Impacts of Different Parent Materials in Red Soil Region on Stability of Paddy Soil Aggregates

Abstract

【Objective】The study was conducted to explore the differences of stability of paddy soil aggregates developed from different parent materials in red soil area, with a view to providing a theoretical basis for the utilization and development of soil resources in red soil area.【Method】Six kinds of paddy soils with different parent materials developed in plough layer and plough bottom were collected from red soil area. Anhydrous alcohol, 0.1 mol/L NaOH solution, 0.002% Na2CO3 solution and 0.1 mol/L NaCl solution were selected as dispersions, and ultrapure water was used as control. The contents of water stable aggregates were determined by wet sieve method.【Result】The contents of water stable aggregates in plough layer was significantly higher than those in plough bottom of paddy soil with the same parent material. There was a significantly positive correlation between the content of water stable aggregate and the content of soil organic matter in paddy soil. After the four dispersions infiltrated the soil, the contents of water stable aggregates were as follows: anhydrous alcohol (86.31%) > Na2CO3 solution (39.03%) > NaCl solution (32.49%) > NaOH solution (10.70%).【Conclusion】For paddy soil in the same soil layer (plough layer), there are significant differences in the water stability of soil aggregates of different parent material types, which rank as: quartzite weathering material > acid crystalline weathering material > lake sediment > river sediment > quaternary red clay > argillaceous weathering material. For the paddy soil developed from the same parent material, the water stability of aggregates in plough layer is significantly stronger than that in plough bottom. Strong alkali environment can significantly reduce the water stability of paddy soil.

Keywords

• soil physics
• soil parent material
• red paddy soil
• water stability aggregates
• chemical stability
• corrosion resistance