Excessive surface nitrogen found in surface water or groundwaters is considered an environmental pollutant. Phosphorus plays a vital role in plant reproduction, Mitchell says. Considered essential to seed formation, this mineral is often found in large quantities in seed and fruit. Adequate phosphorus is characterized by improved crop quality, increased root growth, better flowering and fruit set and earlier crop maturity. Potassium plays a role in many physiological processes vital to plant growth, from protein synthesis to maintenance of plant water balance.
Potassium also helps protect plants from drought and diseases.