Improvement of petroleum hydrocarbon remediation using the oat plant in the soil treated by poultry manure

This greenhouse experiment aimed to investigate the effects of poultry manure (PM) on the growth of oat plant (Avena sativa) and removal of total petroleum hydrocarbons (TPHs) from soil. The treatments consisted of three TPH levels (4%, 6%, and 8% w/w) and two PM levels (zero and 1%) at three replications. According to the findings, shoot height, number of leaves, and the fresh and dry weight of the shoots and roots of oat decreased significantly with 6% and 8% TPHs compared to 4% contamination level. On the other hand, the removal of TPHs and microbial respiration rate significantly increased by 16.8% and 78.18%, respectively in the PM treatment compared to the non-PM treatment. The rate was estimated at 28.85% and 27.03% in the soil cultivated by oat compared to the unplanted soil, respectively. The highest and lowest removal rate of TPHs was observed in the soil cultivated with oats in the PM treatments containing 4% of the TPHs (45.25%) and unplanted treatments without manure containing 8% of TPHs (11.38%). Therefore, it could be concluded that the addition of PM to the soil cultivated with oat in the soils with TPH contamination could increase the microbial respiration rate of the soil, as well as the removal of TPHs.