Potash Fertiliser: Getting the Most From Potassium, and Why Silicon Matters Too

What potash is and what it does

Potash is the general name for potassium fertilisers. The most common form in Australia is muriate of potash (MoP), which is about 50% potassium, or 60% K2O on the bag label. When your soil test says potassium is low, potash is the fix.

Potassium is linked to water regulation, disease resistance and grain fill. It controls the stomata that let the plant breathe and manage water, which is why potassium deficiency shows up worst in dry years. A crop short of K wilts faster, fills grain poorly and cops more disease.

Potassium deficiency is common on lighter soils and under heavy hay or silage removal, because every bale takes K off the paddock. If you are cutting hay, you are mining potassium.

Potash vs potassium silicate: the confusion worth clearing up

Many farmers looking at potassium come across potassium silicate, which is sold as a silicon product. The names sound similar, but they are very different tools.

Liquid potassium silicate is a small dose foliar product. It supplies some potassium and some silicon in a soluble form, sprayed on the leaf in litres per hectare. It suits horticulture and intensive crops where foliar programs are already running.

MaxSil Powder is a soil applied broadacre product supplying 40,000 ppm soluble silicon, applied at kilograms per hectare, not litres. It is built for scale: broadacre cropping, pasture and blending, at a typical starting rate of 50 kg/ha confirmed by a MaxSil agronomist after a soil test. If you want silicon across hundreds of hectares, a foliar liquid is not the economical way to do it.

Cost per kg of plant available silicon

This section is reserved for the MaxSil team's silicon normalised price comparison, showing the cost per kilogram of plant available silicon across common silicon sources. Check back soon, or ask for the figures when you get a quote.

Placeholder for the MaxSil team to insert its silicon normalised price comparison.

Why silicon belongs in the same conversation as potash

Potassium and silicon are linked to the same outcomes: water regulation, disease resistance and stress tolerance. They get there by different mechanisms. Potassium works inside the plant's chemistry, regulating water movement and enzyme function. Silicon works physically, depositing in cell walls to make tissue tougher and helping the plant manage water and ions under stress.

Because they complement rather than compete, the two fit naturally in the same program. A crop with good K and good silicon status is better set up for a dry finish than a crop with either alone.

Silicon pays off most under stress: drought, heat, salinity, acidity, pest and disease pressure. If you are spending on potash to protect yield in tough seasons, silicon is the logical partner.

How to add silicon to a potash program

MaxSil blends with standard fertilisers and goes out through standard spreading gear, so adding it to a potash pass costs nothing extra in machinery. MaxSil Powder suits broadacre and blending. MaxSil Granules suit direct drill or broadcast on cereals and pasture. Mini Prill and Blade round out the range for row crops and turf.

Start with a soil test and a strip trial. MaxSil offers a free soil test analysis: send your results and an agronomist will tell you whether silicon is likely to be limiting and at what rate.