There are many bio-fertilizers that can be added to agricultural soil in different ways, either by scattering or by mixing them with sand or soil, or by mixing them with the seeds of plants to be planted.
Biofertilizers are also mixed with irrigation water, and there are also biofertilizers that can be sprayed on the vegetation, and some biofertilizers only work with certain crops, such as blue-green algae, which only work in rice cultivation, as the environmental conditions become suitable for the growth of algae and thus benefit from it rice plants.
In general, biofertilizers can be divided according to the role they play and the nature of the microorganisms they contain, as follows:
1: Solvent-based and mineralized phosphate fertilizers, which contain bacteria or fungi.
2- Nitrogen-fixing fertilizers. These fertilizers either contain bacteria or algae.
3- Phosphate-dissolving and nitrogen-fixing fertilizers at the same time.
First – Phosphate-dissolving biofertilizers:
* Phosphate-dissolving biofertilizers contain bacteria:
This quality results in fertilizers that are suitable for all crops and lands and contain bacteria of the type – Ba – cillus megatherium phos -phorticum. It is highly efficient in re-dissolving insoluble phosphate in the soil, and thus plants can benefit from it and become soft for plants, which can provide an addition New phosphate fertilizers and saving 50% of the added fertilizers, and this reduces environmental pollution by not adding new chemical fertilizers, in addition to the quality and characteristics of production.
* Fertilizers containing mycorrhiza fungus:
This pollen benefits many crops, especially in tropical regions that suffer from phosphate fixation in the form of an image that is not suitable for plants to absorb, such as di- and tri-calcium phosphate.
Where these fungi represent a unique state of cooperation with the roots of plants, especially some higher plants, and they play the role of the root hairs of plants and help them absorb water and mineral salts from the soil, such as phosphorus, iron, and the rest of the other mineral elements.
This quality works with forest trees, as it increases the plant’s ability to absorb invalid elements, especially phosphorus, as a result of its secretion of phosphate-dissolving enzymes. It also secretes organic acids and carbon dioxide that dissolves more phosphate.
Biofertilizers that fix atmospheric nitrogen:
They are fertilizers that contain microorganisms that fix atmospheric nitrogen, and some of them may be specialized for a specific crop, and some of them are not specialized, but are suitable for all crops. They have been chosen according to the standards of efficiency in fixation and their compatibility with environmental conditions.
Among the most important bio-fertilizers that stabilize nitrogen are the following.
* Biofertilizers symbiotic, such as two contracts, which live a common and cooperative life with plants.
* Some of them contain bacteria that fix atmospheric nitrogen in a free way without the existence of a cooperative living with plants, but rather depend on themselves in providing their nutritional needs, such as azotobacter bacteria, which live freely in the soil and fix atmospheric nitrogen by possessing the nitrogen enzyme, which is the basis in the process of fixation Atmospheric nitrogen.
These fertilizers are suitable for some field crops such as wheat, barley and corn, and some of them are suitable only with legumes, and some of them are suitable for fruit trees and vegetable crops, and these vital nitrogen-fixing fertilizers lead to a 35% reduction in the total costs of nitrogen fertilizers.
Biofertilizers containing blue-green algae.
They are strains of blue-green algae with a great ability to fix atmospheric nitrogen non-symbiotically in rice fields, as the algae fix it in their bodies by converting nitrogen into compounds that the plant can benefit from, and they also secrete substances that stimulate plant growth, and these vital fertilizers increase the yield by 30%.
Fertilizers that combine phosphate dissolution and atmospheric nitrogen fixation:
There are many types of them, as there is a pollen for each crop, whether field, fruit or vegetables, and it provides the use of phosphate and nitrogen fertilizers.
Methods of adding and using biofertilizers:
1- The method of inoculating the seeds used in cultivating a specific area (one feddan of seeds) with fertilizer or pollen prior to planting, where the package is sufficient for one feddan of seeds.
2- The necessary amount of fertilizer / acre should be spread on the surface of the soil, provided that it is mixed with a quantity of dry silt or soggy sand with water, then it is spread or placed in a pile under the plants or next to the plants.
3- Spraying biofertilizer on the leaves of plants from fruit trees or some other crops, which are often yeasts used to revitalize plants.
The addition of well-decomposed organic fertilizer must be taken into account during the preparation and preparation of the land for cultivation, as the presence of organic materials helps to activate the biofertilizer and increase the benefit from it as much as possible.