بررسي اثر كاربرد گاوآهن بر گرداندار مركب بر شكست سخت لايه شخم

The Effect of a Combined Moldboard Plow to Break Plow Pan

Nowadays using combined machines in tillage systems is unavoidable. Moldboard plows are being widely used without conducting necessary pre-investigation in Iran. Previous studies indicated that continuos use of moldboard plow resulted in plow pan at a depth ranges 25-35 cm. Farmers often use subsoiler for breaking plow pan similar to deep hard pan although these two layers are not similar particularly for depth. The aim of this research was to improve the common moldboard plow for breaking the plow pan during plowing. Therefore, a combined plow developed with similar shank to chisel plow placed on behind of the moldboard. The shanks adjusted to work at 7-10 cm deeper than moldboard plow. Field tests were conducted in a research station located at 3 Km south-west of Karaj region with loamy soil texture. Two treatments of combined plow and conventional moldboard plow were compared by using t-test statistical analysis. Parameters such as bulk density, penetration resistance, soil failure profile, soil disturbed area, draft and specific draft were either measured or calculated and then compared for treatments. Results indicated that combined plow could break the pan by improving soil physical properties as well as soil failure profile and disturbed area significantly. Combined plow increased draft 15% compared to conventional plow. As new plow resulted in greater disturbed area, the difference for specific draft decreased to 6%. This study suggests that the combined plow can be subsitute to conventional plow in soil with considerable plow pan.