Background
To test whether the developed methodology works in practice and to determine how this methodology can be improved, a pilot is being implemented within the Public-Private Partnership (PPP) Carbon Faming. The goal of this pilot is to analyze how the methodology is used, whether the sequestered carbon can be accurately measured on agricultural farms, and if the carbon credit system is economically applicable. Finally, the pilot focuses on the administrative and organizational functionality of the methodology.
Objectives
The main objectives of the pilot are:
- Testing and learning how the methodology is implemented on agricultural farms.
- Testing if the available information is sufficient for a reliable calculation and monitoring of carbon sequestration.
- Evaluation of experiences by the farmers in applying the methodology, and whether it is economically and administratively feasible for implementation.
Pilot Participants
The pilot has engaged farmers involved in carbon farming with the project partner Agrifirm. In this pilot, 20 participants started in 2022 with the following characteristics:
- Diversity in the agricultural system of the participants.
- Support from the participants.
- Representativeness of the group for the larger group of arable farmers.
- Ability to perform relevant analyses with the collected data.
Data was collected from these agricultural entrepreneurs to calculate potential carbon sequestration. Data collection was carried out by looking back for a maximum of 5 years.
The data sources include:
- Participant's farm management input: crop rotation plan, fertilization plan, stable systems, vision.
- Soil analysis reporting.
- Fertilization plan from Agrifirm system.
- Combined declaration: Plot/field identification.
- Nutrient cycling assessment.
Evaluation of the implementation of the methodology
This part evaluates the methodology and writing of a project plan for the group of farmers. This is done as described in the Method Document for Carbon Sequestration SNK in mineral soils (Dutch only). What problems do we encounter when writing the project plan? Is there room for differences in interpretation, resulting in different amounts of carbon credits? How can these problems be solved?
The central question also addresses whether conducting soil sampling adds value to the (SNK) methodology, as opposed to performing model calculations only, in terms of the accuracy of predictions of net carbon sequestration?
Finally, it explores whether the model's input data are sufficiently accurate and versatile (for example, data on the species composition of soil cover and the amount of biomass) or if further improvements are needed to model more distinctive scenarios for carbon sequestration?
Results are expected in the course of 2024.
Evaluations of the effects on the companies
This section examines the calculated carbon sequestration and field measurements. It also looks at the data availability for the calculations with the tool. The Soil Carbon tool (BodemCoolstof, Dutch only) has been used to calculate the effects of the practices. This tool is available on the farmmaps.eu platform and uses the Rothamsted Carbon model to calculate the soil carbon balance based on field data.
A backward evaluation is based on historical data from a number of farms dating back to 2011. A farm can be chosen to be part of the backward evaluation if it has historical data on crop and land management available and precisely knows which carbon practices were implemented. Scenarios are identified based on continuing historical performance from 10-15 years ago versus their actual practices over the past 10-15 years.
The key questions in the evaluation were: 1) Is the right data available for the calculations, 2) What efforts are needed for data collection, 3) Can previously sequestered soil carbon be calculated, 4) What is the difference in calculated and measured carbon storage, 5) Do the practices comply with the methodology for carbon certificates (SNK)?
For the calculation part, questions 1, 3, and 4 were considered. Questions 2 and 5 will be addressed later, because the effort of data collection and compliance with the carbon certificate framework SNK are separate from the calculations themselves.
Is the right data available for the calculations?
Information was collected from about ten farms to calculate carbon sequestration. Many of these farms were excluded from the evaluation because there was insufficient data available, or there was a 'mismatch' in required data. To calculate additional carbon sequestration, a 'baseline' must be compared to a 'scenario'. If one of these is missing, a plot is excluded. Additionally, management data from 10 years is necessary. If there is less data available, a plot is also excluded. If calculations had to be made from 2015 because a certain management or scenario was initiated from that year (t=0), a soil sample from that year is also necessary. The primary reason for fields being excluded was the unavailability of a soil sample for this starting year of the calculation.
Can previously sequestered soil carbon be calculated?
For all fields, more carbon sequestration was calculated for the scenario than for the baseline. Almost all fields already had a positive calculated balance, meaning that in most cases, carbon was already being sequestered in the baseline. Most measures involve changing the type of crop or type of manure. Additionally, in some cases, a cover crop was also added. These actions lead to adding more carbon to the soil, which in these cases also translated into an increasing soil carbon content over time.
What is the difference in calculated and measured storage?
Measuring the difference between the baseline and the alternative scenario is difficult in practice, because you cannot perform both at the same time. However, to get an idea of how calculation and measurement relate to each other, a recent measurement was taken alongside one at the beginning of the usage change (t=0). The measurement in the starting year (t=0) served as the model's starting point, aligning with each other. The recent measurements were compared with the model's calculation. From this, it seems that the measurements align closely. Both the calculation and measurement may deviate somewhat from the actual value in the field, but it appears that the calculation is consistently slightly higher than the measurement. This could be because the model assumes optimal crop development leading to more carbon input, while in reality, the crop may have developed less.
Where do we go from here?
The model, combined with field measurements, serves as a good indicator of the potential for additional carbon sequestration and its magnitude. Interesting next steps lie mainly in standardizing data collection to prevent fields from being excluded. Good documentation on the practices taken is also important to make them testable against carbon certificate frameworks.
Experiences of the companies
This section focuses on two questions:
- Does the pilot show deviations between the experiences of farmers with certain carbon farming practices, and the nationally proposed possibilities?
- Do case studies show a positive financial result when comparing implementation costs with the revenues from the carbon certificates that can be generated?
The initial results with the participants show that the commitments undertaken by farmers can be perceived as high. Farmers will not solely focus on carbon sequestration, especially in high-cash crops. Maintaining soil quality with a stable and diverse soil life to promote good yields is considered important. Carbon sequestration adds to this.
For maintaining soil quality and yield, flexibility in management is desired. The carbon farming method will need to take this into account. There is an understanding that it will be difficult for arable farmers to retain carbon in the soil for a long time (sustainability). It is also realized that in arable farming, the achievable profit might be very limited, contrary to expectations in grassland and fiber crops. Additionally, there is strong criticism of how non-agricultural companies want to offset emissions by sequestrating carbon in agricultural farms.
Participants who are retiring within the 10-year timeframe experience significant uncertainties about business succession. Upon the takeover of their business, they do not see it as realistic for the next generation to take over carbon farming obligations. The financial margins are too small, making it unlikely for potential acquiring candidates to accept obligations from carbon farming contracts.