Interaction of ammonium nutrition with essential mineral cations.

The article focuses on the interactions between ammonium (NH4⁺) nutrition and essential mineral cations in plants, highlighting their impact on plant growth and ammonium toxicity. It reviews how NH4⁺ uptake and assimilation acidify the rhizosphere and apoplast, influencing the availability and homeostasis of macronutrients such as potassium (K⁺), calcium (Ca²⁺), magnesium (Mg²⁺), and micronutrients including iron (Fe), manganese (Mn²⁺), copper (Cu), zinc (Zn), and nickel (Ni). The review emphasizes that NH4⁺ toxicity is multifactorial, with nutrient imbalances—particularly disruptions in K⁺ and Fe homeostasis—playing key roles in plant sensitivity to high NH4⁺ levels. It suggests that optimizing the balance of these nutrients and soil pH is critical for improving the efficiency and environmental sustainability of NH4⁺-based fertilization strategies, while calling for further research into the molecular mechanisms underlying these nutritional interactions.