ByGaryH
Have researchers mastered effective soil carbon calculation?
A new approach to measure soil carbon stocks has been developed, which could enable the implementation of ‘carbon farming’, according to its developers.SoilCASTOR, the work of scientists at Wageningen University and Research in the Netherlands, uses satellite data, soil measurements using a portable spectrometer and machine learning techniques to precisely calculate soil carbon.
The model has been tested on farms in Iowa and Arkansas in the US, with a total of 205 soil samples taken in total.
“Results show that the estimates are precise and repeatable and that the approach could be rapidly scalable,” the researchers wrote in the journal Agronomy for Sustainable Development.
Addressing barriers
The development of the new protocol was a response to the limitations of satellite-only models, which lack appropriate resolution and are unable to monitor change over time. The scientists also pointed to the high cost of supplementing satellite data with chemistry approaches in the field, as well as labour demands.
“For every two hectares, about one sample is required to achieve a robust estimate of the farm carbon stock with a deviation less than 5%,” they explained.
“This implies that with relatively low labor time investment large areas can be covered, overcoming a key obstacle in the implementation of carbon farming.”
Ready for carbon farming schemes?
The method should be included in soil carbon sequestration offsetting schemes, and connected to advice on how to increase carbon stocks, they continued. Further developments could include it being applicable to a wider range of field types, such as grasslands, as well as over a number of years’ resampling.
“It could be investigated if this approach would also be appropriate for regional approaches (including multiple farms) instead of the current single farm-level focus. Another key element which can be further investigated is the maximum level up to which soil carbon stocks can be increased,” they added.
