Graslander Uitgawe 1: Nampo - Page 11

LIME 1 HOW LONG DOES IT TAKE FOR LIME TO WORK? Since water is required for lime to react with the soil, the effects of a lime application will be slower in dry soil. It often takes a year or more before a response can be measured, even under perfect conditions. However, a response may be observed within weeks of the application when soil-pH is extremely low. The fraction of the lime application finer than 250 micron reacts the fastest with the soil where the larger fraction from 250 micron to 1.7mm takes a bit longer. It is important to apply lime immediately after the growing season or crop removal to allow lime to react, ensuring correct soil-pH before the next growing season. 2 HOW LITTLE OR HOW MUCH LIME CAN BE APPLIED AT ONE TIME? The amount of lime needed depends on the type of crop being grown. In situations where soil-pH is extremely low and a large amount of lime is recommended, it may be a good idea to spread the cost over two to three years by annually applying one-third or half of the lime needed. Lime additions vary from 0.5 to 5 tons per hectare depending on the pH rectification requirement and the Calcium Carbonate Equivalent (CCE) of the lime to be used. Quick changes in the soil-pH disturb the soil microbe functions, which in turn disrupt the provision of soil nutrients to the plant roots. 3 FAQ SHOULD LIME BE WORKED INTO THE SOIL OR PLACED ON THE SURFACE? Whenever possible, tillage should be used as a tool to incorporate lime into the soil. When lime is worked into the soil, a larger portion of its surface area is exposed to the soil, allowing for faster reactivity. In instances where the subsoil has a low pH, the lime application should be incorporated deeper into the soil profile. It is not always practically possible to incorporate the lime application to the desired depth and therefore Gra