- Documents and dissemination

- WP 2.1. Soil tillage management

- WP 2.2. and 2.3. Organic fertilization and green manure

- WP 2.4. Intercropping with legumes

The effects of intercropping with legumes on winter wheat performance and quality are assessed under three field experiment programmes (led by ESA and ISARA in France and ART in Switzerland). Various types of intercropping are assessed together with use of living mulch. Each of them aimed to manage the nitrogen resource for better wheat nitrogen nutrition and to mitigate the weed development.

First practice assessed is the combination of winter wheat and pea (changing the part of each crop, the amount and timing of organic fertilization). Cereals may be also intercropped with forage legumes in view of similar objectives. Nevertheless in such systems, the legume remains at wheat harvest and tries to mitigate weed infestation, reduce N leaching, improve the soil N pool. Three factors are particularly investigated in this type of farming system: (1) the choice of the forage legume species which could strongly influence the impact of the association on the nitrogen balance and the mitigation of weeds, (2) the architecture of the system (sowing type and width) which would change the relation of competition between the different components of the system and (3) the date of introduction of the forage legume in the system which will change the dynamics of the system. This kind of association is particularly assessed on various field trials in the SE France.Finally, the use of living mulches for weed suppression, protection against soil erosion and improvement of soil structure, is assessed. This practice consists in growing a main crop on a species pre-sown. Legumes are used to reduce nitrogen competition and improve nitrogen nutrition of winter wheat. Three factors were studied on wheat-living mulch (white clover) associations: (1) the presence of living mulch, (2) the sowing density of winter wheat, (3) the width of wheat sowing. This kind of association is studied in Switzerland.

In all these experiments, the effect of such systems on yield, quality and weed and disease infestation are investigated. The interest of such practices for a better management of nitrogen resource at the level of crop cycle and on a longer scale through the use of legumes is particularly assessed. All these experiments try to give elements to improve crop management strategies on these systems.

Field trials involved in the WP:

Responsible partner:

Assistant professor Guénaëlle Hellou
ESA Angers
Ecophysiology and Agroecology Department
55, Rue Rabelais
B.P. 30748
49007 Angers Cedex 01, France

E-mail: g.hellou@groupe-esa.com