Zeolite for Soil Amendment
Zeolite is able to regulate the release of nutrients in soil and improve soil strength. It doesn't break down over time like other commercially available soil amendments.
Zeolite-based fertilizers are known as “intelligent fertilizers” due to their ability to regulate the release of nutrients to the soil; nutrients are held in the growth zone and are plant accessible but not water-soluble. The availability of nutrients improves the overall strength and performance of plants and produce. Zeolite improves soil structure by pairing cation exchange capacity with an affinity for ammonia and potassium. These properties allow zeolite to buffer soil and prevent the toxicity that is often caused by a buildup of ammonia.
Unlike soil amendments such as lime, zeolite does not break down over time. Instead, it remains in the soil to improve nutrient retention. In agriculture and horticulture, zeolite is used as a slow-releasing carrier of fertilizers and agrochemicals like insecticides, pesticides, and growth stimulators. The mineral is particularly useful for recultivation, increasing the nitrogen balance in light and sandy soil, and increasing the production capacity of acid in devastated soils.
Zeolite also prevents soil compaction and works to increase infiltration, both of which promote aeration of deep root systems due. This process is made possible by the mineral’s high surface area and porosity.
Because of its superior absorption and adsorption properties, zeolite reduces water and fertilizer costs by retaining beneficial nutrients and moisture in the root zone. The porous structure of the mineral promotes active soil that remains aerated and moist over time. Because zeolite is not acidic, its use alongside fertilizers can buffer soil pH levels, which reduces the need for lime applications. Due to these properties, zeolite is beneficial both in terms of economic and environmental factors.
One study by Rehakova tested the impact of zeolitic fertilizer on grasses and forest trees. The results indicated that the biomass of grass increased from 5.9 to 8.8 t/ha (metric tons per hectare) – an increase of 49 percent. Researchers also found that zeolite fertilizer “led to an increase of the share of grasses and decrease of weeds." During the second phase of the study, researchers fertilized pine and beech saplings with zeolite and measured trunk thickness and height at the end of the vegetation period. Results indicated that zeolite fertilizer permitted saplings to withstand replanting shock and begin the decisive three-year period at a faster rate than saplings not fertilized with zeolite.
A second study by Rehakova examined the effect of zeolite in soils that are heavily contaminated with heavy metals and toxic compounds. Through ion exchange of heavy metals and sorption of toxic substances, zeolite blocked toxins from vegetation and root systems in the surrounding environment.