Agron. Sustain. Dev.
Volume 26, Number 1, January-March 2006
Page(s) 61 - 67
Published online 11 February 2006
Agron. Sustain. Dev. 26 (2006) 61-67
DOI: 10.1051/agro:2005061

Olive wastewater as an ecological fertiliser

Ali Mekki, Abdelhafidh Dhouib, Fathi Aloui and Sami Sayadi

Laboratoire des bioprocédés, Centre de biotechnologie de Sfax, BP K, 3038 Sfax, Tunisia

(Accepted 25 November 2005; published online 11 February 2006)

Abstract - The effects of untreated and treated olive mill wastewater on seed germination, plant growth and soil fertility were studied. Tomato (Lycopersicon esculentum), chickpea (Cicer arietinum), bean (Vicia faba), wheat (Triticum durum) and barley (Hordeum vulgare) were tested for the germination index and growth in soil irrigated by olive mill wastewater. Lepidium sativum was used as the standard species for the germination index and phytotoxicity evaluation. We measured soil properties, crop growth, herbage biomass, leaf elongation and productivity. The results show beneficial effects using treated olive mill wastewater. The treated plants showed an improvement in seed biomass, spike number, plant growth, and a similar or even better dry productivity than plants irrigated with water, e.g. Hordeum vulgare 102%, Triticum durum 105%, Cicer arietinum 101% and Vicia faba 102%. An increase in the germination index from 100% to 115% was observed. Soil organic matter, respiration and enzymatic activities were also enhanced by treated olive mill wastewater ferti-irrigation. However, even diluted 10 times, untreated olive mill wastewater inhibited the species germination, e.g. 1.2% for Hordeum vulgare and 40% for Cicer arietinum and Vicia faba, and plant growth (16-42.5%). Leaf necrosis and low productivity were observed in crops ferti-irrigated by untreated olive mill wastewater.

Key words: olive mill wastewater / germination index / phytotoxicity / crop growth / soil fertility

Corresponding author: Sami Sayadi

© INRA, EDP Sciences 2006