来源：ACS Publications
Improving water retention in sandy soils remains critical for sustainable agriculture, with engineered nanoparticles emerging as potential amendments. This study presents a state-of-the-art pedostructure approach to investigate how negatively charged cerium oxide nanoparticles (CeO2–NPs) affect water holding capacity in silty loamy sand soil (83% sand, 13% silt, 4% clay) under saline and nonsaline conditions. Three objectives were addressed: (1) measuring the impact of different CeO2–NP concentrations on WHC and pore-scale water distribution, (2) assessing the effects of salinity on soil water retention and CeO2–NP behavior, and (3) comparing two CeO2–NP application methods (direct injection and mixing) on soil properties.Using the innovative TypoSoil system, we simultaneously measured water content, specific volume, and soil suction to generate water retention curves and soil shrinkage curves. CeO2–NPs at concentrations of 500–6000 mg/kg were applied via both methods, with treatments including 50 mM NaCl achieving final concentrations of 150 mmol NaCl/kg soil to assess salinity impacts. Each soil core underwent six wetting and drying cycles to stabilize hydro-structural properties before measurements.Key findings demonstrate that CeO2–NPs significantly enhance water retention in nonsaline conditions, with micropore surface charge potential energy (E(mi)) increasing from 60 J/kg(soil) in controls to 120 J/kg(Soil) at 6000 mg/kg. This enhancement occurs through water redistribution from macropores to micropores, with micropore water content at saturation increasing from 0.15 to 0.25 kg(Water)/kg(soil). The mixing method proved superior, achieving a 150% increase in water potential versus 100% for injection.Importantly, salinity significantly diminished CeO2–NP effectiveness, reducing E(mi) values by 25–40%, revealing critical limitations for applications in saline agricultural settings. This mechanistic understanding of CeO2–NPs’ effects on soil pedostructure provides valuable insights for developing nanoparticle-based solutions to improve agricultural water management in water-limited regions.
This study aims to investigate the complex interactions between CeO2–NPs and soil physical properties, with a specific focus on how these interactions influence soil water retention under both saline and nonsaline conditions. The increasing use of ENPs in various industrial and agricultural applications has raised concerns about their potential accumulation in soils and their long-term effects on soil health. CeO2–NPs, in particular, are widely used due to their stability and reactivity, making them a pertinent model nanoparticle for this study. The research seeks to explore how CeO2–NPs, which can bind to soil components such as clay particles and organic matter, affect key soil functions, particularly WHC, a critical factor in sustaining agricultural productivity. WHC refers to the soil’s ability to retain water that is available for plant uptake and is heavily influenced by soil structure, texture, and pore size distribution. Understanding how CeO2–NPs interact with these physical properties will shed light on their broader environmental and agricultural implications. The specific objectives of this study are three fold.