| Effects of different mulching treatments on the soil organic carbon content in soil aggregates in a rainfed wheat field |
|
View Fulltext View/Add Comment Download reader |
| |
| DOI：10.7606/j.issn.1000-7601.2016.06.25 |
| Key Words: mulching measures rainfed wheat field soil aggregate organic carbon |
| Author Name | Affiliation | | FU Xin | College of Urban and Environment Science, Northwest University, Xi’an, Shaanxi 710127, China | | WANG Jun | College of Urban and Environment Science, Northwest University, Xi’an, Shaanxi 710127, China | | ZHAO Dan-dan | College of Urban and Environment Science, Northwest University, Xi’an, Shaanxi 710127, China |
|
| Hits: 1192 |
| Download times: 756 |
| Abstract: |
| To investigate the effects of different mulching treatments on soil aggregate distribution and the content of soil organic carbon in soil aggregates four mulching measures were conducted including CK (without mulching treatment), M9000 (straw mulching at a rate of 9 000 kg·hm-2), M4500 (straw mulching at rate of 4 500 kg·hm-2), and PM (plastic film mulching) in a rainfed winter wheat field on Loess Plateau. The results showed that compared with CK, soil total organic carbon (TOC) content by M9000 was increased by 8.1% (P<0.05). TOC content by M4500 and PM had no significant differences. Compared with the CK treatment, soil mechanical-stable macroaggregates content became increased by 6.6% and 4.1% by M9000 and M4500 treatments, respectively. PM treatment macroaggregates content was significantly decreased by 2.5% compared with CK. Compared with CK, the soil mean weight diameter (MWD) by M9000 treatment was increased by 9.2%, and was decreased by 14.8% by PM treatment. The soil geometric mean diameter (GMD) by M9000 treatment was increased by 13.0%, and became decreased by 15.7% (P<0.05) by PM treatment. TOC has close relationships with soil macroaggregate content, MWD and GMD. TOC could increase mechanical-stable aggregates and enhance the stability. Additionally, TOC was mainly concentrated in aggregates with th
e agglomeration >5 mm and <0.25 mm size. M9000 treatment could improve the organic carbon of all the mechanical-stable aggregates size at different degrees, but PM treatment had no effects. Soil organic carbon was mainly stored in the mechanical-stable macroaggre-gate. >5 mm size aggregate contribution is the largest within the total soil organic carbons. M9000 and M4500 treatments could improve the contribution rate of the >0.25 mm size aggregates. Furthermore, there was a significant positive correlation between TOC and >5 mm,<0.25 mm aggregates organic carbon, indicating that >5 mm and <0.25 mm aggregates could be used as a proxy for measuring changes in soil organic carbon. Therefore, straw mulching could not only enhance the aggregate content and stability, but also increase the organic carbon content in aggregate, which is beneficial for soil carbon sequestration with an optimal treatment rate at 9 000 kg·hm-2. |
|
|
|