Compare the use of manures and fertilizers in maintaining soil fertility.

Manure contains many organic substances of biological origin which can be easily degraded and absorbed by plants. It helps in recycling of biological waste. Manures increase the fertility of soil for long duration without causing any harm. However, the chemical fertilizers (e.g. urea) improve soil fertility for short duration but cause environmental hazard and pollution. Continuous use of fertilizers in a particular area / crop field causes destruction of soil fertility and makes it arid.