Data from: Conservation tillage mitigates the negative effect of landscape simplification on biological control

Biological pest control is a key ecosystem service, and it depends on
multiple factors acting from the local to the landscape scale. However,
the effects of soil management on biological control and its potential
interaction with landscape are still poorly understood. In a field
exclusion experiment, we explored the relative effect of tillage system
(conservation vs. conventional tillage) on aphid biological control in 15
pairs of winter cereal fields (barley and wheat) selected along a gradient
of landscape complexity. We sampled the abundance of the main natural
enemy guilds, and we evaluated their relative contribution to aphid
predation and parasitism. Conservation tillage was found to support more
abundant predator communities and higher aphid predation (16% higher than
in the fields managed under conventional tillage). In particular, both the
abundance and the aphid predation of vegetation- and ground-dwelling
arthropods were increased under conservation tillage conditions.
Conservation tillage also increased the parasitism rate of aphids. A high
proportion of semi-natural habitats in the landscape enhanced both aphid
parasitism and predation by vegetation-dwelling organisms but only in the
fields managed under conventional tillage. The better local habitat
quality provided by conservation tillage may compensate for a low-quality
landscape. Synthesis and applications. Our study stresses the importance
of considering both soil management and landscape composition when
planning strategies to maximize biological control services in
agro-ecosystems, highlighting the role played by conservation tillage in
supporting natural enemy communities. In simple landscapes, the adoption
of conservation tillage will locally improve biological control provided
by both predators and parasitoids mitigating the negative effects of
landscape simplification. Moreover, considering the small scale at which
both predation and parasitism responded to landscape composition, a
successful strategy to improve biological control would be to establish a
fine mosaic of crop and non-crop areas such as hedgerows, tree lines and
small semi-natural habitat patches.