27/08/2026
Burnt Lime and Agricultural Lime are different substances and serve different purposes in farming and construction.
Burnt Lime, also known as quicklime or calcium oxide, is produced by heating calcium carbonate sources - limestone, chalk, or seashells - to roughly 900–1000°C, a process called calcination. This releases carbon dioxide (Co2), leaving behind reactive lumps of calcium oxide (CaO). It is made in kilns by burning, or at home using a hot fire to reach these temperatures.
Burnt Lime / QuickLime is used for soil stabilization and pH adjustment, offering rapid reactions. Burnt lime was also used in the past as a sterilant to kill unwanted pests/bugs especially on vegetable cropping lands where there was a quick rotation of crops.
- Critical Safety Precautions - Protective Equipment: Quicklime is highly caustic. Wear safety glasses, a dust mask, and heavy-duty protective clothing, as it can cause severe burns on contact with moisture.
- Exothermic Reaction: When handling, keep it away from water. Slaking (adding water) causes an extreme exothermic reaction, temperature exceeds 100ºC
Agricultural Lime, made by crushing and grinding limestone rock, is more gradual and mainly used to boost soil acidity and calcium levels. Understanding their differences can help optimize soil health and crop yields.
Burnt lime was used aggressively in the past and gained the reputation of making the father rich and the son poor. Why .
Two reasons.
(1) During the making of burnt lime the Co2 ( carbon and oxygen )is driven off and when it is spread on soils it combines, or tries to combine, back with the carbon and oxygen in the soils basically robbing the soils of any available carbon and oxygen present .
(2) Burnt lime kills not only bad bugs in the soil but also kills good bugs in your soils. When you use burnt lime you will get a green flush in the following crop from the release of nitrogen made available from decaying bugs/bacteria killed by the burnt lime. After that you will have a dead soil till the good bacteria return. The same can be said for Magnesium oxide but because it is only used at much lighter rates the effect is no where near as severe.
Farmers should be aware that when they buy aglime from an organisation that also makes burnt lime a part of their business that sometimes when they have a failure in the processing of burnt lime it is dumped in the Aglime pile. Sure it will give you a quicker reaction. If you are just leasing some acreage for this crop it does not matter to you the condition of the soil as you leave but if you own the land you will pay the price in the future.
