Important nutrients for fertilisation
For effective fertilisation, all the required nutrients must be harmonised. The limiting factor here is the element that is least present in the soil solution (Liebig’s law of the minimum). The main nutrient elements include – in decreasing order of occurrence in plant matter – nitrogen, potassium, calcium, magnesium, phosphorus and sulphur. In addition, silicon and sodium are also important for certain crop species.
In terms of quantity, nitrogen is the most commonly occurring. As such, it is one of the core elements of crop nutrition and an important building block for microorganisms. It is also a component of many organic compounds, such as amino acids, vitamins and chlorophyll. As is only rarely found in parent rock and mineral soil matter, nitrogen has to be added to arable land via suitable fertilisers. The nitrogen supply of crops is frequently a yield-limiting factor. As such, an adequate dose usually results in a high yield.
Potassium is responsible for the osmotic pressure in crops and therefore for regulating the water balance. Similar to magnesium, it is also necessary for the activation of certain enzymes. A good supply of potassium increases drought and frost resistance. A deficiency, on the other hand, can cause increased leaf wilt, particularly around the edges of the leaves. This in turn can cause chlorosis and necrosis in crops.
Phosphorus is present in the Earth’s crust and is an important element for all living things. As part of the food chain, it makes its way via the soil to plants, animals and ultimately humans. Phosphorus is responsible for supplying cells with energy (ADP, ATP synthesis), and is used as a cell building block and in the formation of organic substances. A lack of phosphorus in soil has a negative effect on crop growth, particularly in the form of deficiency symptoms such as necrosis and chlorosis.
Sulphur is a component of many plant constituents, such as amino acids, enzymes and vitamins. A lack of sulphur disrupts the synthesis of protein and chlorophyll, which causes yellowing, initially in young leaves then later all leaves. In rapeseed, a sulphur deficiency can result in a complete yield loss. A sufficient sulphur supply is therefore incredibly important for the production of high-quality food.