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In the department of Daloa in Côte d'Ivoire, many coffee and cocoa plantations that have fallen into decline and been left fallow are in the process of being reclaimed by their former or new users. In order to prevent the failure of the planned new crops, this study was initiated to determine how the soils under these fallows function, which is essential for developing sustainable management strategies for them. Thus, seven fallows older than ten years were identified. In each of them, a 10,000 m2 plot was delimited and three soil pits were set up. In one pit, three soil samples were taken. After analysis of these samples in the laboratory, correlations and balances between certain physico-chemical soil components were calculated. The results show that organic matter contributes in some places to the constitution of the CEC (r ˃ 0.70) and thus participates in the soil's function as a reservoir of nutrients. On the other hand, when the soils are leached, the organic matter binds to the sand remaining in the profile and, because of its coarse particles, it hardly contributes to the constitution of the CEC (r = -0.70). However, whatever the case, the stability balances between the soil nutrients are globally favourable due to the long duration of the fallows (Ca/Mg close to 2 while K/Mg, (Ca+K)/Mg and C/N varied from 0.10 to 0.50, 15 to 30 and 9 to 12, respectively). Pending consideration of the functioning of the biological component of the soils studied, organic matter appears to be the most determining factor in their overall functioning.

The morphopedological characterization of the soils of Zépréguhé (Centre-West of Côte d'Ivoire) only exists on a small scale, whereas this support is essential for the arboriculture on which the region depends. This study aims to establish the morphopedological and typological characteristics of the soils of the Daloa area and particularly the soils of the locality of Zépréguhé located between longitude 6°22'18'' West, latitude 6°54'09'' North and 250 m above sea level. The soil pits were opened over a toposequence 551 meters long and the profiles were described following the approach of the Office de Recherche Scientifique et Technique d'Outre-Mer (ORSTOM). This study carried out in April 2022 showed that the soil types in the area are rejuvenated reworked ferrallitic soils (Plinthic Lixisols) on the summits, hardened reworked ferralitic soils (Plinthic Lixisols) on the mid-slope, depleted reworked ferrallitic soils ( Plinthic Arenosols) on the lower slope and hydromorphic soils depleted of alluvial input (Fluvisols) in the lowland. From the point of view of agricultural suitability, the soils on the summit physically present characteristics favorable as a whole to any kind of cultivation. The mid-slope soils would be favorable for low-rooting speculations, while the soils on the lower slope show potential characteristics favorable to all crops. Lowland soils present constraints related to shallow hydromorphy, dominance of sand and the very thin layer that can be exploited by plant roots.

A study on soil mineral fertilization was carried out over three years in three cocoa farms in the Nawa region of south-western Côte d'Ivoire. The aim of this study was to evaluate the effects of mineral fertilizers on the decomposition time of cocoa leaf litter. The experimental design was Fisher block with four treatments (T0, T1, T2, T3) repeated three times. The treatments were for T0, the control without fertilizer, for T1, NPK fertilizer 0-23-19, for T2, NPK fertilizer 0-15-15 + 17 CaO + 5 MgO + 1 B2O3 + 0.5 Zn and for T3, NPK fertilizer 4-10-10 + 19 CaO + 4 MgO + 0.8 B2O3 + 0.3 Zn. In each treatment, 3 plots of 1 m2 were delimited with a 1 cm2 mesh wire grid. The rate of decomposition of the cocoa leaf litter was made by measuring twice a year the weight loss of the ground litter contained in the plots. Comparison of the average decomposition rates between treatments showed that the fertilized soils had the best rates during the first 6 and 12 months of the trial. In Soubré, the T2 treatment (24.6±0.6%) in the 6th month and the T1 (72.6±6.6), T2 (82.4±1.6) and T3 (78.8±4.0%) treatments in the 12th month had the best decomposition rates. At Divo, treatment T1 (38.8±0.5%) in month 6 and treatments T1 (57.8±1.7%), T2 (67.9±10%) and T3 (66.9±7.7%) in month 12 were the best. At Méagui, decay rates did not differ between treatments throughout the trial. The application of mineral fertilizers resulting from soil diagnosis reduced the decomposition time of the cocoa leaf litter.

1 RESUME Une étude sur la fertilisation minérale et organique liquide a été conduite sur la tomate en petite saison de pluie au Sud et au Centre-Ouest de la Côte d’Ivoire sur deux années, afin d’améliorer la fertilité du sol et le rendement de la tomate. De manière spécifique, il s’agissait d’évaluer les effets des traitements de quatre doses d’engrais organique liquide associées ou non à l’engrais minéral sur la teneur du sol en matière organique, le rapport C/N et le rendement. Le dispositif expérimental était un split-plot avec quatre répétitions ayant pour facteur principal, l’engrais minéral et le facteur secondaire, l’engrais organique à quatre doses (Lha-1) : C0 = 0 (témoin), C1 = 2,5; C2 = 3,75 et C3 = 5. Les résultats ont montré que le traitement T10 (50 % engrais minéral + 3,75 Lha-1 engrais organique) a amélioré la teneur du sol en matière organique, et le rendement. Cependant, le traitement avec 3,75 Lha-1 d’engrais organique utilisée seule a amélioré le rapport C/N du sol. Effects of liquid organic (NPK 5-9-18) and mineral (NPK 12-11-18) fertilizers on soil organic matter of and tomato yield in the South and the Mid-west of Ivory Coast ABSTRACT A study on the mineral and liquid organics fertilizations was conducted on tomato during short rainy season in South and Central West regions of Ivory Coast over two years to improve soil fertility and tomato yield. Specifically, the treatment effects of four doses of organic fertilizer, associated or not with the mineral fertilizer on the content of the soil organic matter, the C/N ratio and the yield. The experimental design was split-plot, with four repetitions having as principal factor, the mineral fertilizer and the secondary factor, the organic fertilizer in four doses (L ha-1): C0 = 0 (control); C1 = 2.5; C2 = 3.75 and C3 = 5. The results showed that the treatment T10 (50 % mineral fertilizer + 3.75 Lha-1 of the organic fertilizer), better improved the content of the soil organic matter and the yield. However, the treatment with 3.75 L ha-1 of organic fertilizer used alone has increased advantage the report C/N of the ground.

This study was carried out to investigate the relationship between earthworm trophic groups and soil morphology and chemical attributes, and moreover, to determine which of these attributes would be most significant in explaining the distribution of earthworm communities in agro-ecosystems in the Centre-West region of Cote d’Ivoire. Earthworms' soil morphology and soil samples were studied in three agro-ecosystems: 20-year-old cocoa plantations, 5-year-old mixed cocoa plantations and mixed crop-fields. The semi-deciduous forests near the agro-ecosystems were also sampled and considered as control plots. Earthworm global densities varied on average between 53.9 ± 7.9 and 86.0 ± 19.0 individuals m−2 and biomass between 16.5 ± 3.1 and 20.6 ± 4.1 g m−2 under these ecosystems. Path analysis produced a significant model: soil morphology and chemical attributes under different agro-ecosystems affected the density and biomass of earthworm trophic groups, and these attributes are potential regulators of the fauna communities. The morphological components related to dead leaves (r2 = 0.73, P

Dans la région du Bélier en Côte d'Ivoire, on rencontre de vastes étendues de zones humides, dont certaines commencent à être exploitées en rizières. La présente étude a consisté à élaborer, en utilisant un nombre très limité de données, un modèle de prédiction de l'extension des zones humides de fond de vallée d'un périmètre de cette région. Ce modèle prédictif a été calibré à partir des caractéristiques topographiques et hydrographiques de 2500 pixels déterminés selon une procédure d'apprentissage automatique. La précision globale et l'indice Kappa qui en sont ressortis sont estimés respectivement à 82,08 % et 82,05 %. Après extrapolation du modèle à l'ensemble du périmètre d'étude, on a obtenu une prédiction de l'extension des zones humides qui concorde très bien avec la réalité du terrain décrite par 2425 données ponctuelles d'observation (précision globale = 69,23 % et indice Kappa = 69,19 %) et par une carte d'occupation du sol. In the region of Belier (Côte d'Ivoire), there are wide areas of wetlands, with some of which began to be exploited in rice. In this study, the work consists in developing a prediction model to localize the potential wetlands of valley bottom in an area of the region of Belier. This prediction model was calibrated with topographic and hydrographic criterions of 2500 pixels which were determined using a machine learning procedure. The overall accuracy and the Kappa index obtained after the evaluation of the model are, respectively, 82.08 % and 82.05 %. Applied to whole the study area, the prediction model permits to mapping wetlands as well as it's reflected in the field reality described by 2425 punctual data of observation (overall accuracy = 69.23 % and Kappa index = 69.19 %) and a land use map.

Objectif: L’objectif de cette etude etait d’evaluer le pouvoir fertilisant de deux fumures organiques (fiente de poulet et tourteaux de coprah) sur les parametres de croissance du bananier plantain ( Musa paradisiaca ) cultive sur sables quaternaires du littoral ivoirien. Methodologie et resultats: L’etude a ete menee a la station de recherche Marc Delorme du Centre National de Recherche Agronomique (CNRA) au Sud de la Cote d’Ivoire sur sables quaternaires du littoral ivoirien avec la variete PITA 3 de bananier plantain avec la fiente de poulet et de tourteaux de coprah. L’essai a ete conduit suivant un dispositif experimental en blocs aleatoires randomises a trois repetitions. Les plants de bananier de la variete PITA 3 ont ete soumis durant dix semaines a huit traitements avec trois traitements a base de fiente de poulet : T2 (500g/plant), T3 (750g/plant) et T4 (1000g/plant), trois traitements a base de tourteaux de coprah : T5 (500g/plant), T6 (750g/plant) et T7 (1000g/plant), un traitement a base d’engrais chimique : T1 (35 g/plant d’uree + 40g/plant de chlorure de potassium) et un traitement temoin (sans apport de fertilisants). . Les observations ont porte sur la circonference au collet, la taille des plants de bananiers, la surface foliaire et le nombre moyen de feuilles vivantes. Les resultats obtenus ont montre que sur les sables quaternaires du littoral ivoirien, les plants de bananiers traites avec 750 g/plant de fiente de poulet ou de tourteaux de coprah ont genere les meilleures croissances. Cependant, la fiente de poulet a la dose de 750 g/plant a permis d’obtenir les meilleures valeurs moyennes de nombre de hauteur des plants (58,24+9,26), de circonference au collet (17,119 + 2,77), de surface foliaire (1534,452 cm2) et de feuilles vivantes (9,16 + 1,46) au cours de l’etude. Conclusion et application: Sur les sols sableux du littoral, la fertilisation des sols en culture du bananier plantain peut etre assuree convenablement par une fertilisation a base de fiente de poulet relativement accessible pour les producteurs generalement a revenus economiques tres faibles, a la dose de 750 g/plant pour assurer la bonne croissance des plants pour une culture de bananier plantain reussie durable, respectant l’environnement. Toutefois a defaut de la fiente de poulet, le tourteau de coprah egalement a la dose de 750g/plant, pourrait constituer une alternative pour la fertilisation des sols en culture de bananier plantain sur sables quaternaires du littoral ivoirien. Mots-cles: Banane ( Musa spp.), fiente de poulet, tourteaux de coprah, sols sableux, engrais chimiques, Cote d’Ivoire English Title: Evaluation of the fertilizing power of two organic fertilizers (chicken dung and coprah meal) on the growth parameters of the plantain banana tree ( Musa paradisiaca ) grown on quaternary sands of the Ivorian coast. English Abstract Objective: The objective of this study was to assess the fertilizing properties of two organic fertilizers (chicken droppings and coprah meal) on the growth parameters of the plantain banana tree ( Musa paradisiaca ) grown on quaternary sands of the Ivorian coast. Methodology and results: The study was conducted at the Marc Delorme research station of the National Centre for Agronomic Research (CNRA) in southern Cote d'Ivoire on the quaternary sands of the Ivorian coast with the PITA 3 variety of plantain banana tree with chicken droppings and coprah meal. The test was conducted using an experimental device in randomized random blocks with three replicates. Banana tree plants of PITA 3 have been subjected to eight treatments for ten weeks with three chicken dung treatments: T2 (500g/plant), T3 (750g/plant) and T4 (1000g/plant), three coprah meal treatments: T5 (500g/plant), T6 (750g/plant) and T7 (1000g/plant) and a control treatment (without fertilizers). Observations included collar circumference, banana plant size, leaf surface and mean number of live leaves. The results obtained showed that on the quaternary sands of the Ivorian coast, banana plants treated with 750 g/plant of chicken droppings or coprah meal have generated the best growth. However, chicken dung at the 750 g/plant dose yielded the best mean values of plant height (58.24+9.26), collar circumference (17.119 + 2.77), foliar surface (1534.452 cm2) and living leaves (9.16 + 1.46) during the study. Conclusion and application: Soil fertilization in plantain banana cultivation can be adequately ensured in coastal sandy soils by fertilization based on chicken droppings that are relatively accessible to producers with generally very low economic incomes, at a dose of 750 g/plant to ensure the proper growth of plants for a successful, sustainable plantain cultivation that respects the environment. However, in the absence of chicken droppings, the coprah meal also at the dose of 750 g/plant, could be an alternative for fertilization of soils in plantain banana tree culture on the quaternary sands of the Ivorian coast. Keywords: Banana ( Musa spp.), Chicken manure, coconut cake, sandy soils, chemical fertilizers, Cote d’Ivoire