Estimation of nitrogen runoff loss from croplands in the Yangtze River Basin: A meta-analysis
Estimation of nitrogen runoff loss from croplands in the Yangtze River Basin: A meta-analysis
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长江流域农田氮径流损失估算的荟萃分析
DOI：
10.1016/j.envpol.2020.116001
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发表时间：
2021
影响因子：
8.9
通讯作者：
Dingjiang Chen
中科院分区：
文献类型：
--
作者：
Yufu Zhang;Hao Wu;Mengya Yao;Jia Zhou;Kaibin Wu;Minpeng Hu;Hong Shen;Dingjiang Chen
农田氮素径流损失是造成全球非点源水污染的主要原因之一。区域尺度农田氮素径流损失的定量知识对于制定可持续的农业氮素管理和有效的水氮污染控制战略至关重要。这一荟萃分析量化了氮素径流损失率，并确定了调节长江流域旱地(n=1570)和水田(n=434)氮素径流损失的主要因素。结果表明，旱地和水田的总N(TN)径流损失率从上游向下游持续增加。径流深度、土壤氮素含量和施肥量(化肥+有机肥)是调节旱地TN径流损失变异的主要因素，而稻田径流深度和施肥量是影响TN径流损失的主要因素。综合了这些影响因素的多元回归模型有效地预测了旱地(校正：R2=0.60，n=0.242；验证：R2=0.55，n=104.)和水田(校正：R2=0.70，n=1189；验证：R2=0.85，n=0.82)的TN径流损失率。模型估算出2017年长三角地区农田全氮径流损失负荷为0.54(95%氯：0.23-1.33)tg，旱地为0.30(95%氯：0.15-0.56)tg，水田为0.24(95%氯：0.08-0.77)tg。广西、江西、福建、湖南、河南被确定为长江流域内农田全氮径流损失热点。模型预测，在5种情景下，万家寨农田的TN径流损失负荷将减少0.8-13.7%，径流量减少的情景TN负荷减少幅度更大。减少旱地氮素径流流失应主要集中在土壤氮素利用和径流管理上，而减少氮肥用量和径流是水田最敏感的策略。要有效减少农田氮素径流损失，必须实行水、土、肥一体化管理。
Nitrogen (N) runoff loss from croplands due to excessive anthropogenic N additions is a principal cause of non-point source water pollution worldwide. Quantitative knowledge of regional-scale N runoff loss from croplands is essential for developing sustainable agricultural N management and efficient water N pollution control strategies. This meta-analysis quantifies N runoff loss rates and identifies the primary factors regulating N runoff loss from uplands (n = 570) and paddy (n = 434) fields in the Yangtze River Basin (YRB). Results indicated that total N (TN) runoff loss rates from uplands and paddy fields consistently increased from upstream to downstream regions. Runoff depth, soil N content and fertilizer addition rate (chemical fertilizer + manure) were the major factors regulating variability of TN runoff loss from uplands, while runoff depth and fertilizer addition rate were the main controls for paddy fields. Multiple regression models incorporating these influencing factors effectively predicted TN runoff loss rates from uplands (calibration: R2= 0.60, n = 242; validation: R2= 0.55, n = 104) and paddy fields (calibration: R2= 0.70, n = 189; validation: R2= 0.85, n = 82). Models estimated total cropland TN runoff loss load in YRB of 0.54 (95% Cl: 0.23–1.33) Tg, with 0.30 (95% Cl: 0.15–0.56) Tg from uplands and 0.24 (95% Cl: 0.08–0.77) Tg from paddy fields in 2017. Guangxi, Jiangxi, Fujian, Hunan and Henan provinces within the YRB were identified as cropland TN runoff loss hotspots. Models predicted that TN runoff loss loads from croplands in YRB would decrease by 0.8–13.7% for five scenarios, with higher TN load reductions occurring from scenarios with decreased runoff amounts. Reducing upland TN runoff loss should focus primarily on soil N utilization and runoff management, while reducing N fertilizer addition and runoff provided the most sensitive strategies for paddy fields. Integrated management of water, soil and fertilizer is required to effectively reduce cropland N runoff loss.