What fertilizers to apply on your site? The large selection is puzzling, and the assortment is constantly replenished with progressive varieties that are replacing traditional fertilizers. A detailed study of this issue is indispensable.
Classification of fertilizers by composition
The main criterion by which fertilizers are distinguished from each other is their composition. Based on this characteristic, they are divided into:
organic – represented by substances and materials of animal or plant origin. In them, nutrients are present in a limited amount and become available only after the mineralization of organic matter by soil organisms;
mineral – is an industrial product that is obtained as a result of the synthesis of several components or by processing and grinding agricultural ores mined in nature. Nutrients are contained in them in the form of mineral salts and are absorbed by the plant after dissolving in water;
bacterial – special preparations-inoculants, which help to improve the soil microclimate.
Types of organic fertilizers
Organic fertilizers have a complex effect on the soil. Their introduction helps to improve the physical parameters and structure of the soil, stimulate the activity of microorganisms, and replenish the reserves of micro- and macroelements. Moreover, their composition is very variable, and the fertilizing effect depends on the origin and method of preparation.
Common organic fertilizers:
Manure – it is recommended to apply it in a semi-rotten form after disinfection from weed seeds has taken place in the process of decomposition, and organic compounds break down into simpler forms.
Poultry manure is the most concentrated of all animal fertilizers. It is introduced into the soil in the form of liquid fertilizing (the ratio of manure: water – 1:20) or in a solid dry form after mixing with humus or earth
Compost – is prepared from plant residues (tops, fallen leaves, sawdust, cut grass), which are mixed and filled with liquid manure, solutions of poultry manure, nitrogen organic fertilizers, fertilizers or bacterial preparations.
Siderata – green manure crops (phacelia, rye, lupine, oil radish, vetch) are mown several weeks after germination and embedded in the soil. Thus, soil decompaction occurs, microbiological processes are stimulated, the root layer is replenished with organic matter.
Types of mineral fertilizers
The nutrient in the composition of mineral fertilizers is called the active substance (AD), and its content is measured as a percentage. This allows you to calculate the optimal fertilizer application rate depending on the needs of the plants.
There are two large groups of mineral fertilizers:
- Simple – contain one nutrient.
- Complex (or complex) – contain 2 or more nutrients.
In turn, simple ones are divided into:
nitrogen (N) – the most common are ammonium nitrate and more concentrated carbamide (urea). They are readily soluble and highly mobile.
For this reason, nitrogen fertilizers are applied from early spring and throughout the growing season in the form of top dressing. Their use for the autumn digging is irrational – during the winter, nitrogen is washed out by rain and melt waters outside the arable layer and becomes inaccessible to young plants.
phosphorus (P) – simple superphosphate (20% of ae) and double (45% of ae), which, in comparison with other phosphorus-containing fertilizers, dissolves most easily in water, has become widespread. At the same time, it moves poorly and can be bound by the soil into compounds that are difficult for plants to access.
Its introduction is most effective for the main plowing, locally in rows or nests during sowing (planting), and also as top dressing. A prerequisite for this is deep planting in the soil.
Phosphorus fertilizers scattered over the soil surface or embedded in the upper drying layer are ineffective.
potash (K) – these include potassium chloride (up to 60% of the AI), potassium salt (40%), potassium magnesium (up to 28%)
Their use is especially important on light sandy and sandy loam, as well as peaty soils that contain a small amount of available potassium. For more efficient use, they are brought in in the fall for deep digging or plowing.
Complex (complex) fertilizers save time, money and labor costs when it is necessary to balance plant nutrition on several elements at the same time.
The ratio and content of NPK in them is different, therefore, when used on different soils and under different crops, they can be supplemented with simple fats. For example, the popular nitroammophoska containing 16% nitrogen, phosphorus and potassium, when applied in autumn, can be supplemented with superphosphate or potassium chloride.
The same effect is achieved if, by combining simple fertilizers, you prepare a mixed one. However, this should be done carefully, in accordance with the recommendations of the table, in order to prevent deterioration of the physical properties of fats, a decrease in their solubility or loss of nutrients.
The above mineral fertilizers are a source of macronutrients that are consumed by plants in large quantities (NPK).
At the same time, full nutrition of a plant organism is impossible without microelements, which are required in microscopic doses. We are talking about boron, copper, iron, sulfur, manganese, cobalt, zinc, etc.
Microfertilizers can be roughly divided into:
mineral – relatively recently there was no alternative to such varieties. Some of them are still used for pre-sowing seed treatment or spraying of plants. The most famous are boric acid, copper sulfate, manganese sulfate;
chelated – new generation fertilizers containing one or more microelements in the most easily digestible organometallic form. As a rule, they are used for foliar dressing, as they are well absorbed by the leaf surface, or are introduced through a drip irrigation system. Once in the soil, chelates do not bind into insoluble complexes and for a long time mineral fertilizers remain available for the root system.
Recently, concentrated complex water-soluble fertilizers are becoming more and more relevant, the composition of which is developed taking into account the needs of each crop. They are very easy to use, allow you to provide plants with an even rationed nutrition and avoid overdose.
Varieties of bacterial fertilizers
There are no nutrients in their composition, but there are bacteria, the activity of which makes it possible to mobilize the accumulation of nutrients in the root layer and improve its general condition.
The most common ones are:
- nitragin and rhizotorfin – are produced on the basis of nodule bacteria, which, entering into symbiosis with the roots of legumes, fix atmospheric nitrogen and convert it into a form accessible to plants;
- phosphorobacterin – the spores contained in it are capable of removing phosphorus from organic compounds;
Competent use of fertilizers allows you to avoid depletion of the soil in the beds and annually receive consistently high yields of excellent quality.