Large amounts of solid urban waste (SUW), sometimes containing trace metal (TM), are used to fertilize agricultural soils. The aim of this study was to assess concentrations of TM in peri-urban agricultural soils exposed to SUW inputs around Bobo-Dioulasso. Composite samples of fourteen soil profiles (0-20 cm, 20-40 cm and 40-60 cm) were collected in the classified Dindéréso forest in the outskirts of Bobo-Dioulasso. Inductively coupled plasma mass spectrometry (ICP/MS) was used to analyze TM concentrations in the samples. Concentrations of Cd, Cr, Cu, Ni, Pb and Zn varied broadly according to the sampling sites and soil horizons. The maximum concentrations of the analyzed elements in all sites were lower than the limit concentrations. Regardless soil horizons, the pollution index were less than 1, suggesting that the sampled soils were not subject to multiple contaminations of TM. D’importantes quantités de déchets urbains solides (DUS), renfermant parfois des éléments traces métalliques (ETM), sont utilisées pour fertiliser les sols agricoles. Le but de cette étude est d’évaluer les concentrations en ETM des sols péri-urbains de la ville de Bobo-Dioulasso soumis à l’épandage des DUS. Des échantillons composites de sols ont été prélevés, suivant les horizons 0-20 cm, 20-40 cm et 40-60 cm, sur quatorze sites dans la forêt classée de Dindérésso située à la périphérie de la ville de Bobo-Dioulasso. L’analyse des échantillons de sol a été effectuée par spectrométrie de masse avec plasma à couplage inductif (ICP/MS). Les résultats montrent que les concentrations en Cd, Cr, Cu, Ni, Pb et Zn des sols sont très variées. Elles varient en fonction de l’ETM, du site et de l’horizon du sol. Les concentrations des différents ETM dans les sols sont inférieures aux valeurs limites sur tous les sites. L’index de pollution de chaque site est inférieur à 1, quel que soit l’horizon de sol, suggérant ainsi que les sites de la zone ne font pas l’objet d’une contamination multiple de leurs sols par les ETM.

The Intensification of cowpea production is a priority because of its role in household income generation and its contribution to food security. To evaluate the effect of organic fertilizers on cowpea productivity, a dispersed block experiment design was set up in Saria in the semi-arid zone of Burkina Faso during the 2017 and 2018 cropping seasons. The combination of Biodeposit (Agro and Elixir) and Organova were used alone or in combination with mineral fertilizer. The results showed that during the two years, the highest cowpea grain yields were obtained with the Organova + the recommended mineral fertilizer and Biodeposit Agro + the recommended mineral fertilizer. The combination of organic fertilizers and recommended mineral fertilizer resulted in a 45% and 59% increase respectively with Organova and Biodeposit (Agro + Elixir). These two fertilizers then have the same effects on cowpea productivity. In the semi-arid zone where there is competition for organic resources, organic fertilizers can be used in combination with mineral fertilizer to improve cowpea productivity.

The management of invasive aquatic plants (IAPs), which is primarily accomplished through manual grubbing, incurs significant costs for populations, especially since the operations must be renewed on a regular basis. Converting IAPs into biochar for use as soil amendment will help offset the costs of this mechanical control strategy, while also improving carbon sequestration, soil fertility and crop yields. The objective of this study is to examine the effects of using IAPs biochar amendment on the quality of acidic soils and subsequently maize growth. Ten treatment groups including nine treatments and one control were established with four replicates each on freshly sown maize soils. Treatments options include applying IAP biochar (group 1), different combinations of IAP biochar and poultry manure (group 2), and mineral fertilizer (group 3). After 37 days, the average height of maize plants in the control group is 68.83±7.91cm, compared to 69.82 ± 7.34 cm (group1), 64.44 ± 7.82cm (group 2) and 69.08 ± 9.51cm (group 3). Multivariate analyses suggest that the IAPs biochar have significantly higher potential to improve plant growth parameters than either poultry manure or synthetic fertilizer. Based on the foregoing, the use of IAPs biochar amendment should be promoted among smallholder farmers because it is environmentally friendly, easy to produce, has a lower operational cost than other fertilizers, and has been shown to improve the acidic and impoverished dryland soils prevalent in Burkina Faso.

Objectifs : L’une des contraintes majeures des systèmes de production agricole au Burkina Faso demeure la dégradation des sols. La présente étude menée à Kongoussi (Burkina Faso) avait pour objectif de déterminer les effets du Biocharbon utilisé comme amendement sur le sol et les paramètres agronomiques du mil. Méthodologie et résultats : Un dispositif en blocs simple comportant 3 traitements en 5 répétitions a été utilisé. Les traitements comprenaient T0= Fumier + NPK, T1= Biocharbon + Fumier + NPK, T2= Biocharbon + NPK. Les matières fertilisantes ont induit une amélioration des paramètres chimiques du sol. Les meilleurs paramètres chimiques du sol ont été observés avec T1 (Biocharbon + Fumier + NPK) qui a permis l’obtention du plus grand rendement grains du mil comparativement à ceux obtenus avec les traitements T0 (Fumier + NPK) et T2 (Biocharbon + NPK) qui étaient statistiquement équivalents. Conclusions and application des résultats : La combinaison du biocharbon au fumier améliore la fertilité du sol et le rendement du mil. Cela constitue une solution intéressante en vue restaurer et ou maintenir la fertilité des sols, accroitre les rendements des cultures tout en réduisant les effets néfastes des changements climatiques à travers la séquestration du carbone dans le sol. La technologie du Biocharbon constitue une alternative intéressante pour la valorisation des résidus culturaux peu ou pas exploités pour améliorer durablement la qualité des sols et assurer la sécurité alimentaire tout en protégeant l’environnement. Mots-clés : fertilité des sols ; Biocharbon ; amendement organique ; séquestration du carbone, ABSTRACT Combined effects of biocharbon and manure on physico-chemical properties of a tropical ferruginous soil under millet cultivation in the semi-arid zone of Burkina Faso Objectives: One of the major constraints of agricultural production systems in Burkina Faso is the low soil fertility. The objective of this study conducted in Kongoussi (Burkina Faso) was to determine the effects of Biochar used as soil amendment in combination with manure on soil fertility and some agronomic parameters of millet. Methodology and results: A simple block disign with 3 treatments in 5 replicates was used. The randomly distributed treatments included T0= Manure + NPK, T1= Biochar + Manure + NPK, T2= Biochar + NPK. The Lompo et al., J. Appl. Biosci. 2021 Effets combinés du biocharbon et du fumier sur les propriétés physico-chimiques d’un sol ferrugineux tropical sous culture de mil en zone semi-aride du Burkina Faso. 16173 applied fertilizers improved some soil chemical parameters. The best soil chemical parameters were observed with T1 (Biochar + Manure + NPK), which induced the highest millet grain yield as compared to those obtained with T0 (Manure + NPK) and T2 (Biochar + NPK), which were statistically equivalent. Conclusions and application of findings : The combination of biochar with manure improves soil fertility and millet yield. This is an interesting solution to restore and/or maintain soil fertility, to increase crop yields while reducing the adverse effects of climate change through carbon sequestration into the soil. The Biochar technology is an interesting alternative for the valorization of crop residues little or not well exploited in order to sustainably improve soil quality and food security while protecting the environment. Keywords: Crop production ; Soil fertility ; Biochar ; organic amendment, carbon sequestration.