摘要
本文以位于华北平原的河北省农林科学院大河试验站冬小麦-夏玉米轮作系统为研究对象,应用RZWQM(Root Zone Water Quality Model)模型对华北地区2010年冬小麦-夏玉米的1个轮作周期内土壤剖面水分和剖面硝态氮累积、作物产量、硝态氮淋失以及氨挥发进行模型模拟。本文利用并通过RZWQM模型在不同梯度施肥情况下讨论了施肥量对小麦-玉米轮作体系中硝态氮淋溶和氨挥发特性,并尝试通过拟合出的回归曲线来确定施氮量和硝态氮淋失和氨挥发之间的关系。设置冬小麦-夏玉米轮作周期施纯氮量分别为575 kg-hm-2(N3)、400 kg-hm-2(N2)、215 kg-hm-2(N1)和0 kg-hm-2(N0)4个处理,应用轮作周期中玉米数据进行模型参数率定,应用小麦进行模型参数的验证。结果表明:模型的玉米率定以及小麦验证的过程中结果偏差均在可接受范围内,剖面水分率定均方误差(RMSE)最高为0.019 cm3-cm-3,平均相对误差(MRE)最高为15.98%;剖面硝态氮累积验证结果 RMSE平均值为4.580 mg-kg-1,MRE平均值为52.63%。在模型验证的小麦-玉米季土壤基础上,硝态氮淋溶和氮挥发都与施氮量呈一定线性相关关系。综上结论,本试验结果能较好地模拟华北地区土壤剖面水分、硝态氮积累,以及施氮量对土壤硝态氮淋失和氨挥发的影响,为预测和估算土壤适宜施氮量提供了便捷可靠的方法。但RZWQM模型验证参数过程还需要进一步的校正与完善。
Rational management measures involving crop selection, tillage, crop rotation, fertilization, etc. are important for prevention of contamination and protection of soil and water resources. A number of field studies conducted under subsurface drainage conditions with various management practices have focused on reducing N loss through runoff. Also several models have been developed to evaluate the effects of the management measures on N loss through runoff. Models such as SWAT, DNDC and RZWQM were developed to simulate physical, chemical and biological responses of root-zone soil system to various agricultural management practices. Most of these models have been extensively tested under various soil, climate and agricultural management conditions. They have been used to assess the effects of agricultural practices on crop production or crop rotation systems and the related water and nitrate transport processes. In this study, the Root Zone Water Quality Model（RZWQM） was used to simulate water and nitrate nitrogen accumulations in the soil profile, nitrate nitrogen leaching and ammonia volatilization and yield of winter wheat/summer maize rotation systems in the North China Plain. The objective of the study was to explore the feasibility of predicting optimum nitrogen fertilization process using the RZWQM. A rotation trial of winter wheat and summer maize was conducted on Dahe Experiment Station of Hebei Academy of Agricultural and Forestry Sciences. Four nitrogen fertilizer rates [575 kg·hm^-2（N3）, 400 kg·hm^-2（N2）, 215 kg·hm^-2（N1）, and 0 kg·hm^-2（N0）] were set for the winter wheat/summer maize rotation system. While data for maize was used to calibrate the RZWQM, data for wheat was used to validate the model. The results showed the deviations in the model calibration and validation were acceptable. The Root Mean Square Error（RMSE） of soil water content was as low as 0.019 cm^3·cm^-3 and the Mean Relative Error（MRE） was 15.98%. RMSE and MRE for accumulated soil nitrate were 4.580 mg·kg^-1 and 52.63%, respectively. There were significant linear correlations between nitrogen use and nitrate leaching as well as ammonia volatilization in winter wheat/summer maize rotation systems. In summary, the RZWQM effectively simulated the transport processes of water and nitrogen in the soil profile in the North China Plain. Thus the study provided a convenient and reliable method of prediction and estimation of transport processes of water and fertilizer in root-zone soil. Irrespectively, there was the need for further research on extended RZWQM model application and robust calibration of critical parameters to increase the model simulation efficiency.
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2015年第2期150-158,共9页
Chinese Journal of Eco-Agriculture
基金
公益性行业(环保)科技项目(201309035-1)
"十二五"国家科技支撑计划课题(2012BAD15B02)资助
