Abstract
The first step of this study was manufacturing two shapes of subsoiler tines in a local work shop in Mosul city, they were: tapered-top with constant width and tapered-top with gradual width tine according to the conventional tine dimensions. The field performance of these tines Then compared with the conventional tine in silty clay soil field. Three depths of subsoiling have been studied, 20, 30, 40 cm in two cases of soil cultivated and uncultivated. This was done through measuring several indicators; disruption area, soil moisture content, soil penetration resistance at/beneath the depth of subsoiling in the middle and end of season, and saturated soil hydraulic conductivity at subsoiling depth in the end of season. Randomized Complete Block Design by using Split-Split design was followed. The main results are: The tapered-top tine with gradual width has achieved the highest values for disruption area and soil moisture content at/beneath subsoiling depth in middle and end of the season, and achieved the lowest values for soil penetration resistance at subsoiling depth in middle and end of season. While the tapered-top tine with constant width has achieved the lowest values for soil penetration resistance beneath subsoiling depth in middle and end of the season. The subsoiling depth of 40 cm has achieved the highest values for disruption area and soil moisture content at/beneath subsoiling depth in the middle and end of season, While the subsoiling depth of 20 cm has achieved the lowest values of soil penetration resistance at/beneath subsoiling depth in the middle and end of season and soil saturated hydraulic conductivity. The cultivated soil case has achieve the highest values for disruption area, soil moisture content at/beneath subsoiling depth in middle and end of season and saturated soil hydraulic conductivity.
