Effect of cattle manure on soil physical properties on a sandy clay loam soil in North-West Iran

Organic matter affects crops growth and yield either directly by supplying nutrients or indirectly by modifying soil physical properties such as stability of aggregates, porosity and available water capacity that can improve the root environment and stimulate plant growth. The objective of this study was to evaluate effects of cattle manure on infiltration, available water capacity as well as some soil physical properties on a sandy clay loam soil lack of plant in Ardabil province, Iran. This objective was examined by supplying 9 iron cylinders of 57 cm in inner diameter and about 40 cm in height. The cylinders were filled with sandy clay loam soil of 30 cm in height. Cattle manure was applied at 0, 30 and 60 Mg ha(-1) at three replications in a completely random design. Nine months after cattle manure application, soil properties were measured. Statistical analysis showed that soil bulk density and particle density decreased significantly (P<0.05) and porosity, organic matter content and saturated hydraulic conductivity increased with application of 30 and 60 Mg ha(-1). After measuring infiltration, coefficients of Philip's equation (sorptivity (S) and constant coefficient (A)) were estimated by nonlinear regression using SPSS software. The results indicated that application of cattle manure did not significantly (P<0.05) affect S but showed effect on A significantly (P<0.05). Mean weight diameter (MWD) of the aggregates in 30 and 60 Mg ha(-1) treatments was significantly (P<0.05) greater than in control treatment. Available water capacity (AWC) decreased with application of 30 and 60 Mg ha(-1) but the statistical results showed AWC was just significantly (P<0.05) affected by application of 60 Mg ha(-1).