Soil Moisture Responses to Long-Term Nanobubble Water Applications: Exploring Potential Mechanisms

This study examined the long-term effects of nanobubble-saturated water (NBSW) on silty clay loam and sandy loam soils, with an emphasis on soil moisture dynamics, water balance, compaction, and electrical conductivity (EC) over a 1.5-year experimental period. NBSW did not induce a significant long-term increase in soil moisture storage compared to conventional watering, though there were short-term changes. In both soils, NBSW caused higher cumulative evaporation and reduced leaching in water partitioning. Compaction increased over time, and this response was stronger under NBSW, with a greater increase in silty clay loam than in sandy loam. EC remained higher in both soils under NBSW treatment, with a greater temporal increase in sandy loam and permanently higher levels in silty clay loam, indicating more dissolved-ion retention in the soil profile and less leaching. Compaction and EC were normalized to the maximum measured soil moisture. This study reveals that NBSW has a greater long-term influence on water-loss partitioning and root-zone solute dynamics than it does on long-term soil water storage.