This study investigated the effects of sawdust as a soil amendment on certain growth parameters of Solanum esculentum Linn. grown in soil polluted with various concentrations of waste engine oil, and changes in the ph...This study investigated the effects of sawdust as a soil amendment on certain growth parameters of Solanum esculentum Linn. grown in soil polluted with various concentrations of waste engine oil, and changes in the physicochemical proper- ties of the soil. The purpose was to assess the soil remediation potentials of sawdust in waste engine oil-polluted soil. The experiment was divided into three regimes： control （air-dried soil without waste engine oil and with clean sawdust）, pol- luted （waste engine oil-contaminated soil）, and amended （oil-polluted soil amended with sawdust）. Enough 3-kg soil samples were sieved and air-dried to prepare five treatment levels of waste engine oil-contaminated soil （30 mL, 1%; 60 mL, 2%; 90 mL, 3%; 120 mL, 4%; and 150 mL, 5%）, as well as five additional treatment levels （the same amounts ofoil contamination） in soil amended with sawdust. The treatment levels were replicated five times in a completely randomized design. A nursery bed was planted with a hybrid tomato variety （Roma V F） obtained from National Horticultural Research Institute （NIHORT） in Ibadan, Nigeria. During the maturation period, the growth parameters such as plant height, number of leaves, and number of branches per plant were determined and then the harvested plants were oven dried at 70 ℃for 48 hours to determine their dry weights. The effects of the sawdust amendment on the soil were assessed by determining the soil pH （glass electrode pH meter）, total nitrogen （Kjeldahl method）, total phosphorus （Bray-1 solution）, and potassium （on the leacheate by a flame photometer）. Chromium, lead, and cadmium contents were determined using an atomic absorption spectrophotometer. Analysis of variance and a Duncan multiple-range test were employed to test significant differences in the soil properties of the three regimes. The growth performance ofSolanum esculentum Linn. in the amended regime （soil with sawdust） at the 150-mL waste engine oil-contamination level was significantly higher than in the polluted regime （soil without sawdust）. After plant harvest, the pH of the soil was shown to be clearly affected by the addition of waste engine oil. The control soil （air-dried only, no sawdust, no oil） had the highest pH value, 6.60, which was significantly different from the pH values at other levels of waste engine oil contamination. However, when amended with sawdust, the control soil had a significantly lower pH value than the unamended control soil. This study further demonstrates that sawdust has the potential of amending waste engine oil-contaminated soil for increasing tomato growth performance because it is capable of increasing the soil nutrient content and reducing the soil total hydrocarbon content.展开更多
文摘This study investigated the effects of sawdust as a soil amendment on certain growth parameters of Solanum esculentum Linn. grown in soil polluted with various concentrations of waste engine oil, and changes in the physicochemical proper- ties of the soil. The purpose was to assess the soil remediation potentials of sawdust in waste engine oil-polluted soil. The experiment was divided into three regimes： control （air-dried soil without waste engine oil and with clean sawdust）, pol- luted （waste engine oil-contaminated soil）, and amended （oil-polluted soil amended with sawdust）. Enough 3-kg soil samples were sieved and air-dried to prepare five treatment levels of waste engine oil-contaminated soil （30 mL, 1%; 60 mL, 2%; 90 mL, 3%; 120 mL, 4%; and 150 mL, 5%）, as well as five additional treatment levels （the same amounts ofoil contamination） in soil amended with sawdust. The treatment levels were replicated five times in a completely randomized design. A nursery bed was planted with a hybrid tomato variety （Roma V F） obtained from National Horticultural Research Institute （NIHORT） in Ibadan, Nigeria. During the maturation period, the growth parameters such as plant height, number of leaves, and number of branches per plant were determined and then the harvested plants were oven dried at 70 ℃for 48 hours to determine their dry weights. The effects of the sawdust amendment on the soil were assessed by determining the soil pH （glass electrode pH meter）, total nitrogen （Kjeldahl method）, total phosphorus （Bray-1 solution）, and potassium （on the leacheate by a flame photometer）. Chromium, lead, and cadmium contents were determined using an atomic absorption spectrophotometer. Analysis of variance and a Duncan multiple-range test were employed to test significant differences in the soil properties of the three regimes. The growth performance ofSolanum esculentum Linn. in the amended regime （soil with sawdust） at the 150-mL waste engine oil-contamination level was significantly higher than in the polluted regime （soil without sawdust）. After plant harvest, the pH of the soil was shown to be clearly affected by the addition of waste engine oil. The control soil （air-dried only, no sawdust, no oil） had the highest pH value, 6.60, which was significantly different from the pH values at other levels of waste engine oil contamination. However, when amended with sawdust, the control soil had a significantly lower pH value than the unamended control soil. This study further demonstrates that sawdust has the potential of amending waste engine oil-contaminated soil for increasing tomato growth performance because it is capable of increasing the soil nutrient content and reducing the soil total hydrocarbon content.
