数据库(WoS), 收集1980—2020年冬小麦-夏玉米轮作体系硝态氮淋溶领域的相关文献, 采用回归方程和T检验等统计学方法分析不同施氮水平、作物种类和监测方法对冬小麦-夏玉米轮作体系硝态氮淋溶的影响。结果表明, 随着化肥施氮量的增加, 小麦季和玉米季硝态氮淋溶量均呈指数增长趋势。小麦季和玉米季平均施氮量差异不显著, 但小麦季硝态氮淋溶量和淋溶率显著低于玉米季(P<0.01)。在施氮量接近的条件下, 采用渗漏计法和溶液提取器法测得的硝态氮淋溶量和淋溶率没有显著差异, 两种方法均可作为监测硝态氮淋溶的可靠方法在田间应用。回归方程对施氮量和硝态氮淋溶量的拟合在施氮量低于300 kg?hm?2时较好, 随着施氮量的增加拟合精确度降低。玉米季硝态氮淋溶风险大于小麦季, 冬小麦-夏玉米轮作体系中玉米季的硝态氮淋溶现象需要引起重视。
关键词:冬小麦-夏玉米轮作/
硝态氮淋溶/
施氮量/
渗漏计/
溶液提取器
Abstract:Nitrogen (N) leaching is one of the main routes of N loss in farmlands. The entry of nitrate N into water can cause human poisoning and water eutrophication, resulting in serious damage to human health and ecological environments. This study was carried out to explore the effects of different N fertilization rates, crop types, and monitoring methods on nitrate N leaching in the winter wheat and summer maize rotation system, which is the main cropping system used in China. To this end, the China National Knowledge Infrastructure (CNKI) database and Web of Science (WoS) Core Collection database were used to collect publications on nitrate N leaching in winter wheat and summer maize rotation systems from 1980 to 2020. Data from these papers on the effects of N application rates, crop types, and monitoring methods on nitrate N leaching from winter wheat and summer maize rotation systems were then analyzed using regression and T tests. It was found that an increase in the N fertilization rate exponentially increased the nitrate N leaching amount in this cropping system. The fitted equations for the relationship between nitrate N leaching amount and N fertilization rate in the winter wheat and summer maize seasons were y = 0.4633e0.0109x and y = 1.1011e0.0103x, respectively. Although there was no significant difference between the N fertilization rates in the winter wheat (218 kg?hm?2) and summer maize seasons (190 kg?hm?2), the nitrate N leaching amount (8.8 kg?hm?2) and rate (3.5%) in the winter wheat season was lower than those (amount: 13.9 kg?hm?2; rate: 6.4%) in the summer maize season. In both the winter wheat and summer maize seasons, there was a significant exponential correlation between the N fertilization rate and nitrate N leaching amount, as measured using two different methods — lysimeter and solution collection, resulted in fitted equations of y = 0.2448e0.0143x and y = 0.6108e0.0098x in the winter wheat season, respectively, and y = 1.0284e0.0102x and y = 0.972e0.011x in the summer maize season, respectively. Thus, both methods can be used to measure nitrate N leaching reliably. The fitting accuracy of the regression equation for the N application rate and nitrate N leaching amount was better when the N application rate was less than 300 kg?hm?2, but the accuracy decreased with a further increase in the N application rate. In conclusion, because more nitrate N leaching occurs in the summer maize season than in the winter wheat season, the leaching problem in the summer maize season necessitates greater attention.
Key words:Winter wheat-summer maize rotation/
Nitrate nitrogen leaching/
Nitrogen fertilization rate/
Lysimete/
Solution collection
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