Types of Chemical Fertilizers
There are two types of fertilizers:
Organic Fertilizers:
The decaying animals refuse and excreta along with rotten leaves and fruits form useful humus. This humus when mixed with soil, it increases the fertility of soil. This type of fertilizer is called organic fertilizers.
Inorganic Fertilizers:
These fertilizers are used to replace mineral ions for better production of crops. Usually three chemicals are added for the purpose. These are nitrogen, phosphorus and potassium. These artificially fertilizers are called inorganic fertilizers.
Hazards of Using Chemical Fertilizers:
- i) Continuous usage of chemical fertilizers causes loss of organic fertilizers in soil.
- ii) Unabsorbed nitrates are carried by rainwater into the rivers and sea, which harm the aquatic life.
iii) The top layer of soil damaged due to continuous usage of these fertilizers.
Solution:
- i) These problems can be reduced by using that chemical which are less soluble and slowly release nitrogen into soil.
- ii) Use of organic fertilizers should be increased to avoid these problems.
The first stage of the formation of the classical school (late 17th – early 18th centuries) includes the development of W. Petty, P. Bouagillebert, the school of physiocrats, who came out with well-reasoned criticism of mercantilism, began to search for wealth in the sphere of production, study the functioning of a simple commodity economy and put forward a labor theory cost. The second stage in the development of the classical school (the last third of the 18th century) is associated with the works of A. Smith, who was engaged in the development of problems of reproduction