INFLUENCE OF DIFFERENT SOIL TILLAGE AND C ROPPING SYSTEMS ON AGGREGATE STABILITY

In this study the influence of different farming systems concerning th e dynamics of aggregate stability of arable soil during one growing se ason was investigated. The main emphasis of the descriptions is based on a comparative interpretation of stability values of a reduced tille d crop rotation changing within a four-years-rhythm and of a conventio nally tilled monoculture (Zea mays L.). The soil samples were collecte d from March to October 1992. The testing of aggregate stability of sa mples taken at six different points of time shows that the plots with reduced tillage and crop rotation show a significantly higher stabilit y than the conventionally tilled ones. There are positive correlations in aggregate stability between the separately tested layers (0 to 10 cm, 10 to 20 cm). The water content tested at the time when the sample s were taken can not be connected with the level of the aggregate stab ility. The seasonal variation of the stability of soil structure can b e used as an argument for adequately investigating a dynamic system su ch as the aggregate stability of soil only through a diacronic approac h.