The impact of concentrated pig production in Flanders: a spatial analysis

Historically concentrated livestock production and, consequently, manure production and management in Belgium have resulted in severe environmental impacts. One major impact, nitrate leaching from soil to surface water, is being tackled through the European Nitrates Directive by imposing strict fertilization standards. However, another significant impact of manure management is the emission of greenhouse gasses (GHG - CO2, CH4, NH3 and N2O) into the air, thereby contributing to global warming. Calls have been made to reduce the high manure pressure and related environmental effects in Belgium by relocating and more evenly spreading livestock production. This paper explores the spatial spreading of CO2-equivalent emissions from livestock production in Belgium and attempt to answer the following question: ‘Can spatial reallocation of livestock production in Belgium reduce the impact of GHG emissions?’. This question is translated into several research objectives: 1) conduct an economic (cost minimization) and environmental (GHG minimization) optimization for 3 manure management scenarios, 2) determine the main differences between both approaches, and 3) determine the marginal spatial impact on CO2 emissions of a decrease in manure pressure (i.e., increased spreading of pig production). To conduct the analysis, a model was developed that builds on the spatial mathematical programming multi-agent manure allocation model developed by Van der Straeten et al. (2010). Three options for manure management are inserted: transport of raw manure from nutrient excess to nutrient deficit areas, biological treatment of manure (manure processing) and manure separation. The model optimizes, at municipal level, either the cost-efficiency, either the environmental effect of the manure market in Belgium based on Belgian fertilization standards. While cost-efficiency is calculated based on transport distances and cost of manure separation and processing, GHG emissions, and hence, carbon footprint, are determined based on a life cycle analysis type calculation. The results of the model simulations show that, while the economic optimum is reached by maximizing the transport of raw manure until fertilization standards are fulfilled and subsequently separating and processing the excess manure, the environmental optimum, from a carbon footprint point of view, is reached by separating all manure as this option has the lowest CO2 emissions, mainly due to the limited manure storage time. Moreover, the analyses indicate that rearrangement of the spatial spreading of livestock production in Belgium will not substantially decrease CO2 emissions. As manure storage is the main contributor to the carbon footprint, solutions should rather lie in changing these storage systems.