Optimizing Weight Method to Evaluate Nitrogen Release Characters of Polymer-Coated Urea in Paddy Soil under Field Conditions |
| |
| Authors: | Xin Yang Shaofu Wu Jianqiu Chen Yuanhong Zhu |
| |
| Affiliation: | 1. Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China;2. Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China;3. Agricultural Extension Station of Shaoxing, Shaoxing, China;4. Shandong Kingenta Ecological Engineering Group Co., Ltd., Linshu, China;5. National Engineering &6. Technology Research Center for Slow and Controlled Release Fertilizers, College of Resources and Environment, Shandong Agricultural University, Taian, China;7. Department of Crop and Soil Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA |
| |
| Abstract: | Polymer-coated urea can improve nitrogen (N) use efficiency of rice. But, the nitrogen release characters from flooded paddy soil are lacking. Traditional weight methods use a vacuum oven to dry. Depending on the coating, some polymer-coated urea still retain water after drying. A new weight method was proposed: washing fertilizer granules in the buried bags with distilled water, and transferring to a plastic bag, then placing it at ?80°C for 2 h, and then transferring to the lyophilizer to dry for 24 h. The method was compared with chemical analyses. This result indicated that the weight method can be used for determining N release characteristics in paddy soil. In the whole growing season, over 75% of N was released. Different amounts of granules in the bag can influence the result. The release rate of 10.0 g in bags was higher than 3.0 g. Surface applied polymer-coated urea has a higher rate than deep application. |
| |
| Keywords: | Lyophilizer polymer-coated urea surface applying weight method |
|
|
