In the growing seasons 2020 and 2021, HKScan used precise measuring technology on the Agrofood Ecosystem® pilot farms. Carbon flux measurements were used to measure the variation in carbon dioxide levels. The data shows that good biomass and high amount of chlorophyll increase the carbon sequestration potential of the field.
HKScan is targeting a carbon-neutral food chain by the end of 2040. We work together with contract farmers and partners to achieve carbon neutrality. Datasense’s measurement services and carbon flux measurement chambers were used in the pilots. The carbon flux chambers contain Vaisala’s sensor technology.
Carbon sequestration verification studies are being carried out at about twenty sites across Finland.
Carbon flux chambers measure carbon dioxide levels in the air
Carbon flux chambers are used to measure the variation of carbon dioxide level in the air. As the gas-tight chamber closes, the carbon dioxide level in the air decreases. If the vegetation inside the chamber absorbs more carbon dioxide from the air than is released from the soil and vegetation, it can be stated that the vegetation absorbs carbon from the air.
“Under favourable conditions, fields sequester 40 kilos of carbon dioxide per hectare per hour,” says HKScan’s Research Manager Heikki Aro.
If the vegetation for some reason cannot photosynthesise or the level of photosynthesis is lower than CO2 released from soil respiration, the carbon dioxide level in the chamber starts to rise. In that case, the field block releases carbon into the atmosphere.
Cover crops bind carbon effectively
Carbon binding of catch crops was a good example of the operation of a carbon flux measurement chamber and of a clearly environmentally sound measure. The carbon flux measurement showed that vegetation was binding carbon well into the autumn. The longer photosynthesis takes place in the field, the better for the environment.
Grass farming also has a positive impact on climate. In contrast, a tilled or stubbled field turns into carbon emissions in the autumn after harvest.
The picture taken on 22 September 2020 shows a carbon flux measurement chamber on a catch crop field.
The picture shows a measurement period of 24 hours. According to the results, cover crops bound carbon while a stubble field acted as a source of emissions. Variation in the amount of light had a direct impact to the photosynthetic efficiency.