Fertilization as an ameliorative measure - examples of the research at the Faculty of Forestry and Environment CUA in Prague

Fertilization represents a measure, used as exceptional treatment managing forest stands and ecosystems as a whole. It is used since the beginning of the 20th century worldwide, starting in the Central Europe. The beginnings were on empirical basis, later on, the scientific background was developed profoundly. Several forms and methods, as well as aims are topical at present: - Since the beginning, restoration of degraded sites and amelioration of primarily extreme soils was the aim. In the poorest regions, e.g. in the NE Germany, different means were used to increase site productivity and stability. Also in the Czech countries, amelioration played important role restoring degraded and devastated localities. - To increase site productivity, commercial fertilization was used worldwide, as well as it was applied in all continents with intense forestry practices. It became a part of the "silviculture" sensu stricto in the commercial, industrial forestry. - Supporting the growth and prosperity of forest plantations, on sites of different characters, was a broadly intended target of fertilizers application. - Since the air pollution calamity, fertilization is one of the main counter-treatments for improvement of the situation, lowering and preventing the soil acidification and nutritional degradation. Both direct as well as indirect methods are used. At the direct fertilization, nutrients in the fertilizers increase and improve the nutrient cycles over the degraded or natural level. This causes an increase in the forest ecosystem production as the main aim of such a treatment. In the indirect way, the amelioration material accelerates the bio-cycles by improving biological activities of the soil - liming is the best example of these activities. Nutrients are mobilized by enhanced activity of the soil biota, increasing organic matter mineralization and decay. This also represents the main ecological risk of these activities: the enormous and non-natural organic matter decay. Different types of fertilizer can be used: liquid, firm, powdered, pelletized, based on natural substances such as carbonates or silicate nutrient-rich (basic) rocks. In all cases, the uses of all these treatments have to be based on the detailed ecological analysis of the locality, of the site and of the forest stand. Only in this case, fertilizer effects can be optimized and the risks minimized.