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| Simulation and Analysis of Nitrate Leaching and Water and Nitrogen Use Efficiencies in Farmland Under Organic and Mineral Fertilizer Management Practices |
| Received:February 08, 2015 |
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| KeyWord:fertilizer management practices;soil-crop system model;nitrate leaching;water and nitrogen use efficiencies;water and nitrogen balance |
| Author Name | Affiliation | E-mail | | LIANG Hao | Department of Soil and Water Sciences, China Agricultural University, Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture, Beijing 100193, China | | | HU Ke-lin | Department of Soil and Water Sciences, China Agricultural University, Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture, Beijing 100193, China | hukel@cau.edu.cn | | LI Bao-guo | Department of Soil and Water Sciences, China Agricultural University, Key Laboratory of Arable Land Conservation in North China, Ministry of Agriculture, Beijing 100193, China | |
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| Abstract: |
| The objectives of this study were to quantify water and nitrogen use efficiencies(WUE, NUE) and N balance in farmland under different fertilizer management practices, and to recommend optimal fertilizer management practice. Based on six year(1992—1998) field experimental dataset under different fertilizer management practices(traditional mineral fertilizer, T1; organic manure, T2; combined organic manure and mineral fertilizer, T3), the WHCNS(Soil Water Heat Carbon and Nitrogen Simulation) model was calibrated and validated, and then was used to simulate the crop yield, nitrate leaching, WUE, NUE and N balance under different fertilizer management practices. Results showed that the amount of total drainage of three treatments during six years was as high as 1230 mm, accounting for 35%~38% of the total rainfall(no irrigation). The WUEs for three treatments were in order of T3>T1>T2, which was in consistent with the crop yields. The T3 treatment had the highest yield, while the T2 was the lowest. The main fates of N in the farmland were crop uptake and nitrate leaching. Nitrate leaching in the T1 treatment was the highest, amounting to 33.6% of total fertilizer inputs, whereas the lowest in T3, which was about 23.5% of total N applied. The NUEs was in the following order:T3>T2>T1. Compared to the initial soil mineral N, soil N after six-year cultivation was reduced by 144 kg N·hm-2 in T1, while the reduction was only 55 kg N·hm-2 and 79 kg N·hm-2 in T2 and T3. The present findings indicate that combination of organic manure and mineral fertilizer is the best management practice, which not only reduces nitrate leaching, but also enhances WUE and NUE and maintains soil N balance. |
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