The effect of nitrapyrin on microbiota and emissions of greenhouse gas from livestock by-products

The livestock by-products (LBP) using as fertilizers are characterized by such unfavorable environmental characteristics as emissions of greenhouse gases (N2O, CO2, CH4) and the presence of a specific microbiota leading to soil and water biological contamination. The waste processing by nitrapyrin reduces the negative environmental impact of LBP. Currently, nitrapyrin is used as a nitrogen fertilizer stabilizer that reduces nitrogen losses by direct inhibition of soil microorganisms (MO) oxidizing ammonium nitrogen to nitrate. It was found that 0.05 g/L nitrapyrin application to the liquid pig manure effluents decreases the CH4 and CO2 emissions, as well as the species diversity and the number of opportunistic pathogens that promote the transfer of antibiotic resistance genes into natural environments. The number of such MO as Klebsiella sp., Proteus spp., Bacteroides sp., Pseudomonas spp., Candida sp. decreased by 2-4 orders of magnitude due to nitrapyrin. Only anaerobic bacteria of the genus Clostridium and aerobic mold fungi of the genus Aspergillus showed the resistance to the appropriate reagent, the number of the above MO remained almost unchanged in the nitrapyrin variants. The most significant decrease in CO2 emission (2-5 times compared to control) was observed in the first 3-4 days after the nitrapyrin application. The CH(4 )emission in nitrapyrin variants was lower than in the control during the whole observation period (13 days). The obtained experimental data can be used in the development of reagent formulations to improve microbiological characteristics and to reduce greenhouse gases emission from manure collection systems of livestock enterprises.