Effects of latex and poly-DADMAC on erosion, hydrophobicity and water-retention on two different soils

Abstract

Latex (natural polymer) and poly-DADMAC (synthetic polymer) were applied to a red brown earth (Alfisol) and a Wiesenboden (Mollisol). Run-off, infiltration, sediment loss and water stable aggregates were measured after subjecting the soils to simulated rainfall. Water retention of latex and poly-DADMAC amended soils was determined. The MED test for hydrophobicity was also carried out for the latex-treated soil. Latex decreased run-off and erosion, and increased infiltration on both soils. Poly-DADMAC minimized run-off and erosion, and increased infiltration on the Wiesenboden. It increased run-off and decreased infiltration on the red-brown earth; however, it still decreased erosion. Latex increased the percentage of water-stable aggregates > 2 mm on the red-brown earth, but it had less effect on the Wiesenboden. Poly-DADMAC decreased the percentage of water-stable aggregates < 0.125 mm on both soils after simulated rainfall. Both latex and poly-DADMAC had little effect on water retention of the red-brown earth and the Wiesenboden. Application of 1.5 g kg-1 of latex increased MED values of both soils, to give values that indicate moderate water-repellence but should not affect plant growth. Generally, latex was more effective on the red-brown earth and poly-DADMAC was more effective on the Wiesenboden. It seems that latex can be effective on all soil types, but poly-DADMAC will have more effect on clay soils.