Manipulating plant species diversity with cover crops - enhancing both biodiversity and weed management in cereals?

Summary in the original language of the document

Summer annual plant species dominate the weed flora if crop rotations primarily consist of spring-sown crops. In addition, some perennial species, such as Cirsium arvense (L.) Scop., Elymus repens (L.) Gould and Sonchus arvensis L. thrive in cereals and impede cropping particularly in organic production systems. In Finland, spring cereals account for more than 50% of the arable land and, although more than 150 weed species have been recorded in Finnish farm fields, only some 10-15 species are prevalent in cereals both in terms of density and biomass production and not many of these provide notable ecosystem services.
In organic production of cereals, the integrated weed management strategies should include cropping measures and crop sequences which create more balanced and manageable weed floras, which consist of less harmful species for crop production. Cover crops and their management are of interest in this respect.
Cover/catch crops were studied in the field experiments that started at Luke Jokioinen in 2015 as a part of PRODIVA project*. Various leguminous species and some grass species (ryegrasses, rye, timothy) were grown in mixtures and sown at high seeding rates with the aim to hamper the growth of weeds as well as to support biodiversity at higher trophic levels. The cover crops were sown in organically grown spring barley in 2015 and, subsequently, in winter wheat in May 2016. Some experimental aspects and first results will be presented and discussed in the EWRS working group meeting.
*The PRODIVA project, funded by the Core Organic Plus ERA-NET action, was started in 2015 with the aim to promote crop diversification and demonstrate its impact on weed infestation. More information at : http://coreorganicplus.org/research-projects/prodiva/.