Irrigation
with gaseous nanobubble (NB)-containing water has been
demonstrated to promote seed germination and plant growth. To further
reveal the impacts of NBs on plant growth, this study compared soil
chemical properties and the release of soil elements (e.g., NH4
+, K+, and Mg2+) before and
after immersion with different gaseous NBs such as oxygen (O2), nitrogen (N2), hydrogen (H2), carbon dioxide
(CO2), and air. Exposure to NBs resulted in different influences
on the soil pH, dissolved oxygen (DO), redox potential, and nutrient
release. For instance, O2 NBs significantly increased both
DO and redox potentials of the treated soil. CO2 NBs increased
the release of Ca2+, Mg2+, and PO4
3– from the treated soil, whereas N2 NBs only improved the NH4
+ release from the
soil. Finally, multiple-factor correlation analysis and principal
component analysis revealed intercorrelations between the different
soil properties and confirmed that the nutrient ion release was highly
dependent on the type or composition of NBs.