Treated livestock wastewater influence on soil quality and possibilities of crop irrigation.

This work aims to investigate how livestock wastewater irrigation affects the quality and agricultural potential of soil. The experiments took place in 2019 on a research station with an area of 10 ha (Moscow region, Russian Federation), divided into two even sites of 5 ha (control, experimental). Eleven germination experiments were carried out to determine the influence of livestock wastewater irrigation on radish seeds (1 - control; 10 - irrigation with liquid and solid phases of wastewater samples mixed with pure water). The experimental and control plots appeared to differ in terms of the bulk density of soil. Changes occurred in all horizons (p ≤ 0.05) but a soil layer with a depth of 0.2-0.4 m. Soil horizons in the experiment plots all exhibited lower porosity (p ≤ 0.05) except for the topsoil, and the water capacity was higher in the topsoil (p ≤ 0.05) and near-surface layer (p ≤ 0.05). The experiment showed higher concentrations of hummus (p ≤ 0.01) and phosphorus (p ≤ 0.01). As for nitrogen, significant changes only occurred in the topsoil (p ≤ 0.01). In the germination experiments, more than 90% of radish seeds germinated. Besides, their root length was higher compared to the control (p ≤ 0.05). The results of the study suggest that livestock wastewater can benefit crop cultivation after preliminary treatment. Finally, the experiments revealed a reduced soil salt accumulation.