Continuous redox potential measurements in zero tilled and ploughed clay soils

Zero tillage with a crop covered soil surface change topsoil structure affecting soil physical conditions. In the present study, tTwo long-term tillage field experiments were utilized to investigate the effects of tillage intensity on soil properties. Our aim was to investigate the effects of tillage intensity change on the living conditions of soil microbes. Four identical measurement stations to determine soil conditions all year round were prepared on ploughed and zero tilled plots. In the present paper, the results of continuous soil redox potential and temperature determinations in the layer of 10–15 cm during one year (June 2009 to May 2010) are introduced. The variation of redox potential results was high as was expected. When the data of one year was examined, clear positive linear dependence between soil redox potential and temperature was observed. Based on the mean values of one year experimental period, no marked differences in topsoil redox potential between autumn ploughed and zero tilled soil were observed. Both during the growing season and outside the growing season after heavy showers, there were periods during which topsoil redox potential decreased rapidly and the change was longer than usually in connection with rapid changes. During these periods, there were differences in soil redox potential between tillage treatments caused probably by the differences in soil structure, temperature and moisture conditions, and the interaction between soil conditions and crop development stage.