Why are fertilizers used on a farm?

Fertilizers - are used on farms to increase crop yields by ensuring that soils contain the chemical elements required by growing plants. These chemical elements include oxygen, carbon, hydrogen, nitrogen, phosphorous, potassium, sulphur, calcium, magnesium, and iron. If soils are lacking in any of these, the deficiency can be made good by the right fertilizer.

   Until the 19th Century, farmers relied mainly on the application of natural fertilizers to put "goodness" back into the land. They used manure from the stock-yards and, in the case of coastal areas, sea­weed from the shore. Lime was also applied to prevent acidity. This method of soil rejuvenation went a long way to maintain the presence of chemical elements. But it often did little to improve soils already lacking in certain chemicals.

Nowadays soils are analysed to find out deficiencies which can be made up by the application of the appropriate chemical fertilizers. Of course, the chemicals alone do not guarantee a successful crop. The continued application of the natural fertilizers, such as manure and humus (decayed vegetable matter) is also essential.