Granular-Lime and AgLime are produced from the same parent material: calcium carbonate. Calcium carbonate - in rock form in the quarry - is blasted, crushed, washed, dried, ground and screened to different degrees, resulting in varying particle sizes. AgLime generally consists of coarser particles and Granular-Lime consists of superfine particles bound to form a granule which dissolves almost instantly in the presence of water. Granular-Lime and AgLime are made of the same material, therefore they work the same way to alter soil pH.
A particle of lime is made up of billions of ions of calcium and carbon. Each of these particles has the ability to react with the hydrogen ions which make the soil acidic. Granular-Lime is finer than AgLime, more surface area is available from Granular-Lime to react with the acidic soil solution and therefore it has greater potential to raise soil pH. This means less Granular-Lime is required than AgLime to get the same lift in pH.
Granular-Lime is cost effective.
It is often thought that Granular-Lime is more expensive than AgLime. On a per tonne basis, this is true however, when you take fineness and reactivity into consideration, far less Granular-Lime is needed to make the same pH adjustment that AgLime will make. Calculated per acre, Granular-Lime is often more cost effective than AgLime.
Granular-Lime is 97.9% utilised.
Many people will tell you that AgLime lasts longer than Granular-Lime. AgLime has a percentage of product that stays in the soil and remains unreactive. When a particle of AgLime is worked into the soil, it begins to react with the hydrogen ions in the soil solution around it, and pH near that particle rises. As this happens, the weaker acid soil solution is less able to penetrate to the centre of the AgLime particle. That particle then sits in the soil inactive until the soil pH drops to the point when lime was first applied. At a low pH, the field is not productive. By using Granular-Lime, 97.9% of the material applied reacts making Granular-Lime more efficient.
Granular-Lime can be used to make large pH corrections.
It is difficult to properly make large pH corrections. Farmers should be careful with AgLime recommendations requiring greater than 2tonnes/acre to be applied. Amounts greater than 2 tonne can cause over liming in the root zone, which can cause similar nutrient uptake issues as that caused by acidic soil. Similarly, famers should never apply more than 300 kg of Granular-Lime in one application. Due to this restriction it can be difficult to make large pH adjustments in one application. However, Granular-Lime is easy to apply with your own equipment, and additional Granular-Lime may be stored on farm and applied to soil in subsequent applications making it possible to make larger adjustments to soil pH with less risk.
Granular-Lime makes it easy to maintain correct pH levels.
As AgLime requires specialist equipment to apply, it can be difficult and time consuming to arrange. As a result, lime has become an input applied to a field when it is no longer productive giving fields’ peaks and troughs in terms of productivity. This method is inefficient. If mass applications of product were efficient, fertiliser would be applied in the same method. With Granular-Lime, we can avoid this in-efficiency and once pH is corrected to proper levels, we can then use maintenance dressings to maintain pH, and keep fields productive longer.
As such, Granular-Lime is an effective, efficient, easy to use product and another tool in your arsenal to maintain field productivity and maximise your resources.