Context and objectives:
Organic vegetable production systems in greenhouses need to reduce their potential negative impacts on the environment. It is therefore important to investigate the agro-ecological approach. These systems, designed to be resilient by promoting above- and below-ground biodiversity, can also contribute to greater farmers’ autonomy from external inputs, and must preserve the productive and economic potential of the system.
The tests are being carried out at the GRAB experimental station located in Avignon (Provence, France). A "classic" system (BAU) is compared to 5 innovative systems (INN) in 2 plastic 400 m2 tunnels over three years. Three main factors are implemented:
- Flower strips along the tunnel borders to promote functional biodiversity, by encouraging natural enemies. This technique aims to limit phytosanitary treatments and introduce exogenous beneficial insects.
- Crop associations to diversify the growing system by growing several species simultaneously: a mixture of 2 species in summer (tomato + cucumber in 2018) and several leafy vegetables in autumn/winter (lettuce + kohlrabi + spinach + lamb's lettuce in 2018-1019). This factor should reduce the sensitivity of the culture system to airborne and soilborne pathogen problems.
- "transfer mulch", a plant organic material spread in a layer of 5-10 centimeters on the soil surface. This technique aims to limit weed development as an alternative to plastic mulch or weeding operations, stimulate soil biological activity and contribute to crop nutrition, while reducing the use of external fertilizers.
These 3 factors are implemented in different systems, with the most innovative (INN) combining all 3 factors.
We assess nutrient use (especially nitrogen), soil fertility and biodiversity as well as the above-ground fauna and flora. In terms of sustainability, outputs will help to compare the impact on greenhouse gas emissions and other ecological factors. We will also calculate key economic performance indicators for this site.
Jerome Lambion, GRAB
Hélène Védie, GRAB