| dc.description.abstract | Paddy soil tillage in Indonesia is still employed by human power, animal power, and hand tractor which requires more time so that resulting low capacity, whereas the use of four-wheel tractor is relatively little. In application, agricultural mechanization causes reciprocal relationship between soil and tractor. Reqiurements in the application of four-wheel tractors on soil tillage are such the ground pressure must be smaller than soil shear strength and sinkage must be smaller than ground clearance of tractor. In this research, estimation of sinkage determined based on direct shear test on undisturbed soil and disturbed soil. The results shows that increasing water content results in declining soil cohesion and soil shear strength. It leads to bigger sinkage. Analysis of using undisturbed soil produces smallest sinkage in SS location dominated by clay fraction with 0.33- 5.49 cm on soil cohesion 0.282-0.397 kgf/cm2 andbiggest sinkage is in S-14 location dominated by the silt fraction with higger than tractor ground clearance (35.5 cm) and soil cohesion 0.011-0.029 kgf/cm2. Based on the predicted results, four-wheel tractor can only operate in location SS and L-18. | en |
