Individual study: Unsprayed field margins: effects on environment, biodiversity and agricultural practice
de Snoo G.R. (1999) Unsprayed field margins: effects on environment, biodiversity and agricultural practice. Landscape and Urban Planning, 46, 151-160
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Leave headlands in fields unsprayed
A replicated, controlled study in 1990–1993 of six arable farms in the Netherlands (de Snoo 1999) found that unsprayed crop edge headlands were used more by field mice Apodemus spp. than were crop edges sprayed with herbicides and insecticides. Results were not tested for statistical significance. More field mice were caught in unsprayed crop edges (38 mice caught) than in sprayed edges (27 mice caught). Strips 3–6 m wide, 100–450 m long, along the edges of crops, were left unsprayed by herbicides and insecticides and were compared to sprayed crop edges in the same field. Small mammals were surveyed using pitfall traps during 13 weeks in 1990 and 12 weeks in 1991 (all in May–July). The number of strips on which small mammals were surveyed is unclear.
(Summarised by Nick Littlewood)
Leave headlands in fields unsprayed (conservation headlands)
A replicated, controlled study from 1990 to 1993 of 16 arable fields on farms in the Netherlands (de Snoo 1999) found that unsprayed field margins had greater plant and insect diversity and abundance, and more visits by blue-headed wagtails Motacilla flava flava and field mice Apodemus spp. than sprayed margins. Results for vegetation, butterflies (Lepidoptera), insects in the upper parts of the vegetation and birds are presented in (de Snoo et al. 1994, de Snoo 1996, de Snoo & de Leeuw 1996, de Snoo 1997, de Snoo et al. 1998). Unsprayed margins contained greater diversity and abundance of ground-dwelling invertebrate species (14-17 vs 12-14) and ground beetle (Carabidae) activity density tended to be significantly higher than in sprayed margins. Orb-weaving spiders (Araneida) (in winter wheat) and beetles (Coleoptera) (in sugar beet) were more abundant in unsprayed edges than in sprayed edges (in one year), other ground-dwelling groups did not differ with treatment. More field mouse visits were recorded in unsprayed (38 visits) than in sprayed cereal edges (27). Strips 3-6 m x 100-450 m long along field edges were left unsprayed by herbicides and insecticides and were compared to sprayed edges in the same field. Floristic value was sampled in 75 m² plots (mid-June to mid-July). Insects were sampled by: sweep netting in wheat (June), butterfly transects along crop edges (mid-May to July) and pitfall traps (11cm diameter, May-July). Blue-headed wagtail, Eurasian skylark Alauda arvensis and meadow pipit Anthus pratensis visits were recorded in 6 m winter wheat edges using a linear transect census and small mammals were live trapped in winter wheat.