In ancient days when there were no tractors

1.       Science has created the revolution in the field of agriculture with different ways. Now, modern machineries has changed the agricultural activities. In ancient days when there were no tractors, people make their fields with the help of bull and this was very time consuming phenomenon. Science has created the revolution in the field of fertilizer which make the growth of crops very much. The growth of crops has very much importance for the GDP of country because mostly economy of country based on agriculture.