It is a group of fertilizers that combine both phosphorus and potassium into one granule. There are many methods of creation and raw materials used for production. There are several producers of complex fertilizers containing these two elements on the Polish market, such as Zakłady Chemiczne Police, Gdańskie Zakłady Nawozów Fosforowych, Luvena Luboń and Fosfan Szczecin. In addition, the market for compound fertilizers is so powerful that we can choose from a range of products from YARA and from the Eastern market, which supplies high-quality products, including phosphorus-potassium fertilizers.
As with mono ingredients, you should remember about the basic parameters and the action of individual elements in the plant. Then you need to know the ratio in the fertilizers to know how much and what fertilizer we are looking for and what will be optimal for a given crop, type of soil, and the expected yield.
In the entire range of phosphorus-potassium fertilizers, we have those which, due to the method of creation and source of raw material (especially phosphorus), will have different rates of transformation in the soil and thus their availability to plants. For this reason, their prices will also vary significantly. It is good to reach for those from reliable suppliers and preferably directly from the manufacturer's factories.
After finding a low content of available phosphorus or potassium, the dose should be increased by 30 kg P2O5 or K2O/ha, and with very low content - by 40 – 60 kg P2O5 or K2O/ha.
Potassium salts can be mixed with superphosphate ammonium phosphate, which allows the simultaneous application of fertilizers. Very good yield-forming results are obtained when using multi-component granulated fertilizers containing phosphorus, potassium and nitrogen, in the form of Nitrofoska (NPK Mg), Polifoska (PK, NPKMg), Polimag (NPK MgS) or Polidap (NP).
Today we also have fertilizers based only on P and K, of the PK type. However, most of them are supplemented with nitrogen as well as microelements.
Multicomponent fertilizers include those that contain more than one of the basic nutrients for plants, referred to as macroelements. Such a fertilizer may contain nitrogen (N) in its composition - it can be in various forms: ammonium, nitrate or amide, phosphorus (P) and potassium (K). Additionally, as a supplement, they may contain additional macronutrients, such as: magnesium (Mg), sulfur (S) or calcium (Ca). The content of nutritional micronutrients, such as boron (B), copper (Cu), iron (Fe), manganese (Mn), molybene (Mo) and zinc (Zn), is also possible.
Individual nutrients may be present in different proportions or not in the composition of a given fertilizer. Thanks to this, you can adjust the right power supply to the specific requirements of entire groups of plants, individual species as well as the seasons.
Multicomponent fertilizers can be divided into mixed and complex fertilizers. Mixed fertilizers are obtained during mechanical mixing of single fertilizers. We can also make them on our own. Complex fertilizers, on the other hand, are obtained by a chemical reaction of several chemical compounds containing plant nutrients.
Forms in which multi-component fertilizers occur:
It is advisable to mix both loose and granular form with the top layer of soil when the fertilizer has nitrogen content. This will prevent the loss of this macronutrient.
When choosing mineral multi-component fertilizers, pay attention to the so-called secondary components, namely sulfur and chloride content. These components are often intrinsic to one of the nutrients in the fertilizer. Some plants are sulfur-loving, so for them we should choose fertilizers containing sulfur, especially for plants with high requirements for this ingredient. For individual plants, it is also worth choosing:
The biggest advantage of multi-component mineral fertilizers is that you can adapt them to the requirements of the individual plants. Besides, they are convenient and practical to use, they can be used for pre-sowing and top dressing, they are much safer than single-component fertilizers. Always give individual doses of the preparation according to the manufacturer's instructions, thanks to which you can be sure that their action will be effective.