Individual study: Effects of manipulating crop architecture on weed and arthropod diversity in winter wheat
Smith B. & Jones N.E. (2007) Effects of manipulating crop architecture on weed and arthropod diversity in winter wheat. Aspects of Applied Biology, 81, 31-38
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Plant cereals in wide-spaced rows
A replicated, controlled study in 2002 and 2003 of wheat fields at ten sites in England (Smith & Jones 2007) found that sowing crops in wide-spaced rows had little effect on plant cover and species richness or arthropod abundance. There was no significant difference in weed cover (1-2%), crop cover (30-48% vs 33-55%) or plant species richness (7 vs 7 species) between fields with wide-spaced rows and control fields. There was little effect of wide-spaced rows on arthropod abundance. However, in 2002, wolf spiders (Lycosidae) were more abundant in fields with wide-spaced rows (0.9 individuals) than controls (0.4), the opposite was true for rove beetles (Staphylinidae: 4 vs 6 individuals in fields with wide-spaced rows and controls respectively). Wide-spaced rows were sown at double the normal width (25 cm between rows). Vegetation composition was sampled within 24 quadrats (0.25 m²) in May and July (2002 and 2003). Arthropods were sampled in the same locations using D-Vac suction sampling (May, June, July), sweep netting (May, June) and pitfall traps open for 7 days (June). This study was part of the same replicated, controlled study (SAFFIE – Sustainable Arable Farming For an Improved Environment) as (Morris et al. 2004, Ogilvy et al. 2006, Smith et al. 2009).
Create skylark plots
A replicated, controlled study in 2002 and 2003 at ten sites in England (Smith & Jones 2007) found that plant species richness and arthropod species richness in one of two years were higher in wheat fields with undrilled patches than control fields. Weed and crop cover did not differ significantly between treatments (weeds: 1-2%; crops: 33-55%), but plant species richness was higher in fields with undrilled patches (11 species) than control fields (7 species). Weed cover and species richness were also significantly higher on undrilled patches (1-22% cover; 9-10 species) than the surrounding field (1-4%; 5-8 species). In 2002, arthropod species richness and rove beetle (Staphylinidae) abundance were higher in fields with patches than control fields (10 vs 6 arthropod species; 9 vs 6 rove beetles), there was no difference in 2003. In 2002, wolf spiders (Lycosidae) were more abundant in undrilled patches than the surrounding field (1.1 vs 0.4 individuals), whereas the opposite was true for rove beetle abundance (4 vs 9 individuals), species richness (4 vs. 6 species) and in 2003 abundance of ground active invertebrates (0.3 vs 104 individuals). In 2002, arthropod abundance was higher in the surrounding fields than undrilled patches in May (23 vs 16 individuals), but higher in undrilled patches than surrounding fields in July (53 vs 36). Undrilled patches (4 x 4 m) were created at a density of 2 patches/ha in an otherwise conventionally managed crop. Vegetation composition was sampled in 24 quadrats (0.25 m²) in May and July 2002 and 2003. Arthropods were sampled in the same locations using D-Vac suction sampling in May, June, and July and in pitfall traps for 7 days in June. This study was part of the same replicated, controlled study (SAFFIE – Sustainable Arable Farming For an Improved Environment) as Morris et al. 2004, Ogilvy et al. 2006, Smith et al. 2009.