Pedosphere 17(5): 639--645, 2007
ISSN 1002-0160/CN 32-1315/P
©2007 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Ammonia volatilization and nitrogen utilization efficiency in response to urea application in rice fields of the Taihu Lake region, China |
LIN De-Xi 1,3,4, FAN Xiao-Hui1,2, HU Feng3, ZHAO Hong-Tao1 and LUO Jia-Fa5 |
1 Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China). E-mail: dexzlin2000@yahoo.com.cn;
2 Department of Soil and Water Science, Tropical Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Homestead, FL33031 (USA);
3 College of Resource and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China);
4 College of Resource and Environmental Sciences, Fujian Agriculture & Forestry University, Fuzhou 350007 (China);
5 Land and Environmental Management Group, AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton (New Zealand) |
| ABSTRACT |
| Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N fertilizer treatments, applied in triplicate, were 0 (control), 100, 200, 300, or 350 kg N ha-1. After urea was applied to the surface water, a continuous airflow enclosure method was used to measure ammonia volatilization in the paddy field. Total N losses through ammonia volatilization generally increased with the N application rate, and the two higher N application rates (300 and 350 kg N ha-1) showed a higher ratio of N lost through ammonia volatilization to applied N. Total ammonia loss by ammonia volatilization during the entire rice growth stage ranged from 9.0% to 16.7% of the applied N. Increasing the application rate generally decreased the ratio of N in the seed to N in the plant. For all N treatments, the nitrogen fertilizer utilization efficiency ranged from 30.9% to 45.9%. Surplus N with the highest N rate resulted in lodging of rice plants, a decreased rate of nitrogen fertilizer utilization, and reduced rice yields. Calculated from this experiment, the most economical N fertilizer application rate was 227 kg ha-1 for the type of paddy soil in the Taihu Lake region. However, recommending an appropriate N fertilizer application rate such that the plant growth is enhanced and ammonia loss is reduced could improve the N utilization efficiency of rice. |
| Key Words: ammonia volatilization, N application rate, N utilization efficiency, paddy soil, rice yield |
| Citation: Lin, D. X., Fan, X. H., Hu, F., Zhao, H. T. and Luo, J. F. 2007. Ammonia volatilization and nitrogen utilization efficiency in response to urea application in rice fields of the Taihu Lake region, China. Pedosphere. 17(5): 639-645. |
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