Pedosphere 8(4): 331--336, 1998
ISSN 1002-0160/CN 32-1315/P
©1998 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Ammonia volatilization from winter wheat field top-dressed with urea |
TIAN Guang-Ming1, CAO Jin-Liu2, CAI Zu-Cong1 and REN Li-Tao2 |
1 Institute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) 2 Jurong Agriculturul School of Jiangsu, Jurong 212400 (China) |
ABSTRACT |
Ammonia volatilization was measured with a continuous air flow enclosure method from a winter wheat field in the Experimental Farm of Jurong Agricultural School to investigate its main influencing factors. The experiment with five treatments in triplicate, no N (control), 100, 200 and 300 kg N ha-1 with rice straw cover at a rate of 1 500 kg ha-1 and 200 kg N ha-1 without rice straw, started when the winter wheat was sown in 1994. Sixty percent of the total amount of N applied was basal and 40% was top-dressed. The measurement of ammonia volatilization was immediately conducted after urea was top-dressed on soil surface at wheat elongation stage in spring of 1996 and 1997. The results showed that there was a diurnal variation of ammonia volatilization rate from the winter wheat field, which synchronized with air temperature. N losses through ammonia volatilization increased with increasing N application rate, but the ratio of N lost through ammonia volatilization to applied N was not significantly affected by N application rate. The coverage of rice straw had no significant effect on ammonia volatilization. Soil moisture and rain events after urea was top-dressed affected ammonia volatilization significantly. |
Key Words: ammonia volatilization, urea, wheat |
Citation: Tian, G. M., Cao, J. L., Cai, Z. C. and Ren, L. T. 1998. Ammonia volatilization from winter wheat field top-dressed with urea. Pedosphere. 8(4): 331-336. |
|
View Full Text
|
|
|
|