Impact of Organic Crop and Livestock Systems on Earthworm Population Dynamics

Summary in the original language of the document

Earthworm population dynamics and diversity were evaluated in long-term farming systems experiments at the West Virginia University Organic Research Farm from 2000-2007. Farming systems included vegetable and field crop rotations, with versus without annual compost amendments. Field crop rotations with livestock included three years of clover-grassland. Earthworms were monitored by hand-sorting soil samples. Aporrectodea caliginosa and Lumbricus rubellus were the most common species observed. Cultivation adversely affected earthworm populations in all systems, while compost amendments either had no effect or increased earthworm populations. The population structure shifted toward younger age classes and lower biomass. Inclusion of clover-grassland in the rotation for pasture and hay production for sheep had no significant effects on populations in the field crop systems.