Soil Cation Exchange & pH Buffering Simulator

Soil particles — clay minerals and humus — carry a fixed number of negatively charged exchange sites that hold onto positively charged cations. This simulator visualizes that population of sites directly: hundreds of tiny orbiting cations, colored by whether they are base cations (Ca²⁺, Mg²⁺, K⁺) or acid cations (H⁺, Al³⁺). Add acid or lime and watch cations swap places on the exchange complex while a live titration curve traces how soil pH actually responds — steeply for a sandy, low-CEC soil, and much more slowly for a clay- or humus-rich, high-CEC soil that can buffer far more acid or base before its pH moves.