Evaluation Of Soil Fertility Under Industrial, Irrigated And Continuous Sugar Cane Cultivation In The Integrated Agricultural Unit Of SUCRIVOIRE-Zuénoula (Centre West Of Côte d'Ivoire)

This study was carried out to evaluate the soil fertility in continuous and irrigated cultivation of sugar cane. To do this, soil samples were taken from the top 20 centimeters of the soil, in the three different sectors of the sugar cane plantations and on another plot left fallow for nearly 20 years, at the integrated agricultural unit of Zuenoula. These samples underwent physical and chemical analyzes in the laboratory following standard procedures. The results obtained show that the soil texture is of the sandy loam type for the fallow and the pivot P17B, silt and fine silt respectively for the pivots P27B and P20A. For the chemical parameters, apart from the pH, which has acceptable values for sugar cane, on all the plots studied, the other parameters, in particular, organic carbon, organic matter, nitrogen, assimilable phosphorus, potassium, calcium, magnesium and cation exchange capacity, show mixed values. Thus, the soil fertility potential under pivots P17B and P20A can be described as low, while it is medium under fallow and relatively high under pivot P27B. This variability of these physical and chemical characteristics from one plot to another requires specific manure recommendations. However, a strong correlation was found between the rate of fine soil elements (clay + fine silt) and most soil chemical parameters. From the content of fine elements in the soil of the fallow land, the modeling equation for this relationship made it possible to show that the fallow land improves the chemical characteristics of the soil, of the order of 10% for the pH, 22% for assimilable phosphorus, 74% for potassium and more than 100% for organic carbon, nitrogen, cation exchange capacity, calcium, as well as the Ca/Mg ratio. This clearly demonstrates that fallowing allows a restoration of the fertility of soils that would be degraded by the continuous cultivation of sugar cane. Keywords—continuous cultivation of sugarcane; degraded soils; fallow; restoration of soil fertility