The legacy of William H. Patrick Jr. in wetland biogeochemistry began with his early research on the chemical, physical, and biological processes in submerged rice soils. His early research with rice soil established fundamental understanding and scientific principles on how soil submergence affects nutrient transformations, nutrient availability to plants, the formation and emission of greenhouse gases, and the fate and bioavailability of heavy metals. This subsequently helped provide the framework for wetland biogeochemistry research. It additionally continued to contribute to the fundamental understanding for the chemistry and biology of ‘wetland’ rice soils on which management practices for increasing nutrient use efficiency, mitigating greenhouse gas emissions, and sustaining increased yields of rice for global food security are built. Rice researchers are now faced with challenges of developing cultivation and management practices for ‘wetland’ rice soils, which will achieve higher rice yields with less use of increasingly scarce irrigation water, reduced area of arable land, and need for greater efficiency of input use for protecting the environment and ensuring attractive profitability in rice farming. Scientific principles established for ‘wetland’ rice soils through the legacy of William Patrick’s research remain relevant and important as rice researchers tackle emerging challenges in ensuring a sufficient supply of rice at affordable price.