Effect of tillage systems on the variability of soil-water tensions and soil-water content

Field experiments were conducted on a Webster silty clay loam soil to study the effect of four different tillage systems (no-till, chisel plow, paraplow and moldboard plow) on soil-water tension and soil-water content. The results of this study indicated that tillage systems affected the soil-water tensions in the surface layer (0 to 0.3 m) of the soil in 1984, but the differences were not statistically significant at the 5% level in 1983. Results showed that the variability (standard deviation and range) of soil-water tensions increased when the soil became drier under all tillage systems, but the variability began to decrease at about 45 kPa of soil-water tension and continued to decrease further at higher values of soil-water tensions (reaching up to 80 kPa).