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ORGANIC MATTER/ HUMUS CONTENT

Importance of humus content:

Organic matter/ humus is one of the most important substances in the soil. A soil with a high content of humus has less problems with dryness; the adhesion of water and nutritious elements is much better and there is less chance of their being washed out. Especially in the case of clay soils, organic matter/ humus provides for a better structure and makes the soil easier to cultivate. For the rest it gives room to the soil biota and other life in the soil. For some sorts of cultivation (usually for crops which grow with the use of little nitrogen) a low content of organic matter is desired. The decomposition of organic matter releases an amount of nitrogen on an annual basis. The lower the value number is for organic nitrogen within the organic matter, the lower the amount of nitrogen is which is being released annually. For a number of bulbs (for breeding), a lower content of organic matter is desired in order to obtain a lovely bulb.

Walk ability of sports fields.

Lawns and sports fields should have a value number around 4% for organic matter. In the case of a higher content, the lawn or field can be covered with medium coarse yellow sand in order to improve the walk ability. Two hundred litres of moderately coarse sand is given per 100m2, eventually once every two or three years.

Improvement of the humus content

The content of organic matter/humus can be increased by applying high doses of peat compost, garden peat or very ripened compost. On heavy clay soils, application of peat compost (compost into which garden peat has been incorporated) is preferable. On sand soils, it is also possible to use garden peat (but not peat dust or something similar). Some effect can be expected after the use of minimally 3-5 m3 of garden peat per 100m2. Farmyard manure maintains and, to some extent, increases the humus content only a little. To compensate for the annual loss of humus through digestion, normal use of concentrated organic fertilizers will not be sufficient. To improve the soil fertility and the moist content of the soil, a layer of 3-6 cm of coarse organic material can be put as a mulch on the soil. The life in the soil will be stimulated, and the amount of unwanted weeds is lowered.

In short the importance of organic matter in the soil:

- accommodation of soil life.

- storage of nutritious elements.

- structural support.

- stimulation of root growth

Possibilities for improvement of the content of organic matter:

- nutritiously-poor organic material.

- relatively much material is needed for a small improvement.

The content is expressed in the weight percentage of dry soil.