Which micronutrient facilitates the uptake of iron in alkaline soils?

The concept of micronutrients is crucial in understanding plant nutrition, particularly in how they interact with soil conditions. Chelated iron, the correct answer, refers to iron that is chemically bonded to another molecule, which helps prevent it from being rendered insoluble in alkaline conditions. In alkaline soils, the pH can lead to iron becoming less available to plants due to precipitation or complexation, which makes it difficult for plants to absorb.

When iron is chelated, the bond between iron and the chelating agent allows it to remain soluble and bioavailable, thus facilitating its uptake by plant roots. This is particularly important in alkaline soils where high pH levels can inhibit the natural availability of iron in its unchelated form.

In contrast, while magnesium and potassium are important micronutrients for plant health, they do not play a direct role in the uptake of iron from alkaline soils. Unchelated iron, although it is a source of the nutrient, would not effectively solve the problem of iron availability in alkaline conditions without complexation. Thus, using chelated iron is a focused solution for addressing iron deficiency in these specific soil types.