A yearly spraying of olive mill wastewater on agricultural soil over six successive years: impact of different application rates on olive production, phenolic compounds, phytotoxicity and microbial counts.
Olive mill wastewater (OMW) spraying effects onto olive-tree fields were investigated. Three OMW levels (50, 100 and 200 m(3)ha(-1)year(-1)) were applied over six successive years. Olive-crop yields, phenolic compounds progress, phytotoxicity and microbial counts were studied at different soil depths. Olive yield showed improvements with OMW level applied. Soil polyphenolic content increased progressively in relation to OMW levels in all the investigated layers. However, no significant difference was noted in lowest treatment rate compared to the control field. In the soil upper-layers (0-40 cm), five phenolic compounds were identified over six consecutive years of OMW-spraying. In all the soil-layers, the radish germination index exceeded 85%. However, tomato germination test values decreased with the applied OMW amount. For all treatments, microbial counts increased with OMW quantities and spraying frequency. Matrix correlation showed a strong relationship between soil polyphenol content and microorganisms, and a negative one to tomato germination index.
UR Etude et Gestion des Environnements Urbains et Côtiers, Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, BP 1173-3038 Sfax, Tunisia.
Salwa
S
Magdich
Raja
R
Jarboui
Béchir Ben
BB
Rouina
Makki
M
Boukhris
Emna
E
Ammar
D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D007220:Industrial Waste / Q000009:adverse effects / Q000032:analysis*; D018551:Solanum lycopersicum / Q000187:drug effects / Q000254:growth & development; D031658:Olea / Q000187:drug effects / Q000254:growth & development*; D010636:Phenols / Q000032:analysis / Q000494:pharmacology / Q000633:toxicity; D059808:Polyphenols / Q000032:analysis / Q000494:pharmacology / Q000633:toxicity; D031224:Raphanus / Q000187:drug effects / Q000254:growth & development; D012621:Seasons; D012988:Soil Microbiology; D014416:Tunisia; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000494:pharmacology* / Q000633:toxicity*
D007220:Industrial Waste; D010636:Phenols; D059808:Polyphenols; D014874:Water Pollutants, Chemical