EGU22-6937
https://doi.org/10.5194/egusphere-egu22-6937
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

The effects of drip irrigation with nanobubbles aerated water on soil N transformation

Shahar Baram1, Maya Weinstien1,2, Guy Kaplan1,2, and Shmulik Friedman1
Shahar Baram et al.
  • 1Institute for Soil, Water and Environmental Sciences, Agricultural Research Organization (ARO), Volcani Research Center, Soil Chemistry, Plant Nutrition and Microbiology, Israel (shaharb@volcani.agri.gov.il)
  • 2Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot Israel

In recent years, irrigation with nanobubbles aerated water (NB-water) [i.e., air or oxygen-NB (ONB)] has emerged as a new method to alleviate transient hypoxic conditions in the rhizosphere. We aimed to study the effect of surface and subsurface drip irrigation with ONB aerated waters [i.e., fresh (0.4 dS/m), secondary urban treated wastewater (TWW; 1.3 dS/m), saline (3dS/m)] on soil nitrogen transformations. Greenhouse lysimeter experiments were conducted in vertisol (58% clay), sand (98% sand), compost, and sand:compost (1:1) mixture, under well aerated and poorly aerated conditions. Ammonium-N to nitrate-N ratios in the irrigation waters ranged from 15% to 50%.  In all the experiments, irrigation with ONB water, with dissolved oxygen (DO) concentrations of 11 to 35 mg/L, increased the transient buildup of nitrite in the porewater, even under well-aerated conditions (soil air O2> 19%). The most significant effects were observed in the sand, sand:compost, and compost media, where nitrite concentrations were 2 – 8 times greater than the controls and reached over 65 mg/L. Despite the increased nitrite concentrations, irrigation with ONB waters reduced the nitrous oxide fluxes by 4 – 85%. Both phenomena suggested higher oxygen availability in the soil. Nitrite buildup implies that ammonia (NH3) oxidation may not be the rate-limiting step of nitrification under irrigation with ONB aerated water. 

How to cite: Baram, S., Weinstien, M., Kaplan, G., and Friedman, S.: The effects of drip irrigation with nanobubbles aerated water on soil N transformation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6937, https://doi.org/10.5194/egusphere-egu22-6937, 2022.