CHAPTER ONE
INTRODUCTION
- Background of the study
Agriculture is a cardinal sector in the economy of any nation. Fertilizer application has over the period been essential in the effective growth of agricultural output. The importance of fertilizer in agriculture cannot be over emphasized; in other to effectively feed the nation and have enough to export, then understanding the importance of fertilizers is paramount. Fertilizers where effectively used from the 19th century in the world to grow crops amongst other things. There are basically two major types of fertilizer viz:
- Organic fertilizer
- Inorganic or synthetic fertilizers
These types of fertilizers have overtime help in boosting agricultural output in Nigeria and by extension help to boost our gross domestic product (GDP).
The nutrients required for healthy plant life are classified according to the elements, but the elements are not used as fertilizers. Instead compounds containing these elements are the basis of fertilizers. The macronutrients are consumed in larger quantities and are present in plant tissue in quantities from 0.15% to 6.0% on a dry matter (DM) (0% moisture) basis. Crops are made up of four main elements: hydrogen, oxygen, carbon, and nitrogen. Carbon, hydrogen and oxygen are widely available as water and carbon dioxide. Although nitrogen makes up most of the atmosphere, it is in a form that is unavailable to plants. Nitrogen is the most important fertilizer since nitrogen is present in proteins. To become nutritious to plants, nitrogen must be made available in a “fixed” form. Only some bacteria and their host plants (e.g. legumes) can fix atmospheric nitrogen (N2) by converting it to ammonia. Phosphate is required for the production of DNA, the main energy carrier in cells, as well as certain lipids.
Micronutrients are consumed in smaller quantities and are present in plant tissue on the order of parts per million (ppm), ranging from 0.15 to 400 ppm DM, or less than 0.04% DM. These elements are often present at the active sites of enzymes that carry out the plant’s metabolism. Because these elements enable catalysts (enzymes) their impact far exceeds their weight percentage. Nitrogen being one of the most important nutrients needed for effective crop growth has prompted the effect of the NPK fertilizer on crop growth.
