Pedosphere 21(6): 753--762, 2011
ISSN 1002-0160/CN 32-1315/P
©2011 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Systematic studies of nitrogen loss from paddy soils through leaching in the Dongting Lake area of China |
JI Xiong-Hui1,2 , ZHENG Sheng-Xian1, SHI Li-Hong1,2 and LIU Zhao-Bing1,2 |
1 Soil and Fertilizer Institute of Hunan Province, Changsha 410125 (China)
2 Hunan Agricultural Environment Research Center, Changsha 410125 (China) |
| ABSTRACT |
| A two-year lysimeter study was conducted to study the effects of different fertilizers and soils on nitrogen leaching loss in a double rice cropping system by considering three major types of paddy soils from the Dongting Lake area. The results showed that N concentration in the leachate did not differ significantly among the treatments of urea, controlled release N fertilizer and pig manure and that all these fertilizers produced higher total nitrogen (TN) concentrations in the leachate compared to the case where no fertilizer was applied. The TN leaching loss following urea treatment accounted for 2.28%, 0.66%, and 1.50% of the amount of N applied in the alluvial sandy loamy paddy soil (ASL), purple calcareous clayey paddy soil (PCC), and reddish-yellow loamy paddy soil (RYL), respectively. Higher TN loss was found to be correlated with the increased leachate volume in ASL compared with RYL, and the lowest TN loss was observed in the PCC, in which the lowest leachate volume and TN concentration were observed. Organic N and NH4+-N were the major forms of N depleted through leachate, accounting for 56.8% and 39.7% of TN losses, respectively. Accordingly, soil-specific fertilization regimens are recommended; in particular, the maximum amount of fertilizer should be optimized for sandy soils with a high infiltration rate. To avoid a high N leaching loss from rice fields, organic N fertilizers such as urea or coated urea should primarily be used for surface topdressing or shallow-layer application and not for deep-layer application. |
| Key Words: double rice cropping, fertilizer application, leachate, nitrogen concentration |
| Citation: Ji, X. H., Zheng, S. X., Shi, L. H. and Liu, Z. B. 2011. Systematic studies of nitrogen loss from paddy soils through leaching in the Dongting Lake area of China. Pedosphere. 21(6): 753-762. |
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