LAPPLICATION DE PHOSPHO-COMPOSTS AU BIOCHAR AMELIORE LA DISPONIBILITE DES NUTRIMENTS DUN SOL SOUS CULTURES IRRIGUEES EN CLIMAT TROPICAL AU BURKINA FASO

High-qualityorganicsoilamendments are essential forimproving the properties of tropical soils and enhancing agricultural production. The objective of thisstudy, conducted in western Burkina Faso, was to assess the effect of different biochar phospho-composts on soilpH, cation exchange capacity (CEC), total and assimilable phosphorus, as well as total and available potassium in an irrigatedenvironment. A Fisher block design withtentreatments, randomlyassignedinto four replications, was set up on the irrigated plain of Bama (Houet Province) and monitoredacrosstwoconsecutiveseasons: rice in the 2023 rainyseason and maize in the 2024 dry season. The tentreatmentsconsistedofmineral fertiliser (FMV), ricestraw phospho-composts without biochar (Pcom) and with biochar (PcomBio), and fruit and vegetableresidues-based phospho-composts without biochar (PcomFL) and with biochar (PcomFLBio). Overall, the CEC of soilsamendedwith phospho-composts, bothwith or and without biochar,wassignificantly (P<0.001) improvedcompared to the controltreatment. The PcomFLBiotreatmentcombinedwith 100% of mineralfertilizer (PcomFLBio-100), enhanced pH-KCl and total phosphorus, assimilable phosphorus and available potassium by 6.72%, 41.97%, 288% and 42.73% respectivelycompared to the absolute control. Additionally, total potassium wassignificantly (P=0.002) improved by PcomBio-100 and PcomFLBio-100 compared to the othertreatments. The addition of rock phosphate and biochar inricestraw and fruit and vegetableresiduescomposts improves the chemicalproperties of irrigatedsoils and ensuressustainable agricultural production.