Soil Particle Settlement Sorting and Distribution Characteristics of Carbon, Nitrogen and Salt During Gradual Thawing
Journal Title: Bulletin of Soil and Water Conservation - Year 2023, Vol 43, Issue 5
Abstract
[Objective] The classification of sediment particles and the accompanying distribution characteristics of carbon, nitrogen and salt in the process of soil thawing layer by layer under snowmelt runoff scenario were analyzed in order to identify the mechanism of soil freeze-thaw erosion and the induced micro-environmental effects on eroding slopes. [Methods] Soil samples were obtained from an eroding slope in the mollisol region of Northeastern China. Air-dried soil was used to fill columns that were subjected to three treatments: non-freeze-thaw, full freeze-full thaw, and gradual progressive thawing after freezing. The soil columns were completely immersed in a water bath so that thawing occurred from outside to inside. All soil samples were then fractionated by settling velocity, and the electrical conductivity (EC), pH value, soil organic carbon (SOC), and total nitrogen (TN) of each particle size were determined and analyzed. [Results] ① The freeze-thaw process reduced the proportion of the soil particles >500 μm and ≤125 μm, but increased the proportion of soil particles between 125 μm and 500 μm. Larger particles had higher EC, but lower SOC and TN. ② Across gradual progressively thawed layers, the outer layer (thawed earlier) had fewer particles ≤63 μm, and the inner layer (thawed later) had more particles between 125 μm and 500 μm. More specifically, EC, SOC, and TN were higher in the larger fractions from the outer layer. ③ Compared with the original soil, 64.8% of the dissolved solids were lost from the soil that experienced gradual progressive thawing, but the loss rate of SOC and TN was only 4.08% and 2.72%, respectively. The loss of dissolved solids and organic matter was greater from the inner layer than from the outer layer. [Conclusion] After freezing and thawing, the degree of fragmentation of the outer layer of soil was large, and the soil particles on the slope tended to become homogenized. Organic matter content varied significantly between particle size classes, and its distribution was more stable in small-grained soils. Salts and organic matter migrated from the inner layer of the soil to the outer layer during the freeze-thaw process, resulting in loss.
Authors and Affiliations
Xinhao Yuan, Xinyao Wang, Fan Li, Ruiqi Wang, Yaxian Hu, Xianwen Li
Keywords
Related Articles
- EP ID EP762685
- DOI 10.13961/j.cnki.stbctb.2023.05.005
- Views 13
- Downloads 0
Interaction Between Intensive Land Use and New-type Urbanization from Perspective of Spatiotemporal Cone
[Objective] The interaction mechanism between intensive land use and new-type urbanization was determined in order to provide a reference for regional high quality development. [Methods] We qualitatively analyzed the int...
Temporal and Spatial Variation of Rainfall Erosivity in Middle Reaches of Yellow River Based on Different Models
[Objective] Based on different models, the spatiotemporal evolution characteristics of rainfall erosivity in the middle reaches of the Yellow River were explored, in order to providing a reference basis for the assessmen...
Farmers’ and Herdsmen’ Sustainable Livelihood Capital and Livelihood Strategy in Enclosed Reserves of Desertified Land
[Objective] The relationship between farming and herding households’ livelihood capital and livelihood strategies was studied, and the spatial differences of farming and herding households’ livelihood capital and the tra...
Soil Selenium Characteristics and Availability in Jujube Orchard in Minqin County of Gansu Province
[Objective] The distribution status and availability of soil selenium in three jujube orchards in Minqin County, Gansu Province was analyzed in order to provide a theoretical basis for the development of the selenium-enr...
Welfare Effect of Farmers’ Participation in Soil Conservation: Concept, Connotation and Evaluation Index Framework
[Objective] A concept, connotation and evaluation index framework of welfare effect of farmers’ participation in soil conservation practices was systematically reviewed, which could provide a scientifical basis for compr...