(i) They improve the soil condition to support plant growth.
(ii) They improve the porosity of the soil to make it capable of absorbing water. Thus improves crops production. (iii) They improve the structure of soil which in turn allows more air to get to plant roots.
(iv) The chance of water storage because of the moisture holding capacity of soil increase.
(v) Natural fertilizer practically do not contain toxic chemicals. Thus, they do not damage the soil and crop yield increase.