Composition, properties and application of phosphate rock as fertilizer

To date, scientists have developed and identified various fertilizers for growing plants. As agricultural practice has shown, one of the most environmentally friendly fertilizers is phosphate rock. This fertilizer has a beneficial effect on the development, growth and productivity of grass crops. However, it has its own individual characteristics for making, which will be discussed in this article.

Description of phosphate rock

Phosphorite flour - natural, mineral fertilizer... In appearance, it is a loose powder of dusty gray or brownish brown color. The production of fertilizer is based on sedimentary rocks, which consist of homogeneous phosphorite solids in a crystalline state. They are mined with clay, sand and other by-products of the earth's crust.

Composition

Phosphate rock has many beneficial properties. It includes:

• phosphorus oxide - from 19 to 30%;
• silicon - 18%;
• calcium - 30%;
• magnesium - 2%.

In addition, flour contains a complex of trace elements such as CuO, F2O3, AL2O3, SO2, ZO2.

Formula

Phosphorus P2O5 and a slightly soluble calcium salt Ca3 prevail in the composition of the phosphorus powder. Its chemical formula can be expressed as Ca3 (PO4) 2.

The laboratory method for obtaining phosphoric flour involves the combination of phosphoric acid with calcium salts:

3CaCO₃ + 2H₃PO₄ = Ca₃(PO₄)₂ + 3CO₂↑ + 3H₂O

Or with calcium hydroxide:

3Ca (OH)₂ + 2H₃PO₄ = Ca₃(PO₄)₂ + 6H₂O

As you can see, phosphorus flour has a difficult-to-digest formula for plants. However, this fertilizer works excellently on peat or podzolic soils, where pH exceeds 7 units. The fact is that an acidic environment converts phosphorus into the form that plants need.

Properties

Phosphate rock is one of the most important fertilizers in plant growing. During use, the powder has the following positive effects on plants:

• root formation;
• stimulation of tillering;
• accelerated growth process;
• winter hardiness;
• increased productivity.

But, despite such positive qualities, fertilizer has its drawbacks. Phosphoric flour is highly water resistant.

Note: Long-lasting phosphoric flour. It can be used once every 4–5 years.

Signs and manifestations of phosphorus deficiency

There are cases when plants stop growing on a sufficiently nutritious soil that does not need fertilization. Many people involved in crop production are wondering what is the reason for this phenomenon. It turns out that the main source of this phenomenon is free hydrogen ions, which accumulate in large quantities in the soil. Under their action, the acidity of the soil increases, and it becomes poorer in phosphorus.

To confirm this assumption, it is enough to pay attention to what wild plants grow on the site. As a rule, on medium - and strongly acidic soils, you can see:

• oak mariannik;
• oxalis ordinary;
• plantain;
• sphagnum;
• creeping buttercup;
• cotton grass;
• Veronica Dubravnaya;
• cat's paw.

In addition to these factors, the increased acidity can be judged by the cultivated plants. With a phosphorus deficiency, they have:

• dryness and blackening of foliage;
• lingering flowering;
• late ripening;
• suspension of growth;
• underdevelopment of the roots.

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Another symptom of increased soil acidity is the red-violet color of plants.

Application of phosphorites

An important advantage of phosphate rock is that it can stay in the ground for a long time and gradually dissolve. In this regard, when using it, you can achieve a double effect, these are:

1. Plants receive the necessary nutrients every year.
2. The acidity level of the soil maintains an acceptable norm.

Moreover, the fertilizer is suitable for almost all cereals and fruit crops.

Standards for open ground

In open ground, phosphorus fertilizer is applied once every 5 years. The best time for this is autumn. This limitation is due to the fact that phosphorus will have time to settle in the soil during the winter, and in spring it will begin to feed the plants.

Pay attention! If phosphoric flour is used to reduce the acidity of the soil, additional organics will need to be used in addition to it.

Fertilizers are applied at the rate of 200-300 g per 1 sq. m.For effective impact, the flour should be evenly distributed throughout the entire area and dug up with the soil at a depth of no more than 15 cm.

Compost rates

Phosphate rock also improves the quality of fertilizers, consisting of a mixture of biological and organic substances, in the decomposition of which microorganisms participated. So, flour is added to unripe compost in a ratio of 20 kg per 1 ton. It will be enough to add 3 kg of phosphorus to the finished compost.

Requirements of plants for phosphorus and trace elements

As mentioned above, phosphorus fertilizers contain a large number of useful elements. Consider how they benefit plants.

Calcium

Calcium plays an important role in plant development. In its deficit, cultures lose their development. As a rule, their growth stops, the top dies off, inflorescences fall off, fungal diseases develop. This negative impact reduces the amount of yield. In addition, the lack of calcium affects the quality of the fruit. They lose their presentation, taste and shelf life.

Silicon

An element such as silicon contributes to the nutrition of plants with useful microelements found in the soil. The fact is that it crushes apatites to small particles, due to which they are better absorbed by herbal crops. At the same time, the plants become more dense and resistant to lodging.

Trace elements

The rich complex of microorganisms has a beneficial effect on plant health.In the zone where they occur, the development of pathogenic microorganisms decreases. Due to this, herbaceous plants do not succumb to various diseases and become more resistant to the invasion of insect pests.

Despite the fact that magnesium in phosphate rock is only 2%, it is also worth noting for its benefits for plants. This trace mineral promotes energy production and has a positive effect on yield quality.

Impact on crops

As mentioned above, phosphate rock can be used for almost all types of crops. However, there are some plants that do not assimilate phosphorus. Let's look at some of the most common types of crops and their relationship with phosphate rock.

Lupine buckwheat mustard

These green manures assimilate poorly soluble phosphates quite well. This is due to the fact that they themselves are soil enrichments. Sowing them improves the physical and chemical properties of the soil. The earth becomes rich in organic matter and nitrogen.

Peas sainfoin clover hemp

These plants, as well as green manure, interact with phosphorite. This effect is facilitated by the fact that crops have a significant release of acids through the root system. In addition, in their composition, calcium prevails over phosphorite. Due to this, sparingly soluble phosphorite decomposes faster and transforms into soluble salts.

Cereals flax beets potatoes vetch

This group of herbaceous and root crops assimilates phosphorus from phosphate rock only on acidic soils. This is due to the fact that plants absorb small amounts of calcium. Accordingly, their root system does not release enough acids to break down phosphorus.

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Barley spring wheat flax tomato turnip millet

These plants do not tolerate acidic soil well. The conditions for their growth should be soil with a neutral pH. level.

Application on various types of soils

A distinctive feature of phosphate rock is that, depending on the soil, it is used as the main and additional fertilizer.

On acidic soils

Soil with a high level of acidity is very poor in potassium and phosphorus. Therefore, it does not conduct heat well and interferes with the nutrition of plants with useful substances. To reduce such a negative effect, phosphate rock is introduced into acidic soil as the main fertilizer once every few years.

When improving

Phosphate rock can also be used on fertile soils. Here, as a rule, it acts as an additional fertilizer in improving the quality of the yield of fruit crops.

Features of use

Phosphate flour, like any other fertilizer, has its own individual characteristics in use.

Application methods

The efficiency of phosphorite is influenced by its correct introduction into the soil. To enrich and maintain the soil, fertilizer is applied dry. As top dressing, phosphate powder must be diluted with water and sprayed on the plants.

Dosage

The dosage of phosphate rock depends on the types of its purpose and the quality of the soil. To improve soil fertility, fertilizer is applied in the following doses:

• in the soil of light texture - 0.8–1 t / ha;
• in soil with a heavy texture - 2–2.5 t / ha.

If phosphorite is used as an additional top dressing, it is diluted in water in a ratio of 20 g per 1 bucket.

What cannot be applied to the soil at the same time

When applying phosphorite, it is very important to consider its chemical properties. The fact is that this fertilizer is not compatible with some compounds. Among them are:

• a piece of chalk;
• dolomite and limestone flour;
• ash;
• slaked lime.

If these compounds have already been introduced into the soil, phosphorus can only be used next year, since their combination will cause significant damage to plants.

Security measures

Phosphate rock is considered a fairly environmentally friendly fertilizer. However, it still contains toxins. Therefore, soil cultivation must be carried out strictly in work clothes, gloves, glasses and a protective gauze bandage. After the treatment of the soil and plants is carried out, clothes must be cleaned of fertilizer residues, and hands and face should be washed with soap.

Differences between phosphate rock and superphosphates

Some novice gardeners believe that there is no difference between phosphate rock and superphosphate. However, they thereby make a big mistake. Each of these fertilizers has a different value in certain types of soil. So, unlike phosphorites, superphosphates are not useful on acidic soil. But they are quite valuable on neutral and alkaline soils. Moreover, they are water-soluble and are introduced only in liquid form.

Alternative replacement for phosphate rock

On acidic soils, plants can be grown without the use of phosphate rock. To do this, it will be enough to apply mineral fertilizers that contain phosphorus. These substances include:

• phosphate slag - phosphorus content 6–20%;
• precipitate - phosphorus content of 27–48%.

These fertilizers are used only as a pre-planting base material. As a supplement, they are of no value.

As you can see, phosphorus flour is an indispensable tool for every gardener. Using this fertilizer, you can restore the quality of the soil, and significantly increase crop yields. However, do not forget about the rules and dosages of application. A large amount of fertilizer can negatively affect the plants.