Redistribution and availability of iron, manganese, zinc, and copper in four Malian agricultural soils amended with solid municipal waste compost

Municipal waste compost can improve the fertility status of tropical soils. The redistribution of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in tropical soils after amendment with solid municipal waste compost was investigated. Four tropical agricultural soils from Mali characterized by poor trace-element status were amended with compost and incubated for 32 weeks at 35 degrees C. The soil were analyzed at the beginning and the end of the incubation experiment for readily available fractions, organic fractions, and residual fractions as operationally defined by sequential extraction. Readily available Fe increased significantly with compost application in most soils. Readily available Mn was mostly unaffected by compost application. After 32 weeks, readily available Zn had increased, and readily available Cu had decreased. Readily available levels of the elements remained greater than deficiency levels in the compost-amended soils. Organic fractions of the elements increased after compost addition. The organic fractions and residual forms, depending on the element and the soil, remained constant or increased within the duration of the experiment.