摘要
在玉米-大豆轮作系统中种植冬季覆盖作物黑麦有助于减小地下排水量和硝态氮(NO_3^--N)的流失量。该研究利用美国爱荷华州的试验数据校正和验证了DRAINMOD-N II模型在美国寒冷地区的适用性,并模拟长期(20 a)种植冬季覆盖作物黑麦对地下排水量和氮素运移的影响。结果表明,模型模拟地下排水量和NO_3^--N流失量时,Nash-Sutcliffe模型效率系数(Nash-Sutcliffe efficiency,NSE)>0.65、百分比偏差(percent bias,PBIAS)在±25%之间、均方根误差与标准差比值(ratio of root mean square error to standard deviation,RSR)≤0.7均在误差范围内;模拟地下排水中NO_3^--N浓度时,NSE>0.50、PBIAS在±15%之间、RSR≤0.5均在误差范围内,说明模型模拟的效果好。长期种植冬季覆盖作物黑麦可降低排水量8.1%(2.5 cm),减小NO_3^--N流失量16.6%(6 kg/hm^2),NO_3^--N流量加权平均浓度下降了8.6%(1 mg/L,以N计),增加蒸散值5.9%,模型模拟值与实测值拟合效果好,表明模型具有良好的水文和氮素运移模拟功能,可以模拟不同农田管理措施对地下水和氮素运移的长期影响,为优化农田管理措施提供参考。
Planting winter rye cover crop can reduce subsurface drainage and NO3-N loss in corn-soybean rotation. Field data from Iowa was used to calibrate DRAINMON-N II and evaluate its applicability in cold regions in US. This study simulated the long-term （20 years） effects of winter rye cover crop on subsurface drainage and nitrogen dynamics using DRAINMOD-N II. Two treatments were set in Agricultural Drainage Water Quality-Research and Demonstration Site in Iowa. One treatment was with rye planting in winter （rye-maize-rye-soybean rotation） and the other was bare in winter （only maize-soybean）. The experiments lasted for 5 years from 2005 to 2009. The drainage was collected and NO3--N content in the drainage was measured. The DRAINMON-N II model was used for simulation of change in the drainage and NO3--N content from 1990 to 2009. The results showed that the DRAINMON-N II model satisfactorily simulated subsurface drainage and NO3-N loss with Nash-Sutcliffe efficiency （NSE） larger than 0.65, percent bias （PBIAS） smaller than 25%, and ratio of root mean square error to standard deviation （RSR） not larger than 0.70. Flow-weighted average NO3-N concentration （FWANC） were simulated satisfactorily, with NSE larger than 0.50, PBIAS within 25%, and RSR not larger than 0.50. The errors between simulation and measurements of drainage and NO3-N loss mainly reflected in March when temperature was low （average monthly temperature was -4.1 ℃）, which may partially cause by drainage delay. Also the larger wind speed （4 m/s） which can take away 20% of snow could affect our estimates. These results suggested that DRA1NMOD-N II had good applicability in Iowa and could simulate the long-term effect of winter rye cover crop on subsurface drainage and NO3--N loss. Long-term simulations （1990-2009） indicated that adding winter rye cover crop could reduce drainage, NO3-N loss and FWANC by 8.1% （2.5 cm）, 16.6% （6 kg/hm2, by N） and 8.6% （I mg/L, by N）, respectively. The amount of drainage
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2017年第12期153-161,共9页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家高技术研究发展计划(863计划)(2013AA102904)
高等学校学科创新引智计划(111计划)资助项目(B12007)
Iowa Department of Agriculture and Land Stewardship
