Some chemical properties of irrigated soils around Sokoto Modern Abattoir in north-western Nigeria

Abstract

A study was conducted to determine the physico-chemical properties of irrigated soils of Sokoto Modern abattoir. Soil samples were collected from four identified farms (A,B,C,D) under irrigation that were affected by abattoir effluent. From each farm, three composite samples were collected at the surface (0-15cm) and subsurface (15-30cm) layers. A control sample was collected from an uncultivated land located about 200 meters southwest of the farmlands that was neither affected by abattoir nor fertilizer at the same depths, giving a total of 26 samples. The soils were analyzed for some basic chemical properties following standard methods. The results revealed an alkaline soil with mean pH of 8.6 and 8.5 at surface and subsurface layers, respectively. The organic carbon obtained was high both at the surface (3.72-4.11%) and subsurface (1.08-2.93%) layers, which were about 1.4 to 2.8 times higher than the control values. Total N in surface and subsurface (0.08-0.09% and 0.04-0.07%) and available phosphorus (4.56-5.04 and 3.18-3.56mg kg^-1) values were very low in effluent affected soils and even lower in the control samples. Exchangeable potassium was high with a mean value range of 1.14-1.81 cmol(+)kg^-1 and 0.53-0.73 cmol(+)kg^-1 for the surface and subsurface layers, respectively. There was a general indication of the effect of abattoir affluent on the levels of chemical parameters analyzed, compared to the control samples, except the pH. The soils were relatively fertile and could sustain effective crop production if the pH could be reduced to the levels favourable to crops and microbial activity.