[1]JU Li,LI Fucheng.Effects of Rotary Tillage on Vertical Distribution Patterns of SOC and Total Nitrogen in Purple Soil[J].Research of Soil and Water Conservation,2019,26(05):7-13.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
26
Number of periods:
2019 05
Page number:
7-13
Column:
Public date:
2019-09-06
- Title:
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Effects of Rotary Tillage on Vertical Distribution Patterns of SOC and Total Nitrogen in Purple Soil
- Author(s):
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JU Li1, LI Fucheng2
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1. Sichuan Academy of Water Conservancy, Chengdu 610072, China;
2. School of Environment and Resource, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China
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- Keywords:
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soil; tillage erosion; magnetic tracer; tillage translocation; tillage direction; soil organic carbon
- CLC:
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S157.1;S153.6
- DOI:
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- Abstract:
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The ilmenite powder was artificially added to the soil surface to trace the vertical and downslope redistribution process of surface soil. By comparing the vertical distribution characteristics of soil organic carbon and total nitrogen before tillage, the coupling effects of vertical and lateral transfers of soil by rotary tillage on vertical distribution of soil organic carbon (SOC) and total nitrogen (TN) in purple soil are revealed after 20 and 40 simulated tillage operations. The erosion depth exceeds the original soil layer thickness at the summit of the slope, but the soil layer thickness is still the same as the tillage depth after intensive tillage due to the dual roles of tillage:translocation of soil along the slope and vertical transfer of soil or rock fragments. The depth distribution of soil magnetic susceptibility shows that tillage causes the vertical downward movement of the soil. The intensive tillage leads to the vertically downward transfer of SOC, but vertical redistribution patterns differ from one another at different slope positions. Due to upward migration of rock fragments and downslope transport of soil, SOC concentrations reduce significantly at the summit positions of the slope. SOC in the surface layer (0-5 cm) decreases at the toeslope position, but it increases significantly in 5-20 cm layer, because intensive tillage translocates the soil with low concentrations of SOC and TN derived from upper position of slope. These results suggest that the soil vertical movement interacting with the downslope movement under contour tillage by rotary cultivator results in significant different vertical distribution patterns of SOC and TN in the tillage erosion area and tillage deposition area.