Soil Properties on Farmers' Fields Amended with Untreated Solid Urban Wastes in Ouagadougou Peri-urban Area, Burkina Faso

Abstract

In Burkina Faso untreated Solid Urban Wastes (SUW) are commonly used as agricultural fertilizers. This study aims to highlight the impacts of this current practice on soil agronomic properties and crop production. Sampling was carried out in Ouagadougou sub-urban agricultural fields. Agronomic tests, physical and chemical analyses were carried out following lab common procedures. The fertility of the soils was assessed through a greenhouse experiment with maize as test crop. The results showed that amendment significantly increased the pH, total C, N, P and available P contents as p-values were <0.01 for these parameters. The averages maize height and aboveground biomass yield in amended plots were 124 % and 164 % higher than in the non-amended plots respectively. Also, trace metal elements (Cu, Zn, Pb, Ni and Cr) concentrations were higher in the amended fields than in the control ones, suggesting that urban waste also carries contaminants that constitute risks for public health. This research showed that the use of SUW as fertilizer has agronomic advantages as it increases the essential nutrient content of the soil and regulates its pH. However an adequate pretreatment is necessary to avoid risks related to contaminants such as trace metal elements.

Keywords

• Untreated urban wastes
• Agricultural fertilizer
• Crop production
• Trace metal elements
• Burkina Faso