Soil Fertility Reclamation of Abandoned Mining Sites through Organic Intervention

Abstract

Tin mining in the period of its boom left large areas of land unsuitable for crop production. The financial benefits of tin mining were short-lived and cannot be quantified with the consequences of its devastation, which is still negatively impacting on the environment. Many of the devastated lands were abandoned due to soil infertility. Smallholder farmers are battling with restoring soil fertility for crop production. This study was conducted on smallholder farms in a devastated and abandoned area due to tin mining of the Bukuru-Rayfield, Sabon-Gida mining zone of Jos Plateau where contrasting organic interventions by farmers were observed. This was also confirmed by laboratory and geostatic spatial variation. A total of 35 soil samples were taken at a depth of 0-20cm, prepared and analyzed in the laboratory.  Continuous surfaces were later generated through geostatistics. Results indicated that organic matter had significant negative correlations with exchangeable acidity (-0.879), clay (-0.633) and silt (-0.616) but significant positive correlations with potential hydrogen (pH) (0.885), nitrogen (N) (0.991), phosphorus (P) (0.954), potassium (K) (0.911), calcium (Ca) (0.920), magnesium (Mg) (0.911) and sand (0.824). Most of these correlations were done at 0.01 level of significance. High concentration of pH, organic matter (OM), N, K, Ca, Mg and sand occurred in the north western part of the study area (Farm A). In contrast, exchangeable acidity, silt and clay had less concentration in the north western part of the study area (Farm A), with highest concentration in the W and SW parts (Farm C). Spatial variability from geostatistics indicated that all the soil variables had strong spatial dependency. The results of this study unveiled that nutrients needed for higher productivity were made available by the smallholder farmer of farm A through dumping of households’ domestic wastes for ten years. These abandoned mining sites later became agriculturally productive. This study will serve as advisory to smallholder farmers as a way of improving soil productivity in tin-devastated farmlands.