Derkach S. Optimization of microbiological processes during the composting of substrates based on chicken litter.

This thesis is dedicated to the investigation of the peculiarities of microorganisms’ successions while chicken litter composting and the development of the technology for production of bioorganic fertilizers with the usage of selected cellulosolytic microorganisms. The peculiarities of successions of microorganisms during composting of substrates based on chicken litter were studied. We have determined the promising stages of microorganisms’ successions during composting, from the point of view of introduction of the representatives of certain physiological trophic groups of microorganisms to the substrate. There was determined the possibility of assuring the controlled process of chicken litter composting, as a result of following the terms of the introduction of active strains of cellulosolytic microorganisms to the composted substrate. We have selected the association of micromycetes Trichoderma harzianum 128, which consists of two strains. The association is an active producer of a number of cellulosolytic enzymes, characterized by a lack of phytotoxicity and zoopathogenicity, has high antagonistic activity to phytopathogens and the ability to synthesize extracellular phytohormones. The introduction of the association T. harzianum 128 to the mixture of chicken litter with peat and straw is appropriate on the second month of composting; under these conditions, the maximum number of introduced fungi on the seventh month of composting rates to 9.7 million CFU / g of dry substrate; on the eighth month their number remains sufficiently high (8.8 million CFU / g of dry substrate), this time matches with the completion of the process of organic matter composting. The introduction of the association T. harzianum 128 to the composted substrate contribute to the intensity of straw decomposition and the accumulation of carbon and nitrogen in the compost, its enrichment with the physiologically active substances, which increases its value. It has been determined that the experimental composts obtained with the association of T. harzianum 128, contain high concentrations of substances of growth stimulating activity. It has been experimentally shown that it is meaningful to use the compost locally (for convenience, in granules). The efficiency of experimental fertilizer has been checked for three years in field experiments with potatoes. The obtained data show the highest increase of crop yield with the application of compost obtained under the influence of T. harzianum 128. Thus, the growth of the potato yield on average over three years was 31.6% in comparison with the control. The usage of compost obtained with influence or T. harzianum 128 in the potato growing technology improves the quality of product: the content of starch and ascorbic acid in the tubers increases, and the nitrate content is reduced.