Study on Improvements of Modifiers on Soil Water-Stable Aggregates and Its Mechanisms in Aeolian Sandy Soil
Liu Heman · 2007
Four kinds soil structural modifiers, i.e.PAM,β-cyclodextrin,water super absorbent polymer,and humic acid,were used and trained in soil column to study the effects of modifiers on soil water-stable aggregates in Aeolian Sandy land.In addition,the mechanisms of the effects and the optimal modifiers' concentration were offered.The results showed that four modifiers all can promote the formation of 0.25 mm water-stable aggregates.At low concentrations(0.05%～0.1%),the increase of soil water-stable aggregates followed the order of water super absorbent polymerβ-cyclodextrinPAMhumic acid,while at high concentrations(0.2%～0.4%),the increase of soil water-stable aggregates followed the order of PAMβ-cyclodextrinwater super absorbent polymerhumic acid.Within the concentration of 0.05%～0.4%,the four modifers,esp.water super absorbent polymer,reduced the fractal dimension of aggregates and improved the structure in the studied soil.The four modifiers also may effectively reduce the soil bulk density at the low concentration.Regression analysis and anova analysis indicated that water super absorbent polymer was mainly increased 1~5 mm aggregates' content in soils and the effective concentration of water super absorbent polymer was about 0.05%.