Zeolite Application in Crop Production

According to the United States Geological Service (USGS), zeolites (Fig. 1) are hydrated aluminosilicates of alkaline and alkaline-earth metals with very porous structure. Zeolites are used as pet litter, in animal feed, in wastewater treatment, and as soil amendments. Identified about 200 years ago, there are over 40 different types that include analcime, chabazite, clinoptilolite, erionite, ferrierite, heulandite, laumontite, mordenite, and phillipsite. Those commonly used in crop production as soil conditioners are clinoptilolite, erionite, and mordenite. Zeolites are mostly present in soils and sediments, with clinoptilolite as the most abundant type. In 2019, the United States had nine zeolite mines producing an estimated 98,000 tons of natural zeolites, a 14% increase from 2018. Chabazite is mined in Arizona (Hyde, 1982; Flanagan, 2020) and clinoptilolite in New Mexico (Hyde, 1982). Although reported to have benefits as soil conditioners and rowth media, these are less common than other uses. This bulletin gives a summary of the benefits of zeolite soil conditioners with respect to nutrient management and water retention, provides suggested application rates, and discusses challenges associated with the use of zeolite soil conditioners.