Date of Award:
Master of Science (MS)
Plants, Soils, and Climate
Daniel T. Drost
Crops grown in sandy soils require frequent irrigation. As a result, nitrogen (N) fertilizers. such as ammonium sulfate((NH4)2SO4), are leached from the rooting zone of crops. This loss of N increases N fertilizer use and the potential for nitrate (NO3-) contamination of water. Ammonium-loaded clinoptilolite (NH4+-Cp) may reduce this N leaching, increase N fertilizer use-efficiency, and prevent NO3- contamination of water while sustaining normal crop growth.
The potential of NH4+-Cp as a N fertilizer was assessed in three leaching experiments without plants and two leaching experiments with plants. Pots containing rounded quartz sand were amended with (NH4)2SO4 and one of three NH4+-Cp size fractions: small (
Finally, in two leaching studies, pots containing the sandy soil were planted with sweet corn and grown for 35 d and 42 d, respectively. No differences were found among N sources in corn relative growth rates, leaf area ratios, and net assimilation rates, even though the corn plants that were fertilized with NH4+-Cp assimilated significantly more N than the (NH4)2SO4-fertilized plants. The pots fertilized with NH5+-Cp leached
In the greenhouse, NH4+-Cp is a slow-release fertilizer that will reduce N leaching while maintaining normal plant growth. However, field studies are needed to confirm the suitability of NH4+-Cp as a slow-release fertilizer under field conditions.
Perrin, T. Scott, "A Slow-Release Nitrogen Fertilizer: Ammonium-Loaded Clinoptilolite" (1997). All Graduate Theses and Dissertations. 7181.
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