Getmanenko V. Transformation of soil organic matter under the effect of municipal sewage sludge and composts application

Object - processes that characterize changes of organic matter, agrochemical parameters of a soil and accumulation of heavy metals in a soil and plants under the effect of application of sewage sludge (SS) and composts based on it. Purpose - to establish the patterns of soil organic matter transformation under the effect of application of sewage sludge and composts based on it and substantiate an advisability of their use to improve soil humus. Methods - modelling, modelling and vegetative, laboratory and modelling, analytical, mathematical statistics. Theoretical results - appropriateness of the use of SS and composts based on it for optimizing soil humus is theoretically substantiated. The parameters of organic matter transformation of chernozem podzolic under the effect and aftereffect of SS application were found. A significant increasing compared to the control of humus content (17 %), labile and water-soluble forms of organic matter in the soil (26 % and 33 % respectively) and raising of its humification (up to very high) was established. Accumulation of agronomically valuable humic acids of first and second fractions (up to 50 % compared to the control) confirmed the activation of humus regradation in chernozem podzolic influenced by SS. It is established that for carrying out soil humus control characteristics of organic components of fertilizer, especially, content of total carbon, humic acid and humification index should be consider. Practical results - the effectiveness of the use of sewage sludge and composts based on it in agriculture was proved. It was revealed that the rational use of SS in fertilization system provides crop productivity increasing, the soil fertility parameters improving, preventing heavy metals pollution. Technologies of improving meliorative properties of SS by bioconversion together with wastes containing carbon was developed, implementing of this technology ensures production of fertilizer with balanced chemical composition, advanced characteristic of organic matter, which does not contain high concentrations of heavy metals and phytotoxical compounds. Two utility model patents were obtained on research materials: No 102255 "Method of production of compost based on urban sewage sludge", No 103225 "Method of processing of long-term storage sewage sludge into fertilizer". Novelty - composition of sewage sludge according to criteria to potential of humus formation is analyzed in detail; level of soil suitability for sewage sludge application in case the use to improve soil humus is established; technology of sewage sludge processing into fertilizer with improved meliorative properties by optimizing parameters of an initial mixture and bioconversion conditions is advanced; patterns of soil organic matter transformation under the effect of application of sewage sludge and composts based on it are established. Degree of application - the main results of research were used during conducting of design and exploration works by Kharkiv branch of the State Institution "Soils Protection Institute of Ukraine". The proposed system of spring barley fertilization with the use of SS was implemented in the LLC "Agrodar" Zmiev district, Kharkiv region on the area of 7.0 hectares. Materials of the thesis were used in the educational processes of bachelor's and master's preparation of Lviv National Agrarian University and Kharkiv National Agrarian University named after Dokuchaev. The field is agriculture.