Let us go back to the basics and learn chemistry that would be extremely helpful in understanding its applications in gardening. Chemical elements analysis reveals that plants need definite proportions of specific elements.
Plant growth is solely dependent on 17 different elements. Presence of all these chemical elements in perfect proportion is primarily responsible for the healthy growth of a plant. As a gardener, you must know about these 17 essential elements. All these elements have been classified into specific categories. Basis of such classification is also interesting to understand. Let us open it up.
Air and Water Macronutrients
There are three (03) macronutrient elements that a plant can derive from air and water. Carbon(C), Hydrogen (H), and Oxygen (O) are these three elements. Clean environment with clean air and quality water are not only important for humans but also for the plants.
Some essential elements are primarily derived from the fertilizers. Nitrogen (N), Potassium (K), and Phosphorus (P) are three elements. Fertilizers are the best sources for their replenishment as these elements are required in comparatively large quantities and at regular
frequency. These elements are responsible for the maximum growth of the plants. Adding fertilizers to the soil is one of the best methods to maintain a minimum required level of replenishment.
As the name suggests, secondary micronutrients are added with primary micronutrients. More often the process of such addition is coincidental in nature. Calcium (Ca), Magnesium (Mg), and Sulfur(S) are three such secondary micronutrients. When you add lime in any form these elements are coincidentally added to it and plants derive them accordingly.
In chemistry, they are better known as “Trace Elements”. We may also call them minor micronutrients for gardening purposes. These elements are not required in large quantities rather just a trace present would suffice. There are eight (08) such trace elements that are essential for plant growth. These are Manganese(Mn), Boron(B), Iron(Fe), Chlorine(Cl), Cobalt(Co), Molybdenum(Mo), and Zinc(Z).
Common soils contain sufficient quantities of the micro-nutrients. However, a soil test would be better to identify any further need that can be replenished externally. If you apply good soil-building -practices you will perhaps never face any problem.
If you are using synthetic fertilizers in your garden then you must be aware of the fact that there are no trace elements in it. On the other hand, applying organic fertilizers is far better as there are trace elements present in sufficient quantity. Manure, compost, green manures, and mulching are most recommended for this purpose.