Evaluation of coulters for cutting sugar cane residue in a soil bin

Conservation tillage is a method of cultivating crops which improves soil conservation and can produce lower production costs than conventional tillage systems. Although these systems have been widely adopted in recent decades for many crops, they are not generally accepted for sugar cane producers, because the presence of crop residues covering the soil surface makes fertilizer application more difficult during ratoon cultivation. In a conservation tillage system, in order to perform the necessary cultivation tasks adequately, soil-engaging implements need to be equipped with residue-cutting tools. Laboratory experiments were conducted to evaluate the performance of toothed coulters in comparison with notched coulters and smooth coulters, in cutting sugar cane crop residue. The draught force, the torque required by the coulters, and the amount of uncut crop residue (per linear metre) were measured in a soil bin filled with a sandy clay loam soil. Tests were conducted at two working depths (80 and 100 mm). The results showed that toothed coulters performed best, since they were more efficient than smooth and notched coulters in cutting crop residue, with smaller torque, and lower vertical and draught force requirements. (C) 2008 IAgrE. Published by Elsevier Ltd. All rights reserved.