Interrelation between soil physical properties and Enchytraeidae abundances following a single soil compaction in arable land

In spring 1995 a silty clay soil was compacted dynamically by wheeling with graded wheel loads up to 6 times. The reaction towards wheeling was record ed immediately. In the following 3 years some soil physical parameters as w ell as the Enchytraeidae abundances were recorded regularly. To the first w heeling, the soil reacted plastically in vertical direction. The reaction b ecame elastically after the 4th wheeling. After the 6th passage with a 5-to nnes wheel load soil structure collapsed totally, which can be concluded fr om the stress ratios. After the wheeling event, abundances of Enchytraeidae decreased obviously compared to uncompacted plots. The increase in air per meability, air capacity, and the decrease of soil bulk density depend on pr imary tillage events. The recovery of Enchytraeidae abundances developed in parallel. Abundances seem to be regenerated in the 3rd year after the whee ling event. Primary tillage can help to induce biological and macroscopic c ompaction event.