Plant Nutrients

Seventeen chemical elements are known to be important to a plant's growth and survival. The seventeen chemical elements are divided into three main categories: macronutrients or primary nutrients, secondary nutrients, and micronutrients or trace elements. Supplemental nutrients supplied in the form of fertilizer allow your plants to reach their maximum potential.

These nutrients are found in the air and water. In a process called photosynthesis, plants use energy from the sun to change carbon dioxide (CO 2 - carbon and oxygen) and water(H 2 O- hydrogen and oxygen) into starches and sugars. These starches and sugars are the plant's food. Photosynthesis means "making things with light".

Since plants get carbon, hydrogen, and oxygen from the air and water, there is little gardeners and farmers can do to control how much of these nutrients a plant can use.

Non - Mineral Nutrients: The None - mineral nutrients are hydrogen (H), oxygen (o), and Carbon (C). These nutrients are found in the air and water. The rest of the elements, called nutrients, are absorbed from the growing medium and nutrient solution.

Each nutrient in the above categories can be further classified as either mobile or immobile. Mobile nutrients - nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and zinc (Zn) - are able to translocate, move from one portion of the plant to another as needed . For example, nitrogen accumulated in older leaves translocates to younger leaves to solve a deficiency. The result, deficiency symptoms appear on the older, lower leaves first.

Immobile nutrients - calcium (Ca), boron (B), chlorine (Cl), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), silicon (Si), and sulfur (S) - do not translocate to new growing areas as needed. They remain deposited in their original place in older leaves. This is the reason deficiency symptoms appear first in the upper, new leaves on top of the plant.

Mobile nutrients translocate within a plant. They move to the specific part of the plant where they are needed; this causes the older leaves to show deficiencies first.

Author: Robert R. Wright