Document Type : Research Paper
Authors
1
Rangeland and Watershed Management Department, Faculty of Water and Soil, University of Zabol
2
M.Sc. in Watershed Management, Faculty of Water and Soil, University of Zabol
10.22059/ijswr.2025.403696.670019
Abstract
Water erosion is a major factor in decreasing soil quality and fertility in arid and semi-arid ecosystems. This study examined how different levels of water erosion affect the physical, chemical, and microbial properties of soil at Cheheltan Forest Site, Bam County. Soil samples were collected at four erosion levels: no erosion, low, moderate, and severe erosion. Measurements included soil texture, bulk density, moisture, pH, organic and inorganic carbon and nitrogen, organic carbon, total nitrogen, available phosphorus and potassium, ammonium, and nitrate. Biological indicators such as catalase enzyme activity, microbial carbon and nitrogen stocks, basal microbial respiration, microbial populations, and overall soil microbial contribution were also evaluated. Results showed that as erosion severity increased, organic carbon decreased from 6.6 to 4 g kg⁻¹, total nitrogen from 0.6 to 0.3 g kg⁻¹, and available potassium from 156.3 to 83.28 mg kg⁻¹. Enzyme activity, microbial stocks, respiration, and microbial populations also declined significantly, with soil microbial contribution reaching 0.65 in severely eroded plots. Correlation analysis revealed that biological indices had positive and significant relationships with organic matter, total nitrogen, available phosphorus and potassium, and soil moisture. Conversely, sand percentage was negatively related, while clay and silt percentages showed positive relationships with microbial activity. These findings highlight that water erosion severely compromises the biological stability and function of soil ecosystems by reducing organic matter and nutrients and altering soil texture. Sustainable soil management is crucial to preserve soil fertility and ecological functions in these regions.
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