It is tied up by soil minerals and slowly released to growing plants. However, only about 30 pounds of this will be removed from the garden in the vegetables. This leaves an excess of 80 pounds of phosphate to build up in the soil. Zinc deficiencies usually show up in early spring as a dwarfing and yellow striping between the leaf veins. It is seen most frequently on corn in Alabama.
Iron deficiencies produce a yellowing of leaves with veins remaining green.
The best solution is to prevent the problem by soil testing and using low phosphorus fertilizers on soils already testing HIGH or VERY HIGH in phosphorus. HIGH in phosphorus. Use a low phosphorus mixed fertilizer. These are difficult to find because most mixed fertilizers are formulated with ammonium phosphates.