مرکز منطقه ای اطلاع رساني علوم و فناوري - Effects of Polyvinylalcohol (PVA) Application on Structural Stability Parameters and Runoff Looses

Abstract :

Erosion is the most important degradation type threatening natural resources. Increasing soil’s resistance against erosive forces is one of the fundamental principles of sustainable soil management. The objectives of this study were to determine effects of PVA applications on soil structural parameters of three soils with different textures (clay, loam, sandy loam) and to assess effectiveness of PVA on reducing runoff and soil losses under artificial rainfall conditions. The rainfall simulator was set to 70 cm height with 40 mm h^-1 rainfall intensity. The soil pan was located with 9% slope gradient. The results indicated that the PVA applications increased aggregate stability in all aggregate fractions ( 0.25, 0.25-0.5, 0.5-1, 1-2, 2-4, 4-6, 6-8 and 8 mm) in all three soils and also significantly increased mean aggregate stability of soils at p 0,05. Dispersion rate decreased and the resistance of soil against erosion increased in all PVA treated soils. There were great differences in soil and water losses removed by runoff among soils studied. The highest soil and water losses occurred in loam and sandy loam textured soils, respectively. The results of this study clearly indicated that soil and water losses were significantly reduced by PVA applications. On the average, soil losses decreased about 77% and water losses nearly 18% in PVA treated soils.