Effect of phosphate mining on food security and soil nutrient status in Osukuru-Rubongi Mining area, Tororo District.

Abstract

The study was conducted in Osia parish, Rubongi sub-county-Tororo District where phosphate mining site is situated though the processing plant lies in Osukuru parish of Osukuru sub-county. The main objective of the study was to investigate the impact of phosphate mining on soil nutrients notably NPK and soil properties especially pH and O.M. the study also explored local farmer’s perception of effect of project development on food security. Various methods were used in data collection. These included interviews using questionnaires and focus group discussions. Soil samples were systematically collected along well established transects that were spaced 50m apart and between each transect. The air-dried soil samples were pounded, sieved through 2 mm to remove any debris then subjected to physical and chemical analysis following standard methods described by Okaleboet al. (2002)’. Soil pH was measured in a soil water solution ratio of 1:2.5; Organic matter by potassium dichromate wet acid oxidation method; total N determined by Kjeldhal digestion. Extractable P was determined by Bray P1 method while exchangeable bases were measured from an ammonium acetate extract by flame photometry. Social survey data were entered into SPSS statistical software and subjected to descriptive statistical analysis to obtain frequency, percentages and Chi-square values. The results show that there is drastic deterioration in the quality of soil as a result of phosphate mining activities. The soil pH changed from 6.22 in the control site to 5.70 in mine. Soil organic matter content, levels of total nitrogen and potassium declined drastically from 0.54%, 0.05% and 0.38cmoles/kg at the phosphate mine site compared to corresponding levels of 1.94%, 0.13%, and 0.76cmoles/kg respectively in the control. Phosphorus level was higher in the phosphate mine at 141.14ppm/kg compared to the lower corresponding value of 119.96ppm/kg at the control site. Food production significantly (P<0.05) reduced around the mining area. This study conclusively suggests that food shortage persists,affecting local tribal mine workers and poor. Soils within the mine have showed significant decline (p<0.05) in nutrient levels and change in soil pH respectively compared to corresponding control except phosphorus. Human labour has become scares in the area causing labour shortages in farms. This study recommends restoration of the fertility status. The fertility of the soil will be increased by the addition of fertilizers with proper N: P: K ratio. Preferably leguminous plants with high foliage ability should be planted in order to reclaim the un-fertile and residual mine soil.