EFFECTS OF LATEX AND POLY-DADMAC ON EROSION, HYDROPHOBICITY AND WATER-RETENTION ON 2 DIFFERENT SOILS

Latex (natural polymer) and poly-DADMAC (synthetic polymer) were appli ed to a red brown earth (Alfisol) and a Wiesenboden (Mollisol). Run-of f, infiltration, sediment loss and water stable aggregates were measur ed after subjecting the soils to simulated rainfall. Water retention o f 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 soi ls. Poly-DADMAC minimized run-off and erosion, and increased infiltrat ion on the Wiesenboden. It increased run-off and decreased infiltratio n on the red-brown earth; however, it still decreased erosion. Latex i ncreased the percentage of water-stable aggregates > 2 mm on the red-b rown earth, but it had less effect on the Wiesenboden. Poly-DADMAC dec reased the percentage of water-stable aggregates < 0.125 mm on both so ils after simulated rainfall. Both latex and poly-DADMAC had little ef fect on water retention of the red-brown earth and the Wiesenboden. Ap plication 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-b rown earth and poly-DADMAC was more effective on the Wiesenboden. It s eems that latex can be effective on all soil types, but poly-DADMAC wi ll have more effect on clay soils.