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

Explanation

Effects of using manures on soil quality :
(i) The manures enrich the soil with nutrients.
(ii) They provide a lot of organic matter (humus) to the soil and thus restore water retention capacity of sandy soils and drainage in clayey soil.
(iii) The addition of manures reduces soil erosion.
(iv) They provide food or soil organisms, like soil friendly bacteria.
Effects of using fertilisers on soil quality :
(i) By the continuous use of fertilisers, the soil becomes powdery, dry and rate of soil erosion increases.
(ii) Fertilisers are nutrient specific. By the use of fertilisers, the amount of organic matter present in soil decreases which further decreases the porosity of soil and the plant roots do not get oxygen properly.
(iii) The nature of soil changes to acidic or basic.