The effect of oily waste and nutrient amendments on soil fertility and oat growth

Abstract

Growth chamber and incubation experiments were conducted with a sandy, marginal agricultural soil from the Brown soil zone near Richmound, Saskatchewan. The objective of the study was to determine how oily waste from heavy oil upgrader affects soil fertility, plant growth and microbial activity under controlled environmental conditions. The growth chamber study examined the effect of adding oily waste alone and in combination with fertilizer and hog manure on: 1) soil macronutrient supply 2) growth and nutrient uptake by oats and 3) relevant physical properties affecting plant growth Addition of urea and manure with the sludge resulted in significantly higher supplies of available nitrogen than in sludge only amended soil. This was a contributing factor to significantly higher yield of oat plants and nutrient uptake in these two treatments. To achieve adequate plant growth, oily waste addition should be accompanied by a supplemental source of plant nutrient to compensate for nutrient immobilization while the sludge is decomposed by soil microorganisms. Sludge had no detrimental effect with regard to soil salinity and sodicity. Addition of sludge increased the organic carbon content of the soil and fertilizer application appears to increase the conversion of oily waste carbon to humus. Combination of fertilizer with sludge had no effect on accumulative CO2 production over sludge alone.