Agro-Ecological Practices Benefits on Nutritional Value of Cereals and Legumes in Burkina Faso: Sorghum-Legume Intercropping and Soil Enrichment with Biomass

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Résumé

Summary Agriculture in the sub-Saharan zones must be focused on preserving nutrients to meet the nutritional needs of populations. Cereal-legume crop combinations are an agro-ecological solution adopted by sub-Saharian farmers. The aim of this study was to determine the impact of cereal-legume crop associations and legume biomass enrichment on the protein, iron and zinc content of cereal grains and legumes. Sorghum was associated with cowpea, peanut, mung bean and Bambara nut in a triple trial on a homogenised soil; for each trial, a plot of pure crop was carried out. A triple trial was carried out using legume biomass to enrich the soil for sorghum. Nutritional characteristics of the grains were analysed using the AOAC method, physical parameters were analysed using the MARVIN seed analyser. A 14.1% increase in protein content was obtained in sorghum grains combined with bambara nut and 31.6% in sorghum grains grown on soil enriched with biomass. Zinc levels rose from 27% in sorghum associated with cowpea. The nutrient contents of legumes varied little apart from the raw ash content of bambara nut which decreased by 21% and an increase of mung bean iron content when associated with sorghum (13,5%) and an decreased of iron content of cowpea associated with sorghum (14.4%). The thousand-grain weight (11.14%), of Cowpeas increased, while the grain area (15.48%), of Bambara nut increased. This suggests competition between sorghum and legumes, which varies the nutrient content and physical characteristics of grains. The combination of sorghum and cowpea would be the most beneficial for sorghum.

Mots-clés

crop association, sorghum, legumes, nutritional characteristics