Soil Chemical Properties and Nutrient Dynamics: pH, Cation Exchange Capacity, Nutrient Cycling, and Constraints to Plant Growth

Abstract Soil chemical properties regulate nutrient availability, toxicity, buffering capacity, and interactions between plants, microbes, and soil minerals. Among these properties, soil pH, cation exchange capacity (CEC), base saturation, and the dynamics of macro- and micronutrients play central roles in determining soil fertility, ecosystem productivity, and long-term sustainability. This narrative review synthesizes current understanding of key soil chemical properties and nutrient dynamics, with particular emphasis on nitrogen (N), phosphorus (P), potassium (K), sulfur (S), calcium (Ca), and magnesium (Mg). It further examines the processes governing nutrient cycling, losses, and transformations in soils, and discusses major chemical degradation pathways, including soil acidity and salinity. Drawing on peer-reviewed literature from Google Scholar, the review highlights interactions between soil chemistry and biological processes, identifies critical thresholds affecting plant growth, and discusses management implications for sustainable agriculture and ecosystem resilience, particularly under increasing pressures from land-use intensification and climate change. Keywords: soil chemistry, soil pH, cation exchange capacity, nutrient cycling, soil salinity, soil acidity, macronutrients, micronutrients