Optimising Subsidiary Crop Applications in Rotations (OSCAR): A Perspective for the North Africa Region

Background: For sustainable improvement of wheat-based farming systems in the North Africa, there is a need to improve plant health, soil health and fertility. One approach to achieve this is by integrating subsidiary crops (SC) as living or dead mulches or cover crops with the main crops in rotations, which will increase plant species and microbial diversity and reducing water demand in dry climates. Methods: A collaborative research project funded by EU FP 7 (Project No. 289277) was initiated in April 2012, in partnership with European Union (public research organizations and private sector small and medium enterprises of Germany, Norway, Sweden, Denmark, the Netherland, UK, Poland, Switzerland and Italy), Brazil and Morocco (INRA-Morocco and ICARDA), in order to enhance understanding and use of SC systems, develop suitable farm technologies, increase the range of SC species, and enhance understanding of impact of SC on soil ecology, biology and microbial diversity and crop pests and diseases. Results: Based on two field experiments in Morocco (Sidi AI-Aidi and Sidi Allal-Tazi), the project will assess the economic and ecological impact including legume root health and soil health, fertility and microbial diversity and compare the results with other sites in Europe. Screening of new species and genotypes will result in identification of range of potentially useful plant species for SC for the North Africa and Europe. The identified SC species will be tested for their potential as forage and for extraction of useful biochemicals. Conclusion: The results of the project as a whole will be of use for and improve sustainability in low-input, organic, and conventional farming systems in the North Africa, Latin America and Europe

Towards identification of novel legume species of potential interest as cover crops and living mulches for the North Africa region.

Subsidiary crops (SC) grown either as cover crops (CC) preceding or following the main crops, or as living mulches (LM) together with the main crops can deliver multiple ecological services within farming systems. These include increasing the duration of soil cover in the rotation, increasing plant and microbial diversity, improving plant health, soil health and fertility, minimizing the use of tillage and agrochemicals, enhancing biological N fixation and soil C content, and reducing water demand in dry climates. However, species available for growing as SC for dry areas are limited. To identify species of potential interest to CC and LM, we screened 197 accessions from the ICARDA genebank, belonging to 142 species/sub-species at Rabat, Morocco in one square meter plots. The preliminary assessments based on visual observations enabled us to identify: (1) 21 accessions belonging to Medicago and Trifolium species with prostrate growth habit, early maturity and senescence, determinate growth cycle and good potential for seed production, as potentially suitable for LM; and (2) 28 accessions belonging to Vicia, Lathyrus, Medicago and Trifolium species with high biomass and competitive ability, and also good potential for seed production, as potentially suitable for CC or green manure crops. Further evaluations in replicated trials are in progress. The selected accessions have been planted in the field during autumn 2013 at Sidi El Aidi