At the core of the growth and germination of plants lie the nutrients they receive from the soil. The nutrients required for growth are classified into two groupings, macronutirents and micronutrients. Macronutrients are those that are needed in very large amounts, and whose absence can do a great harm to the development of the plant life. These nutrients include calcium, nitrogen, phosphorus, and potassium, and are very sparse in most soils, making them the primary ingredients in most fertilizers. The other, more common macronutrients are called secondary nutrients, as they are not of as much importance. Micronutrients, the other classification, consist of all the other elements and compounds required for sufficient growth, such as iron, boron, manganese, copper, zinc, molybdenum and chlorine. In some cases, these nutrients are found to be missing in soils, but it is extremely uncommon.
As plants need to retrieve all of their nutrients from the soil, many methods have been developed in order to find ways to improve or change the soil to suit the plant's needs.
Soil, in science as well as in common gardening, must undergo detailed inspection, to detect such things as the pH of the soil. A soil with a pH above 7.0 is called an alkaline soil, and will commonly kill plants. Mineral content, as mentioned above, is also a concern, and must be clearly monitored. After inspection, it is common for minor organic materials outside fertilizers to be applied, such as peat moss, ground bark, or leaf mold. It is after these steps that fertilization must occur, leading to a debate which has plagued gardeners and scientists alike: organic or chemical?
Fertilizers, in both natural and synthetic breeds, are carriers of the primary and secondary nutrients that are found less often in even the most fertile soils. Fertilizers are...