THE EFFECT OF TILLAGE TREATMENTS ON SOIL WATER HOLDING CAPACITY AND ON SOIL PHYSICAL PROPERTIES

The effect of tillage treatments (moldboard plowing, chisel plowing, and disk plowing) on soil water holding capacity and on soil physical properties was investigated. Soil physical properties include soil bulk density and infiltration rate. Soil bulk density was measured on cores obtained by a manually operated tool. Infiltration rate of the soil in all treatments was measured using double ring infiltrometer. Soil response was measured to 40 cm soil depth. Soil water holding capacity was investigated by plotting soil water characteristic curves for different tillage treatments. These curves were constructed by measuring soil moisture potential and moisture content. Potential was measured using watermark sensor and moisture content was measured by gravimetric method. These measurements were replicated three times. The Statistical Analysis System (SAS) computer package was used to analyze the data. ANOVA procedure was used to evaluate the significance of each parameter and their interactions. Significant differences were reported for the 10% probability level. Data obtained from the experimental plots showed that infiltration rate was strongly affected by tillage treatments in the top soil. Dry bulk density from 0 to 20 cm was affected by tillage treatments and from 20 to 40 cm by axle load. Tillage systems generally affected the ability of the soils to hold moisture and the available water capacity.