Ferralsols of southern Côte d'Ivoire under strong land pressure: What alternative to an improving soil fertility for a sustainable cassava production?

Abstract A study carrying on the morphological and physical properties of soils has been conducted in the South of Côte d'Ivoire, in the locality of Dabou. This region is submitted to a strong land pressure and a competition between food and industrial crops. This competition took place to the detriment of cassava on ferralsols poor in organic matter. In order to understand the behavior of these soils, the main physical parameters have been described. The transects of about 300 m were opened in three villages and the pedological profiles have been described on a scale of 1/5000. The pH has especially been put in evidence because the soils under industrial crop are frequently fertilized to the detriment of food crops. The studies put in evidence an acidification phenomenon of the ferralsols. The soils were modal ferralsols or typical in absence of coarse element. It has also been noted an enrichment of the soils in thin element in depth but neither of cuirassing nor compactness. The morphology of soil was not a constraint for plant but an important constraint bound to the acidification of soils exists. To overcome this constraint, the use of organic manure was recommended in a good cropping system

Chapitre 10. Le carbone des sols des zones de forêts et de savanes en Côte d’Ivoire

Introduction Malgré l’augmentation de la production agricole mondiale ces dernières décennies, près d’un milliard de personnes souffrent de la faim, principalement en Asie du Sud et en Afrique subsaharienne. En effet, les systèmes de production agricole dans ces régions, déjà sujets à un stress climatique élevé, sont très peu productifs (Aggarwal et al., 2013). En outre, les productions non alimentaires occupent une part croissante des terres arables (Ruf, 2012). L’alternative la plus évident..

Carbone des sols en Afrique

Les sols sont une ressource essentielle à préserver pour la production d’aliments, de fibres, de biomasse, pour la filtration de l’eau, la préservation de la biodiversité et le stockage du carbone. En tant que réservoirs de carbone, les sols sont par ailleurs appelés à jouer un rôle primordial dans la lutte contre l’augmentation de la concentration de gaz à effet de serre. Ils sont ainsi au centre des objectifs de développement durable (ODD) des Nations unies, notamment les ODD 2 « Faim zéro », 13 « Lutte contre le changement climatique », 15 « Vie terrestre », 12 « Consommation et production responsables » ou encore 1 « Pas de pauvreté ». Cet ouvrage présente un état des lieux des sols africains dans toute leur diversité, mais au-delà, il documente les capacités de stockage de carbone selon les types de sols et leurs usages en Afrique. Il propose également des recommandations autour de l’acquisition et de l’interprétation des données, ainsi que des options pour préserver, voire augmenter les stocks de carbone dans les sols. Tous les chercheurs et acteurs du développement impliqués dans les recherches sur le rôle du carbone des sols sont concernés par cette synthèse collective. Fruit d’une collaboration entre chercheurs africains et européens, ce livre insiste sur la nécessité de prendre en compte la grande variété des contextes agricoles et forestiers africains pour améliorer nos connaissances sur les capacités de stockage de carbone des sols et lutter contre le changement climatique

Assessment of low-input technologies to improve productivity of early harvested cassava in Côte d'Ivoire

In Cote d'Ivoire, smallholder farmers cultivate cassava on poor, highly weathered soils without improved varieties or fertilizer inputs. Land pressure combined with high demand result in premature harvests and low yields. Furthermore, subsistence agriculture limits the adoption of input-intensive technologies. This study aimed at identifying integrated soil fertility management systems for increasing cassava productivity and profitability in two locations in southern Cote d'Ivoire. The integrated technical interventions included improved cassava genotypes and modified spacing, legume intercropping, and application of fertilizer at moderate doses. Overall, an improved cassava variety (Yavo) generally out-yielded the other varieties at both sites. Legumes performed better at the higher soil fertility site and gave higher grain yield and biological nitrogen fixation in a 2x0.5m cassava spacing compared to 1x1m. The response of cassava to nutrient amendments varied between sites, suggesting the need for site-specific adaptations. Fertilizer application was essential to avoid cassava yield reduction upon legume intercropping as a result of competition for nutrients and N immobilization and delayed re-mineralization of legume residues. Growing legumes, however, substantially increased profitability. Hence, better synchronization of legume sowing, legume residue and fertilizer application in relation to cassava growth phases is needed

Intensification pathway for improvement of smallholder cassava production systems in Southern Côte d'Ivoire

In order to intensify cassava production in southern Cote d'Ivoire, multiple farmers' field trials were carried out in two important cassava-producing areas (Dabou and Bingerville). The effectiveness of an Integrated Soil Fertility Management (ISFM) approach as intensification pathway was evaluated for poor sandy soils. Overall, ISFM-based systems outperformed the local cultivation system. The average cassava yield was 14.5 and 6.5 t ha(-1) and 12.6 and 5.7 t ha(-1) for the ISFM and traditional systems, in Dabou and Bingerville, respectively. The average profitability of ISFM systems was ca. 2500 Euro ha(-1), whereby 66% was generated by cowpea intercrop, which yielded on average 3.1 t ha(-1). Taking into account the limited farmer's resource endowment and poor soil fertility, ISFM is a crucial component for sustainable intensification of cassava production and poverty alleviate in southern Cote d'Ivoire

Influence of Organic Fertilization on the Physico-Chemical and Organoleptic Quality of Attiekes of Three Varieties of Cassava (Manihot esculenta C.)

Cassava occupies an important place in the food security of populations in Côte d'Ivoire. There are many products derived from cassava but«attiéké» remains the flagship product in Côte d'Ivoire. Faced with the productivity challenges, organic fertilization is increasingly used by farmers in order to sustainably increase cassava production. The perspective of our study is to assess the effects of the uncombined use of cowpea and poultry manure as organic soil fertilizers on certain physicochemical and sensory characteristics of «attiékés» of three varieties of cassava. To do this, on an experimental plot installed, cowpea fertilization was tested at planting densities of 62,500; 250,000 and 125,000 plants/ha and poultry manure at rates 5; 15 and 5 t/haon, respectively, the cassava varieties Yavo, BoCou1 and Yacé.The results obtained show that cowpea and poultry manure increased the dry matter content respectively by 3.99 and 3.53 % in the Yavo variety by 3.57 and 18.06 % in the BoCou 1 as well as by 17.43 and 17.64 % in the Yacé. For the other parameters of pH, titratable acidity, total carbohydrates and free glucose, the variations depended on the variety and the level of fertilization. The sensory attributes of attiekes from these varieties grown on fertilized soil have been accepted by consumers in terms of color, smell, taste and consistency. In addition, they were rated less good than the controls obtained without fertilizer due to color, taste and consistency, while in terms of odor, it would be the same rating

EFFETS DU BIOCHAR DE RÉSIDUS D'ANACARDE SUR LA PRODUCTIVITÉ DE LA CULTURE DE LUFFA AU NORD DE LA COTE D'IVOIRE

<h2><strong>RESUME</strong></h2><p> </p><p><strong>Contexte</strong> : La culture du luffa (<i>Luffa cylindrica</i>) est pratiquée dans la région Nord de la Côte d'Ivoire, selon des systèmes extensifs. La production est entravée par la faible fertilité des sols et le manque, voire la faible utilisation, de fertilisants. <strong>Objectif : </strong>L'objectif de la recherche était d'évaluer l'impact du biochar issu de résidus d'anacarde sur la productivité de la culture en vue d'une valorisation de cette bio-ressource. <strong>Méthodes</strong> : Quatre traitements ont été comparés dans un dispositif en bloc de Fisher avec trois répétitions : 1) témoin sans fertilisant, 2) biochar de résidus d'anacarde, 3) dose normale d'engrais minéral (NPK, urée) et 4) biochar + demi-dose d'engrais minéral. Les variables mesurées incluaient la hauteur des plants, le nombre de fruits par plant, le poids des fruits par plant et le rendement. <strong>Résultats</strong> : Les résultats ont révélé un effet inhibiteur du biochar sur la croissance et le rendement du luffa. L'application de doses modérées d'engrais minéral en combinaison avec le biochar s'est avérée bénéfique pour accroître le rendement de la culture. Les rendements obtenus pour les différents traitements étaient respectivement de 5,66 ± 0,98, 3,38 ± 0,66, 8,81 ± 0,45 et 9,20 ± 0,24 t/ha pour les traitements témoin, biochar, engrais minéral et biochar + engrais minéral. <strong>Conclusion</strong> : L'application du biochar issu de résidus d'anacarde par les agriculteurs, sans ajout minimal d'engrais, pourrait constituer un obstacle à l'intensification durable des cultures. La réaction des différentes cultures à l'application du biochar mérite d'être évaluée en vue d'une meilleure valorisation de ces bio-ressources en production agricole.</p><p><i><strong>Mots-clé</strong>s :</i> <i>Luffa cylindrica, Biofertilisant, Anacardium occidentale, Côte d'Ivoire</i>.</p><p> </p><h2><strong>ABSTRACT</strong></h2><p> </p><p><strong>Context</strong>: The cultivation of luffa (Luffa cylindrica) is practiced in the Northern region of Côte d'Ivoire, using extensive farming systems. Production is hampered by low soil fertility and the absence or limited application of fertilizers. <strong>Objective</strong>: The research aimed to assess the impact of cashew residue-derived biochar on the productivity of luffa cultivation for the valorization of this bio-resource. <strong>Methods</strong>: Four treatments were compared in a Fisher block design with three repetitions: 1) control without fertilizer, 2) cashew residue-derived biochar, 3) normal dose of mineral fertilizer (NPK, urea), and 4) biochar + half-dose of mineral fertilizer. Measured variables included plant height, number of fruits per plant, fruit weight per plant, and yield. <strong>Results</strong>: The findings indicated an inhibitory effect of biochar on the growth and yield of luffa. The application of moderate doses of mineral fertilizer in combination with biochar proved beneficial in increasing crop yield. Yields obtained for different treatments were 5.66 ± 0.98, 3.38 ± 0.66, 8.81 ± 0.45, and 9.20 ± 0.24 t/ha, respectively, for control, biochar, mineral fertilizer, and biochar + mineral fertilizer treatments. <strong>Conclusion</strong>: The application of cashew residue-derived biochar by farmers without minimal addition of fertilizer could pose a challenge to the sustainable intensification of crops. The response of different crops to biochar application deserves evaluation for a better utilization of these bio-resources in agricultural production.</p><p><i><strong>Keywords: </strong>Luffa cylindrica, Biofertilizer, Anacardium occidentale, Côte d'Ivoire.</i></p><p> </p&gt