Abstract
By-products of animal husbandry (BPAH) such as manure, manure effluents (ME) are widely used as organic fertilizers. The main disadvantage of the appropriate fertilizers is the high content of microorganisms (MO) untypical to uncontaminated natural environments, including pathogenic ones. Currently used natural methods of BPAH neutralization can significantly reduce the risks of transferring pathogenic and opportunistic MO into fertilized soil, but do not completely exclude them. The study examined the effects of long-term (more than 7 years) introduction of a neutralized liquid fraction (LF) of pork ME and cattle ME on the chemical composition and sanitary and hygienic condition of the soil of arable fields and wooded areas located at 500 m from the boundaries of the fields. Prolonged application of LF led to an increase in the content of organic matter, mobile phosphorus, potassium and sulfur, an increase in the amount of absorbed bases, a decrease in metabolic acidity in arable land compared with adjacent forest areas. However the sanitary condition of both arable land and adjacent territories deteriorated significantly. A significant increase in the total microbial number (TMN) was revealed in all soil samples in comparison to the normative indicators. Particularly high values of TMN were found in soil fertilized with cattle manure. The corresponding soil was characterized by the highest content of organic matter and neutral reactions of the environment, which provided favorable conditions for the active development of saprophytic microbiota. Fresh faecal contamination was detected in all selected soil samples. Soils are characterized as highly polluted. According to the indicators of the index Escherichia coli, Enterococcus and Clostridium perfringens, the soils of all studied sites are moderately dangerous. Higher values of the corresponding indices were found in arable land fertilized by the LF of pork farms and in the territories adjacent to arable land. In the course of sanitary and bacteriological studies, eggs of helminthes were not found in the soil.