Effects on macronutrient contents in soil-plant irrigated with different quality waters and wastewaters

The goals of this research were focused on investigating the effects of irrigation with untreated wastewater, ozone-enhanced primary treated wastewaters (O3EPTW), tap water and tap water + fertilizer on the macronutrient content in soil and plant tissues. The effect on plant development was evaluated by growing Lactuca sativa in soils irrigated with these different quality waters and wastewaters, and by determining the macronutrients content in water, soil and plants. In this study, the soils irrigated with O3EPTW showed increased organic matter concentrations, which is advantageous for crop cultivation. The electric conductivity for the O3EPTW irrigated soils remained below those of the tap water + fertilizer and untreated wastewater. The soil irrigated with tap water + fertilizer showed a marked decrease in pH, and its long-term use could lead to soil acidification. Macronutrient levels in plant tissues (N, K and Mg contents) were similar for all irrigation waters, except for tap water which always remained lower than the others. It was concluded that the use of O3EPTW may become a good irrigation alternative that can be employed without the health risks associated with the use of untreated wastewaters, also reducing the adverse effects on soil's salinity or acidification.