Modelling representative and coherent Danish farm types based on farm accountancy data for use in environmental assessments

There is a need for valid and representative data on the production, resource use and emissions from different farm types in Denmark for public regulation and assessment. The data should be usable for both area-based environmental assessment (e.g. nitrate leaching per ha) and product-oriented environmental assessment (e.g. greenhouse gas emissions per kg pork). The objective of this study was to establish a national agricultural model for estimating data on resource use, production and environmentally important emissions for a set of representative farm types.Every year a sample of farm accounts is established in order to report Danish agro-economical data to the ‘Farm Accountancy Data Network’ (FADN), and to produce ‘The annual Danish account statistics for agriculture’. The farm accounts are selected and weighted to be representative for the Danish agricultural sector, and similar samples of farm accounts are collected in most of the European countries. Based on a sample of 2138 farm accounts from year 1999 a national agricultural model, consisting of 31 farm types, was constructed. The farm accounts were grouped according to the major soil types, the number of working hours, the most important enterprise (dairy, pig, different cash crops), livestock density, etc. For each group the farm account data on the average resource use, products sold, land use and herd structure were used to establish a farm type with coherency between livestock production, feed use, land use, yields, imported feed, homegrown feed, manure production, fertilizer use and crop production. The set of farm types was scaled up to national level thus representing the whole Danish agricultural sector and the resulting production, resource use and land use was checked against the national statistics. Nutrient balance methodology and state-of-the-art emission models and factors were used to establish the emissions of nitrate, phosphate, ammonia, nitrous oxide, methane and fossil carbon dioxide from each farm type. In this paper data on resource uses and emissions from selected farm types are presented and it is demonstrated that this approach can lead to an agro-environmental inventory, which is consistent with national level estimates and still has the advantage of being disaggregated to specific farm types. Conventional dairy farm types in general emitted more nitrate but less phosphate compared with pig farm types. The methane emission was higher from dairy farm types compared with all other farm types. In general the conventional dairy farms emitted more nitrate, ammonia, and nitrous oxide, compared with organic dairy farms.