Potassiums

The chemical speciation of plant-assimilable potassium is the potassium K ion, absorbed from the soil solution. Other species may exist, but most of them are not available for our sports surfaces.

Natural potassium salts originate from the drying out of ancient seas, especially in the Upper Permian period, 200 million years ago. The salts in seawater crystallised in order of solubility, so that above the ClNa salt layer there was a shallower layer of potassium minerals.

Potash refers to potassium compounds in general, although potassium is a potash caustic is the common name for potassium hydroxide KOH.

Potassium chloride is the most common potassium fertiliser and provides a high degree of salinity (salt index of 2.2); it comes from marine deposits, so we have minerals such as sylvinite, sylvinite, etc. On the other hand, potassium sulphate is the result of reacting potassium chloride (it is more recommendable in the sense that it provides less salinity, as it has a salt index of 0.9) with sulphuric acid, or potassium nitrate (salt index of 1.6) when reacting with nitric acid. Therefore, the use of one fertiliser or another gives us an idea of the effect on the parameter introduced with POGO of the salt index, as all fertilisers contribute salinity to the soil, although some do so to a greater extent than others. All potassium fertilisers are made from brine or underground potash deposits.

All these fertilisers react neutrally in the soil, with the exception of KNO3, which increases the pH.  

Regardless of the potassium supplied through fertilisers (greens), it appears in natural soils by mineralisation and disintegration of all rocks containing potassium minerals, mainly potassium feldspars and micas. In reality, although it is not available, this fraction of potassium is the majority in natural soils, forming part of the crystalline networks.