Organic fertilizers mean adding organic matter to the land or increasing its content. This organic matter is given to the soil after its decomposition is complete, and what it contains of nutrients in a form suitable for absorption by tree roots, in addition to its effect on improving the physical and chemical properties of the soil. The organic matter is usually the products of the decomposition of organisms. Live plant or animal or a mixture of them .
The source of the organic matter :
Organic matter is all plant and animal materials that originate in the soil to which they are added, regardless of the stages of decomposition they have reached. It includes the bodies of various animals, insects, their droppings, and the microorganisms found in the soil. The most important sources of organic matter in the lands can be summarized as follows :
1- Plant residues from leaves, stems and roots
2- Remnants of micro-organisms and high-
grade organisms 3- Municipal organic
fertilizers 4- Industrial organic fertilizers (crop residues and urban garbage )
5- Green manure
6- Slaughterhouse waste and sewage
Decomposition of organic matter :
The basic condition for the decomposition of organic matter in the soil is the availability of sufficient numbers of microorganisms and the provision of appropriate conditions for the growth and activity of these organisms. And elements that are absorbed by the roots of plants .
What is the importance of organic fertilizers???
Organic fertilizers are added to plants and orchards to achieve the following purposes :
1- Improving soil properties by dismantling soil particles, especially heavy ones, and improving its aeration so that air and water permeate with it .
2- Increasing the ability of the soil to retain water, especially sandy lands .
3- Increasing soil fertility and increasing its cationic capacity .
4- Increasing the soil content of various nutrients. When the decomposition of organic matter is completed, the elements (nitrogen, phosphorous, potassium and some micro-elements ) are increased.
5- When organic matter decomposes, it produces many organic acids and carbon dioxide, which dissolves in the ground solution, forming carbonic acid. These acids dissolve the nutrients in the soil, especially (phosphorous, iron, zinc, manganese and copper) and make them more absorbable by the roots of trees .
Types of organic fertilizers :
Among the most important organic fertilizers that are used to fertilize plants and fruit trees are :
1- Municipal fertilizer: Municipal fertilizer is considered one of the most important organic fertilizers used, which works to improve the physical and chemical properties of soil and is an important source for providing the soil with some microelements such as boron, copper and manganese. It is known that the chemical composition of municipal fertilizers is complex and varies according to the type of animal from which the fertilizer is taken, in addition to its age and feeding method, in addition to the method of composting and storage . Potassium is 2.1%, but in general it increases the percentage of organic matter in the soil .
2- The sebla : It is a special type of organic fertilizer that consists of animal dung and urine. It is widely used in fertilizing fruit trees. It is richer than municipal fertilizer in its content of nutrients and organic matter. The percentage of total nitrogen in it is about 1.5 %, phosphorous is 1% , and potassium is 1.1%.
3- Bird and poultry waste: It is considered one of the best types of organic fertilizers because it contains a high percentage of different nutrients and the benefit of trees from it is high, and the percentage of total nitrogen in it ranges about 2.1-4.2% and phosphorous is 1.1-2.4% And potassium 0.2-2.2%.
4- Dried blood: rapidly decomposing, rich in nitrogen (10%) and found suitable for absorption by tree roots, but it contains low levels of phosphorous and potassium .
5- Cottonseed meal: It represents one of the products of cottonseed pressing and contains a high percentage of protein, fats, carbohydrates and various nutrients. The total nitrogen content in it is about 7%, phosphorous is 5.2% , and potassium is 1.2 %.
6- Powder: It is prepared from drying human waste in special basins that the total percentage of nitrogen is about 8.1 % , phosphorous is 5.2 % and potassium is 6.0 %.
The best way to add organic fertilizers :-
Organic fertilizers are added to the orchids by spreading them on the surface of the soil and then hoeing or plowing to reduce the loss of nitrogen during the decomposition process and to facilitate the spread of the active elements to the area of the spread of the roots to facilitate their absorption by the trees. The fertilizers are also added by spreading them around the trees and placing them in trenches Next to trees and then covered with soil, and it was found that scattering organic materials around tree trunks and plowing them with soil is the best and most efficient method due to the regular distribution of organic fertilizers, where the root system benefits from this addition efficiently .
The optimal date for adding organic fertilizers : Organic
fertilizers are added to fruit orchards early during the winter season and long before the growing season and activity, because the organic matter needs a long time to decompose and become valid and easy to absorb by the roots of trees at the beginning of the growing season in the spring .
The needs of fruit trees of organic fertilizers : –
The needs of fruit trees of organic fertilizers vary according to the type and age of the fruit. Usually about 2-3 harvests of municipal fertilizer are added to each young tree (before it reaches flowering and fruiting), while about 3-8 extracts of municipal fertilizer are added for each A tree when it reaches the stage of flowering and fruiting .