P - Phosphorus

In plants, phosphorus is essential for respiration and energy transfer. Without an adequate supply of phosphorus, plant growth is diminished, maturity delayed, and yield reduced.

If your plants are small, are producing little or no flowers, have weak root systems or a bright green or purplish cast, you may be lacking phosphorus.

When plants die, phosphorus is returned to the soil, where it can be used by soil microorganisms and other plants. The cycle repeats until phosphorus is lost at the bottom of the seas and becomes fixed in sedimentary rock, to be released if the rock surfaces and is weathered.