Vol. 7, Issue 9, Part B (2025)

Polyhalite, a naturally occurring evaporite mineral containing potassium, calcium, magnesium, and sulfur, has emerged as a promising multi-nutrient fertilizer for enhancing crop productivity and soil health. This study investigated the molecular mechanisms of nutrient uptake in polyhalite-amended soils by integrating soil chemistry, plant physiology, and molecular biology approaches. A controlled greenhouse experiment was conducted using Triticum aestivum grown under four treatment levels of polyhalite (0, 50, 100, and 150 kg ha⁻¹). Results demonstrated that polyhalite significantly improved soil-available K, Ca, Mg, and S, which translated into increased shoot nutrient concentrations, biomass accumulation, and enhanced root growth. Molecular analysis revealed the upregulation of nutrient transporter genes, including HAK/KUP (K⁺), CAX (Ca²⁺), MRS2 (Mg²⁺), and SULTR (SO₄²⁻), indicating that polyhalite stimulates transcriptional regulation associated with nutrient acquisition. Strong positive correlations between transporter expression and shoot nutrient content highlighted the mechanistic link between soil nutrient supply and plant uptake capacity. Additionally, rhizospheric enzyme activities, particularly dehydrogenase and phosphatase, were elevated in polyhalite treatments, suggesting that microbial processes further supported nutrient mobilization. The integrative effect of enhanced soil nutrient availability, transporter gene regulation, and microbial activity underscores polyhalite’s potential as a sustainable fertilizer solution. The findings validate the hypothesis that polyhalite amendments improve nutrient use efficiency not only through direct nutrient enrichment but also via molecular and biochemical pathways. Practical recommendations include adopting polyhalite as part of balanced nutrient management strategies, optimizing application rates to avoid diminishing returns, and promoting its use in nutrient-demanding cropping systems. This study provides a mechanistic foundation for the agronomic benefits of polyhalite and emphasizes its role in advancing sustainable, resource-efficient, and climate-resilient agriculture.