Pedosphere 16(6): 806--812, 2006
ISSN 1002-0160/CN 32-1315/P
©2006 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effect of N fertilization on grain yield of winter wheat and apparent N losses |
CUI Zhen-Ling1 , CHEN Xin-Ping1, LI Jun-Liang2, XU Jiu-Fei2, SHI Li-Wei2 and ZHANG Fu-Suo1 |
1 College of Resources and Environmental Science, China Agricultural University, Beijing 100094 (China). E-mail: cuizl@cau.edu.cn;
2 Department of Agronomy, Laiyang Agricultural College, Laiyang 265200 (China) |
| ABSTRACT |
| Excessive nitrogen (N) fertilizer application to winter wheat is a common problem on the North China Plain. To determine the optimum fertilizer N rate for winter wheat production while minimizing N losses, field experiments were conducted for two growing seasons at eight sites, in Huimin County, Shandong Province, from 2001 to 2003. The optimum N rate for maximum grain yield was inversely related to the initial soil mineral N content (Nmin) in the top 90 cm of the soil profile before sowing. There was no yield response to the applied N at the three sites with high initial soil mineral N levels (average 212 kg N ha-1). The average optimum N rate was 96 kg N ha-1 for the five sites with low initial soil Nmin (average 155 kg N ha-1) before sowing. Residual nitrate N in the top 90 cm of the soil profile after harvest increased with increasing fertilizer N application rate. The apparent N losses during the wheat-growing season also increased with increasing N application rate. The average apparent N losses with the optimum N rates were less than 15 kg N ha-1, whereas the farmers' conventional N application rate resulted in losses of more than 100 kg N ha-1. Therefore, optimizing N use for winter wheat considerably reduced N losses to the environment without compromising crop yields. |
| Key Words: apparent N losses, optimum N rate, residual soil nitrate N, soil mineral N, winter wheat yield |
| Citation: Cui, Z. L., Chen, X. P., Li, J. L., Xu, J. F., Shi, L. W. and Zhang, F. S. 2006. Effect of N fertilization on grain yield of winter wheat and apparent N losses. Pedosphere. 16(6): 806-812. |
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