Hazards, uses and alternatives

the essentials in brief

• There are numerous Phosphate fertilizer with different levels of phosphate between 5 and 52 percent.
• They should only be used if there is a proven lack of phosphate in the soil or Plants are applied.
• Phosphate fertilizers contain heavy metals such as cadmium and chromium, which are deposited in plants and animals as well as in the soil and groundwater.
• Before an application is a Soil analysis The dosage can also be reduced by adding manure.

What is phosphate fertilizer?

Phosphorus (P) together with nitrogen (N) and potassium (K) form the three main nutrients necessary for growth of plants are vital and are therefore the most important components in every full and NPK fertilizer are. Sometimes there can be a lack of phosphorus, which significantly impairs the formation of flowers and fruit as well as the healthy growth of ornamental and useful plants. In this case, a special one

Phosphate fertilizers consist of the salts of phosphoric acid (H3PO4). Since pure phosphorus is only poorly soluble in water, it must first be chemically processed before it can be used as a fertilizer. Various acids break down the required calcium phosphate. Only then are the nutrients available to plants.

Composition and properties

Rock phosphorus is mined in huge mines

The raw phosphorus required for phosphorus fertilizer is mostly obtained by mining from natural deposits that have formed from deposits of former marine animals that are millions of years old. Many of these deposits are located in the countries of North Africa as well as South Africa, Jordan, China and Russia. The world's largest phosphate producer is Saudi Arabia. In addition, rock phosphate is obtained from the remains of sea birds, the so-called guano.(€ 9.82 at Amazon *)

The plants take up the processed phosphorus through their roots, whereby the fertilizer is best available at a pH value between 6 and 7. Various phosphorus foliar fertilizers are available in stores, but these only help for a short time - the lion's share of the nutrient is ultimately absorbed by the roots.

Digression

Thomas flour - a cheap but problematic phosphate fertilizer

Effects and effects

Phosphorus is an important component of every plant cell. The element is essential for the functioning of the metabolism in all ornamental and useful plants. A phosphorus deficiency, which is determined either by a growth depression in plants or, more often, by a soil analysis, should therefore be remedied immediately. The use of a phosphorus fertilizer, if applied correctly, has the following effects:

• Roots grow deeper, so the plants can be better cared for
• the bud and flower formation is supported
• Support of cell division and thus leaf and shoot growth
• Support of resistance to diseases and pests

So that the phosphorus fertilizer can work optimally, you should before using it

• conduct a soil analysis
• and only apply the phosphorus fertilizer if the analysis shows a deficiency
• then carry out a pH test

If the soil is too acidic (pH value below 5.5), it must first be brought into the optimal range between 6 and 6.5 by means of liming. If the result is more than 7, it is better to choose a water-soluble phosphate fertilizer.
But be careful: Phosphate fertilization not only affects the plants, but also directly affects the soil and the groundwater. Too high a proportion of phosphate in water can be recognized by excessive algae growth, and it also dies Aquatic plants and aquatic organisms such as fish, snails, mussels and crabs due to the Lack of oxygen. This effect can often be observed in bodies of water that are located in heavily farmed regions. For this reason, phosphate fertilization should only be carried out if it is really unavoidable.

Digression

Caution, highly toxic!

Phosphate fertilizers contain highly toxic components

Phosphate fertilizers are indispensable, especially in industrial agriculture, in order to achieve the highest possible Income to achieve. However, these fertilizers are also highly problematic as they are heavily contaminated with toxic heavy metals, especially uranium and cadmium. By using such a fertilizer, these toxins inevitably find their way into our food via plants and animals. There is currently no statutory maximum uranium content in Germany, just a recommendation from the Federal Ministry of Food and Agriculture. The maximum value here is 50 milligrams of uranium per kilogram of phosphate fertilizer.

Types of phosphate fertilizers

Numerous phosphorus fertilizers are available on the market especially for home and hobby gardens. In addition to pure phosphorus fertilizers, you can also choose complex fertilizers with a high phosphorus content. Typical examples are universal or Complete fertilizer as well as NPK fertilizers, because in these products the three main nutrients nitrogen, phosphorus and potassium form the most important and thus the largest components in terms of quantity.

The following table gives you an overview of common single and multi-component fertilizers.

For the home and hobby garden, multi-component fertilizers that contain both phosphorus and other nutrients are usually completely sufficient. Phosphate fertilizers with a very high phosphate content, for example

• Diammon phosphate (DAP) with 46 percent phosphate content
• Monoammon phosphate (MAP) with 52 percent phosphate content

however, are primarily used in agriculture. If you need a fertilizer with a high phosphate content for your home garden, it is better to choose so-called superphosphate. This contains calcium phosphate and sulfuric acid, with the phosphate content fluctuating between 16 and 22 percent depending on the manufacturer.

Correct application

If the phosphate fertilizer is not used properly, it can have dire consequences

Phosphate fertilizers require proper handling in order to avoid possible overdosing and thus unnecessary exposure to heavy metals. It is not only a question of the correct, needs-based dosage, but also the timing and method of application.

time

When you apply phosphate fertilization primarily depends on the specific product that you want to apply:

• Water-soluble phosphate fertilizers: such as B. Superphosphate is applied to the earth as a basic fertilizer in spring. Choose granulated fertilizers as these will be released faster.
• Phosphate fertilizer with a high proportion of rock phosphates: are applied in autumn. They are particularly suitable for acidic soils / soils with a low pH value

Liquid fertilizers containing phosphate are practical, as you simply add them to the irrigation water and water the plants directly with it. You can also use these during the growing season.

Dosage and effects

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Phosphate fertilizers should be applied as close as possible to the roots, as this is the only place where they develop their effect. In contrast to nitrogen fertilization, however, you do not have to fear any damage to the roots. And so is fertilized:

• Observe the manufacturer's instructions regarding dosage and use.
• The dosage also depends on the specific phosphate content of your garden soil.
• We recommend around 30 to 60 milligrams of phosphate fertilizer per square meter for superphosphate.
• Sprinkle the phosphate fertilizer directly on the root disc of the fertilizing Plant.
• Use a spreader to evenly fertilize larger areas, such as lawns.
• Work in the granules on the surface.
• Water vigorously so that the fertilizer dissolves and seeps into the soil.

Lower the dosage by applying organic fertilizer in the form of compost or manure at the same time. Manure, in particular, allows the amount of fertilizer to be reduced by up to 40 milligrams per square meter. When using compost, you need 15 milligrams less phosphate fertilizer per square meter.

frequently asked Questions

Are there alternatives to phosphate fertilizers?

Manure is a great alternative to phosphate fertilizer

Yes, fertilize your garden with manure. This contains a high proportion of natural phosphate (analogous to sea bird droppings), but it takes some getting used to for some gardeners. Make sure that poultry manure, in particular, must have rotted well before you spread it! Otherwise, agricultural scientists all over the world are researching alternatives to mineral phosphorus fertilizers discover - it is high time that the world’s phosphorus deposits are slowly coming to an end to.

Do you even need special phosphorus fertilizers in the garden?

No, phosphorus fertilizers can be used in home and hobby gardens - with the exception of one through a soil sample confirmed deficiency - practically superfluous, especially if the garden is mainly fertilized with manure and compost will. Many supposed signs of a phosphorus deficiency in plants can also be attributed to other causes which is why you should fertilize if possible, if only because of the high proportion of pollutants should refrain.

How do I perform a soil analysis?

Since a suspected lack of phosphorus should not be fertilized on suspicion, a soil analysis must be carried out beforehand. Of course, you don't do this yourself. You take soil samples from various places in your garden and send them to a specialized institute for soil analysis. You will then receive an evaluation and fertilizer information.