Pesticide application and water quality in Doho and Kibimba rice irrigation schemes, eastern Uganda

Abstract

The number and amount of agrochemicals used has increased dramatically world over and their toxic nature has raised concern about environmental impact and effects on human health. Considering that agriculture is a major source of income in most developing countries, crop damage from pest infestation is of great concern to many farmers. These farmers are therefore motivated to apply pesticides. However, runoff from such farmlands unintendedly contaminates the water sources thereby causing harm to aquatic life and contaminates drinking water. This study was carried out at Doho and Kibimba irrigation schemes, which are the two commercial paddy rice growing areas in Uganda. The aim of this study was to investigate the effect of pesticide application on water quality in these two schemes and assess community awareness of the dangers of pesticide application. A cross sectional research design was used to collect data. A total of 60 samples (30 from each site) on physicochemical characteristics were collected in situ using standard equipment. 200 local community members (100 from each scheme) were randomly selected while on the farm and interviewed. Statistical analyses were conducted using Statistical Package for Social Sciences (SPSS) program, version 20. Results showed that there were significant spatial differences in all the physical chemical properties of water in Doho Rice Scheme (P<0.05), while significant spatial variations were recorded for only pH, temperature at Kibimba rice scheme (P<0.05). Independent t-test results showed that water pH, temperature and turbidity varied significantly between Doho and Kibimba (P<0.05). Herbicides such as rocket, Diazine, Cypermatrine glyphosate were being used by famers with rocket frequently used at Doho while glyphosate was the only one used at Kibimba. Majority of the farm workers at Kibimba (96.9%) reported to have always used protective devices when handling pesticides and the reverse was true for farm workers at Doho despite the training on pesticide usage. The study therefore recommends regular water quality monitoring and sensitization of farmworkers on the dangers of improper pesticide use.