Visitors to Morley and people who live locally are noticing a new arrival in one of our fields. Dr Georgina Barrett, the research scientist from BBRO overseeing the project hosted and funded by TMAF, describes what’s going on, why, and how.
“The UK government has set a Net Zero target for 2050. Net Zero is when the amount of greenhouse gas emitted is equal to that captured. Agriculture has a key role to play in reaching this target as plants and soil can capture and store large amounts of carbon.
Measuring emissions in agriculture is important to understand how close to Net Zero we are and what can be done to reduce emissions and increase carbon capture. Some aspects are straightforward such as using more efficient tractors and less fertiliser. But understanding the emissions from crops and soil is much more challenging. This is because the emissions are on a field scale and can be heavily influenced by the weather and soil properties. At a small scale, chambers the size of a lunchbox can be used to measure emissions. But this doesn’t really capture the scale and variability of a whole field.
Field work for the real picture
To measure emissions at field scale we use flux towers. These look like a met office weather station but have more sensors. In addition to standard weather sensors measuring rain, temperature, humidity and windspeed, the flux towers measure a range of soil parameters including soil temperature and wetness as well as the light intercepted by the crop.
Most crucial is the gas analyser which measures the amount of CO2 in the air and coupled with the rest of the sensors, and using some complex calculations, can give a measure of the CO2 being emitted or taken up across a whole field.
This is all remotely recorded and uploaded via a phone network so data can be analysed and checked regularly. The large number of sensors means that the system requires a lot of power, and this must be generated on site as the towers are not in a location that enables access to mains power. For this reason, a large solar panel is required to ensure the system has the power it needs to reliably run.
Carbon emission changes with the season
A typical crop cycle will see CO2 being emitted from the bare soil before the crop emerges. This then declines as the plants grow and take up CO2 for photosynthesis. This uptake increases further as the crop grows and produces more biomass.
This baseline measure of CO2 will be used to understand emissions from different crops as there is data lacking on crop emissions on a field scale. In addition to this there is another flux tower in a neighbouring field at Morley which will be used to compare emissions from different management practices. To start with, ploughing and a cover crop (a crop grown purely to enhance soil health) will be compared. In addition to this the sugar beet crop will be monitored to ensure it remains healthy and yields well.
Team work with towers over time
The towers will be in place for 18 months to capture emissions from the sugar beet crop and into the following wheat crop. They will then be relocated to capture another sugar beet crop, with this process happening 3 times in a 6-year period. By the end of the project the data will be used to guide best practice with regards to greenhouse gas emissions on farm and help direct future agricultural policy concerned with Net Zero and soil health.”
Find out more about TMAF’s Carbon Monitoring in Sugar Beet.