Open access publications in the SLU publication database

In Sweden, there are large areas of agricultural land that are not used for the production of food and feed. A large part of this area constitutes of so-called marginal agricultural land, i.e. small and irregular-shaped fields and fields with less fertile soils. Headlands and border strips can also be regarded as marginal land, as the crop yield normally is lower on these areas in comparison to other parts of the field.
The demand for renewable and carbon dioxide neutral fuels is expected to increase in the future. Energy grasses, for example reed canary grass (Phalaris arundinacea L.) (RCG), can be used to produce solid fuels in the form of bales or pellets. Other energy grasses such as ley can be used to produce biogas.
The purpose of this study was to analyse the costs and economic profitability of producing energy-grass fuels on marginal agricultural land in Sweden. One objective was to assess which types of marginal fields, harvest systems and regions that have the best possibility for competitive production of energy grass. The economic value of reduced nutrient leakage, and the energy demand in the form of diesel fuel, was also evaluated.
Small and irregular-shaped fields, fields with less fertile soils, headlands and border strips were included, all located in four different regions (the municipalities of Svalöv, Ronneby, Vingåker, Skellefteå), representing different cultivation conditions. These fields were compared to ‘normal' fields, i.e. fields with an average yield and an acreage of 5,0 ha, and ‘large' fields, i.e. fields with an acreage of 15,0 ha. The economic profitability of RCG and ley was compared with the profitability of fallow land and the cultivation of winter wheat and spring barley. Sensitivity analyses were performed regarding varying product prices, halved machinery and labour costs, different machinery sizes (‘small' or ‘large' machines), taking the economic value of reduced nutrient leakage into account, harvesting of the biogas crop as bales or with a direct chopping waggon, use of fresh or stored grass for biogas production, etc.
The most important conclusions were:
* The cultivation of RCG and ley had a negative net economic gain for all marginal field categories and locations. Fallow had a higher economic competitiveness than both RCG and ley for all marginal field categories and locations, also compared with spring barley.
* RCG used as a solid fuel in boilers generally had a higher competitiveness than ley for biogas. However, when the ley was used fresh without storage, its competitiveness improved considerably.
* Taking the economic value of reduced nitrogen leakage into account, the economic profitability was positive for all RCG alternatives. Also for ley to biogas, the profitability was improved considerably.
* 'Large' machines resulted in lower costs than 'small' machines for all studied crops, regions and field types, including small and irregular-shaped fields. However, a prerequisite was that the annual machinery usage was at a high level.
* Generally, the costs in SEK/MWh were highest for headlands, while the economic profitability in SEK/ha were lowest for small and irregular-shaped fields.
* The economic profitability differed considerably between the locations, mainly as a result of the differences in yields and geographical conditions (field area, etc.).
* The use of diesel fuel, in relation to the energy harvest per hectare, was 1-4% for RCG and 4-10% for ley (Svalöv).