Beneficial links for the control of aphids: the effects of compost applications on predators and prey

Use organic rather than mineral fertilizers

Two replicated controlled trials in Warwickshire, UK (Bell et al. 2008) found that adding compost or green manure to wheat fields increased numbers of arthropod predators and springtails (Collembola) in the soil at or close to where the compost was added. The effect was local and did not translate to a field-scale increase in numbers of ground active arthropod predators when 1.5 to 3 m-wide strips of compost were added to fields. There were also fewer cereal aphids (pests) (Aphidoidea) in plots with compost applied, but in field-scale experiments this difference was not statistically significant. In the small scale experiment, half of 160 plots 30 x 35 cm in size (2000) or 20 plots of 4 m² (2001 and 2002) were treated with mushroom compost in April, half were not. Arthropod predators in the soil were sampled within sunken bowls between April and May each year. In the large-scale experiment, 20 x 10 m plots were treated with compost in one 3 m-wide strip, two 1.5 m-wide strips, or not given compost. There were six replicates of each treatment. Arthropod predators were sampled in a large pitfall trap and two 0.5 m² quadrats 1-6 m away from the experimental treatments. Springtails were counted from soil cores in the compost strips and 1 m and 6 m away.