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

(N/A) Use of manure in maintaining soil quality:
$(i)$ Manures are a very rich source of organic matter (humus) for the soil. Humus helps to restore the water retention capacity of sandy soil and improves drainage in clayey soil.
$(ii)$ Manures are sources of beneficial soil organisms,such as soil-friendly bacteria.
Use of fertilizers on soil quality:
$(i)$ Excess use of fertilizers causes dryness of the soil,which increases the rate of soil erosion.
$(ii)$ Continuous use of fertilizers decreases the organic matter content,which reduces the porosity of the soil,preventing plant roots from getting sufficient oxygen.