Phosphorus fertilizers belong to the class of mineral fertilizers. The main element contained in them belongs to the macronutrients that crops need as a priority. Despite the fact that in the Soviet Union at the time of the large-scale chemical reclamation, soils were phosphatic, for many years not using these fertilizers, cultures removed this element from the substrate with the crop, which again made it necessary to introduce them.
The concept of phosphate fertilizers
In addition to phosphorus, other fertilizers are also part of these fertilizers. Therefore, the calculation upon application is carried out on the active substance (d.v.). Plants do not absorb any phosphorus; P 2 O 5 is available to them. Few cultures are able to extract this element from hard-to-reach compounds. One of them is lupine.
Range
The main phosphate fertilizers are superphosphates (single and double) and phosphate rock. The latter species contains a lot of inaccessible macrocell under consideration, therefore, it finds limited application. It is mainly used in the case when it is necessary to carry out chemical reclamation of vast areas, since over time, inaccessible phosphorus transforms into a form easily accessible to plants.
Despite the fact that in stores you can find fertilizers supposedly intended for various crops, they are all universal and can be used for any plant.
Here are the main names of phosphate fertilizers: superphosphate, borofoska (fat, which contains in addition to phosphorus trace element boron), phosphate rock. In addition, this macrocell is contained in complex and complex fertilizers: nitrophos, azophos, ammophos, and some others.
Characterization of superphosphate as the main phosphorus fat
The composition of this phosphoric fertilizer includes phosphoric acid, monocalcium phosphate, magnesium and sulfur. It can be made in both powder and granular forms. The latter is considered more effective. It can be used on absolutely any soil and soil for all crops. It helps to increase the immunity of plants, which allows them to withstand low temperatures.
It is produced under the names Simple Plasma Superphosphate, which contains 19-20% D.V., as well as Double Superphosphate, containing up to 46% D.V.
Fertilizer is best applied in the autumn during the main filling of the soil. In the spring-summer period it can be used in dissolved form. It is used both for field crops, and for vegetables, fruits and berries.
Characterization of some complex and complex fertilizers containing phosphorus
Diammophos for gardeners is called hydrophosphate. It contains a large amount of active substance. It is used not only to supply this macroelement to cultivated plants, but also to neutralize soil acidity. When combined with organic fertilizers, a concentrated mixture is obtained that can cause root burns, so they must be insisted. It is mainly used in presowing dressing. Under the potato make a teaspoon of granules in the hole. Fertilizing tomatoes or cucumbers is carried out during the flowering period by applying in a dissolved form under the roots. Sometimes this phosphorus fertilizer is applied to the wells before planting.
Borofoska in addition to phosphorus has boron in its composition. Despite the fact that this element is required a little, it is vital for various cultivated plants. It must be added to the main dressing, since phosphorus has a sparingly soluble form. The fertilizer also contains calcium, which helps to increase the reaction of the environment and reduce acidity.
Classification
All considered forms are divided into the following types:
- Water soluble - simple and double superphosphate.
- Lemon and citrate soluble - precipitate, bone meal. They are mainly used in presowing application.
- Sparingly soluble - vivianite and phosphate rock. They only react with sulfuric or nitric acids, not reacting with the weak of these classes.
Even phosphorus can be found in complex and complex fertilizers containing not only one macrocell, but also two or three, and may also contain some trace elements.
Appointment of phosphoric tuks
They are intended for:
- increase crop yields;
- improving organoleptic indicators of the economically valuable part of the crop;
- acceleration of the passage of interphase periods;
- improving the immunity of cultivated plants against pests and diseases;
- increase resistance to climatic conditions.
As a rule, the critical period in plants for the application of this element, which is part of phosphorus fertilizers, is the stage of formation of the root system. This is due to the fact that at this time the plants are the most weakened, in need of additional nutrition.
Main application period
In the case of using hard-to-reach forms in mineral tuks, phosphorus fertilizers are applied at a dose of 2 / 3-3 / 4 in the fall under the main tillage in industrial conditions. The introduction is carried out to the depth of the root system. Under berry, woody and ornamental plants they are brought directly into the hole. The greatest amount of this macrocell is required for row crops, for example, potatoes, beets, carrots, tomatoes, cabbage, as well as berries and fruits.
Gardeners make phosphate fertilizers to a depth of half a meter. The introduction is carried out by creating circles with a drill having a diameter of 2-2.5 cm, after about 1 meter. They are filled with granular types of data fat. In the absence of a drill, scrap can be used. To dissolve fertilizers, the soil must be shed with water.
About 75 g of superphosphate should be applied under one young apple tree, and 200 g under the fruiting one. The doses comparable to the young apple tree are applied under the cherry. Under gooseberries and currants make up to 50 g per 1 meter. If manure is introduced at the same time, the doses can be halved. In the garden, the fertilizers in question are used either in autumn or in spring.
The given doses are indicative and should be established by an agrochemical study of the soil, in which the amount of available element for plants and the need of each individual culture in it are determined.
Presowing and sowing application of phosphoric tuks
In spring, in the presowing dressing of the soil, the remaining 1 / 3-1 / 4 doses of phosphorus fertilizers are applied. 10-15 kg of active substance per hectare is applied during sowing, simultaneously with its implementation. If fertilizers contain phosphorus in an easily accessible form for plants, then the main application from autumn can be carried over to spring. In this case, it will coincide with pre-sowing fertilizer for annual crops.
Top dressing
Mostly fertilizing is carried out with nitrogen fertilizers. But sometimes it becomes necessary to use both phosphorus and potassium fat. The critical period for plants with respect to phosphorus is the flowering period. At this time, and you need to feed this macro.
Professionals determine the need for fertilizing according to the sheet diagnostics. However, in personal subsidiary plots it is quite difficult to implement it, therefore, the need for fertilizing with phosphorus fertilizers should be determined by visual signs.
These include the slow development of cultivated plants. They may have a dwarf appearance, fruits and leaves have a truncated appearance. The latter acquire a bluish-greenish tint. The lower ones acquire a dark copper or violet-black color. In this case, the leaves curl and fall, and a purple hue is noted on the petioles. The color of the fruits of the plants also changes, but it is too late to feed the plants when they receive the fruits.
Not only is phosphorus deficiency harmful to plants, overfeeding is also dangerous for them.
Excess fertilizer can be identified by new leaves. They are notable for their small thickness; intervein chlorosis is present on them. Their tops and edges have areas that may seem scorched.
The internodes with an excess of phosphorus become shorter. In addition, in plants that are overfed with these fertilizers, the color of the leaves changes to a darker one. With an excess of this element, productivity decreases. In the lower leaves, twisting with the appearance of spots is noted.
Thus, the use of phosphorus fertilizers can be carried out at different times.
Production of synthetic types of phosphoric tuks
Their receipt is carried out according to a specific technological scheme. The main component of the considered tuks is phosphorus ore, which can be represented as phosphorites or apatites.
The process of phosphorus fertilizer production begins with the purification of ore from impurities. In the future, it is crushed to a flour state, saturated with various acids, including phosphoric, nitric and sulfuric. Then, phosphate reduction is carried out, after which a high-temperature treatment is performed. As a result, manufacturers receive synthetic mineral phosphorus fertilizers.
Finally
Many gardeners ask the question: “Phosphoric fertilizers - which ones?” These include fertilizers, the main element of which in the composition is phosphorus. Based on this, part of complex and complex fertilizers can also be attributed to phosphorus fertilizers. They are made from natural ores. The main species used for application on any soil is superphosphate. Phosphate rock can be used in chemical reclamation. Feeding with phosphorus fertilizers is carried out according to leaf diagnostics or by visual signs, which are manifested mainly on the leaves of cultivated plants.