Effects of distinct manure amendments on microbial diversity and activity in Chernozem and Retisol

Abstract

The application of manure has the potential to enhance soil health by increasing organic matter content and stimulating dormant soil-borne microorganisms. However, this treatment also carries the risk of side effects, including the invasion and spread of manure-borne pathogens. To assess the survival of manure-borne microbes in soil and their introduction into the soil microbiome, a laboratory experiment was conducted. Fresh cattle, swine, and poultry manures were applied at a rate of 50 t/ha to two different soil types: Chernozem and Retisol. The soil samples, including both control and manure-amended soils, were incubated in microcosms for a period of 6 months. Analysis of the samples was performed prior to fertilization, as well as at 1- and 6-months intervals following manure application. The analysis involved determining the gene numbers of archaea, bacteria, and fungi, as well as examining the taxonomic and physiological profiles of the microbial communities. The response of the microbial communities in the two soils to the manure application varied. In Chernozem, there was an increase in microbial abundance, activation of archaea and bacteria, and a moderate shift in the structure of prokaryotic community. On the other hand, the microbial community in Retisol did not show significant activation due to the manure amendments, but notable changes in both community structure and functioning were observed during the experiment. It was found that more manure-borne genera survived after 6 months in Retisol compared to Chernozem. Consequently, manure amendments could pose a greater risk of microbial contamination in soils characterized by low microbial activity and abundance.