Linyphiid spider populations in sustainable wheat-clover bi-cropping compared to conventional wheat-growing practice
Published source details Gravesen E. (2008) Linyphiid spider populations in sustainable wheat-clover bi-cropping compared to conventional wheat-growing practice. Journal of Applied Entomology, 132, 545-556.
Actions
This study is summarised as evidence for the following.
| Action | Category | |
|---|---|---|
Undersow spring cereals, with clover for example Action Link |  | |
Reduce fertilizer, pesticide or herbicide use generally Action Link | |
Undersow spring cereals, with clover for example
A replicated, controlled, randomized study of undersown and conventional cereal systems in Denmark (Gravesen 2008) found that undersown crops had higher money spider (Linyphiidae) web density, adult Bathyphantes gracilis and Tenuiphantes tenuis (both money spiders), springtail (Collembola) and vegetation density compared to conventional crops. Web density was higher in undersown crops (unfertilized: peak 250-300/m², low fertilizer input: 200-250/m²) than conventional crops (low fertilizer input: 150-200/m², high-input: 100–150/m²). More adult Bathyphantes gracilis were found in undersown crops (5 individuals/m²) and Tenuiphantes tenuis in unfertilized undersown crops (4/m²) compared with the high-input conventional system (1/m²). Springtail density was significantly higher in the fertilized (2350 individuals/m²) than unfertilized undersown crops (1600/m²) and conventional crops (low-input: 1250/m², high-input: 300/m²). Sixteen experimental plots (12 x 50 m) were established in a randomized block design. Treatments were wheat with clover Trifolium spp. undersown, without or with nitrogen fertilization (50 kg/ha), or conventional wheat with low (50 kg/ha) or high nitrogen fertilization (160 kg/ha), only the latter received pesticide applications. Money spider web densities, vegetation density (lower layer only, i.e. clover and weed layer) were sampled between May-October 1995-1997. Money spiders and springtails were sampled in 1996.
Reduce fertilizer, pesticide or herbicide use generally
A replicated, controlled, randomized study of undersown and conventional cereal systems in Denmark (Gravesen 2008) found that money spider (Linyphiidae) web density increased with reduction in fertilizer; the same was true for springtail (Collembola) density in conventional but not undersown crops. Money spider web density tended to be higher in undersown crops with no fertilizer (peak 250-300/m²) than low fertilizer input (200-250/m²) and in conventional crops with low fertilizer input (150-200/m²) than high-input (100–150/m²). Springtail density was significantly higher in the fertilized (2350/m²) than unfertilized undersown crops (1600/m²), but higher in the low-input (1250/m²) compared to high-input conventional crops (300/m²). Sixteen experimental plots (12 x 50 m) were established in a randomized block design. Treatments were: wheat with clover Trifolium spp. undersown, with or without nitrogen fertilization (50 kg/ha), or conventional wheat with low (50 kg/ha) or high nitrogen fertilization (160 kg/ha), only the latter received pesticide applications. Money spider web densities, vegetation density (lower layer only, i.e. clover and weed layer) were sampled between May-October 1995-1997. Money spiders and springtails were sampled in 1996.
