Lime & Gypsum Products
Note: Your soil test results and your crop and/or animal need of calcium and/or magnesium will help you decide which lime to buy.
Our high quality liming products are:
‘PENLIME’ (Calcium Carbonate) [AgLime]. This form of material is the most commonly used liming product. It consists of limestone crushed to a fine powder and is usually the most cost-effective material for correcting soil acidity, and where high Calcium (Ca) is required. (i.e. Ca = 37%-40%)
Southern Quarries Dolomitic or Hi-Mag Lime has calcium and magnesium carbonate. Good quality dolomite has an NV of 95-98, and contains 22% calcium and 12% magnesium. It is good for acid soils where supplies of (both) calcium and magnesium are low. It should not be used constantly because it may cause a nutrient imbalance. (i.e. The material is two parts calcium to one part magnesium (2:1), whereas the soil Ca:Mg ratio should be around 5:1.
Magnesite (magnesium carbonate) is made from crushed magnesium carbonate rock. It has an NV of 95-105 and is used where there is a soil magnesium deficiency.
Gypsum (calcium sulphate) is classified by the Fertilisers Act as a liming material, but is not considered one in agriculture because it does not reduce soil acidity. Although it is used mainly to improve structure of sodic clay soils, it also reduces aluminium levels when applied to some soils.
Calcium is required in cell division, cell wall strength, hormone/enzyme synthesis and increase the plant’s ability to resist pathogen attack. Calcium in the soil prevents the dispersion of clays and as such assists its aggregation, thus allowing root and water penetration. Calcium also acts to reduce soil sodicity, where Sodium ions are replaced by Calcium ions in the soil solution.
Sulphur is a plant macronutrient and is essential in protein synthesis and flavour development of many crops. Microbes in the soil also require Sulphur for their growth and development.
Thus gypsum is most important where soils are dispersive and require aggregation, as in hard-setting heavy clays. Gypsum use will ultimately encourage better rooting of crops in dispersive soils. Gypsum is also important in the provision of adequate sulphur for plant nutrition.