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首页> 外文期刊>Transactions of the ASABE >Modeling nutrient runoff yields from combined in-field crop management practices using SWAT. (Special Issue: Soil and water assessment tool (SWAT) modeling technology: current status.)
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Modeling nutrient runoff yields from combined in-field crop management practices using SWAT. (Special Issue: Soil and water assessment tool (SWAT) modeling technology: current status.)

机译：使用SWAT对结合的田间作物管理实践的营养径流产量进行建模。 （特刊：水土评估工具（SWAT）建模技术：当前状态。）

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摘要

Cropland best management practice recommendations often combine tillage and nutrient application improvements to reduce nutrient losses with surface runoff. This study used the Soil and Water Assessment Tool (SWAT) model to evaluate nutrient runoff yields from conventional-till and no-till management practices with surface and deep-banded fertilizer application in a sorghum-soybean rotation. The model was calibrated for three field plots (0.39 to 1.46 ha) with different combinations of practices and validated for three field plots (0.40 to 0.56 ha) during 2001 to 2004. Daily performance of the calibrated SWAT model in simulating total N for all treatments was satisfactory for median-based Nash-Sutcliffe model efficiency (Ef* of 0.54 to 0.64), good to very good for percent bias (PBIAS of 31% to 7%), and satisfactory to good for median-based root mean square error to observations standard deviation ratio (RSR* of 0.72 to 0.62). Performance was slightly lower and more variable for total P calibration (Ef* of 0.42 to 0.62, PBIAS of -48% to 2%, and RSR* of 0.76 to 0.62). Monthly statistics improved for total P runoff yield compared to daily performance, but changed little for total N runoff yields, probably due to the stronger influence of outliers in the N data. Based on validation results, SWAT was more robust in simulating total N runoff yields from the treatment with less soil disturbance (NT/SB) and total P for the two treatments with more soil disturbance (NT/DB and TILL). A major concern was that SWAT predicted greater annual average total N runoff yields for no-till treatments than for tilled treatments, which was contrary to measured values at the study site. This reinforces a fundamental research issue that tillage system effects on nutrient losses are still very much uncertain and thus may not be properly modeled. The SWAT model generally underpredicted monthly total N yields for all treatments in the higher-precipitation months of May and June and overpredicted total N and total P yields from September through November. Calibration for N and P resulted in identical calibration parameters for NPERCO (1.0), RSDCO (0.05), BIOMIX (0.2), PPERCO (10), PHOSKD (175), and UBP (50) regardless of tillage practice or fertilizer application method. Together with results that calibrated parameters for runoff (CN, Ksat, AWC) and erosion (Cmin) differed among the treatments, this study found that differences in nutrient yields among tillage and fertilizer management may be adequately modeled with SWAT by calibrating runoff and sediment yields only, and that further calibration of nutrient parameters may not improve model results.
机译：农田最佳管理实践建议通常将耕作和养分施用的改进相结合，以减少养分流失和地表径流。这项研究使用土壤和水评估工具（SWAT）模型来评估在高粱-大豆轮作中常规耕作和免耕管理实践下使用表面肥料和深层肥料施用的养分径流产量。使用不同的实践组合对三个田间样地（0.39至1.46公顷）进行了模型校准，并在2001年至2004年期间对三个田间样地（0.40至0.56公顷）进行了验证。校准后的SWAT模型在模拟所有处理的总氮量方面的日常性能对于基于中位数的Nash-Sutcliffe模型效率（E f *为0.54至0.64）是令人满意的，对于百分比偏差（PBIAS为31％至7％）是很好到非常好，对于基于中位数的均方根误差与观测值的标准偏差比（RSR *为0.72至0.62）。对于总P校准，性能稍低，并且变化更大（E f *为0.42至0.62，PBIAS为-48％至2％，RSR *为0.76至0.62）。与每日平均水平相比，每月总磷径流量的统计数据有所改善，但总氮径流量的统计数据变化不大，这可能是由于异常值对N数据的影响更大。根据验证结果，SWAT在模拟土壤扰动较少的处理（NT / SB）和两种土壤扰动较大的处理（NT / DB和TILL）的总P时，模拟总N径流产量更有效。一个主要的担忧是，SWAT预测免耕处理的年平均总氮径流量比耕作处理的高，这与研究地点的测量值相反。这强化了一个基本的研究问题，即耕作制度对养分流失的影响仍然非常不确定，因此可能无法正确建模。 SWAT模型通常会低估5月和6月高降水月份所有处理的月总N产量，而高估9月至11月的N和P总产量。不论耕作实践或施肥方法如何，对N和P进行校准都会得到NPERCO（1.0），RSDCO（0.05），BIOMIX（0.2），PPERCO（10），PHOSKD（175）和UBP（50）相同的校准参数。结合不同处理对径流（CN，K sat ，AWC）和侵蚀（C min ）的校正参数的结果，该研究发现，不同养分之间的养分产量也存在差异仅通过校准径流和沉积物产量，可以使用SWAT对耕作和肥料管理进行充分建模，而进一步校准养分参数可能不会改善模型结果。

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