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| Submitter's Name |
Wei Yang |
| Session Name |
Poster Session - Agricultural/Silvicultural Water |
| Poster Number |
15 |
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| Author(s) |
Wei Yang, China Agricultural University (Presenting Author) |
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Gary Feng,
USDA-ARS, Genetics and Sustainable Agricultural Research Unit |
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Pinfang Li, China Agricultural University |
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Haile Tewolde, USDA-ARS, Genetics and Sustainable Agricultural Research Unit |
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Simulating longer-term performance of cover crops on water drainage and nitrogen cycling in corn and soybean rotation with RZWQM2 |
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Planting winter cover crops in soybean and maize rotations is a potential approach for reducing subsurface drainage and nitrate-nitrogen loss. However, the longer-term (2005-2009) impact of this practice needs to be further investigated. The RZWQM2 model was used to simulate the longer-term effects of the practice on water drainage and nitrogen cycling by using a winter cover crop within a corn-soybean rotation. The RZWQM2 model was calibrated satisfactory in terms of crop yield, biomass, and N uptake, with percent error (PE) was within ±15% and relative root mean square error (RRMSE) <20% except for biomass and rye N uptake. Simulated daily and annual drainage and annual NO3-N loss were also satisfactorily, with efficiency of model (EF) >0.60, d-index <0.85, and percent bias within ±22%. The simulation in soil water storage was unsatisfactory but comparable to other studies. Longer-term simulations showed that applying a winter cover was effective to reduce annual NO3-N loss by 14.6 kg N ha-1 (17%) and subsurface drainage by 3.2 cm (15%), respectively, and increased annual ET by 5% (2.9 cm). |
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