Studium a výzkum možností využití digestátu k přípravě hnojivých substrátů

Abstract

Dissertation deals with the digestate as a waste sludge from the biogas station, and the possibilities of adjustment of its properties in order to increase its fertilising function. The theoretical part describes the operation of biogas plants and the chemical reactions taking place in them. Thus, the method of anaerobic digestion and the formation of digestate itself are introduced. Then, the work describes the digestate, digestate production, and its use due to the legislation possibilities. Following the possibilities of using digestate for fertilization, the basic principles of plant nutrition are discussed. The theoretical part further describes various alternative options for digestate management, which are currently being tested in research. Subsequently, it focuses in more detail on the main topic of the work, i.e. the use of digestate for the preparation of fertilizing substrate. The practical part is directly focused on the creation of the mixture, which could serve as a digestate based fertilizing substrate. About 50 mixtures of digestate with other waste materials are formed and their fertilizing ability is tested. In the first phase, tests are performed on a laboratory scale. Samples that show positive effects of growth stimulation, are compared with vermicompost based digestate and finally tested on a pilot scale. During pilot testing, we have been neglected ideal conditions of the experiment, which were used in laboratory conditions, but the experiment is governed by the principles of common farming practice. Based on the obtained results, a substrate formed under the name DIGESTFERT 1 was proved to be suitable for practical use. This substrate showed similar or higher effects of stimulating plant growth than a commercially available substrate for sowing. The differences were reflected in the ability of the plants to germinate, but also in the size of the plants or the total dry matter content of the biomass.