Abstract:
The aim of this study is to characterize the mineral-magnetic properties of commercial plant substrates and assess their effect on tomato seedling growth. Ten samples of different growth media (potting soils, mixes, and vermicomposts) were analyzed using magnetic methods: magnetic susceptibility (χ), frequency-dependent susceptibility (χFD), anhysteretic and isothermal remanent magnetizations (ARM, IRM), hysteresis parameters, and thermomagnetic analysis. Elemental composition was determined using a handheld pXRF spectrometer. The dominant magnetic mineral was identified as relatively coarse-grained maghemite. A strong positive correlation was observed between χ and K2O content. In a laboratory germination experiment with tomato seeds, a significant relationship was found between the ARM/IRM ratio and the average seedling length. The results suggest that magnetic measurements can serve as a rapid and indirect indicator for assessing the nutrient potential and chemical composition of substrates used in agriculture.