Poultry litter is increasingly used as organic amendment in market gardening in Côte d'Ivoire. To know about the sustainability of this practice, its impacts on soil quality should be known. This study aimed at assessing the effect on soil fertility of composted poultry litter addition for 16 years following two distinct ways, and identifying soil parameters driving cucumber yield. Trials were laid out in a Fisher randomized block design with 3 treatments replicated 5 times each: Control (C), Surface-applied compost (SAC) and Buried compost (BC). Soil (0-20 cm) chemical characteristics and cucumber growth and yield parameters were measured. Values of all parameters were higher with compost addition compared to the control, except for the C:N ratio. SAC and BC showed similar values of organic C, total N, CEC, pH and available phosphorus. However, Ca 2+ , Mg 2+ , K + and base saturation were higher in SAC than in BC. Relative to values in the control, the greatest changes in soil parameters were observed with exchangeable cations, followed by soil organic matter. Soil organic C and total N concentrations have doubled in SAC while Ca 2+ , Mg 2+ , and K + increased at greater rate (702.4, 400.9 and 186.67% respectively). Also, cucumber growth parameters were the highest with compost addition compared to the control. Significant effect of the compost application way on cucumber was also observed: collar diameter, leaf area and fresh fruit yield in SAC (0.72±0.02 cm, 258.9±12.3 cm 2 , 11.1±1.3 t ha -1 , respectively) were higher than in BC (0.56±0.01 cm, 230.2±2.5 cm 2 , 5.4±0.5 t ha -1 respectively). Fruit yields in SAC and BC were four times and twice higher than in the control (2.6±0.3 t ha -1 ), respectively. Cucumber growth parameters were determined by soil concentration in Mg 2+ while yield was determined by Ca 2+ . Composted poultry litter should be promoted for a sustainable soil fertility management in vegetable farming systems.

Animal wastes may be promoted as an alternative to mineral fertilizers that remain unaffordable to the overwhelming part of smallholder farmers in Sub-saharan Africa. However for an efficient use, mechanisms that underly their impact on crops should be well understood. This study was conducted in mesocosm to evaluate impacts of two ways of composted poultry litter (CPL) addition on growth and nutrient use efficiency by cucumber. It included three treatments with five-bucket replicates each: Control, CPL applied on soil surface (CS) or buried to 10 cm-depth (CB). Dry CPL was added at the rate of 0.5 kg bucket -1. At harvest, root distribution was examined in the 0-5, 5-10 and 10-20 cm depths. Dry biomasses of roots, shoot and fruits were also determined and allowed for calculation of diverse indexes of biomass allocation (root:shoot ratio, root weight ratio, stem weight ratio, leaf weight ratio) and nutrient use efficiency (factor productivity of the compost, partial factor productivity of nutrients, agronomic efficiency of compost, and apparent agronomic efficiency of nutrients). The results showed that application of CPL led to a significant improvement of all considered parameters except for the leaf weight ratio which was higher in the control (44.1±3.3) than in CS (28.1±1.9) and CB 31.2±3.5). Total lateral root length was significantly higher in CS than in CB (113.5±10.7 cm vs. 75.5±9.0 cm). The number of lateral roots per plant in the 0-5 cm soil layer was higher in CS than in CB (5.4 vs. 1 root plant -1 ); the reverse was observed in 5-10 cm (1.2 vs. 4.4 root plant -1). Both fresh fruit yield and total dry mass were positively correlated to root attributes. These were themselves negatively impacted by soil acidity. All nutrient use efficiency indexes were higher in CS than CB. The CPL improved the agronomic performance of cucumber particularly when applied at soil surface.

In spite of the low agronomic performances of Ivorian cashew orchards, Côte d'Ivoire recently became the first worldwide producer and exporter of raw cashew nuts. To maintain this ringleader position, several factors should be understood including the ecological factors supporting this success. Pollination service due to bees was recognized to impact cashew production. Therefore, determining cashew trees that are more attractive to bees can contribute to promote pollination activities. To detect these cashew trees possessing the flowers preferred by bees, two types of investigations were undertaken: (1) a socioeconomic survey in 3167 cashew hectares belonging to 381 producers and (2) an experimental detection of the bees' floral preference. As results, 58 of the 381 interviewed producers had identified the bees' floral preference resulting in a detection of 681 cashew trees. The flowers of the preferred cashew trees were visited 5 times more and they attracted 3 times more bee foragers as compared to nonpreferred cashew trees. These findings may be included in research programs focus on: (i) improvement of agronomic performances and (ii) effective management of bees' community.

Effets du vermicompost à base de coques de cacao et de graminées sur quelques paramètres agronomiques de la tomate du concombre et chou à Yamoussoukro