摘要
应用DNDC模型（denitrification-decomposition model）对黄淮海平原的典型平原小流域——天然文岩渠流域的土壤水分渗漏和氮素淋失状况进行了模拟.水氮控制田间试验的验证结果表明,模型对1 m土体日储水量、下界面硝态氮浓度、土壤水日渗漏量和氮素日淋失量的模拟均较理想,模拟值与实测值的相关系数分别达到了0.94（n=40）、0.66（n=49）、0.89（n=40）和0.94（n=39）,均方根误差则分别为15.66 mm、2.66 mg.kg-1、9.00 mm和0.94 kg.hm-2.模型在流域范围的模拟结果表明,冬小麦-夏玉米轮作农田在多年平均气象条件和常用水肥管理模式下,土壤的水分年渗漏量在220～327 mm之间,氮素年淋失量在73.1～100.6 kg.hm-2之间.水氮淋失的空间和时间分布不均,淋失最严重的区域为固定细风沙土、砂土分布区,淋失时间主要集中于施肥、灌溉或强降雨之后.灌溉措施不当,施肥盲目以及土壤自身保水保肥能力差,是导致土壤水肥流失的主要原因.
Soil water drainage and nitrogen leaching in Tianranwenyanqu Basin was simulated using DNDC model. The model was validated by data of the water and nitrogen controlling experiment in the basin. The correlation coefficients between simulated and measured values of daily 1 m soil water storage, lower boundary NO3- -N concentration, soil water drainage and nitrogen leaching were 0.94 （ n = 40）, 0.66 （ n = 49）, 0.89（ n = 40）, 0.94（ n = 39） ; and RMSEs were 15.66 mm,2.66 mg·kg-1 ,9.00 mm,0.94 kg·hm-2 ,respectively. The validated model was then used to simulate soil water drainage and nitrogen leaching in the basin. The results show that, under mnlti-year average climate and conventional management condition, annual soil water drainage and nitrogen leaching of winter-wheat and summer-corn rotation fields in this basin were 220-327 mm and 73.1-100.6 kg· hm-2, respectively. The distribution of water drainage and nitrogen leaching were uneven in time and space, leaching happened mainly after fertilization, irrigation or heavy rainfall, and sandy soil regions were the most serious nitrogen leaching area. Unreasonable irrigation, fertilization and poor water and fertilizer preserving capability of the soils, were the major causes of soil water drainage and nitrogen leaching.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第3期864-869,共6页
Environmental Science
基金
国家重点基础研究发展规划(973)项目(2005CB121100)
国家科技支撑计划项目(2006BAD10A06-03)
中国科学院知识创新工程重要方向项目(KZCX2-YW-406)
