Farm-level assessment of CO₂ and N ₂O emissions in Lower Saxony and comparison of implementation potentials for mitigation measures in Germany and England

Greenhouse gases (GHG) emissions from agricultural farming practice contribute significantly to European GHG inventories. For example, CO2 is emitted when grassland is converted to cropland or when peatlands are drained and cultivated. N2O emissions result from fertilization. Enabling farmers to reduce their GHG emissions requires sufficient information about its pressure-impact relations as well as incentives, such as regulations and funding, that support climate-friendly agricultural management. This paper discusses potentials to improve the supply of information on: farm-specific climate services or impacts, present policy incentives in Germany and England that support climate-friendly farm management and related adaptation requirements. Tools which have been developed for a farm environmental management software (to be added after review because of potential identification) are presented. These tools assess CO2 emissions from grassland conversion to cropland and peatland cultivation, as well as N2O emissions from nitrogen fertilization. As input data, the CO2 tool requires a classification of soil types according to soil organic carbon storage. The input data based on soil profile samples was compared with reference data from the literature. The N2O tool relies on farm data concerning fertilization. These tools were tested on three farms in order to determine their viability with respect to the availability of required data and the differentiation of results, which determines how well site-specific conservation measures can be identified. Assessing CO2 retention function of grassland conservation to cropland on the test farms leads to spatially differentiated results (~100 to ~900 potentially mitigated t CO2 ha-1). Assessed N2O emissions varied from 0.41 to 1.1 t CO2eq.ha-1 a-1. The proposed methods support policies that promote a more differentiated funding of climate conservation measures. Conservation measures and areas can be selected so that they will have the greatest mitigation effects. However, even though present policy instruments in Germany and England, such as Cross Compliance and agri-environmental measures, have the potential to reduce agricultural GHG, they do not appear to guide measures effectively or site-specifically. In order to close this gap, agri-environmental measures with the potential to support climate protection should be spatially optimized. Additionally, the wetland restoration measures which are most effective in reducing GHG emissions should be included in funding schemes.