Consequently the availability of P in calcareous soils is relatively low. However, repeated applications of large amounts of P fertilizer results in the accumulation of P in most cultivated calcareous soils. Accumulated P is slowly released into the soil solution to become available to plant roots. However, K is readily leached out of the root zone in sandy or gravelly soils. Therefore split applications of K fertilizer are recommended.
Calcareous soils have an abundance of calcium available for plant uptake.
Application of calcium fertilizer is not necessary. Although Mg concentrations in calcareous soils are not low, crops grown on calcareous soils often show Mg deficiency symptoms. The high calcium concentrations in calcareous soils suppress Mg plant uptake and its translocation from the roots to the upper plant parts. Magnesium can be applied as a dry fertilizer or as a foliar application. Foliar applications of magnesium nitrate and magnesium sulfate have been shown to be efficacious.