Synergistic roles of carbon dioxide nanobubbles and biochar for promoting direct CO < sub > 2 < /sub > assimilation by plants and optimizing nutrient uptake efficiency

This study investigates the synergistic role of carbon dioxide nanobubbles (CNBs) and biochar (BC) on seed germination, plant growth, and soil quality, employing Solanum lycopersicum (tomato) and Phaseolus vulgaris (beans) as test plant species. CNBs, generated and dispersed in both distilled water (DW) and tap water (TW), exhibited distinct characteristics, with TW-CNBs being larger and more stable (peak values of around 18.17 nm and 299.5 nm, zeta potential (ZP) of -5.91 mV), while DW-CNBs have peak values of around 1.63 nm and 216.1 nm, ZP of -3.23 mV. The results show that CNBs increased seed germination by 8-20%. CNBs in BC amended soil further promoted plant height and leaf number. CNBs increased dissolved CO2 levels to 2-24 ppm within 40 min, while BC enriched soil organic carbon from 19.20 to 24.96 ppm in beans and 18.33-22.35 ppm in tomatoes. The pH levels decreased from 7.68 to 3.78 for TW-CNBs and from 7.41 to 2.13 for DW-CNBs. Additionally, the electrical conductivity (EC) decreased from 112.1 to 99.6 for TW-CNBs, while it increased from 4.15 to 32.1 for DW-CNBs. Together they significantly increased soil available phosphorus and potassium to 4.03-8.06 and 3.58-7.16 kg ha-1; and 5.67-55.74 and 17.57-43.79 kg ha-1 in bean and tomato, respectively. Variations in nutrient concentrations were observed, with substantial increase in Na (16.27% and 6.58%), Zn (3.39% and 0.46%), and Mg (5.05% and 1.44%) content for beans and tomatoes, respectively. Structural equation mod...
Source: Environmental Research - Category: Environmental Health Authors: Source Type: research