The Effect of Biological Secondary Treated Domestic Wastewater on Agronomic Properties and Element Content of Some Forage Plants

Abstract

Aims: This study was carried out to determine the effect of domestic advanced biological treated domestik wastewater on the agronomic properties and nutritional content of some forage crops, as a result of the increasing interest in the use of treated wastewater in agriculture. Material and methods: Biologically treated domestic wastewater was diluted with 25%, 50% and 75% pure water and applied to crested wheatgrass (Agropyron cristatum Geartn), orchard grass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) pots according to field capacity. Results: Alfalfa, orchard grass and crested wheatgrass plants were used as trial plants. The effect of the diluted wastewater application on the height of crested wheatgrass, orchard grass and alfalfa was significant. From the first mow, alfalfa and orchard grass had increased green and dry weights per pot, with the most marked increase for alfalfa. The wastewater ratios caused an increase in nutrient and metal concentrations in the three plants, while a decrease in the Se concentration in alfalfa and crested wheatgrass. Diluted wastewater not effected alfalfa Ca concentration significantly. While the dilute wastewater significantly and positively effected the relationship of orchard grass with all elements, but Se affected negatively. Soil organic matter and electrical conductivity increased and pH decreased with increasing wastewater ratio. Discussion: Diluted domestic water application played an important role in nutrient and metal concentrations by mediating increased plant element uptake associated with soil organic matter and electrical conductivity responses. Conclusions: However, long-term field studies are required to determine the dilution rate at which the salinity risk threshold can be determined.