Pedosphere 21(4): 464--472, 2011
ISSN 1002-0160/CN 32-1315/P
©2011 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Nitrogen balance and loss in a greenhouse vegetable system in southeastern China |
MIN Ju, ZHAO Xu, SHI Wei-Ming , XING Guang-Xi and ZHU Zhao-Liang |
| State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008 (China) |
| ABSTRACT |
| High rates of fertilizer nitrogen (N) are applied in greenhouse vegetable fields in southeastern China to maximize production;however, the N budgets of such intensive vegetable production remain to be explored. The goal of this study was to determine the annual N balance and loss in a greenhouse vegetable system of annual rotation of tomato, cucumber, and celery at five N (urea) application rates (0, 348, 522, 696, and 870 kg N ha-1 year-1). Total N input to the 0-50 cm soil layer ranged from 531 to 1 053 kg ha-1, and N fertilizer was the main N source, accounting for 66%-83% of the total annual N input. In comparison, irrigation water, wet deposition, and seeds in total accounted for less than 1% of the total N input. The fertilizer N use efficiency was only 18% under the conventional application rate of 870 kg N ha-1 and decreased as the application rate increased from 522 to 870 kg N ha-1. Apparent N losses were 196-201 kg N ha-1, of which 71%-86% was lost by leaching at the application rates of 522-870 kg N ha-1. Thus, leaching was the primary N loss pathway at high N application rates and the amount of N leached was proportional to the N applied during the cucumber season. Moreover, dissolved organic N accounted for 10% of the leached N, whereas NH3 volatilization only contributed 0.1%-0.6% of the apparent N losses under the five N application rates in this greenhouse vegetable system. |
| Key Words: ammonia volatilization, intensive production, N input, N leaching, N use efficiency |
| Citation: Min, J., Zhao, X., Shi, W. M., Xing, G. X. and Zhu, Z. L. 2011. Nitrogen balance and loss in a greenhouse vegetable system in southeastern China. Pedosphere. 21(4): 464-472. |
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