Effects of different levels of spent engine oil on soil physicochemical properties using different texturally contrasting soils.

Abstract

Three texturally contrasting soils: Sandy loam (SL), Loamy sand (LS) and Sandy clay loam (SCL) were potted 4 kg each with a polythene bag and polluted with 10% w/w (122ml/kg), 20% w/w (245ml/kg) and 0% w/w (0ml/kg) of spent engine oil. The soil was thoroughly mixed with spent engine oil and allowed to stay for three weeks to allow for proper absorption of the engine oil. Thereafter, air-dried crushed and sieved poultry manure was applied to the soil in each polythene bag at a rate of 40 t/ha. The spent engine oil-soil-organic manure mixture was watered to field capacity 3 times per week for two weeks after which the seeds of sunflower was sown. Soil samples were collected and analyzed at the end of the study which lasted for 12 weeks. Spent engine oil affects soil physicochemical properties as the bulk density, aggregate stability, state of aggregation, mean weigh diameter, phosphorus, Nitrogen, organic matter and pH both in water and KCl increases with increase in pollution rates while the cation exchange capacity, hydraulic conductivity, total porosity and microporosity decreases with increase in pollution rate. The physicochemical properties varies across the different soil types but loamy sand soil recorded a favourable parameters that will enable plant growth compared to other soil types.