Weed Dynamics According to Soil Nutrient Content in Rice Cultivation in Burkina Faso

Background: Weed communities can respond differently to soil nutrient availability and rice cultivation ecology, yet this relationship remains insufficiently described for rice systems in Burkina Faso. Aim: This study assessed weed dynamics according to fertiliser treatment and rice cultivation type to support sustainable weed management. Method: A greenhouse experiment was conducted using a split-plot design with three rice cultivation types: irrigated, lowland and rainfed rice, and five fertilisation treatments: NPK, urea, DAP, potassium fertiliser and no fertiliser. Weed abundance, biomass, chlorophyll content, flowering rate, species composition, diversity indices and phytosociological groupings were evaluated up to 60 days after infestation. Results: Weed abundance varied significantly with rice ecology, fertiliser treatment and their interaction. The highest weed populations at 15 and 45 days after infestation occurred in unfertilised lowland rice, whereas the highest populations at 30 and 60 days were recorded in lowland rice fertilised with urea. Fresh biomass was highest in lowland rice with NPK, while dry biomass was highest in rainfed rice with DAP. Dicotyledons and therophytes were the dominant groups, representing 69.70% and 75.76%, respectively. Cyperaceae, Fabaceae and Poaceae were the main families. Indicator and frequent species included Coldenia procumbens, Cyperus difformis, Ludwigia erecta, Cyperus rotundus, Ludwigia palustris, Scoparia dulcis and Grona trifolia. Conclusion: Rice cultivation ecology and fertiliser type influenced weed emergence, growth and community composition. Nutrient management should therefore be considered when developing integrated weed management strategies for rice cultivation in Burkina Faso.