Phosphate fertilizers

Phosphorus is responsible for the quality of photosynthesis, respiration and metabolic processes. It helps plants absorb nitrogen, potassium and magnesium better. A sufficient amount of available phosphorus ensures high yields and excellent fruit quality.

What is phosphate fertilizer

Phosphate fertilizers are mineral substances, the basis of which is phosphorus in a form available to plants. These fertilizers are produced mainly from natural ores – apatite and phosphorite, which our country is rich in.

Phosphate fertilizers are divided into 2 groups:

• water-soluble – simple and double superphosphate;
• insoluble in water – bone meal, phosphate rock, thermal phosphates, tomasslag and so on (1).

Importance of Phosphate Fertilizers

Phosphate fertilizers are the most important source of nutrition for plants, because they are responsible for several factors:

• increasing the yield of fruits and grains;
• improvement of taste and nutritional qualities of fruits and berries;
• improvement of decorative qualities of plants;
• increased immunity to viral and fungal diseases;
• increase in frost resistance and winter hardiness;
• slowing down the aging of plants.

It is noticed that good nutrition of plants accelerates the ripening of the crop.

Equally important, phosphorus is responsible for nitrogen uptake (1).

Due to the fact that phosphorus fertilizers are slowly absorbed, it is almost impossible to “overfeed” the plants with them, and the application itself is recommended to be done 1 time in 2-3 years.

Types and names of phosphate fertilizers

The range of phosphorus fertilizers for gardens and orchards is small, but phosphorus is also found in complex mineral fertilizers.

The following phosphate fertilizers are most widely used by gardeners:

Superphosphate simple or monocalcium phosphate

Chemical formula – Ca (H₂РO₄)₂. Contains from 16 to 20% phosphorus. This fertilizer is highly soluble in water and weak acids. It is a powder of light gray or dark gray color due to the presence of gypsum. The high sulfur content (10%) makes this type of fertilizer the most relevant for growing vegetables of the cabbage family and potatoes. The fertilizer also contains 6% nitrogen, 17% calcium and 0,5% magnesium.

Thanks to the production of a granular form of superphosphate, the fertilizer is free from many disadvantages – it does not cake and has a low moisture content.

It is used on all types of soil, but on acid soils it has low efficiency.

Superphosphate double

Formula — Sa(N₂РO₄)₂. Concentrated phosphorus fertilizer in the form of a grayish powder or granules. In fact, it is an enriched superphosphate with a share of available phosphorus from 42 to 50%. Does not contain gypsum.

Applies to all types of soil.

Please note that superphosphates cannot be mixed with ammonium, sodium and calcium nitrate, urea, lime and chalk!

Superphos

A new type of concentrated granular phosphate fertilizer with a phosphorus content of 38 to 40%, mostly in water-soluble form.

Phosphoric flour

A sparingly soluble phosphorus fertilizer of natural type, environmentally friendly, as it is finely ground gray or brown phosphate rock. Contains up to 30% phosphorus. Doesn’t stick, spreads well.

Assimilated in an acidic environment, so it is used mainly on acidic soils or simultaneously with the introduction of manure.

Bone (bone) meal

It is a fine grinding of the bones of farm animals. It is considered an environmentally friendly fertilizer. It is hardly soluble, but on acidic and slightly acidic soils it is absorbed by plants much better, which affects their productivity. Contains up to 35% phosphorus and 1% nitrogen.

The use of phosphate fertilizers

In order for phosphate fertilizers to be effective, it is important to choose the right one, and most importantly, to use it correctly.

Superphosphate granules should be located in close proximity to the roots, since this type of fertilizer is immobile in the soil. However, it can also be applied throughout the site, if mixed with organic matter.

Phosphorite and bone meal are scattered over the entire area of ​​u2buXNUMXbthe area intended for planting, since the more they react with the soil, the easier it is for plants to obtain phosphorus from them (XNUMX).

Based on this, summer residents are recommended 3 ways to use phosphorus fertilizers:

• scatter over the entire surface of the soil and then dig up – this method is used on acidic soils for bone and phosphate rock;
• apply directly to the planting pits and holes – this is an option for superphosphate;
• bring into the near-stem circle to the depth of the roots – the older the tree or shrub, the deeper its roots are, therefore, every 3 years, along the periphery of the crown, the pits are made each time deeper than the previous ones and fertilize, closing up with chopped green manure or plant residues.

When applying phosphate fertilizers, certain rules should be observed:

• do not mix alkaline phosphate fertilizers (superphosphates) with ammonium forms of nitrogen fertilizers;
• superphosphate granules are mixed with ammonium nitrate immediately before application;
• to fertilize young plants, superphosphates are mixed with dolomite flour to reduce acidity (3).

Pros and cons of phosphate fertilizers

The advantages of using phosphate fertilizers are that they are responsible for the active growth and high-quality fruiting of plants. Their resistance to diseases and climatic conditions. With an overdose of phosphate fertilizers, plants practically do not suffer.

The disadvantages include the features of the use of phosphate fertilizers. For example, superphosphates, in order to unlock their potential, must be applied strictly to the root placement zone, and phosphate rock should be dispersed and incorporated into the soil throughout the site. Phosphoric mineral fertilizers do not have a quick effect. Therefore, with a pronounced deficiency of phosphorus in the summer, I use either special liquid forms of phosphorus for plant nutrition, or green fertilizer from herbs rich in phosphorus.

The use of phosphate fertilizers in the garden and vegetable garden

Phosphorus deficiency leads to the death and fall of leaves, the suspension of plant growth and development, and the death of the root system. The first signs of phosphorus starvation of plants look like this:

• dark green leaves begin to take on shades of blue, purple or purple depending on the crop;
• the leaves become smaller and bend to the top, yellow-brown spots appear along the edges;
• young leaves depart from the branches at an acute angle;
• in the spring on the branches, the lower buds do not open, the development phases are delayed.

Although phosphorus fertilizers are not applied every year, when signs of phosphorus deficiency appear, top dressing is necessary.

Superphosphates. They are applied both in dry form and in the form of a solution. To prepare a solution, 100 g of simple superphosphate is poured with hot water, stirred, then the solution is adjusted with cold water to 10 liters. In this form, a solution is added at the rate of 0,5 l per bush (for vegetable crops). In spring, it is recommended to scatter granules (10 g per 1 sq.m.) over perennial flower beds with rakes or a flat cutter.

Simple superphosphate is applied in autumn at the rate of 30-60 g per sq. m.

Double superphosphate is applied in autumn at the rate of 14 – 28 g per sq. m., when planting trees and shrubs – from 150 g per planting pit.

It is considered effective to fertilize fruit and berry plants with a solution of superphosphate in the spring – 50 g per 10 liters of water at the rate of 0,5 liters per square meter. m. near-trunk circle. When laying strawberry beds per 1 sq.m. make 25 – 50 g of superphosphate.

The effectiveness of superphosphates increases with the simultaneous introduction of organic matter.

Bone flour. It is also better to use with organics. The best option is to add 1 handful of humus to the planting hole and add bone meal:

• when planting cucumbers and tomatoes – 2 tbsp. spoons;
• when planting zucchini, pumpkins, peppers, eggplants and potatoes – 1,5 tbsp. spoons;
• when planting cabbage – 1 tbsp. spoon.

Phosphate flour. It is applied once every 1 years in the fall for digging at the rate of 3 kg per hundred square meters.

Popular questions and answers

We asked about phosphate fertilizers agronomist Oleg Ispolatov – he answered the most popular questions of summer residents.

Sources of

1. Kovalev N.D., Atroshenko M.D., Deconnor A.V., Litvinenko A.N. Fundamentals of agriculture and crop production // M .: Selkhozizdat, 1963
2. Kidin V.V., Torshin S.P. Agrochemistry. Textbook // M.: Prospekt, 2016
3. Osipov A.I. The role of fertilizers in soil fertility and plant nutrition // Health is the basis of human potential: problems and ways to solve them, 2020 https://cyberleninka.ru/article/n/rol-udobreniy-v-plodorodii-pochv-i-pitanii-rasteniy