
Sixteen chemical elements are necessary for plant growth. Three are non-mineral elements that come from air and water; thirteen are mineral elements that come from the soil. All of these elements are used as plant nutrients or to make plant nutrients.
Being familiar with the elements necessary for plant growth will help you diagnosis many plant problems and aid you in the selection of plant foods and fertilizers and soil amendments.
Here is a primer on elements necessary for plant growth, the basic plant nutrients.
Non-mineral nutrients: elements from air and water:
- Carbon (C)
- Hydrogen (H)
- Oxygen (O)
Plant photosynthesis coverts carbon dioxide (CO2–carbon and water) and water (H2O –hydrogen and oxygen) into starches and sugars that plants use as food.
Mineral nutrients:
Elements from air and soil:
- Nitrogen (N)
- Elements from soil and fertilizers:
- Phosphorus (P)
- Potassium (K)
- Calcium (Ca)
- Magnesium (Mg)
- Sulfur (S)
- Boron (B)
- Chlorine (Cl)
- Copper (Cu)
- Iron (Fe)
- Manganese (Mn)
- Molybdenum (Mo)
- Zinc (Zn)
Mineral nutrients from the soil are dissolved in water and absorbed through plant roots. These elements are responsible for plant growth, plant functioning, leaf, flower, and fruit production, and plant health. When soil does not contain all of these elements or nutrients, gardeners add natural soil amendments or fertilizers to make up for the deficiency.
Mineral macronutrients and micronutrients:
Mineral nutrients are divided into major or macronutrients and minor or micronutrients. Macronutrients are further divided into primary macronutrients and secondary macronutrients.
The primary macronutrients are:
- Nitrogen (N)
- Phosphorus (P)
- Potassium (K)
These nutrients are usually in the soil in some amount unless plants have already used them. When the soil lacks these nutrients, they can be added with natural soil amendments–such as aged compost or aged manure–or specific natural or synthetic fertilizers.
The secondary macronutrients are:
- Calcium (Ca)
- Magnesium (Mg)
- Sulfur (S)
These nutrients are usually in the soil. When they are lacking, they can be added with natural soil amendments–such as aged compost–or specific natural or synthetic fertilizers.
Micronutrients:
Micronutrients are also known as minor nutrients or trace elements. Plant micronutrients include:
- Boron (B)
- Chorine (Cl)
- Copper (Cu)
- Iron (Fe)
- Manganese (Mn)
- Molybdenum (Mo)
- Zinc (Zn)
Micronutrients are needed only in very small amounts. When micronutrients are lacking, they can be added with natural soil amendments–such as grass clippings or leaves–or natural or synthetic fertilizers.
More tips at Vegetable Plant Nutrients: Sources and Deficiencies