Clinoptilolite Zeolite Influence On Nitrogen Mineraliztion From Dairy Manure.

Development of best management practices can help improve nitrogen (N) availability to plants and reduce losses to the environment.   A pot study was conducted to determine the influence of the zeolite mineral Clinoptilolite (CL) on N mineralization from solid dairy manure in a Wolverine sand (Mixed, frigid Xeric Torripsamment).  Manure was applied at an estimated first growing season plant available N rate of 224 kg N ha^-1.  Treatments consisted of CL added to soil at rates of 0, 6.7, 13.4, 20.2, 26.9, and 44.8 Mg CL ha^-1, and   each treatment was replicated four times.  Eleven harvest times (0, 7, 14, 21, 28, 42, 56, 84, 177, 267 and 365 days after study initiation) of all treatments and replications were established.   Inorganic N (IN) and NO₃-N increased over time and NH₄-N decreased over time. Clinoptilolite addition and rate did not influence the nitrification rates of initial NH₄-N in manure added to soil or mineralization of ON in soil over a 1-yr period.   It is possible that adsorption of manure derived K out competed the NH₄-N for CL exchange sites. The ON concentration decreased by approximately 18% over the course of the study across all treatments, with decreases occurring after 84 days to the end of the study.  The utilization of CL in Wolverine sand to alter mineralization of N from dairy manure was not effective in this study.