The relationship between redox potential and nitrification under different sequences of crop rotations

Redox potential (RP) is an easily measured soil characteristic which is affected by many of the chemical, physical and biological processes in the soil, but it has been largely ignored as a useful characteristics in arable soil. The influence of different sequences of crop rotation on RP and nitrification in the topsoil and the subsoil of a Luvic Chernozem were investigated during the vegetation season (April–July) of the years 1994–1999. RP was higher in the topsoil (0–30 cm) than in the subsoil (30–60 cm). In aerobic field conditions we found a significant difference in RP values between cropping sequences. The highest RP and lowest potential nitrification was under the cropping sequence of barley preceded by sugar beet and the lowest RP and highest potential nitrification was found under wheat after alfalfa. RP was negatively correlated with potential nitrification under all copping sequences in the topsoil. We assume that RP could be used as an important indicator of processes in the field, not only in anaerobic soil conditions but also in aerobic conditions.