Integrating Biochar to Sustain Lettuce Production in Sandy Soils of Burkina Faso Under Water-Limited Conditions

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Résumé

Valorization of agricultural residues into biochar for soil applications offers dual ben-efits of waste management and sustainable agriculture. However, the mechanisms governing sandy soil and lettuce response to biochar under deficit irrigation are not well understood. TheThis study evaluated the effects of biochar types on sandy soil physio-chemicalphysiochemical properties and lettuce (Lactuca sativa L.) yield at different irrigation levels. A field experiment was performed using a randomized com-plete block design with four treatments (soil only, cotton stalk biochar, cashew nut-shells biochar, and a mix of cotton stalks+ cashew nutshells biochar) and three irriga-tion regimes (100%, 80, and 60% of crop water requirements ETc) in Ouagadougou, Burkina Faso. The results showed that biochar -amended soils had consistently higher water retention and macro nutrientsmacronutrients, resulting in higher fresh, mar-ketable lettuce yields under deficit irrigation compared to untreated soils. Compared to other treatments, a mix of cotton stalks-stalk and cashew nutshells-nutshell biochar produced the highest yield (18.1 tons/ha) under moderate irrigation (80% ETc). Achieving optimal yields with 20% less irrigation water indicates biochar’s wa-ter-saving potential in climate-resilient vegetable farming. These findings underscore the potential of combining deficit irrigation and biochar for sustainable vegetable production to mitigate food security in water-scarce regions.

Mots-clés

Biochar, soil amendment, deficit irrigation, lettuce productivity, agricultural waste transformation, climate-resilient farming, sustainable agriculture.