Scarce under-utilised arable land biomass could be used in circular economy by maximising transport efficiency

A significant amount of land is used in agricultural production in Finland, and emissions from land use, for example, are generated by agriculture. On the other hand, the role of agriculture is expected to become more prominent in society's sustainability solutions, as agricultural systems and the land they use not only produce food, but can also be linked to the production of other materials and energy.

One way to address the sustainability challenges in agriculture is to strengthen activities based on circular economy. In circular economy, all raw resources and materials are used as efficiently as possible. In agriculture, it aims to create opportunities to reduce carbon emissions, recycle nutrients and support renewable energies, among other things.

Unutilised biomass is growing on fields under agri-environmental management

So-called agri-environmental fields include, for example, natural fields with grass and buffer zones. They are maintained to promote carbon sequestration, to improve the condition of arable land and to prevent nutrient leaching, among other things. Some of these areas are covered by the agricultural funding system, i.e. they are maintained with agri-environmental payments.

Green biomass grown in these marginal areas may not be used at all if farms have no use for, e.g., grazing animals or harvesting dried hay. However, biomass could be used for processing bio-based products or for energy production, such as biogas production integrated in agriculture.

Due to the limited area available on a farm, voluntary mowing and biomass collection is often not profitable. Regional availability and transport costs are key constraints to the profitability of biomass utilisation.

Does the potential for efficient utilisation differ between areas with scarce and abundant biomasses?

The University of Oulu Kerttu Saalasti Institute explored the potential for a more intensive use of biomass from agri-environmental fields as part of the project "Growth from cycles with new generation green technologies" (KASKI). According to the study, the amount of agri-environmental field areas varies both between farms and regions. Therefore, the study wanted to look at two regions in Northern Ostrobothnia: the municipality of Ii was described as an area of scarce biomass and the Nivala region as an area of abundant biomass.

The aim of the study was to find out whether spatially based analyses and Geographic information systems (GIS) could be used to find effective ways of exploiting even scarcer biomasses.

In practice, the GIS was used to measure the spatial accessibility of biomass and to examine the logistical optimisation of collection options. A spatial data-based modelling method for transport routing can be used to combine road network data and field parcel data.

Open access field parcel spatial data was used to obtain location information and attribute data on the area and the agricultural land use class. The amount of biomass was estimated to be a good 12 fresh tonnes per hectare. By linking the spatial data of the biomass to a spatial data model of the transport network, it was possible to analyse the accessibility of the biomass on a road network basis at a precise scale.

Accessibility was considered according to the amount of biomass available, at different transport distances. In addition, transport efficiency was considered in terms of kilometres travelled per tonne of biomass collected.
The study compared the regional accessibility and transport efficiency of scarce and abundant biomass by creating two imaginary scenarios for biomass collection. The transport options modelled were a smaller capacity tractor transport and a larger capacity combined transport vehicle.

A map of the Ii region showing the locations and area relations of agricultural parcels under environmental management and logistical alternatives from the parcels to the collection point along tractor and combined transport routes.
Figure 1. Modelling scenarios for tractor transport (a) and combined vehicle routing transport (b) in the Ii region.
A map of the Nivala region showing the locations and area relations of agricultural parcels under environmental management and logistical alternatives from the parcels to the collection point along tractor and combined transport routes.
Figure 2. Modelling scenarios for tractor transport (a) and combined vehicle routing transport (b) in the Nivala region.

Even in areas of scarce biomass, the utilisation of biomass can prove effective

In the study it was found that there can be large regional differences in biomass accessibility, as shown in the figures above. However, the analysis of transport efficiency shows that even in areas of scarce biomass, transport efficiency can still be good, almost equal to that in areas of more abundant biomass.

A spatial analysis and different transport scenarios can therefore be used to determine whether large enough quantities of agricultural and rural side streams can be found for circular economy use within sufficiently short transport distances. Routing modelling can be used to make accurate regional comparisons of accessibility and logistics.

However, it was found that the spatial data on field parcels needs to be improved in order to better identify the actual amount of unused biomass.

The rate of biomass utilisation in the agri-environmental lands covered by the study varies between farms, depending, among other things, on the type of agricultural production. For example, some areas may be used for grazing. More accurate statistics are therefore needed to estimate the amount of unused biomass, for example by specifying information on grazing and other biomass use at farm or regional level.

The research was carried out in KASKI project implemented between 1.6.2021–31.10.2023 by Iin Micropolis Oy, Iilaakso Oy, the Kerttu Saalasti Institute of Regional Excellence Research Group at the University of Oulu and the Chemical Process Engineering Research Unit at the University of Oulu. Funding is provided by the Regional Council of North Ostrobothnia and the European Regional Development Fund, as part of the European Union's response to the covid-19 pandemic. The side-stream analyses have been carried out by the Regional Excellence Research Group.

Research article:
Ollila, Katri ja Kotavaara, Ossi (2023). Measuring Accessibility and Optimising Logistics of Marginal Land Grass Biomass in the Case of Northern Ostrobothnia, Finland. European Countryside, 15(4) 542–562.

Report published about the same topic in Finnish:
Ollila, K. & Kotavaara, O. (2023). Open access field parcel data open up new opportunities for the use of rural side streams – Sub-report of the project Growth from the circulation with green techniques (KASKI). Publication of Kerttu Saalasti Institute of the University of Oulu 3/2023. ISSN 2814-4406.