Pedosphere 17(1): 97--100, 2007
ISSN 1002-0160/CN 32-1315/P
©2007 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Light fraction carbon and water-stable aggregates in black soils |
SHI Yi , CHEN Xin and SHEN Shan-Min |
| Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China). E-mail: shiyi@iae.ac.cn |
| ABSTRACT |
| The distribution of light fraction carbon (LF-C) in the various size classes of aggregates and its relationship to water-stable aggregates as well as the influence of cultivation on the organic components in virgin and cultivated black soils were studied by wet sieving and density separation methods. The total organic carbon (TOC) and LF-C were significantly higher (P ≤ 0.05) in the virgin soils than in the cultivated soils. The LF-C in aggregates of different size classes varied from 0.9 to 2.5 g kg-1 in the cultivated soils and from 2.5 to 7.1 g kg-1 in the virgin soils, whereas the ratio of LF-C to TOC varied from 1.9% to 7.3% and from 5.0% to 12.2%, respectively. After being incubated under constant temperature and controlled humidity for three months, the contribution of LF-C to TOC sharply decreased to an amount (1.7%-8.5%) close to the level in soils that had been cultivated for 20 to 25 years (1.3%-8.8%). As a result, the larger water-stable macro-aggregates (especially > 1 mm) decreased sharply, indicating that the LF-C pool in virgin soils declined quickly after cultivation, which reduced the water stability of soil aggregates. |
| Key Words: black soil, light fraction carbon, water-stable aggregates |
| Citation: Shi, Y., Chen, X. and Shen, S. M. 2007. Light fraction carbon and water-stable aggregates in black soils. Pedosphere. 17(1): 97-100. |
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