Final answer:
Lime and other soil amendments are added to soil when it is too acidic and needs pH adjustment. Organic amendments improve soil texture and nutrient availability, while fertilizers supply plants with essential nutrients. The timing depends on soil and plant needs.
Step-by-step explanation:
Lime or other soil amendments are typically added to the soil when the soil pH is not optimal for plant growth. For instance, slaked lime (calcium hydroxide) or limestone (calcium carbonate) are used to correct acidic soils to a pH level that is more suitable for plants. This amendment process is a crucial aspect of soil fertility management, intended to enhance plant growth by improving nutrient availability and the physical properties of the soil.
Organic amendments like coir, bark, and sawdust can also be added to improve soil texture and nutrient availability through increased cation exchange capacity and the growth of beneficial microorganisms. Fertilizers, on the other hand, are primarily used to provide essential nutrients to the plants. The timing of the application depends on the specific needs of the soil and the plants being cultivated.
It is also important to consider the type of crops being grown since nitrogen-rich fertilizers might be necessary to support certain plants. Crop rotation and the use of organic matter such as manure can also contribute to maintaining and improving soil health. Overall, understanding soil chemistry and biology is essential for determining when to add amendments or fertilizers.