Assessment of nitrogen flows at farm and regional level when developing the manure management system

The nitrogen flows on large-scale livestock enterprises in Leningrad Region were considered to determine how to take integrated manure management decisions towards reducing the nitrogen losses and, consequently, the environmental pressure. Nitrogen surplus and Nitrogen use efficiency values, calculated for large-scale mixed (crop-animal) dairy farms, demonstrated the promising ways of nutrient loss reduction through application of low-emission technologies, the efficient use of manure in the crop sector, and the improvement of environmental management. To provide scientific grounds for creating a centralized animal/poultry manure management system Nitrogen surplus and Nitrogen use efficiency were calculated for 17 administrative districts and Leningrad Region as a whole.

Priority environmental concern in livestock and poultry farming in Leningrad Region is manure utilisation on largescale agricultural enterprises. Nitrogen use efficiency (NUE) and Nsurplus values, obtained when calculating the nitrogen balances (Bittman, S. a.t al., 2014) for the whole Leningrad Region, its 17 administrative districts and individual agricultural enterprises were used as environmental assessment indicator. The calculations were based on available statistical information and farm survey data.