SOIL TILLAGE IMPACT ON THE DIURNAL REDOX-POTENTIAL CYCLE

Tillage-induced changes in soil physical properties affect the chemical and biological properties of that soil. The objective of this study was to determine the influence of soil tillage on the structure of redox-potential cycles in the field. Platinum electrodes and Cu-constantan thermocouples were installed under two field treatments (rototillage/residue incorporated or no-tillage/surface residue) at 7-, 15-, and 22-cm soil depths, and readings taken at intervals of 2 and 3 h during the 1986 growing season. During the early part of the corn (Zea mays L.) growing season, water evaporation was minimal and soil temperatures were higher in the rototill than the no-till treatment. During a later part of the growing season, water evaporation was high and on a diurnal cycle, and both redox potentials and soil temperatures followed diurnal cycles.