Moursalou Koriko

Clay and Soil Photolysis of the Pesticides Mesotrione and Metsulfuron Methyl

Photolysis may represent an important degradation process of pollutants at the surface of soil. In the present work, we report a detailed study on the degradation of two pesticides: mesotrione and metsulfuron methyl using a sunlight simulator. In a first step, we studied the photochemical behaviour at the surface of clays from the kinetic as well as from the analytical point of view. In both cases, the quantum yields were found to be higher when compared to those obtained in aqueous solutions. The effect of iron(III), water, and humic substances contents was studied. In the former cases, an increase of the degradation rate was observed while an inhibition was observed with the latter owing to a filter effect phenomenon. In a second step, we studied the photodegradation at the surface of natural soil and identified the generated byproducts. They appear to mainly arise from photohydrolysis process.

Carbon Mineralization of Agro-Food Waste Compost in Soil Under Controlled Conditions

Compost mineralization study under controlled conditions is a way to predict the compost behavior in the soil. It permits to know how much compost to bring to the soil to ensure a good amendment and how long the compost will last in the soil. Six composts obtained from agro-food waste are incubated under controlled conditions in order to follow the carbon mineralization. Soil-compost mixtures (100:1) are incubated at 2/3 of soil moisture capacity for 75 days and under ambient temperature (30 °C). The soil-compost mixtures released and during 75 days and15.96 to 27.52 mg of C-CO2, versus 4.89 mg for the control without compost. This correspond to the carbon potentially mineralizable varing between 25 and 46% of the total organic carbon. The pH of composts and their C/N ratio have effected carbon mineralization. keywords: Compost, Organic carbon, Mineralization, Soil.