Pig Manure Management: A Methodology for Environmentally Friendly Decision-Making.

The current trend towards larger pig farms increases their profitability but might harm animal welfare and the environment. More efficient pig manure management is a way to address this challenge. Available manure handling and utilisation systems may feature from 8 to 50% nutrient loss to the environment. Therefore, the proper choice of technological solutions is of high priority. In regard, the study developed a methodology including calculation, analysis and modelling techniques for the accurate accounting of manure amount, its fractions and their nitrogen and phosphorus content for different processing technologies with due regard to the limiting factors of the farm and the end-product consumer requirements. The methodology was applied to justify the best suitable processing technology for a large-scale pig farm in the Leningrad Region with 17,800 heads of pigs and 54,750 t of pig manure per year. The selected technology included manure separation into fractions, aeration and secondary sedimentation of the liquid fraction and passive composting of the solid fraction. It demonstrated the total amount of nitrogen (N) and phosphorus (P) in the end-products of 278.94 t per year, with the 26% total nutrients loss on all technological stages, and specific capital and operating costs of USD 55.5 per ton of manure produced. The methodology was tested by comparing the calculated data and the data from previous surveys of 15 pig farms in Russia. The differences between the values were found from 0.9 to 12.5% in mass; 2.8 to 13.9% in N content and 1.7 to 9.9% in P content. The developed methodology supports planning the production of the manure-based end-products in a given amount and with target nutrient content, depending on different processing technological solutions, achieving both economic and environmental goals.

Environmental assessment of livestock farms in the context of BAT system introduction in Russia.

The article focuses on the environmental and economic assessment of animal/poultry manure utilisation technologies as the sources of the greatest negative impact on environment from agriculture. This procedure is especially topical in the context of current transition to BAT system in Russia. Russian BAT reference books on intensive rearing of pigs and intensive rearing of poultry came into force on June 1, 2018. At present, the large-scale livestock farms face the difficult task of selecting efficient technologies for manure utilisation with due account for their performance potential and the opportunities for end products use. To address the relevant practical issues, the criteria for the environmental and economic assessment of technologies were developed for selecting the rational technological solutions adjusted to the conditions of particular agricultural enterprises. Environmental assessment was based on the nitrogen saving coefficient. The developed approaches were applied to a dairy farm for 2600 head, a poultry factory for 1 million head and a full-cycle pig rearing complex for 16,500 head. The best suited technologies of animal/poultry manure utilisation were substantiated for these enterprises, which would allow achieving the reduction in environmental pollution by nutrients at the economically justified costs.