Pedosphere 18(5): 574--581, 2008
ISSN 1002-0160/CN 32-1315/P
©2008 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effect of tillage system on distribution of aggregates and organic carbon in a Hydragric Anthrosol |
GAO Ming , LUO You-Jin, WANG Zi-Fang, TANG Xiao-Hong and WEI Chao-Fu |
| College of Resources and Environment, Southwest University, Chongqing 400716 (China). E-mail: gaoming@swu.edu.cn |
| ABSTRACT |
| The effect of different tillage systems on the size distribution of aggregates and organic carbon distribution and storage in different size aggregates in a Hydragric Anthrosol were studied in a long-term experiment in Chongqing, China. The experiment included three tillage treatments:conventional tillage with rotation of rice and winter fallow (CT-r) system, no-till and ridge culture with rotation of rice and rape (RT-rr) system, and conventional tillage with rotation of rice and rape (CT-rr) system. The results showed that the aggregates 0.02-0.25 mm in diameter accounted for the largest portion in each soil layer under all treatments. Compared with the CT-r system, in the 0-10 cm layer, the amount of aggregates > 0.02 mm was larger under the RT-rr system, but smaller under the CT-rr system. In the 0-20 cm layer, the organic carbon content of all fractions of aggregates was the highest under the RT-rr system and lowest under the CT-rr system. The total organic carbon content showed a positive linear relationship with the amount of aggregates with diameter ranging from 0.25 to 2 mm. The storage of organic carbon in all fractions of aggregates under the RT-rr system was higher than that under the CT-r system in the 0-20 cm layer, but in the 0-60 cm soil layer, there was no distinct difference. Under the CT-rr system, the storage of organic carbon in all fractions of aggregates was lower than that under the CT-r system;most of the newly lost organic carbon was from the aggregates 0.002-0.02 and 0.02-0.25 mm in diameter. |
| Key Words: aggregates, Hydragric Anthrosol, organic carbon, tillage system |
| Citation: Gao, M., Luo, Y. J., Wang, Z. F., Tang, X. H. and Wei, C. F. 2008. Effect of tillage system on distribution of aggregates and organic carbon in a Hydragric Anthrosol. Pedosphere. 18(5): 574-581. |
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