CONTROLLED-RELEASE UREA FOR RICE PRODUCTION AND ITS ENVIRONMENTAL IMPLICATIONS |
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| Authors: | Yuechao Yang Min Zhang Lei Zheng Dongdong Cheng Ming Liu Yuqing Geng |
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| Institution: | 1. Chinese National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Chinese National Engineering Research Center for Slow/Controlled Release Fertilizers, College of Resources and Environment, State Key Laboratory of Crop Biology , Shandong Agricultural University , Tai’an , China;2. Shangdong Kingenta Ecological Engineering Co., Ltd , Lin'shu , China |
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| Abstract: | Controlled-release urea (CRU) and its placement method in rice production were investigated during 2007 and 2008 seasons. Controlled-release urea was applied at 62.5, 125, and 187.5 kg nitrogen (N) ha?1, and the urea was 187.5 kg N ha?1. All the CRU treatments were applied to the nursery beds once, and they were brought into the paddy field during transplanting, while the urea treatment was split into three applications from the plowing to the harvest. The results showed that rice seedlings with CRUs germinated and grow well and there was no salt damage at the nursery stage. The CRU treatment with 125 kg N ha?1 had 33% less N than urea treatment (187.50 kg N ha?1), but it produced significantly higher grain and straw yields, higher total N uptake and total apparent N uptake efficiency. In addition, all the CRU treatments effectively decreased floodwater ammonium (NH4 +)-N and nitrate (NO3 ?)-N concentrations, pH, and N runoff. |
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| Keywords: | coexistence placement nursery beds apparent N uptake efficiency runoff |
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