O. Schmidt et al., Earthworm communities in conventional wheat monocropping and low-input wheat-clover intercropping systems, ANN AP BIOL, 138(3), 2001, pp. 377-388
A comparative study was conducted on earthworm communities in a conventiona
l winter wheat monocropping system and a low-input intercropping system in
which successive crops of winter wheat were direct-drilled into a permanent
white clover sward. Earthworm abundance, biomass and species composition u
nder the two cropping systems in the second and third years of successive c
ropping were assessed each spring and autumn in farm-scale field plots at f
our sites using formalin and electrical extraction methods. The wheat-clove
r cropping system supported larger earthworm communities (overall mean abun
dance 548 individuals m(-2), 137 g biomass m(-2)) than conventional wheat m
onocropping (194 individuals m(-2), 36 g biomass m(-2)). Between one and fi
ve more earthworm species were recorded in the wheat-clover system than in
the wheat system at three out of the four study sites. Wheat-clover croppin
g especially favoured species belonging to the epigeic and epigeic/anecic e
cological groups such as Lumbricus castaneus, L. festivus, L. rubellus, juv
enile Lumbricus and Satchellius mammalis. Earthworm communities in the whea
t-clover cropping system were comparable in size and species composition to
communities normally found in perennial grassland-type habitats such as pa
stures and grass-legume leys.