Evaluation of Biologically Treated Olive Mill Wastewater for Irrigation of Pea Plant

Document Type : Original Article

Authors

1 Microbiology Dept, Institute of Water, Soil and Environment, Agricultural Research Center (ARC),Giza, Egypt

2 Organic Agriculture, Heliopolis university - Agricultural Microbiology Dept, Fac of Agric, Ain Shams Univ, P.O. Box 68, Hadayek Shoubra 11241, Cairo, Egypt

Abstract

This study evaluated the use of biologically treated olive mill wastewater (OMWW) for irrigation of pea plants, rather than discharging this nutrient-rich liquid and polluting the environment. Pea seeds were planted in pots containing soil irrigated with tap water (control), untreated (crude) OMWW, or OMWW treated with the fungus, Pleurotus columbinus, or algae Spirulina platensis or Wollea sp., with two NPK rates. Plant length shoot and root dry weight, nitrogen, phosphorus, potassium, chlorophyll, and carotene contents were measured, along with to nitrogenase and dehydrogenase activity. The highest shoots' N and P contents were recorded in plants irrigated with Sp. platensis- treated OMWW + 100% NPK; while the highest K content was in plants irrigated with crude OMWW + 100% NPK. The highest dehydrogenase activity, 59.01 μg TPF/100 g soils, was recorded in plants irrigated with P. columbinus-treated OMWW supported with 75% NPK, while maximum nitrogenase activity (261.82 μmol/100g soil/day) occurred in plants irrigated with Wollea sp.-treated OMWW with 75% NPK. The highest content of chlorophylls a & b and carotene (0.838, 0.276, 0.252 mg/g dry weight, respectively) were found in plants irrigated with OMWW treated with Wollea sp. and 100% NPK. Thus, biologically-treated OMWW showed promising impacts on plant growth parameters.

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