Agronomic potential of two different glass-based materials as novel inorganic slow-release iron fertilizers.

BACKGROUND: Large amounts of chemical fertilizers are still currently used to compensate the soil nutrients scarcity in order toincrease and sustain crop yield with consequent rising of environmental pollution and health problems. To mitigate these environ-mental risks, fertilizers with slow-release behaviours have been developed. The aim of this study was to assess the agronomicpotential of two different glass-based materials (by-products from the ceramic sector) as inorganic slow-release iron (Fe) fertilizers. RESULTS: The X-ray powder diffraction conrmed the presence of amorphous structure and the richness in Fe of the investi-gated materials. The solubility analysis highlighted the slow Fe release from the glassy network and that the maximum ofthe Fe release was at alkaline pH suggesting their potential use as slow-release Fe fertilizers, especially in calcareous soils.The pot and leaching experiments demonstrated that although the glass-based materials increased the amount of soil availableFe, we did not observe Fe leaching and plant toxicity. This fact would suggest their reliability to increase soil fertility withoutnegative effects on the environment. CONCLUSION: The use of glass-based materials, specically by-products from the ceramic sectors, as inorganic slow-release Fefertilizers can be sustained. The tests performed at three different pH conditions testied the slow-release behaviour of thetested materials and underlined that the Fe release increases at alkaline environment. Therefore, the present study pointedout the glass-based materials by products from the ceramic sector as novel slow-release and environmental-friendly fertilizersin agriculture.