Use of Agroecological Techniques by Smallholder Farmers to Improve Sorghum Productivity in Burkina Faso

The prevailing farming system in Burkina Faso is smallholder agriculture based on cereal production, especially sorghum (Sorghum bicolor (L.) Moench) which form the staple diet for the population. Production is constantly challenged by climate hazards, striga (Striga hermonthica (Del.) Benth.) infestation, inefficient farming practices and declining soil fertility. To address these concerns, one study on several agroecological techniques was conducted from 2013 to 2015 in a participative manner with more than 150 male and female farmers from four communities. Each farmer was asked to test out two or three agroecological techniques of his choice and to measure these new techniques against their usual farming practices. These techniques combined the use of organic fertilizer (5 t/ha) and/or mineral fertilizer (2 g/seed hole) with the systems of crop rotation and mixed cropping, in addition to the improved za? technique and the half-moon method. Plant material was composed of local landraces and improved varieties of sorghum, sesame and cowpea. On-farm application of agroecological techniques resulted in significantly increased sorghum production in all four communities. The rates of increase for grain yield were 8% for the half-moon fields and more than 130% for the rotation systems when compared to the farmers’ usual practices. More limited results were achieved with the chemical components of the soil after two years of experimentation. Only the soil’s organic matter showed improvement over the first year. This study shows that crop rotation, mixed cropping and the improved za? technique in combination with compost and improved drought-resistant varieties constitute agroecological strategies favorable to the intensification and diversification of farming systems in the studied locations. The farmers were above all impressed by the on-site management of compost by means of the za? technique which enabled large-scale fertilization of fields.

Effects of Agroecological Practices on Soil Microbiological Activity in Sudano-Sahelian Zone of Burkina Faso

Microorganisms are key actors in soil quality.However,their activity is influenced by various factors including agricultural practices.This study aimed to assess the effects of 4 agroecological practices on soil microbiological activity in the Sudano-Sahelian area of Burkina Faso.These practices involved(a)the use of organic matter(OM)spread over a plot,with and without micro-dose mineral fertilization and(b)the localized application of organic manure in planting pits dug into hard pan land(zaï),with and without cereal-legume rotation.Microbial biomass(MB)by fumigation-extraction and soil respiration by incubation-extraction were measured on 40 soil samples,taken at 0-10 cm depth.The results indicated higher cumulative values of carbon from respiration on plots with generalized application of OM,with and without mineral fertilizers(113 and 111 mg C-CO_(2)/kg soil respectively),than on plots with localized application,with and without cereal-legume rotation(72.9 and 98 mg C-CO_(2)/kg soil respectively).MB follows the same trend as soil respiration with lower values(21.9 to 50.9 mg C/kg soil respectively).Generalized application of OM with or without mineral fertilizers was more favorable to soil microbial activity.