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Plants in the light

Plant Nutrients 101

Throughout our early education, we were repetitively taught about proper nutrition and eating habits. Vitamins and minerals were discussed, the proper amount of each, and the food pyramid was burned into our minds. Without the right balance, we know our bodies will not grow normally. Have you ever considered that plants have specific nutritional requirements too? Plants, though alien and sort of immobile, are made of the same building blocks all organisms share. To grow normally, plants require 16 (or 17 depending on your research resource) essential elements. Oxygen, hydrogen, and carbon are three essential elements found in the atmosphere. The remaining 13 elements are found in the soil and are broken into three categories based on their importance: macronutrients, secondary nutrients, and micronutrients.

Soil holds so many elements needed for plant food.


First, and most importantly, the macronutrients. Plants need these three elements in the largest amounts and all play major roles in every biological process within plants. Nitrogen (N), the most critical, is a major component of chlorophyll (the green pigment in plants) and it is used to build proteins. Phosphorus (P), the next macronutrient, is a component of the plant’s DNA, helps supply energy to the plant, and is also used to build proteins. Manatee County’s soil has an abundance of phosphorus. The final macronutrient, Potassium (K), is involved with transporting nutrients and regulating the exchange of gases within the plant.

Secondary Nutrients

The secondary nutrients immediately follow the macronutrients in importance. Plants need a moderate amount of these vital elements to grow normal. With that said, they still play a major role in most biological processes within a plant. Magnesium (Mg) is a component of chlorophyll. In fact, it is the central atom of this molecule! Calcium (Ca), the next secondary nutrient, helps form strong cell walls. This improves the plant’s defenses and quality. Calcium is another nutrient our Florida soils have in abundance due to our limestone base rock. Lastly, but not in the least, is Sulfur (S). Sulfur builds proteins and is required for the formation of the chlorophyll molecule.


Last in quantity, but not in importance – the micronutrients.  In order for a plant to growth strong, micronutrients round out their palette of nutrition. Plants need micronutrients in very small amounts. In fact, when in abundancy, micronutrients can be toxic to plants. This category contains the following elements: Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Molybdenum (Mo), Boron (B), and Chlorine (Cl). These elements support a variety of processes and systems within a plant. They help form chlorophyll, activate enzymes, form hormones, and much more.

In conclusion, plants, just like us, require specific nutrients to grow vigorously. If one of these elements is missing or not absorbed in the correct amount, the plant will not be able to grow normally. Three of these elements can be found in the air. The remaining elements are only available in the soil. These soil-bound nutrients are divided into three groups based on their importance. Plants need macronutrients in the largest amounts, then secondary nutrients, and finally, micronutrients. So, the next time you sit down for a healthy meal, make sure your plants get one too!

Upcoming Workshop Info

Of course, if this topic intrigues you, watch for our upcoming workshop on Plant Nutrition 101.  Contact Mack to be put on the waiting list for attendance. 941-722-4524, extension 1821. Are you interested in other workshops? Check out our county calendar of events: Manatee’s Calendar of Events.  If you want to get your soil tested to determine which nutrients are available in your soil, before you do some planting, our UF/IFAS Manatee County Extension Office can provide the forms for testing the soil.  We do not test for nutrients locally; you would be sending the soil for testing at UF main campus soil laboratory.

Article contents written by Mack Lessig, UF/IFAS Manatee County, editing by Lisa Hickey, Sustainable Ag and Food Systems Extension Agent. Contact us if you need additional information (941-722-4524 extension 1821) or (same number with extension 1817.)