Humus increases soil fertility; it also helps soil absorb and retain moisture and promotes the formation of good soil structure. It is an organic matter that forms in soil when plants and other organic materials decompose. The formation occurs naturally through a process known as humification.
Humus promotes plant growth by providing the necessary nutrients and minerals. It supports microbial activity in soil, through which roots are able to absorb nutrients. It acts as a storehouse for essential plant nutrients and helps determine the soil fertility level. It supplies both basic and acidic nutrients for the development and growth of higher plants.
Humus makes the soil more porous, thus improving soil aeration, infiltration and drainage. It buffers a soil’s pH and prevents losses of plant nutrients through leaching. Humus makes soils more granular, improving the aggregation of soil particles.
Humus prevents toxic substances from entering the larger ecosystem. Since it holds plenty of moisture, this increases the soil’s capability to withstand drought. It also serves as a source of food for soil organisms. Humus is described as natural compost. The difference between humus and man-made compost is that the latter is formed in controlled conditions to help speed up the decomposition of plants and other organic matter.