Estimation de la fertilité potentielle des ferralsols par la couleur

Abstract

A farmer-friendly method of determining the most suitable cultivation soils would help in transferring new integrated soil management technologies. The potential for using soil color (Munsell data) was tested by physico-chemical analysis of 1028 ferrallitic soil samples from 289 profiles unequally allocated above 7 deg N in Côte d’Ivoire. Soil hue variations in depth and along the toposequence revealed the existence of vertical and lateral gradients of soil hue. The relative contribution of the different descriptors (clay, sand, carbon, total nitrogen, total phosphorus, potassium, magnesium and calcium) to the three functions extracted using a discriminant analysis to differentiate the four groups of soils with different hues was evaluated as well as the analysis of variance to determine the possible groups number for each one of the descriptors. Differences between physico-chemical components of red (2.5YR and 5YR) and yellow (7.5YR and 10YR) soils were determined, especially for P, Mg and K in extension. A decreasing gradient of inherent soil fertility indicators with an increasing yellowness in soil hue was revealed using multiple regression models. The soils 2.5YR and 5YR were therefore deemed more appropriate for stable and sustainable agriculture.Key words: Hue, ferralsols, fertility, soil use

A Case ofCyperusspp. andImperata cylindricaOccurrences on Acrisol of the Dahomey Gap in South Benin as Affected by Soil Characteristics: A Strategy for Soil and Weed Management

“…However, the trends of variation in soil nutrients were the same along the toposequence of terre de barre as described elsewhere [25]: divalent cations concentrations decreased from the summit to the foot slope, while soil concentrations of monovalent cations increased. Therefore, the influence of soil parameters on weed species occurrence as revealed in our actual study can be considered for the entire Dahomey gap and the other ecologies of West Africa according to the rule of nonreplicated ecological study [15].…”

Soil characteristics and Cyperus spp. occurrence along a toposequence

“…Three sampling places (A, M and H) were identified at each topographic position (summit, upper slope, middle slope and foot slope) along the toposequence as described by Koné et al . (). Topographic sections were considered within about 50 m × 50 m at 100 m apart.…”

Occurrence and Leave Extractable Essential Oil of Lippia multiflora M. (Verbenaceae) as Affected by Soil Acidity, Carbon, Nitrogen and Phosphorus Contents in North Cote d’Ivoire

“…Soil morphological variability along the landscapes of the studied region could be involved in this clustering. In fact, there is highest content of gravels in the soil of hill slope contrasting with that of juxtaposed soils of down slope position which are dominated by colluviums from hill slope (Wambeke, 1974;Koné et al, 2009). This mechanical constraint could have impaired the root development of L. multiflora as described for similar species in such conditions (Boa, 1989) meanwhile, woody trees with more robust roots are frequently observed in the biotope of hill slope (Beaudou & Sayol, 1980) further constraining the occurrence of L. multiflora as C4 plant requiring sunlight (Yao-Kouamé & Fako, 2008).…”

“…However, such analysis was established between soil chemical characteristics and specific weed occurrence in Sub-sahara Africa ecosystems involving soil contents of C, N, P and K along toposequence and fertilizer effects (Udoh, Ogunkunle, & Ndaeyo, 2007;Koné et al, 2013a;Koné, Traoré, & Touré, 2014) somewhat depending on soil pH. Indeed, there is variability of soil fertility potential along toposequence in tropical ecosystem (Koné et al, 2009) that can affect the plant growth.…”