Phosphorus fertilizers: names, application

2024 Author: Howard Calhoun | [email protected]. Last modified: 2024-01-02 13:48

Phosphoric fertilizers belong to the class of mineral fertilizers. The main element contained in them belongs to the macronutrients that crops need in the first place. Despite the fact that in the Soviet Union, during the time of large-scale chemical reclamation, soils were phosphated, long years of not using these fertilizers led to the fact that the crops removed this element from the substrate with the harvest, which again made their application necessary.

The concept of phosphate fertilizers

In addition to phosphorus, these fertilizers also contain other foreign substances. Therefore, the calculation when making is carried out on the active substance (a.i.). Plants do not absorb any phosphorus, available to them is P₂O_{5. Few cultures are able to extract this element from hard-to-reach compounds. Lupine belongs to one of them.}

Assortment

The main phosphate fertilizers are superphosphates(simple and double) and phosphate rock. The latter type contains a lot of the hard-to-reach macronutrient under consideration, therefore, it is of limited use. It is mainly used in the case when it is necessary to carry out chemical reclamation of vast areas, since over time, hard-to-reach phosphorus turns into a form that is 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 on any plant.

Let's give the main names of phosphate fertilizers: superphosphate, borofoska (fat, containing in addition to phosphorus the trace element boron), phosphate rock. In addition, this macroelement is contained in complex and complex fertilizers: nitrophoska, azofoska, ammofoska and some others.

Characterization of superphosphate as the main phosphate fertilizer

This phosphate fertilizer contains phosphoric acid, monocalcium phosphate, magnesium and sulfur. It can be produced in both powder and granular forms. The latter is considered more efficient. 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 Superphosphate", which contains 19-20% AI, as well as "Double Superphosphate", containing up to 46% AI.

Fertilizer is betterto bring in the autumn period at the main filling of the soil. In the spring and summer, it can be used in dissolved form. It is used both for field crops and for vegetables, fruits and berries.

Characteristics of some complex and complex fertilizers containing phosphorus

Diammophos for gardeners and gardeners is called hydrophosphate. It contains a large amount of active ingredient. It is used not only to supply this macronutrient 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 infused. It is mainly used in pre-sowing dressing. Under the potatoes, a teaspoon of granules is added to the well. Fertilization of tomatoes or cucumbers is carried out during the flowering period by applying in dissolved form under the roots. Sometimes this phosphate fertilizer is applied to the holes 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 andcitrate-soluble - precipitate, bone meal. They are mainly used in pre-sowing application.
• Sparingly soluble - vivianite and phosphate rock. They only react with sulfuric or nitric acids, not with weaker ones from these classes.

Phosphorus can also be found in complex and complex fertilizers containing not only one macronutrient, but also two or three, and may also contain some trace elements.

Purpose of phosphorus fertilizers

They are for:

• increasing crop yields;
• improving the organoleptic characteristics of the economically valuable part of the crop;
• acceleration of the passage of interphase periods;
• improving the immunity of cultivated plants in relation to pests and diseases;
• enhance climate resilience.

As a rule, the critical period in plants for the introduction of this element, which is part of phosphate 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 fertilizers, phosphorus fertilizers are applied at a dose of 2/3-3/4 in autumn under the main tillage in industrial conditions. Application is carried out to the depth of the root system. Under berry, woody and ornamental plants, they are brought directly into the hole. Row crops, such as potatoes, beets, carrots, tomatoes, cabbage, as well as berries and fruits, require the greatest amount of this macronutrient.

Gardeners apply 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. Granular types of these fats fall asleep in them. In the absence of a drill, you can use scrap. To dissolve the fertilizer, the soil must be spilled with water.

Under one young apple tree, about 75 g of superphosphate should be applied, and under a fruit-bearing 200 g. Doses comparable to a young apple tree are applied under a cherry. Under gooseberries and currants, make up to 50 g per 1 meter. If manure is applied at the same time, 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 according to the agrochemical study of the soil, which determines the amount of the available element for plants and the need for each individual crop in it.

Pre-sowing and pre-sowing application of phosphate fertilizers

In the spring, the remaining 1/3-1/4 doses of phosphorus fertilizers are applied to the pre-sowing dressing of the soil. 10-15 kg of the active substance per hectare is applied during sowing, simultaneously with its implementation. If fertilizers contain phosphorus in a form readily available to plants, then the main application from autumn can be transferred to spring. In this case, it will coincide with the pre-sowing fertilizer for annuals.crops.

Feeding

Basically, top dressing is carried out with nitrogen fertilizers. But sometimes there is a need to use both phosphorus and potassium fertilizers. The critical period for plants in relation to phosphorus is the flowering period. At this time, you need to feed this macronutrient.

Professionals determine the need for top dressing based on leaf diagnostics. However, it is quite difficult to implement it in personal subsidiary plots, therefore the need for additional feeding 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 take on a dark copper or purple-black color. At the same time, the leaves curl and fall off, and a purple hue is noted on the petioles. The color of the fruits of the plants also changes, but when the fruits are obtained, it is too late to feed the plants.

Not only is under-fertilization of phosphorus harmful to plants, overfeeding is also dangerous for them.

Excess fertilizer can be identified by new leaves. They differ in small thickness, they have interveinal chlorosis. Their tops and edges have areas that may appear burned.

Internodes with excess phosphorus become shorter. In addition, in plants that are overfed with these fertilizers, the color of the leaves changes to a darker one. Atan excess of this element reduces the yield. The lower leaves are curled with spots.

Thus, the application of phosphate fertilizers can be carried out at different times.

Production of synthetic types of phosphate fertilizers

Their production is carried out according to a certain technological scheme. The main component of the fertilizers under consideration is phosphorus ore, which can be presented in the form of phosphorites or apatites.

The process of production of phosphate fertilizers begins with the purification of ore from impurities. Subsequently, it is crushed to a floury state, saturated with various acids, including phosphoric, nitric and sulfuric. Then carry out the reduction of phosphates, and then produce a high-temperature treatment. As a result, producers receive synthetic mineral phosphate fertilizers.

In closing

Many gardeners ask the question: "What are phosphorus fertilizers?" These include such fertilizers, the main element of which 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 type used for application on any soil is superphosphate. Phosphorite flour can be used in chemical reclamation. Fertilizing with phosphate fertilizers is carried out according to leaf diagnostics or visual signs, which appear mainly on the leaves of cultivated plants.