Tomography in the field – new monitoring method for the effects of farming management on the greenhouse gas balance in agriculture, part 2: Development project
The project is funded by European Regional Development Fund (ERDF).
The project is implemented by University of Eastern Finland (coordinator) and Natural Resources Institute Finland (Luke)
Regional Council of Pohjois-Savo
Finland aims to reach carbon neutrality by year 2035, and achieving this goal necessitates quick decisions. Thirteen percent of the greenhouse gas (GHG) emissions in Finland are caused by the agriculture; if the effect of the land use is also accounted for, the GHG load of the Finnish agriculture is almost doubled. Farming techniques – including selection of plant species, fertilization, the use of organic fertilizers and draining – can be used for lowering the emissions caused by production and reducing the carbon footprint of products. To find the most cost-efficient means of reducing the environmental load of production, methods for quantifying the effects of different measures to emissions and production costs are needed. The currently used methods for the GHG balance in field conditions (pointwise chamber measurements and the so-called Eddy covariance measurements) have significant limitations: The chamber measurements affect the target of measurement (the local GHG balance) and, in addition, they are not suitable for continuous monitoring. Carrying out pointwise measurements is also a very tedious task. Eddy covariance method, which enables continuous monitoring and is easy to use, does not account for the spatial variations in, e.g., the soil type and fertilization – and in the GHG balance. Moreover, it suffers from the inhomogeneities and uncertainties related to the environment surrounding the field.
In this project, a new monitoring tool for the GHG balance of agricultural fields is introduced and developed. The new monitoring method uses a measurement system that is based on laser dispersion and absorption, and it can be used for mapping fields of up to a square kilometre area. The device enables long-term monitoring in field conditions. The analysis of the measurement data is based on advanced mathematical modelling, computational physics and inversion. With the aid of computational methods, the sequential measurement data provided by the laser system are converted to tomographic images – maps that represent the distribution of GHG emission source in the field at different instants of time. Unlike Eddy covariance method, the tomographic mapping is insensitive to inhomogeneities and uncertainties related to the environment surrounding the field. Furthermore, it enables determining GHG balance maps that are spatially varying. This project consists of two parts: In the investment project, we purchase an open-path laser dispersion and absorption system which enables the GHG measurements in field conditions. In the development project, this device is utilized and tested; the computational methods for tomographic imaging are designed for its use, and it is applied for GHG measurements in agricultural fields in the test field of Natural Resources Institute (Luke) Maaninka. The project will be carried out by the Department of Applied physics in University of Eastern Finland (UEF) and Luke.
This project will create a new competence center in the region: It will combine the scientific excellences of computational inverse problems research and agronomy. If successful, the project will provide a remarkable practical benefit: The new monitoring tool will complement the existing chamber and Eddy covariance measurements, providing solutions to their limitations in GHG balance quantification. The improvement in the reliability of the monitoring methods can lead to transformation of policies in agriculture; in particular, via the use of these methods, the GHG balance assessment can form a basis for selecting suitable farming techniques. The project also involves two companies: Yara and Valio. In addition, the project affects a large number of small enterprises. In 2020, there were a total of 3181 agricultural and gardening enterprises in Northern Savo. The aim of the project is that the large companies deploy the new solutions developed and certified in the project to their contract farms and partners. The methods developed in the project have a great potential also in other applications: According to Programme of Prime Minister Sanna Marin’s Government, Finland must increase the production of biogas and enhance the exploitation of livestock ordure. Northern Savo has aimed at investments for farm-based or centralized biogas production plants for years. At the moment, the only biogas plant in Northern Savo is the one in Luke Maaninka. However, the time could be right for new openings. Recycled organic fertilizers are currently being developed in on-going projects (Biosfääri (Savonia, UEF, Luke), OrVo (Luke, Savonia), but effects of these fertilizers to greenhouse gas emissions in agriculture are still unknown. In the future, the use of new emission monitoring methods can be an integral part of the product development in biogas and organic fertilizers.
Group members - UEF
Aku Seppänen Associate Professor , Faculty of Science and Forestry, Department of Applied Physics