Between 2020 and 2022, the Serail conducted an experiment in connection with the practice of market gardening on plant cover, without the use of herbicides. The objective: to acquire references on the practice of rolling cover crops in order to be able to plant crops there by practicing reduced tillage at the planting line, a technique also called strip-till. At the start of the project, the station self-built a “Roloflex” type faca roller for a total cost of €6,500 on the premises of the Atelier paysan in Renage (Isère).
Rye and triticale, a winning duo
The aim of the 2021 test campaign was to identify the impact of the seeding rate, from the canopy stage to flowering – after grain filling – as well as the nature of the species making up the mixtures on rolling efficiency. . The mixture of rye and of hives, sown at 120 kg/ha, produced more dry biomass and better competitiveness against weeds, unlike the combination of wheat and peas and oats and faba beans. In 2022, triticale was integrated into the test bed.
After two years of experimentation, the Serail was able to conclude that, under the conditions of the experiment, the date of sowing of the cover crop did not advance that of the rolling. However, it had an effect on the dry biomass of the cover crops. The climatic conditions of the region preventing rolling before June 15 for the species evaluated in the project, it would therefore be possible to consider planting cabbages or leeks after rolling. Regarding weeding, manual passages must be provided for good management of regrowth of the cover in the following crop. The project also showed that tall species such as rye and triticale are good candidates for rolling. The considerable length of their stems favors the action of the knives of the roller, thus depriving the plant of any resource to start again.
What about small areas?
Market gardening on small areas is attracting more and more newcomers. According to the National Federation of Organic Agriculture (Fnab), in 2013, 58% of project leaders set up in this type of market gardening were not from an agricultural background. To help them calculate the viability of their farm, the Serail conducted the Mips AuRA experiment (intensive market gardening systems on small areas). The station demonstrated that “the strong initial investments and the increase in the surface under shelter seem to make it possible to obtain a positive result for the system in a small surface”. The measured turnovers are on average higher in the small area system with 8.70 €/m² against 6.30 €/m² for the traditional system. The working time measured on a small surface is nevertheless more substantial: 20 min/m² developed against 11.6 min/m² on a conventional surface.
