Which iron ion is less prevalent in soil uptake for plants?

The ferric ion (Fe3+) is less prevalent for plant uptake in soil compared to the ferrous ion (Fe2+). Plants primarily absorb iron in its ferrous form because it is more soluble and mobile in the soil, especially under the typical pH conditions that favor its availability. When iron exists as a ferric ion, it tends to form insoluble oxides or hydroxides in most soils, particularly at neutral to alkaline pH levels, which limits its bioavailability to plants.

In contrast, the ferrous ion is more readily soluble in water and remains available for plant roots to absorb. Therefore, it is the preferred form of iron for plants. While nitrates and copper ions are indeed involved in plant nutrition, they serve entirely different roles compared to iron, making them less relevant to the specific question regarding iron ion prevalence in soil uptake. This reinforces why the ferric ion is considered less prevalent for plant uptake than the ferrous ion.