Changes in the content of organic carbon and available forms of macronutrients in soil under the influence of soil contamination with fuel oil and application of different substances

Abstract

The aim of the study has been to determine the effect of soil contamination with fuel oil (0-20 g kg –1 of soil) on the content of organic carbon and available forms of some macronutrients in soil under the influence of different neutralizing substances and crop cultivation. The content of organic carbon as well as available potassium and magnesium in soil was positively correlated with the increasing rates of fuel oil, whereas the fluctuations in available phosphorus did not show any regularity. Among the analyzed elements, the highest increase in the concentration was found for potassium. The content of available macronutrients in soil was correlated with the plants’ yield and uptake of elements. The substances introduced to soil in order to alleviate the effect of fuel oil on soil properties caused the weakest changes in the content of organic carbon but affected most profoundly the content of available potassium and magnesium. Compared to the series without soil amending substances, bentonite caused an increase in the average content of available forms of phosphorus, potassium and magnesium, whereas calcium oxide modified the content of available potassium and magnesium. CaO decreased the content of organic carbon and available phosphorus in soil. The effect of the other tested soil amending substances on the analyzed soil properties was weaker than that produced by bentonite or calcium oxide, and the direction of changes in the levels of the elements depended on the type of a substance.