Infuence of natural zeolite on nitrogen dynamics in soil

Abstract

Sorption of the cations NH 4+, Al3+, Fe 2+, Mn2+, and Mg2+ in powdered zeolite and its mixture with soil was monitored. Morethan 90% of the observed cations were fxed in the zeolite in the frst few minutes of the laboratory experiment, which is a very fast speedof sorption, and the ammonia cations reacted fastest. Consequently, the dynamics of the nitrate and ammoniac nitrogen in soil aferapplication of zeolite in diferent amounts was monitored. A decreased ammonium content was apparent in the variants with zeolite 1month afer zeolite application in comparison with variants without zeolite owing to the specifc fxation of NH 4+ cations in the zeolitelattice (92.5 mg in the control variant and 77.2 81.0 mg per kg of soil in the tested variants). Tree months later, there was an increasein ammonium content in the variants with zeolite of 24% to 59% in comparison with the control variant owing to gradual ammoniumrelease from the zeolite lattice. Six months afer the zeolite application, statistically signifcant diferences were found not only betweenthe control variant and the variants with zeolite, but also between individual variants with various zeolite doses (H = 14.201; P = 0.003according to the Kruskal Wallis test). Te nitrifcation process in the soil was less intense under the infuence of applied zeolite. Tenitrate nitrogen contents in the soil decreased by 66% to 78% in comparison with the control variant in the autumn period; therefore,the amount of nitrate leaching from the soil horizons to the groundwater was less. In summary, zeolite can be considered to be a slow-releasing nitrogen fertiliser.