The SFI offers financial payments to those who adopt variable rate applications, but demonstrating compliance is more than a tick-box exercise, explains Rhiza Product Manager Ben Foster.
The Sustainable Farming Incentive (SFI) has much to offer growers. With 102 actions available across a multitude of activities, the SFI has something for every farm and with a defined payment schedule, participants can plan with confidence.
A core pillar of the SFI is the module on soils and the actions to help you “increase the long-term health, productivity and resilience of your soil”. Who could object to that? The complementary nature of the three soil actions – SAM1, SAM2 and SAM3 – broadly support the same objective but offer different levels of participation depending on the interest of the land manager. The actions for nutrient management – NUM1, NUM2 and NUM3 – have similar objectives but with a specific focus on “increasing nutrient management knowledge, supporting more efficient use of nutrients and encouraging more effective use of organic sources of nutrition”. Again, who could object?
At its core, the SFI offers payment for actions that many consider good farming practice, such as maintaining desirable landscape features or demonstrating adherence to an Integrated Pest Management (IPM) plan. There are some that the land manager can complete themselves and there are others, such as the soil and nutrient management actions, which need to be demonstrated in the form of a plan produced by a suitably qualified person, such as FACTS registered adviser. Fortunately, Agrii’s team of FACTS-qualified crop input specialists and agronomists are trained in the finer details, so are well-placed to help.
Soil pH
Central to both the soil and nutrient management actions is the requirement to maintain the long-term health of the soil and support the wider environment such as surface water and air quality. Although not a specific action, soil acidity (pH) and its role in supporting a functioning soil is widely recognised through these modules.
Data from the 2023 British Survey of Fertiliser Practice reveals that soil pH has been in long term decline – see Fig. 1. pH is only one measure of a soil’s ability to function properly, but it is a useful proxy for overall soil health.
The acidity of our soils needs to be addressed. As values fall closer to 6, essential nutrients such as phosphorous and calcium and micro-nutrients such as magnesium and molybdenum are rendered increasingly unavailable to the growing crop – see Fig. 2.
Soil pH also has an influence on nutrient utilisation, applied as either organic manures and wastes or as mineral fertilisers – see Table 1.
and as a colour-coded map in RHIZA Lime Planner
The RHIZA Lime Planner
Restoring soil pH is a straightforward task. The SAM1 action under SFI more than covers the cost of basic nutrient analysis (P,K, Mg, pH) so long as an organic matter result is included with the analysis package, something RHIZA can also offer. As part of the farm assurance scheme all farms should be conducting soil analysis on every field on a five-year rotation, why not enhance this process by lining up soil sampling with liming rotation to make use of the most up to date field information? This data can be imported easily into RHIZA’s Contour platform to give a digital record, visualise nutrient maps and use the data in RHIZA’s suite of planning tools, such as the Lime Planner tool.
Once the soil sampling data has been uploaded to the Lime Planner module, the user can set a target pH value to create a job sheet report and an application file (in shapefile format) for either variable rate or flat-rate application. This can then be sent to the machinery controller.
Satisfying the PRF1 requirement
The use of data from soil analysis performed in previous seasons is sufficient for variable rate lime and P&K application because the pH value and soil indices won’t change significantly during the season. This is not the case for variable rate nitrogen. How much nitrogen to be applied will depend directly on the crop situation and available soil reserves coming out of the winter. It is for this reason that the PFR1 action requires that where remote sensing is used to calculate the nitrogen requirement it is carried no more than 14 days before application. Those relying on optical imagery derived from the Sentinel-2 satellites struggled to secure images of sufficient value to meet the PRF1 action. Roughly 80% of the imagery produced was rejected.
ClearSky
The only source of guaranteed cloud-free imagery able to meet the requirements of the PRF1 action is from ClearSky. It delivers unparalleled accuracy and consistency when the more traditional optical imagery isn’t available through the use of cloud penetrating synthetic aperture radar (SAR). This system delivers a fresh biomass map of the field on a weekly basis, something that is unique to RHIZA – see Fig. 4.
Unlike other ‘cloud-free’ derivatives, ClearSky does not rely on intermittent clear optical imagery to calibrate predicted changes. This enables a greater degree of confidence in the data supplied to customers.
Analysis by Agrii on 900,000 hectares reveals that the Sentinel-2 system produced, on average, roughly 13.3 clear images per farm in 2023. Using the ClearSky platform increased this to 60.8. This number is improved further if the cloud-free images captured by Sentinel-2 are included.
The adoption of technology that improves the performance and resilience of agriculture is an objective of the SFI. Being able to demonstrate adherence with its actions is more than a tick-box exercise. Participants are expected to demonstrate that they are fulfilling the actions on demand. In some cases, this means producing a report while in others it means producing the actual data employed in the fulfilment of the task. ClearSky ensures that variable rate applications are consistent with crop requirements while making it easy to demonstrate compliance with the PRF1 action.
PRF1: what you must do to get paid and how to do it
PRF1 is the action for the variable rate application (VRA) of nutrients. It is a three-year agreement for which the recipient will receive £27 per hectare per year. There are specific eligibility criteria, mainly relating to land type, but to comply, all major nutrients (N, P, K and Mg) must be applied using VRA equipment pre-programmed with a VRA file using data from zonal soil or crop testing and analysis or remote sensing. The VRA equipment must be connected to a tractor- or sprayer-mounted crop reflectance sensor. The PRF1 does not cover micro-nutrients or lime. The data informing the VRA file must cover a minimum of P, K, Mg and pH. If the data is from zonal soil testing analysis, it must meet the action’s requirements and be less than five years old. For nitrogen, the VRA file must use data from crop testing and analysis or remote sensing of crop reflectance taken no more than 14 days prior to application.
