Leaching behaviour of a sandy soil amended with natural and NH₄⁺ and K⁺ saturated clinoptilolite and chabazite

ABSTRACT

Using saturated or enriched zeolites as slow release fertilizers (SRFs) is considered as an environmental-friendly strategy to enhance use of macronutrients in sandy soils. In this paper, two natural zeolites, clinoptilolite (CLI) and chabazite (CHA) were used as mineral precursors to prepare NH₄⁺/K⁺ saturated clinoptilolite (NH₄⁺/K⁺-CLI) and chabazite (NH₄⁺/K⁺-CHA) as zeolitic nutrient sources (ZNSs). Comparison between the nutrient retention capabilities of these ZNSs was one of the main objectives of this study. The NH₄⁺/K⁺-CLI and NH₄⁺/K⁺-CHA were prepared by soaking the zeolites in NH₄Cl and KCl solutions, respectively. Leaching tests were performed on a sandy soil amended with chemical fertilizers (CFs), NH₄⁺/K⁺-CLI and NH₄⁺/K⁺-CHA to evaluate the leaching properties of them. The results indicated that approximately 84% and 88% of the NH₄⁺ and K⁺ of soils fertilized with CFs were lost during the experiment, respectively. While, the NH₄⁺ and K⁺ losses from soils amended with NH₄⁺/K⁺-CLI and NH₄⁺/K⁺-CHA were 29%, 23%, and 14%, 24%, respectively. Despite of drastic changes in leaching behavior of CFs, nutrient losses from ZNSs were more uniform during the experiments. No significant difference was found between the two studied zeolites on reduction of K⁺ loss. However, CHA was more effective in preventing NH₄⁺ loss during leaching.

KEYWORDS:

• Nutrient loss
• zeolite
• mineral precursor
• slow release fertilizer
• leaching behaviour

Acknowledgement

This study was part of the PhD thesis of Mahboubeh Eslami conducted at the Department of Physics and Earth Sciences, University of Ferrara, Italy. The stage was possible thanks to the financial support of the research project (No: 31201) provided by the Ferdowsi University of Mashhad (FUM) and Ministry of Science, Research and Technology of Iran (MSRTI). The authors would like to greatly appreciate the valuable review comments received from two anonymous reviewers and from the Editor of the Archives of Agronomy and Soil Science, which improved the overall quality and clarity of the manuscript. The authors also would like to thank Dr. Ali Shafiei (Nazarbayev University, Kazakhstan) for reviewing and improving the quality of the manuscript during various stages of the publication process.

Disclosure statement

No potential conflict of interest was reported by the authors.