Winter cover crop effects on nitrate leaching in subsurface drainage as simulated by RZWQM-DSSAT

CORC > 地理科学与资源研究所 > 中国科学院地理科学与资源研究所 > 历年回溯文献

	Winter cover crop effects on nitrate leaching in subsurface drainage as simulated by RZWQM-DSSAT
	Yu Q.; Ma L.; Ma L.
	2008
关键词	Concentration (process) Crops Cultivation Drainage Fertilizers Grain (agricultural product) Groundwater flow Leaching Magnesium printing plates Natural water geochemistry Nitrates Rotation Security of data Waste disposal Wast
英文摘要	Planting winter cover crops such as winter rye (Secale cereale L.) after corn and soybean harvest is one of the more promising practices to reduce nitrate loss to streams from tile drainage systems without negatively affecting production. Because availability of replicated tile-drained field data is limited and because use of cover crops to reduce nitrate loss has only been tested over a few years with limited environmental and management conditions, estimating the impacts of cover crops under the range of expected conditions is difficult. If properly tested against observed data, models can objectively estimate the relative effects of different weather conditions and agronomic practices (e.g., various N fertilizer application rates in conjunction with winter cover crops). In this study, an optimized winter wheat cover crop growth component was integrated into the calibrated RZWQM-DSSAT hybrid model, and then we compared the observed and simulated effects of a winter cover crop on nitrate leaching losses in subsurface drainage water for a corn-soybean rotation with N fertilizer application rates over 225 kg N ha^-1 in corn years. Annual observed and simulated flow-weighted average nitrate concentration (FWANC) in drainage from 2002 to 2005 for the cover crop treatments (CC) were 8.7 and 9.3 mg L^-1 compared to 21.3 and 18.2 mg L^-1 for no cover crop (CON). The resulting observed and simulated FWANC reductions due to CC were 59% and 49%. Simulations with the optimized model at various N fertilizer rates resulted in average annual drainage N loss differences between CC and CON increasing exponentially from 12 to 34 kg N ha^-1 for rates of 11 to 261 kg N ha^-1, but the percent difference remained relatively constant (65% to 70%). The results suggest that RZWQM-DSSAT is a promising tool to estimate the relative effects of a winter crop under different conditions on nitrate loss in tile drains, and that a winter cover crop can effectively reduce nitrate losses over a range of N fertilizer levels.
出处	Transactions of the ASABE
卷	51 期:5 页:1575-1583
收录类别	EI
语种	英语
内容类型	EI期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/24822]
专题	地理科学与资源研究所_历年回溯文献
推荐引用方式 GB/T 7714	Yu Q.,Ma L.,Ma L.. Winter cover crop effects on nitrate leaching in subsurface drainage as simulated by RZWQM-DSSAT. 2008.