The unique and complementary traits of cereal rye (Secale cereale L.) and the legume hairy vetch (Vicia villosa Roth) make winter annual cover crop mixtures of the two species promising for vegetable cropping systems. Informed management of the relative species proportions in the mixture could provide an important means of optimizing performance to serve various farmer goals. A variation of the replacement series experimental design was used to investigate 1) how relative species composition (seeding rates) influence biomass characteristics of cover crop mixtures, and 2) the interactive effects of mixture residues and the use of black polyethylene mulch (PM) on cover crop mixture performance in bell pepper and slicing cucumber cropping systems, based on a systems-level investigation of agro-ecological services that cover crops can provide. Results show that cover crop mixture proportion and the use of PM affect weed communities, soil chemical and biological characteristics, and crop productivity.
The overall objective of this study was to improve our understanding of how species proportions (based on seeding rates) of a mixture of cereal rye and hairy vetch influence cover crop performance in a vegetable production system with respect to crop grown and plastic mulch use. Performance was evaluated based on a systems-level approach to data collection, encompassing the following specific objectives:
- Quantify trends in cover crop establishment and total residue quantity and quality across rye-vetch mixture rates.
Study the effect of mixture rate on winter annual and summer annual weed populations.
Quantify trends in soil inorganic N dynamics across mixture treatments and PM use.
Evaluate the effects of mixture rate and PM use on soil microbial biomass and community functional diversity.
Evaluate the effects of mixture rate and PM use on vegetable yield and fruit quality.