To ensure the sustainability and productivity of the cocoa crop, replanting on non-forested sites such as old orchards or young fallow lands raises the problem of the survival and establishment of seedlings, due to the low fertility of the soil, particularly in phosphorus. Thus, in order to minimize mortality and improve juvenile growth and flowering precocity of cocoa trees, organic, mineral and organo-mineral fertilizers were applied to a fallow land with low phosphate fertility, in Soubré, in the southwest of Ivory Coast. The experimental design was a partially balanced incomplete block design with 12 treatments and three replications. The treatments consisted of two fertilizer applications per year for each plant: compost (T1); phospho-compost (T2); TSP + compost (T3 and T4); NPK based on natural phosphates (T7, T8 and T9), combined with compost (T5 and T6) or phospho-compost (T10 and T11) at different doses. Growth parameters and flowering were evaluated. Treatments T2 (phosphocompost 1 kg), T3 (TSP 75 g + compost 2 kg) and to a lesser extent T11 (NPK 0-15-15 300 g + phospho-compost 1 kg) were the most efficient. They allowed a better growth, a good precocity of crowning and flowering. All the treatments tested did not impact the mortality rate of young cocoa trees. These results could allow farmers to exploit favorably soils with low fertility, with the guarantee of a good establishment of cocoa plants in the field during the juvenile stage.

The high price of chemical inputs has led producers to use other sources of fertilizer such as chicken manure. However, the direct and compost-free application of these wastes as practiced by producers is a potential source of soil acidification and environmental contamination that cannot adequately restore soil fertility. The objective of the study was to evaluate the effects of composting times on the chemical fertility of the composts produced. The study was carried out at the Jean Lorougnon Guédé University in the Tazibouo district of Daloa, in the centre-west of Côte d'Ivoire. Twelve (12) piles of chicken manure were made up of 3 piles per treatment corresponding to the different composting times (T14, T21, T28, T35 days). Four treatments rated T14, T21, T28 and T35 corresponding to 14, 21, 28 and 35 days of composting of the feces were compared to a control treatment T0 (composted chicken feces). The study found that composting chicken manure has positive effects on its chemical fertility by improving the levels of most of the physical and chemical parameters of the composts produced. As a result, composting has reduced concentrations of trace metal elements, such as iron and zinc, in composted chicken droppings, which at high soil levels become toxic to plants. Composting the manure for 14 days by improving the fertility of the composts produced can therefore be recommended to growers for a better chemical quality of the compost produced.