In the early days of farming, people did not understand how plants obtained essential
nutrients. It so happened that wood ash, fish remains and slaughterhouse waste were thrown
on vacant land just to get rid of them. Then, people started to notice that the grass, bushes
and shrubs on this vacant land began to grow very well. They reasoned that if their farmland
were similarly treated, the growth of their crops would also improve. People gradually began
to realize that the nutrients required by plants came from the soil and that the amount of nutrients
could be increased by the application of such organic remains to the soil. Thus started the
manuring process in farming.
The practice of manuring has been practized as early since the seventeenth century. However,
the importance of manuring was not properly understood until scientists began to study the
nutritional needs of plants and gave birth to fertilizers. Thus, gradually, the use of fertilizers
became accepted by farmers.
There are many types of manure and fertilizer currently being used. Manure is a substance
derived from animals and plants. The most important advantage of using manure is the fact
that they not only supply a wide range of plant nutrients, but also improve the structure of
the soil. It cements together the soil particles to form soil crumbs. The crumb structure is a
desirable condition of cultivated soil. The addition of manure to soil will increase the inorganic
and humus content which helps to prevent soil erosion and loss of plant nutrients when it
rains. The common manure used in farming consists of farmyard manure,
compost, blood meal,
bone meal and fish meal.
Unlike manure, fertilizers are inorganic substances which do not improve the structure of
the soil. They only supply extra amounts of nutrients to the growing plants when applied to
the soil. The commercial fertilizers commonly used today can be classified into three major
categories; namely, nitrogen (N), phosphate and potash fertilizers.
Besides knowing the type of fertilizer to use, a farmer also needs to know when to apply
the fertilizer and how to apply it. The fertilizer should be applied at the time when the plants
need a particular nutrient most. The time and method of application will determine how
profitably the fertilizers have been used in farming. Fertilizers which have not been properly
applied cannot be absorbed in large quantities by plant roots. These fertilizers may be washed
away by rain or they may kill the plants. This would mean a definite financial loss for the