The effect of polyacrylamide (PAM) applications on infiltration, runoff and soil losses under simulated rainfall conditions

One of the major causes of soil degradation throughout the world is water erosion. Anionic polyacrylamide (PAM) application to soils is an effective soil conservation practice for reducing runoff and soil losses caused by erosion. It also increases the infiltration rate of soils. The objective of this study was conducted to determine effects of different application rates of PAM (0 (control), 1.667, 3.333 and 5.000 kg.ha-1) on infiltration rate, runoff and soil losses. Polyacrylamide was sprayed on the surface of the experimental soils with different textures. The PAM treated soils were introduced to simulated rainfall at 61 mm/h intensity for an hour. The results indicated that, PAM applications significantly reduced surface runoff and soil losses, but increased infiltration rates. The effectiveness of PAM was higher in clay and clay loam soils than that of sandy clay loam soil. The most effective applications rates of PAM on reducing surface runoff and soil losses and increasing infiltration rates were found to be 3.333 and 5.000 kg.ha-1 . By considering the price and application cost of PAM, It was suggested that 3.333 kg.ha-1 PAM is the most suitable application rate. As compared with the control, it was obtained that PAM application with a rate of 3.333 kg.ha-1 reduced surface runoff and soil losses by 23.1 and 18.5%, respectively and increased infiltration rate by 24%. Key words: Polyacrylamide (PAM), soil erosion, soil loss, runoff, infiltration rate, simulated rainfall.