Omwoma S., Lalah J.O., Ongeri D.M.K., Schramm K.-W.
Department of Chemistry, Maseno University, P.O. Box 333-40105, Maseno, Kenya; Department of Chemical Science and Technology, School of Pure and Applied Sciences, Technical University of Kenya, P.O. Box 52428-00200, City Square, Nairobi, Kenya; HelmholtzZentrum Muenchen, The German National Research Centre for Environment and Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Munich, Germany
Omwoma, S., Department of Chemistry, Maseno University, P.O. Box 333-40105, Maseno, Kenya; Lalah, J.O., Department of Chemical Science and Technology, School of Pure and Applied Sciences, Technical University of Kenya, P.O. Box 52428-00200, City Square, Nairobi, Kenya; Ongeri, D.M.K., Department of Chemistry, Maseno University, P.O. Box 333-40105, Maseno, Kenya; Schramm, K.-W., HelmholtzZentrum Muenchen, The German National Research Centre for Environment and Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Munich, Germany
Sugarcane farming is the most important cash crop cultivation activity in the Lake Victoria basin of Kenya practised in an area covering approximately 114,000 Ha in total. For better yields, various agronomic inputs including fertilizers and herbicides have been used intensively in the farms, causing serious concerns about their potential impacts on the aquatic ecosystems within the lake basin. In this study, the physicochemical features of surface sediment and water including pH, total organic carbon contents and heavy metal (Cd, Cu, Zn, Pb and Cr) loads in River Kuywa and in runoff canals in sugarcane farms in Nzoia nucleus estate within the lake basin were determined to assess the effects of agronomic activities including agronomic inputs in the form of nitrogenous fertilizers [urea and diammonium phosphate (DAP)], herbicides and sewage sludge used in farming on their levels. The results indicated significant differences (p ≤ 0.05) in the heavy metal levels in sediment and water samples taken before and after the farms, respectively, indicating a positive impact on the concentration levels. The canal water and sediment samples' heavy metal levels were also significantly higher than those of the river samples showing that the influent sugarcane farm canal waters transfer these contaminants into River Kuywa. Although the levels of these parameters were significantly higher in the canals than in the controls obtained from outside the sugarcane farms, the heavy metal levels in soil samples from within the farms with similar agronomic activities did not differ significantly among the various plots. The turbidity, electrical conductivity, temperature, water and soil pH and total organic carbon values in samples obtained within the sugarcane farms showed significant seasonal variations and differed significantly from the values in the controls showing a significant negative impact of agronomic inputs on water quality. © 2013 Springer-Verlag Berlin Heidelberg.
Agronomy; Canals; Catchments; Copper; Heavy metals; Herbicides; Hydraulic structures; Lakes; Lead; Phosphate fertilizers; Rivers; Sewage sludge; Surficial sediments; Urea; Urea fertilizers; Water quality; Weed control; Agronomic inputs; Diammonium phosphates; Electrical conductivity; Kenya; Lake Victoria; Physicochemical features; Sugarcane farmings; Total organic carbon content; River pollution; agronomy; cash cropping; crop yield; cultivation; heavy metal; physiological response; sediment pollution; sugar cane; surface water; water pollution; water quality; East African Lakes; Lake Victoria