The Importance of Humus Soil for Plant Fertility

Humus soil promotes plant growth in a number of ways. First, it provides most of the nutrients plants need along with trace amounts of metals and minerals. Secondly, humus contains a range of microorganisms that break down plant waste and help roots absorb nutrients from the soil. Humus can be used as an additive to other types of soils or as the primary soil used for potted plants or rooting beds.

What is Humus Soil?

Humus is the ultimate organic soil. It is made up almost entirely of decomposed plants and other organic materials. Because of the high ratio of organic compounds, humus is also rich in microorganisms, some of which helping in the decomposition and others offering benefits such as aiding plants in absorbing nutrients or combating pathogens in the soil. Humus provides the catalyst that causes plant growth to spike.

Adding Humus to Clay Soil

Clay soil is high in minerals and metals but tends to be low in plant matter and other organic compounds. Adding humus to clay soil brings it into a more viable balance and reduces the density of the soil by separating clay particles and allowing air and water to permeate the soil. To reduce the density of clay soils even further, add sand into the mixture.

Adding Humus to Sandy Soil

Sand is the opposite extreme and has a difficult time retaining nutrients. The large-grained nature of sand allows water to wash through, taking nutrients and minerals away from plant's roots. Blending humus can replace lost nutrients, but you may also want to add a bit of clay to increase the soil's ability to retain moisture. Sandy soils are the least suitable of all soil types, often requiring conditioning before humus can be used.

Using Humus For Potting Soil

For planters and flower pots, humus makes a great potting soil. It is rich in nutrients and is generally a light, fluffy texture, ideal for use in confined spaces. Be sure to check the acidity of the soil to make sure the pH level is between 6.2 and 6.8, or adjust it as needed. Adding lime will reduce the soil acidity and watering with a mixture of 1 part ammonia to 4 parts water will increase the acidity.

Humus is Great for Rooting Beds

Organic soils are ideal for cuttings. The living things within the soil help plants absorb vital nutrients, and that means cuttings must be able to survive long enough to establish new root growth. Additionally, the loose texture of humus will enable transplanting after the roots have been established without damaging them all over again.

Creating Humus at Home

A compost heap is a very good way to generate humus material at home. Coffee grounds, tea leaves and other kitchen waste are mixed up regularly to promote decomposition. Even moldy bread and vegetable cores can be used, and pulled weeds or grass cuttings can be added. Occasionally, add 1 cubic foot of sand or clay to the mixture and the result is ready-to-use soil that is suitable for plants of all types.