The length of time taken to obtain optimum germination and early performance of rice grown on diesel-contaminated soils was investigated. This was meant to inform researchers and farmers of the economic thresholds in using diesel contaminated lands as land is limited in supply in many places of the world and diesel contamination of agricultural lands in most developing countries is an important environmental issue. Soil samples were contaminated at rates of 0 cm³/kg, 12 cm³/kg and 24 cm³/kg and filled into experimental buckets of 10.5 litres capacity. The soil samples were mixed thoroughly to ensure homogeneity before filling the experimental buckets followed by diesel contamination at predetermined dosages. Five rice crops were planted in succession at two weeks interval and the germination percentage and height of seedlings at two weeks after planting determined. Significant difference in germination and plant height was observed when planting was done at the time of pollution. There was no significant difference in germination when seeds were planted at six weeks after contamination. However, the difference in the height of seedlings was significant (p ≤ 0.05) even when planting was done at eight weeks after soil contamination with diesel. There was a positive relationship between the time of planting after contamination and germination of rice seeds, which depended on the level of contamination (r² = 0.631 at 12 cm³/kg contamination and r² = 0.644 at 24 cm³/kg contamination level). For plant height at two weeks after planting, the coefficient of correlation with time of planting after contamination was positive and increased with increased levels of contamination. Rice seeds sown on soils of up to 24 cm³/kg contamination level gave optimum germination when planted at six weeks after contamination but performance of germinated seeds was still significantly low when planting was done even at eight weeks after contamination (p ≤ 0.05).
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