Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 15, 2011
Publication Date: October 6, 2011
Citation: Tarkalson, D.D., Ippolito, J.A. 2011. Clinoptilolite zeolite influence on nitrogen in a manure-amended sandy agricultural soil. Communications in Soil Science and Plant Analysis. 42(19):2370-2378. DOI: 10.1080/00103624.2011.605495. Interpretive Summary: Zeolite minerals may improve nitrogen availability to plants in soil and reduce losses to the environment. A pot study was conducted to determine the influence of the zeolite mineral clinoptilolite on nitrogen mineralization from solid dairy manure in a sandy soil. Manure was applied at an estimated first growing season plant available nitrogen rate of 224 kg of nitrogen per hectare. Treatments consisted of clinoptilolite added to soil at rates of 0, 6.7, 13.4, 20.2, 26.9, and 44.8 Mg clinoptilolite per hectare. Over time (0, 7, 14, 21, 28, 42, 56, 84, 177, 267 and 365 days after study initiation) the nitrate-nitrogen increased, ammonium-nitrogen decreased, but the total inorganic nitrogen increased. Clinoptilolite in soil did not influence the nitrification rates of initial manure ammonium-nitrogen or mineralization of organic nitrogen over a one-year period. It is possible that adsorption of manure derived potassium out-competed the ammonium-nitrogen for clinoptilolite exchange sites. The organic nitrogen concentration was constant up to 84 days then decreased by approximately 18% over remaining time of the study across all treatments. The utilization of CL in Wolverine sand to alter mineralization of N from dairy manure was not effective in this study.
Technical Abstract: Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4-N) in two common Pacific Northwest soils. The effects of CL application rate (up to 26.9 Mg ha-1) either band applied or mixed with a set rate of N fertilizer on masses of NO3-N and NH4-N in leachate and soil were investigated in a column study using a Portneuf silt loam (coarse-silty mixed mesic Durixerollic Caliciorthid) and a Wolverine sand (Mixed, frigid Xeric Torripsamment). All treatments for each soil received a uniform application of N from urea fertilizer, with fertilizer banded or mixed with CL. In the Portneuf soil, band application of CL and N contained 109% more total inorganic N (NO3-N + NH4-N) in the soil/leachate system compared with mixing. In both soils, CL application rate influenced the quantity of NO3-N and NH4-N in the leachate and soil. Application of CL at rates of 6.7 to 13.4 Mg ha-1 resulted in the conservation of inorganic N in the soils. Band applying CL and N seems to conserve available inorganic N in the soil compared with mixing CL and N possibly because of decreased rates of microbial immobilization, nitrification, and denitrification.