Biochemistry: Fertilizers

In Britain and other developed countries, farming is essentially a business. Like all business, the farmer's aim is to make as large profit as possible. To achieve this, the farmer needs to achieve high yields of the crop(s) which provide the best economic return as efficiently and as cheaply as possible. To obtain high yields, farmers need to manipulate the environment of their crops. This is were the fertilizers take their role to help in the farms.

Fertilizer is generally defined as "any material, organic or inorganic, natural or synthetic, which supplies one or more of the chemical elements required for the plant growth". The cheapest and most common fertilizer would be manure. Manure, or faces, is a natural fertilizer. It is a mixture of complex chemicals. Many of these contain the element nitrogen. The complex chemicals act as food for decomposers. Decomposers break down these chemicals into simpler ones such as nitrates. Plants can then absorb these. Decomposers need a good supply of oxygen for this job. The amount of oxygen needed for the complete breakdown of any material is called a biologically oxygen demand, or BOD. Substances which encourage the growth of organisms will have a high BOD.

Primary nutrients are normally supplied through chemical fertilizers. They are chemical compounds containing one or more of the primary nutrients and are generally produced by chemical reactions. Whatever may be the chemical compounds, its most important ingredient for plant growth is the nutrient content.

Artificial fertilizers are much simpler than manure. They are usually a mixture of three or four salts. A salt is made when an acid reacts with an alkali, by neutralization. These salts dissolve quickly in the water in the soil and get into the plant.

Plants need some 14 essential mineral nutrients to grow. Of the,