What are the properties of fertile soil?

The fertility of soil depends on the number of nutrients present in it, to support the growth of plants. Fertility of soil is determined by the presence of ‘micro nutrients’ like sulphur, chlorine, copper, boron, Iron, zinc, cobalt and ‘macro nutrients’ like potassium, nitrogen, and phosphorus in it. Soil fertility increases with the increase of humus content, which is the organic material present in soils produced by the decomposition of plants and animal matter.