Clinoptilolite Zeolite Influence on Nitrogen in a Manure-Amended Sandy Agricultural Soil

Abstract

Zeolite minerals may improve nitrogen availability to plants in soil and reduce losses to the environment. A study was conducted to determine the influence of clinoptilolite (CL) on nitrogen (N) mineralization from solid dairy manure (224 kg N ha⁻¹) in a sandy soil. Clinoptilolite was added to soil at six rates (0 to 44.8 Mg CL ha⁻¹), each sampled during 11 sampling dates over a year. Over time, nitrate (NO₃)-N increased, ammonium (NH₄)-N decreased, but total inorganic N increased. Clinoptilolite did not influence the nitrification rates of initial manure NH₄-N or mineralization of organic N (ON) over time. It is possible that adsorption of manure-derived potassium (K) outcompeted the NH₄-N for CL exchange sites. The ON concentration was constant up to 84 days and then decreased by approximately 18% over the remaining time of the study across all treatments. Clinoptilolite use in this sandy soil did not alter mineralization of N from dairy manure.

Keywords:

• Ammonium
• clinoptilolite
• mineralization
• nitrate
• nitrification
• nitrogen
• zeolite

Acknowledgment

The authors acknowledge the research support from Zeocorp LLC, CRADA No. 58-3k95-8-1283. Mention of a specific product or vendor does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture or imply its approval to the exclusion of other products that may be suitable.

Notes

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