Analysis of Pore Characteristics at Plow Pan of Modified Lime Concretion Black Soil Using CT Scanning
Long-term rotary tillage on sticky lime concretion black soil leads to compaction of plow pan,which seriously affects pore quality.In this study,based on a three-year field improvement experiment combi-ning tillage and fertilization in lime concretion black soil area of south Henan,the plow pan of four treatments including conventional rotary tillage(CK),deep tillage(DT),deep tillage combined with biochar application(DT+B),and deep tillage combined with organic fertilizer(DT+M)were scanned using CT and analyzed u-sing image reconstruction software,and the water infiltration related properties were determined,in order to study the pore characteristics of improved lime concretion black soil and water infiltration capacity,which could help evaluate the soil improvement effects.The results showed that the soil porosity and maximum pore diameter of plow pan showed as DT+B>DT+M>DT>CK.Compared to CK,the DT+B treatment reduced the number of pores with diameter of<40 μm and 40 to 60 μm by 36.6%and 38.5%,respectively,but signif-icantly increased the number of large pores with diameter of 200 to 300 μm and>300 μm by 64.3%and 69.4%,respectively.Deep tillage combined with fertilizer application significantly increased the saturated hy-draulic conductivity in the plow pan,improved the physical indexes such as bulk density and compactness,and enhanced the water infiltration capacity.The effect of DT+B treatment was the best.Correlation analysis results showed that there were significantly positive correlations between big pore structure and soil hydraulics characteristics.Overall,deep tillage combined with biochar application effectively improved soil pore quality and reduced other physical obstacles in the plow pan,which could provide the technical method and reference for improving lime concretion black soil.
Lime concretion black soilImprovement of plow panCT scanningPore characteristicsWater infiltration
万方数据
维普
