The literature consists of two parts. The first part will provide an overview of the existing scientific knowledge about the nature and functions of organic matter in the soil. In addition, attention will also be paid to the effects of organic matter on soil quality and agricultural production. Possible measures to change the organic matter will be discussed with the advantages and disadvantages. The emphasis will be on the situation in Flanders, given both the quantity and nature of the organic matter vary greatly depending on climatic and soil conditions. This part of the literature, sufficient to support sensitizing action to farmers. In a second part of the literature is done, the scientific basis for the recommendation system, so those wherein in detail is necessary to consider the dynamics of organic matter in the soil. This will be ample attention is paid to both the inherent dynamics of the soil organic matter of the organic material when it is administered under the form of crop residues, fertilizer or soil conditioner to the soil. Again, it will be focused as much as possible on the Flemish situation.