Physical and Hydrodynamic Textural Parameters of Soils: The Case of the Rubber Plantations of the Centre National de Recherche Agronomique (CNRA) Anguédédou in South-Eastern Côte d'Ivoire

Abstract

The rubber tree, a species of Amazonian forest tree, is cultivated for its latex, which is rich in natural rubber. Its cultivation is of economic, social, climatic and environmental importance. However, it is often accused of destroying the soil. To clear up this misunderstanding, a study was carried out to characterise the physical and hydrodynamic characteristics of soils under rubber in south-eastern Côte d'Ivoire. According to the biotope (rubber plantation, abandoned rubber plantations and forest) and the age of the rubber plantations, this study selected 12 plots. These included ten rubber plantations that were divided into four age categories: 1-5 years, 6-10 years, 11-20 years, and 21-40 years. Additionally, a secondary forest was also selected as a control, which was located in close proximity to these plantations. Furthermore, a rubber plantation that had been abandoned for more than eight years was also selected considered as a transition between the active plantations and the secondary forest. In these biotopes, soil samples were taken using an auger and sent to the laboratory to determine soil texture. Using the Yoro sand method and the single ring device, the apparent density, porosity and water infiltration rate of the soils were determined. The results show that the soil texture of the CNRA Anguédédou rubber plantations in southern Côte d'Ivoire is generally clayey.  On the other hand, the texture of the soils of the youngest plantations (1 to 5 years old) is silty-clayey with more than 37% clay and a low water content. However, the soils of old rubber plantations with a clay texture have high water content. The soil compactness observed in young rubber plantations is corrected as the plantations age.