The implications of copper fungicide usage in vineyards for earthworm activity and resulting sustainable soil quality

To investigate the impact of copper-containing fungicides (copper oxychloride) on earthworms in South African vineyards, field inventories of earthworms in and between vine rows were carried out and compared to directly adjacent grassland. Also copper content, pH, organic matter content, and soil porosity were determined in these soils. This was combined with laboratory experiments to study the impact of vineyard soil characteristics on the burrowing and dispersal behavior of earthworms. Moreover, the direct toxic action of copper oxychloride on different endpoints of the earthworms (survival and growth) was studied. Copper oxychloride had a negative impact on these endpoints (decreased growth and survival related to increased copper body content) as well as on the behavioral aspect (decreased burrowing rate and avoidance of copper-containing soil). Moreover, there was an inverse relation between burrowing activity and soil bulk density that could also be related to the copper content. This may lead to a decrease in sustainable soil quality in vineyards.