Conservation tillage or residue conservation? An evaluation of residue management in Mexico

Abstract

The key to conservation tillage is the use of crop residues as mulch. However, there is some confusion over the term conservation tillage, among other things, because too much emphasis has been placed on tillage. Since tillage is only one of many factors that affects residue availability in the tropics, residue conservation would seem a more appropriate term in those environments. In Mexico, the emphasis of conservation tillage campaigns has been on no burning and no soil inversion (no plowing). In fact, burning and soil inversion are imcompatible with retaining enough residue to form an effective mulch. However, it should be noted that all uses of crop residues have to be taken into account to practice effective residue conservation, i.e., not only burning or plowing, but also residue extraction, overall incorporation, and weathering, as well as the amount of residue produced. All alternative uses and total residue production should be factored in to the residue balance, which is specific to each locality.