1. Plant Nutrition.
It is well known that plants need nutrients to live, some in greater quantity and others in less quantity.
The process by which the plant obtains from the environment (soil, water and atmosphere) the substances that are necessary to carry out its metabolic processes that allow it to: be born, grow and reproduce is known as plant nutrition.
Said elements required in plant nutrition are basically 16, Carbon, Hydrogen and Oxygen are taken by the plant from the environment, the rest are not easy to absorb and sometimes they must be artificially supplied to the plant.
The remaining 13 elements are known as nutritive elements, nutrients or fertilizers and are classified according to the quantities that are required in the plant or the frequency with which they must be supplied to them.
On many occasions, this plant nutrition cannot be carried out completely and some elements are not absorbed by the plants. This lack of absorption causes metabolic disorders commonly known as nutritional deficiencies.
The most frequent nutritional deficiencies and not as well known as those of macroelements in agriculture are those that are related to microelements, because these are easily blocked in the environment and are scarce. For this reason it is necessary to make these elements available to the plant in fertilization.
2. Nutrition with Microelements:
Microelements are usually used in catalytic functions and are only needed in minimal amounts, although they are widely distributed in soils, some are absent or in low supply in certain areas of the world, due to the fact that the bedrock from which the soil is formed it lacks them, in addition, soil pH conditions, presence of other solutes and oxygen level, can affect the solubility or the capacity of the plant to absorb them, so that deficiencies are not rare.
Specific trace element ion deficiencies are responsible for many typical abnormalities of great interest.
3. State of micronutrients in the soil
All micronutrients specifically in the soil can be found under the following conditions:
Solubilized in water, that is, in the soil solution.
Interchangeable: Ions bound by electrical charges of soil particles.
Chelated, forming complexes: Most of the microelements are heavy metals, capable of forming complexes with complexing or chelating agents of soil organic matter.
Secondary clay minerals and insoluble metal oxides.
Primary minerals: Components of the bedrock.
The first three groups represent the main source of micronutrients and keep a close and proportional relationship to each other, in such a way that if this relationship is altered (extracting a good percentage of one, eroding the soil, modifying pH), the remains of the nutrients.
In group 4 there are minerals adsorbed by soil clays, however, these are in a crystalline state, which prevents their exchange and oxides such as Fe and Mn that can become assimilable.
The elements that are part of the bedrock cannot be used unless they have already undergone physical and chemical processes that free them from said structure.
Micronutrient assimilation.
The assimilation by the plant of both solubilized, interchangeable and chelated, adsorbed or complexed micronutrients is affected by several factors, among them, we can list the following:
pH (Hydrogen Potential).
Organic matter (M.O).
Texture.
Microbial activity.
Weather conditions.
Interactions between nutritional elements.
4. Foliar Nutrition.
When the above factors work more or less optimally, plant nutrition takes place. However, it is very rare, all factors are in favorable magnitudes for such nutrient absorption to occur.
In these cases, foliar nutrition is a great alternative. The nutrition or foliar fertilization of crops is a technique of plant nutrition in which the nutrients are applied directed to the leaves of the plant; the nutrients go in a nutrient spray solution.
This technique bases its effectiveness on the knowledge that the stomata are open during the day and it is possible that the nutrients dissolved in water enter the stomatal chamber and from there to the rest of the plant.
At present there is a wide range of foliar fertilizers, the best ones are those that deliver the element in a complex form that allows a fast absorption and movement speed in the plant, for example, chelated elements.