Themes

Themes We’re Covering at the conference

Formation processes leading to variable charge behaviour, especially from intensive weathering in tropical and subtropical environments.
Parent material influence, including volcanic ash, metamorphic rocks, and laterites, contributing to charge variability.
Geographical spread of variable charge soils and the environmental factors controlling their distribution.

Surface charge characteristics governed by soil pH, organic matter, and the dominance of Fe/Al oxides and kaolinite.
Mineralogical transformations that influence nutrient retention, charge development, and reactivity.
Nutrient sorption dynamics, particularly the strong fixation of phosphate and micronutrients due to high reactivity.

Examination of how variable surface charges (e.g., from iron/aluminium oxides and organic matter) influence the adsorption/desorption of key nutrients like phosphate, nitrate, and potassium.
Analysis of how soil pH and ionic composition alter the surface charge of soil particles, thereby affecting nutrient mobility, leaching, and uptake by plants.
Investigation of how different nutrients (e.g., phosphorus vs. sulfate or calcium vs. magnesium) interact in variable charge soils, influencing nutrient efficiency, fixation, and crop response.

Evaluation of how to optimise fertiliser use (e.g., phosphate and potassium) in variable charge soils to minimise fixation and maximise crop uptake.
Use of lime, organic matter, or gypsum to modify surface charge properties and improve nutrient availability and soil fertility.
Selection of crop types and rotations that enhance nutrient use efficiency and reduce losses in variable charge soils, particularly in tropical and subtropical regions.

Influence of charge on structure, porosity, and aggregation affecting water movement and retention.
Water-soil interactions, especially under fluctuating moisture conditions in humid climates.
Hydrological modelling to predict runoff, infiltration, and erosion risks in variable charge soil landscapes.

High sorptive capacity for heavy metals and organic pollutants due to reactive oxide surfaces.
pH- and redox-sensitive mobility of contaminants in variable charge environments.
Remediation approaches, including biochar, organic matter, and mineral amendments to immobilize pollutants.

Impact of water retention and swelling behaviour on slope strength and landslide potential.
Role of mineralogy and structure in mechanical stability of weathered variable charge soils.
Slope management practices, such as vegetative cover and drainage control, tailored for these soils.

Strong mineral-organic associations that protect soil organic carbon from decomposition.
Role of Fe/Al oxides in long-term carbon stabilization under tropical weathering conditions.
Carbon management strategies, including conservation tillage and organic amendments to enhance sequestration.

Seasonal and environmental charge fluctuations affecting nutrient cycling and biological activity.
Interactions with microbial communities and plant roots influencing ecosystem processes.
Ecological resilience and sensitivity of variable charge soils under natural and anthropogenic pressures.

Climate-induced shifts in pH, redox, and moisture regimes altering charge behaviour and nutrient dynamics.
Feedback mechanisms between variable charge soils, greenhouse gas emissions, and carbon cycling.
Adaptive land management practices to sustain productivity and ecosystem functions under climate stress.