Nitrogen helps plants create the proteins they need to produce new tissues. In nature, nitrogen is usually in short supply so plants have evolved to take up as much nitrogen as possible, even if it means not taking up other necessary elements. If too much nitrogen is available, the plant may grow abundant foliage but not produce fruit or flowers. Growth may possibly be stunted because the plant isn’t absorbing enough of the other elements it needs.
Phosphorous stimulates root growth, helps the plant set buds and flowers, improves vitality and increases seed size. It does this by helping transfer energy from one part of the plant to another. To absorb phosphorous, most plants need a soil pH of 6.5 to 6.8. Organic matter and the activity of soil organisms can also increase the availability of phosphorus.
Potassium improves overall vigor of the plant. It helps the plants make carbohydrates and gives disease resistance. It also helps regulate metabolic activities.
There are 3 additional nutrients that plants need, but in much smaller amounts:
- Calcium is utilized by plants in cell membranes, at their growing points and to neutralize toxic materials. Additionally, calcium improves soil structure and helps bind organic and inorganic particles together.
- Magnesium is the only metallic component of chlorophyll. Without it, plants can’t process sunlight.
- Sulfur is a component of many proteins.
Finally, there are 8 elements that plants need in tiny amounts. These are called micronutrients and include boron, copper and iron. Healthy soil that is high in organic matter usually contains adequate amounts of all these micronutrients.