Effect of Petroleum Produced Water on Seed Germination and Seedling Growth of Four Tree Species in Heglig, South Kordofan, Sudan

Abstract

This study investigated the effect of irrigation with petroleum produced water (PPW), at phases of bioremediation in Heglig, on seed germination, seedling growth and survival of two indigenous species (Acacia seyal and Balanites aegyptiaca) and two exotics (Eucalyptus camaldulensis and Jatropha curcas). The treatments were PPW from lagoons (untreated), reed (Phragmites australis) beds and after reed beds (treated water), and from a well in Heglig (control). The water treatments were analyzed for dissolved oil, total dissolved solids, electrical conductivity, temperature and pH. Seeds from the four species were planted in polythene bags filled with clay soil and placed in Heglig nursery. Water treatments were assigned randomly to each species. Seed germination was monitored daily for three weeks. Seedling survival and shoot length were monitored for four months. Three sequential destructive harvests for seedlings were carried out to measure and calculate biomass parameters. The results showed significant differences among treatments in dissolved oil and total dissolved solids. However, seed germination percentage and rate, and seedling survival for each species were not affected by the treatments. A. seyal showed significant differences in some seedling growth parameters in harvests two and three, whereas the control treatment showed higher values than the other treatments. Balanites aegyptiaca showed significantly higher values for the control treatment in root parameters in harvests one, two and three; and higher values for root weight in harvest three. E. camaldulensis seedling growth parameters showed significant differences among the water treatments in few growth parameters in harvest two, where the control treatment showed higher values than the other treatments. J. curcas seedlings were not affected by the water treatments in the three harvests. The study concluded that seed germination and seedling survival (100%) of the tested species were not affected by PPW. However, some seedling growth parameters were affected, where the control gave bigger seedlings than the other PPW treatments from the phases of bioremediation. The indigenous species were more affected than the exotics and the effect was more pronounced with time.