Agriculture is a human activity in which people use areas of land to produce food, clothing and other necessary materials.
The word "agre" is a Latin word. It means a field. The word "agriculture" means the cultivation of fields and growing crops. But this is the old meaning of this word. Now it also means the use of land to breed animals. At present there are two main branches of agriculture. They are crop growing and animal breeding.
We do not know when people began to grow crops; it was many thousand years ago. Now crop growing is a highly developed branch of agriculture.
The soil is the basis of agriculture. Enough food for all the people can be grown if there is sufficient good soil for crops to produce high yields.
There are two ways to grow enough food. They are the increase in area of arable land and the intensification of agricultural-production in the areas already used for cropping. At present the second way is more important because there is not enough experience to reclaim tropical and subtropical lands.
The intensification of production in the traditional agricultural areas is based on the knowledge of climate, soils and their use, and on a large соllection of high-yielding varieties and hybrids of agricultural crops.
All intensification factors, such as full mechanization, high application of fertilizers and extensive use of herbicides must be used in such a way as not to disturbhe biological equilibrium of the soil.