Can differences in Cirsium arvense and Rumex obtusifolius densities within pastures be explained by soil parameters?

摘要

Some organic farming literature suggests that the presence of weeds in pastures can be explained by problems with the soil. Sixty 1 m2 patches of pasture with different densities of broad-leaved dock (Rumex obtusifolius) were identified across six different paddocks on an organic dairy farm. Various soil parameters were measured in each patch to determine if any of these correlated well with the differing weed densities. Parameters measured included soil pH, moisture, compaction and concentrations of12 nutrients in adjacent perennial ryegrass. This process was repeated for Californian thistle (Cirsium arvense) using a different series of 60 patches. Significant correlations were found between dock density and pH, potassium, magnesium and manganese,and Californian thistle density was significantly correlated to soil pH and sulphur content. However, these correlations were generally weak and are not considered good indicators of whether these weed species would thrive within this particular farm.