When soil nitrate levels are high, plants can accumulate nitrates in certain tissues above what is needed at that stage of growth. A shortage of nitrogen will cause the plant to mobilize extra nitrate stored in older tissue and send it to younger, developing tissue. Soil pH is the important fact in determining which ion is most dominant in the soil solution. Phosphate is also a part of the lipid structure of all cell membranes and DNA Phosphorus deficiency often appears early in plant growth as stunting, with purple or reddish tints in the leaf and vegetative tissues of corn, barley, and some mustard crops. Phosphorus deficiency can sometimes be induced through situations that inhibit root growth, such as soil compaction or cold soil temperatures.
Potassium is an enzyme activator and helps regulate stomates.
In many plants, such as corn, wheat and bean, potassium deficiency results in stunted plants and yellowing of the outer leaf margins of older leaves. Advanced stages will show general bronzing of the areas between the leaf veins. Leaf tissue will eventually brown and die, but petioles will remain green for some time. Calcium is not readily translocated between plant tissues, and plants do not accumulate high calcium concentrations when it is in excess. Proper development of fruits and storage roots are dependent on a constant soil supply of calcium.