Ka. Tarrant et al., EFFECTS ON EARTHWORM POPULATIONS OF REDUCING PESTICIDE USE IN ARABLE CROP ROTATIONS, Soil biology & biochemistry, 29(3-4), 1997, pp. 657-661
The SCARAB project is a held-scale, six-year investigation of the effe
cts of pesticide use on invertebrates and soil microflora in arable cr
op systems common in the U.K. Two pesticide regimes are being compared
: current farm practice (CFP) which represents typical levels of use i
n the study localities, and reduced input approach (RIA) in which inpu
ts have been reduced by 50% and no insecticides used. The treatments b
egan at three farms in 1990, and effects on earthworm populations have
been monitored twice yearly since Spring 1993. Particular attention w
as paid to age and species composition. Results up to Spring 1994 show
ed that although some differences existed between earthworm population
s in RIA and CFP plots they lacked consistency over time and between t
he pairs of plots, and were of negligible magnitude compared with over
all differences between the farms. It was concluded that the two pesti
cide regimes caused no ecologically significant differences in earthwo
rm populations at this stage of the project. The substantial differenc
es in earthworm populations between farms were largely consistent with
the expected effects of differences in climate, soil types, crop type
s, cultivations and pesticide use, although the relative importance of
these factors can not yet be assessed. Crown Copyright (C) 1997 Publi
shed by Elsevier Science Ltd.