Cirsium arvense responses to stubble cultivation and catch crops in organic cropping systems

Summary

Field studies on perennial weeds, such as Cirsium arvense, are necessary to study the systemic effects of weed control. In this study we analyse the responses in above-ground C. arvense biomass and crop yield from results obtained in two organic field experiments, both combining stubble cultivation with post-harvest catch crops. A range of catch crops was investigated, varying in both species mixture and method of establishment, yet stubble cultivation was the only treatment found to reduce C. arvense density. The effect was even seen only in one year when a harsh winter acted synergistically with soil tillage. C. arvense exhibited density-dependent growth, in terms of above-ground biomass at harvest, with an estimated max. exponential growth rate of 0.975±0.1442 y–1 and an equilibrium density of 156±15.89 g m–2, disregarding the effect of harsh winters. We conclude that this logistic growth pattern is important to include in statistical analyses of treatment effects and furthermore suggest additional investigations on the use of catch crops for perennial weed control.