Effect of irrigation with olive mill wastewater on soil hydraulic and solute transport properties

Abstract

To evaluate the effect of olive mill wastewater (OMW) application on soil hydraulic and transport properties, two treatment sites, which had been irrigated with OMW for 5 and 15 years, and one control site being irrigated with freshwater were compared. The transport and leaching experiment results showed that a portion of the total soil water was available for transport processes while the remaining of the soil water was considered immobile and not readily accessible for solutes. The separation in water fractions of different mobilities was surprisingly consistent among OMW treatments. The bromide recovery rate decreased with the application of OMW showing that tracer molecules became trapped within immobile water phases. The application of OMW increased significantly the soil water-holding capacity, whereas the soil hydraulic conductivity in the near saturation range decreased significantly with long-term OMW application. The soil irrigated with OMW had significantly higher organic matter content, lower bulk density and relatively higher total porosity, but lower macroporosity than that of control sites. We concluded that the soil was increasingly coated with complex organic molecules originating from OMW, as a result, solute exchange between inter-and intrasoil aggregate water was hindered. Although OMW could cause soil and water pollution, its use in agriculture is promoted because of high nutrients and organic matter contents.

Effects of two plant growth-promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate deaminase on oat growth in petroleum-contaminated soil

“…With increasing industrialization, environmental problems such as the pollution of the petroleum and saline-alkali fields have become a global issue (Mohawesh et al 2014;Ogri 2001;Sakai et al 2004;Sharma et al 2012). Many developing countries face serious problems with soil pollution, but environmental concerns seem to be a luxury given the economic situation in most countries (Navabakhsh and Tamiz 2013).…”

Effects of deficit irrigation on tomato and eggplant and their infection with the root-knot nematode under controlled environmental conditions

“…Globally, irrigation accounts for 69% of the 3240 km 3 of water withdrawn for human use, and 87% of all water consumed (Gleik 2000). To sustain the rapidly growing world population, agricultural production should be increased (Howell 2001), so far the share of fresh water available for agriculture (72%) is decreasing (Cai & Rosegrant 2003;Mohawesh 2011;Mohawesh et al 2013). Consequently, sustainable methods to increase crop-water productivity are gaining higher value in arid and semi-arid regions (Debaeke & Aboudrare 2004;Mahadeen et al 2011).…”

Impact of olive mill wastewater (OMW) on the soil hydraulic and solute transport properties

“…OMW is a primary waste product of olive oil processing. In several countries where olive oil production is very intensive, OMW is often recycled as a low-cost fertilizer, since OMW is naturally rich in mineral elements (Kavvadias et al 2014;Mohawesh et al 2014;Chatzistathis and Koutsos, 2017;Mekki et al, 2018;Chehab et al, 2019).…”

“…From a hydrological standpoint, several studies have shown that high concentrations of suspended solids, organic matter, potassium (K) and sodium (Na) in OMW have the potential to reduce the saturated soil hydraulic conductivity (Mohawesh et al 2014;Regni et al, 2017). Furthermore, lipidic constituents (i.e.…”