An Experimental Determination of the Specific Soil Resistance of a Sandy Loam Soil Using Vertical Soil Tillage in the Northeast of Mexico

An investigation was carried out to determine the specific soil resistance using a chisel plough prototype for vertical soil tillage in the semi-arid region of the northeast of Mexico. For this a combination of an axial transducer and an integral soil force dynamometer were used with a capacity of 60 and 80 kN of draft, respectively. The equipment for force measurement was developed and calibrated in the facilities of the Department of Agricultural Engineering of the Agrarian Autonomous University Antonio Narro, Mexico. Fourteen (14) arrangements of chisels plough were evaluated and divided into three blocks, for vertical tillage, with and without expanding wings to two different working depths. In the arrangements of the first block of tests, the performance of a chisel with three sizes of wings against two chisels to a depth of 0.20 m was compared. The results showed that there were no significant differences in the specific resistance of the soil, with an average of 83 kNm(-2). In this first block of evaluations, a reduction of specific resistance of 30 % was obtained with the use of a chisel with any size of wings in comparison with a chisel without wings to a depth of 0.30 m (from 121 to 82 kNm(-2)). In the second block of tests, the arrangement of two leading chisels to 0.20 m working depth with a rear chisel to 0.30 at 0.45 m with 0.45m width size wing in comparison with two leading chisels to 0.20 m and a chisel without wings showed a significant difference in the specific resistance from 73 to 84 kNm(-2) respectively. In the third block, two rear tines with wings to 1.20 m of spacing were evaluated. The lowest specific soil resistance was obtained with the use of 0.60m width size wings in comparison with the other wing geometries with values from 84 and 100 kNm(-2) respectively.