Action 1: Characterization and selection of species
This action aims to evaluate the interest of taxa identified as potentially interesting. We will proceed in three steps: the development of grids for the selection and evaluation of taxa, the actual selection of taxa and their supply and finally the evaluation of their interest. Seven partners are involved in this action.
1.1 Construction of evaluation grids adapted to each use situation
This task will consist of listing and prioritizing the criteria to be taken into account for the selection of ground cover species according to their use: within the row, between the tree rows, between greenhouses, edge of plot ... Some of these criteria are common to all uses. For example, all plants should cover the soil quickly and require little maintenance. Others are specific to the usage situation. Here are two examples of criteria sought according to the use situation:
soil management within the row of grapevine in Pays de la Loire: creeping plant, resistant to drought, allelopathic, not too competitive with the vine.
edge of above ground irrigated plots in Pays de la Loire: creeping plant, resistant to trampling, supporting regular watering, highly competitive.
The criteria will be defined by experts and by bibliography.
1.2 Selection of taxa to be tested
The grids built in task 1.1. will be used here to identify and select candidate ground cover species. The list of species will be done by mobilizing the knowledge held by seed partners and distributors. This knowledge can be derived from bibliographical summaries, experiments or expert statements.
1.3 Test of selected species
The species can be tested alone or in a mixture. They will be implemented in mini-plots to i / verify their behavior in relation to the selection criteria, that is to say to validate the theoretical choice made in task 1.2. and ii / collect missing or complementary data, particularly on the procession. The level of identification will be limited at the taxonomic level providing essential information for the interpretation of the data ie diet, host plants for phytophages or prey for predators.
Action 2: Development of multiplication, implantation and driving techniques
For each taxon selected in action 1, we will evaluate the appropriate propagation methods (cuttings, sowing, etc.) if no technical data exists. Different methods of implantation (sowing, hydroseeding seeds or fragments, planting micro-clumps ...) will be evaluated. Finally, we will define the necessary maintenance methods (mowing, weeding, over-sowing ...).
2.1 Multiplication and sales conditioning
This work should identify the best method of multiplication (sowing, cutting) and the best packaging for sale (seeds, carpets, mini-clods ...). For some species this data is already known and will not require work. For others the data is non-existent. We will rely on the biological data of the species to design and test the different methods of multiplication and sales conditioning.
2.2 Implantation and maintenance of cover-crops
Here we will study the best conditions of implantation (sowing, "hydroseeding" seeds or fragments, laying carpets ...), maintenance (mowing, grinding ...) and sustainability (over-sowing ... ) of cover-crops. For example, in horticulture, we will compare the establishment of Phuopsis stylosa carpet or hydroseeding fragments since this plant multiplies very easily by cuttings. In fruit growing, two aspects will be studied in particular to optimize the planting of a ground cover plant. First, a planting of legumes in intermediate culture will be tested before planting fruit trees; this intermediate culture is supposed to improve the conditions of implantation of the future orchard and also of a herbaceous planted to cover the band of soil about one meter on both sides of the line of trees. A re-design of the irrigation system will also be tested with the installation of two underground irrigation ramps on either side of the tree line to improve the distribution of water available for the cover crop.
Action 3: On-farm cover-crops assessment
Action 3 will make it possible to check whether the expected characteristics of the plants (covering rate, effect on weeds, etc.) recorded in action 1 and 2 are found on the different production sites. Moreover, this action will make it possible to obtain new data essential for the transfer of the created routes: effects on the yield, on the populations of pests and auxiliaries on the cultivated plants, on their cost ...
3.1 Behavior of the ground covers
The characteristics of the different cover crops in real situation (soil covering rate, weed competition, entomofauna associated ...) will be compared to those determined in action 1 and 2. This will validate the robustness of the characteristics of cover-crops and to identify the situations to favor.
3.2 Effect of ground cover on crops
Here are the parameters relating to culture that will be studied. This will evaluate the effects of cover crops selected in Action 1 and 2 on crops. For example, we will study the effect of a ground cover on the vigor and yield of perennial crops. For effects concerning biodiversity, we will study the procession of pests and auxiliaries on crops.
Action 4: Project coordination, dissemination and educational transfer
4.1 Project Coordination
4.2. : Dissemination
The objective is to disseminate the results to the actors of the various sectors (PPAM, arboriculture, market gardening, viticulture) by targeting different actors: producers, teachers, agricultural technicians, experimentalists, researchers ...
4.3. : Educational transfer
As part of the Agro-ecological plan for France, with the setting up of regional networks "Teaching to Produce Otherwise", the educational transfer is at the heart of the challenges for the agro-ecological transition. Teachers and their learners will be involved in the monitoring of the tests throughout the project by making observations, interpreting data, writing summaries, making posters ... The steps and results obtained by the various partners can be disseminated via conferences in training institutions or the setting up of data sheets.