Estimation of Nitrogen Fertilizer Use Efficiency in Dryland Agroecosystem |
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Authors: | LI Shi-qing LI Sheng-xiu |
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Institution: | College of Resources and Environmental Sciences, Northwest Science and Technology University of Agriculture and Forestry, Yangling , Shaanxi 712100 |
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Abstract: | A field trial was carried out to study the nitrogen fertilizer recovery by four crops in succession in manurial loess soil in Yangling. The results showed that the nitrogen fertilizer not only had the significant effects on the first crop , but also had longer residual effects, even on the fourth crop. The average apparent nitrogen fertilizer recovery by the first crop was 31.7%, and the accumulative nitrogen recovery by the 4 crops was high as 62.3%, and the latter was double as the former. It is quite clear that the nitrogen fertilizer recovery by the first crop was not reliable for estimating the nitrogen fertilizer unless the residual effect of nitrogen fertilizer was included. |
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Keywords: | Dry farming Ecological systen of farmland Nitrogen fertilizer recovery Residual effect |
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