|Velazquez G., J. - INIFAP|
Submitted to: Southern Conservation Tillage for Sustainable Agriculture Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 9, 2001
Publication Date: July 9, 2001
Citation: Potter, K.N., Velazquez G., J. de J., Torbert, H.A. No-till and residue removal effects on soil carbon content. Stiegler, J., editor. Proceedings of the 24th Annual Southern Conservation Tillage Conference for Sustainable Agriculture. 2001. p. 28-33. Interpretive Summary: Soil organic carbon, an indicator of soil quality, generally increases after conversion from inversion tillage to no-till management practices. However, this assumes that the crop residue is left on the soil surface with no-till. In Mexico, crop residues are often utilized as animal fodder, even with no-till management practices. We conducted a study to determine the effect of removing different amounts of corn residue on soil organic carbon content associated with no-till. No-till practices with all residue removed usually maintained soil organic carbon levels about the same as that which occurred with moldboard plowing. Leaving residue generally increased soil organic carbon content. With higher mean annual temperatures, leaving residues on the surface was less effective in increasing soil carbon content than with lower mean annual temperatures. Higher rainfall usually increased soil carbon content with larger amounts of residue remaining on the surface. Leaving crop residues in the field with no-till management can increase soil carbon contents, but with some climatic conditions the residue may be better used as animal fodder.
Technical Abstract: No-till crop management often results in increased soil organic carbon contents. However, the effect of residue removal with no-till on soil carbon content is not well understood. We conducted a multiyear study at six locations in central Mexico, with a wide range of soil and climatic conditions to determine the effect of varying rates of residue removal and no-till management on soil carbon content. Treatments consisted of annual moldboard plowing and no-till management practices with 100 percent, 67 percent, 33 percent and none of the corn (Zea mays) crop residue retained on the no-till soil surface. No-till practices maintained carbon levels above that of moldboard plowing at five of the six locations even when all crop residues were removed. Retaining crop residues on the soil surface increased soil carbon content, but at a much faster rate in cool conditions than in tropical conditions. Carbon content was greater with higher amounts of rainfall than in the drier regions. No-till will increase soil carbon content, but climatic conditions should be considered to determine if crop residue would be more effectively utilized as animal fodder.