Pedosphere 16(2): 245--252, 2006
ISSN 1002-0160/CN 32-1315/P
©2006 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Leaching and transformation of nitrogen fertilizers in soil after application of N with irrigation: A soil column method |
ZHOU Jian-Bin1,2 , XI Jin-Gen1,3, CHEN Zhu-Jun1 and LI Sheng-Xiu1 |
1 College of Resource & Environmental Sciences, Northwest A&F University, Yangling, Shaanxi 712100 (China). E-mail: jbzhou@public.xa.sn.cn;
2 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100 (China);
3 Southern Subtropical Crops Research Institute, CATAS, Zhanjiang Guangdong 524091 (China) |
| ABSTRACT |
| A soil column method was used to compare the effect of drip fertigation (the application of fertilizer through drip irrigation systems, DFI) on the leaching loss and transformation of urea-N in soil with that of surface fertilization combined with flood irrigation (SFI), and to study the leaching loss and transformation of three kinds of nitrogen fertilizers (nitrate fertilizer, ammonium fertilizer, and urea fertilizer) in two contrasting soils after the fertigation. In comparison to SFI, DFI decreased leaching loss of urea-N from the soil and increased the mineral N (NH4+-N + NO3--N) in the soil. The N leached from a clay loam soil ranged from 5.7% to 9.6% of the total N added as fertilizer, whereas for a sandy loam soil they ranged between 16.2% and 30.4%. Leaching losses of mineral N were higher when nitrate fertilizer was used compared to urea or ammonium fertilizer. Compared to the control (without urea addition), on the first day when soils were fertigated with urea, there were increases in NH4+-N in the soils. This confirmed the rapid hydrolysis of urea in soil during fertigation. NH4+-N in soils reached a peak about 5 days after fertigation, and due to nitrification it began to decrease at day 10. After applying NH4+-N fertilizer and urea and during the incubation period, the mineral nitrogen in the soil decreased. This may be related to the occurrence of NH4+-N fixation or volatilization in the soil during the fertigation process. |
| Key Words: fertigation, irrigation method, N leaching, N transformation, nitrogen fertilizer |
| Citation: Zhou, J. B., Xi, J. G., Chen, Z. J. and Li, S. X. 2006. Leaching and transformation of nitrogen fertilizers in soil after application of N with irrigation: A soil column method. Pedosphere. 16(2): 245-252. |
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