Omya Magprill

High-efficiency magnesium and calcium nutrition and soil conditioning.

Why should I use Omya Magprill?

Omya Magprill is a 2 – 6 mm granulated soil conditioner that adjusts soil pH quickly and provides essential calcium and magnesium nutrition. It is ideal for soils with magnesium deficiency and low pH and can be used in place of, or in combination with, Omya Magprill when higher levels of magnesium are required.

The benefits of Omya Magprill

  • Provides essential calcium and magnesium to enhance crop productivity 
  • Addresses imbalances of the potassium/magnesium ratio 
  • Strengthens the crop against drought and disease  
  • Optimizes photosynthesis for more even crop growth 
  • Corrects soil pH rapidly 
  • Enables precise variable rate application

Not all products are registered for use in all markets. Check with your local Omya representative for more information.

Omya Environmental Solutions helps farmers to improve productivity across the world. See how they do it.

What is Omya Magprill?

Omya Magprill is a granulated soil conditioner made from high quality natural calcium carbonate and dolomite.

Typical values

How does Omya Magprill correct soil pH quickly?

Omya Magprill is made of ultra-fine particles, granulated for easy application. The granules break down rapidly in soil moisture, allowing the fine particles to disperse through the soil profile. The large surface area of the particles reacts quickly with the excess hydrogen in the soil, leaving the exchange sites on the clay humic complex to be filled by the calcium ions. This reduces soil acidity and improves soil structure within the season of application.


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Why is magnesium nutrition important for crops?

Magnesium is a central component of the chlorophyll molecule that is essential for photosynthesis. Unlike calcium, magnesium is highly mobile in the plant, which means it can be relocated to the areas of the plant with the highest demand. For this reason, deficiency is first noticeable in older leaves, that turn yellow as the plant degrades the chlorophyll to release magnesium for relocation to developing leaves.


This has an impact on productivity because of the reduction in photosynthesis. Omya Magprill provides a readily available supply of both calcium and magnesium to the crop. This is particularly important for crops sensitive to low magnesium such as potatoes, sugar beet and field legumes.


How does Omya Magprill help manage the potassium/ magnesium ratio?

Omya Magprill not only corrects soil pH but also alleviates the toxicity of aluminum and other ions in the soil. The presence of potassium will block the uptake of magnesium, so it is important to manage the K/Mg ratio by supplying adequate magnesium. This will help maintain soil structure and health.

soil pH graph

How often should I use Omya Magprill?

Omya Magprill can be applied throughout the season, on its own or with other crop inputs using a standard fertilizer spreader. Application rates depend on soil type, crop and agronomic objectives.  For specific advice to suit your circumstances, consult your agronomist.

omya magprill product on a grass

What results can I expect with Omya Magprill?

Omya Magprill is proven in independent trials to deliver highly efficient soil conditioning and can correct magnesium deficiency in crops. You can read more about our trials results below.