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How Can Lime Technology Products Benefit Your Business?


For half a century Western Australia has relied on the use of lime sand to regulate soil pH. There is no doubt that this has been a successful, but many years later is this ‘one size fits all program’ still the right way to operate? With advancements in technology and the passage of time, it’s not surprising that new and improved lime products have emerged.

Limitations of Existing Advice

One of the main issues with current lime advice is that it may not be effectively addressing soil acidity below the surface layer.

A recent study conducted by Australian Government initiative FUTURESOILS, found that traditional liming methods are not keeping pace with acidification rates in minimum-tillage systems.

In the study, soil surveys show that traditional liming rates are not keeping up with acidification rates. Even in paddocks with a long lime history, under minimum tillage where lime is surface-applied and only incorporated by sowing, a soil pH(CaCl) target of 5.2 has not increased pH below a soil depth of about 7.5cm.

Key recommendations from the study include:
1. Traditional liming practices cannot be relied on to stop acid layers from forming in productive soils.
2. Farmers should collect soil samples in five-centimeter increments to a depth of at least 20cm.
3. Soil remediation plans should incorporate lime to the depth of the acid layers.

What Are Your Options?

Optima Lime are a Western Australian business specializing in lime products for soil pH remediation. We own and operate traditional lime sand pits across the south west of the state, from Dongara to Augusta – so we know lime sand has been a very successful product for soil remediation.

However, we’ve also been talking to farmers about the types of soil health issues identified in the study for a number of years. As technology has improved, we have developed alternative lime product solutions to tackle changing soil pH at depth, stopping the formation of acid layers and the speed of soil pH upgrade.

Farmers using our newer products are now seeing fast and effective soil health improvements from year 1.

Our two flagship products are:

Hi Cal. This is blended Bio-Lime, lime reagents and calcium solubilizing agents for use where tillage is limited, and fast pH management is needed. It is fast acting, significantly reduces freight costs and provides great value per hectare.

Agri Cal. This is the latest development in manufactured lime technology, specifically designed to improve lime performance in minimum tillage farming systems. It is fast acting due to improved solubility, is deeper penetrating for meaningful profile change and provides improved calcium availability.



Let’s look specifically at Agri-Cal and find out how it works:

  • Firstly, ultra-fine particles. Agri-Cal contains a large percentage of particles below 75 microns – the crucial range for lime mobility in the soil. It has up to 10 times more particles below 75 microns than a typical lime sand.
  • Secondly it is up to 1000 times more alkaline than typical lime sand. Harnessing the power of the logarithmic scale Agri-Cal utilises hydroxyl chemistry to shift your soil pH fast.
  • Thirdly it has up to 50 times more soluble neutralizing fractions than a typical lime sand. Soluble neutralising fractions dissolve in rainfall and move easily to depth, seeking out your acidity problems in the sub-soil.


Hi-Cal is the original lime technology product and was our first product in our added value lime range. Think lime sand on steroids. What sets it apart?

  • Fine particle size. Hi-Cal is concentrated on finer particles (below 75 microns). This is the most effective part of lime sand because finer particles penetrate soil deeper and have more surface area for reacting.
  • Soluble calcium content. Hi-Cal contains up to 30 times more soluble Calcium than conventional carbonate limes. The concentration and solubility increase its effectiveness.


The benefits of Agri Cal are:

  • Fast acting for quicker results. Ultra-fine particles and lime technology reagents in Agri-Cal combine to change pH faster for quicker results. See results in year 1.
  • Less product is needed. Combining high-efficiency and rapid action, Agri-Cal can get your pH from A to B with less quantity applied than traditional liming options.
  • Improves calcium availability. It displaces Sodium and Aluminum and help to counteract soil salinity.

The benefits of Hi-Cal are:

  • Faster reactivity. Lime technology reagents in Hi-Cal have a higher pH and can therefore change pH faster for quicker results.
  • Great value per hectare. Perfect for treating large farms in a cost-effective manner, particularly where freight is a major program component.

Additional major on-farm benefits associated with both products are:

  • Reduced freight costs. Freight is a significant component of liming costs. Using the heavily concentrated Agri-Cal or Hi-Cal makes huge savings on one of the major costs associated with liming practices.
  • Protecting crops from damage. This includes improved frost tolerance, improved herbicide performance and improved salt tolerance.
  • Offering long term gains. Continued use improves the physical and chemical soil properties of your farm.
  • Excellent storage. Both products store well in paddock, allowing cartage all year round.


There is plenty of evidence from farmers in WA to support the use of these new products:

  • A test we conducted over the course of two years showed that by switching to Hi-Cal from a traditional liming agent we were able to apply half the amount of product (from 1000 to 500 kg/ha) while meeting or exceeding the performance of the traditional product.
  • Test cases at properties in Wongan Hills and Caudoux that used Hi-Cal experienced increased chemical effectiveness on broadleaf weeds, solid stems in crops and lower fungal issues.
  • Test cases at properties in Muntadgin and Merredin that had been using Hi-Cal for 2 to 3 years reported minimal frost damage and higher than average yields in years when other properties in the area not treated with Hi-Cal experienced significant losses due to frost damage.


Our products (including Lime Sand) are available to purchase through your rural store network including leading independents, Elders, Nutrien and David Grays. Getting started with Hi-Cal or Agri-Cal could not be simpler. Our dedicated staff are on hand to advise you. We can work with you and your team to help develop a suitable plan.

We have 5 lime pits across the South West. They are convenient to access, readily available and fast loading. They have approved and certified weight loading systems, so you can rest easy in the knowledge you’re getting everything you paid for.


So, to summarise:

  • Traditional lime sand advice has been effective, but new research has discovered some problems with a ‘one size fits all approach’.
  • Given the advancements in technology over the past 50 years, it’s not surprising that we have also seen improvements in lime products and methods.
  • Optima Lime has some excellent ‘added value’ lime products you can use on your farm.
  • Their unique specification allows them to act faster to change pH quicker, put other much needed nutrients into the soil and provide solutions to no tillage farmlands.
  • To start talk to one of their product experts and purchase directly from your local rural store.

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