Haplic Chernozem properties as affected by different tillage systems

Abstract

During 2007-2011 we assessed content and quality of humic substances with relationship to soil structure. Object of study was Haplic Chernozem (Hrušovany nad Jevišovkou, Czech Republic) under three different tillage systems: - conventional ploughing to a depth of 0.22 m (CP); - reduced tillage with shallow harrowing to a depth of 0.15 m (RTSH); - reduced tillage with subsoiling to a depth of 0.35-0.40 m (RTS). Isolation of humic acids was made according to IHSS standard method using spectrometer Shimadzu 8700. Aggregates stability was determined by wet sieving method. Results showed that macrostructure stability was directly connected with time of sampling and content and quality of humic substances. After five years of experiment statistically significant differences in humic substances content were found. The highest structure stability quantity and quality of humic substances were achieved under reduced tillage with shallow harrowing.