Strengthening Soil Health with SFI Actions

The Sustainable Farming Incentive (SFI) offers significant benefits to growers, from payments for environmental actions to incentives aimed at enhancing sustainability, productivity, and, crucially, business resilience.

With 102 actions spanning a wide range of activities, the SFI caters to every type of farm. A clearly defined payment schedule ensures participants can plan with confidence.

A central component of the SFI is its module on soils, designed to help you “increase the long-term health, productivity, and resilience of your soil.”

The three soil actions – SAM1, SAM2, and SAM3 – work towards the same overarching goal but allow for varying levels of participation based on the land manager’s priorities. Similarly, the nutrient management actions – NUM1, NUM2, and NUM3 – aim to “increase nutrient management knowledge, support more efficient nutrient use, and promote the effective use of organic nutrition sources.”

At its heart, the SFI rewards actions widely regarded as good farming practice, such as maintaining valuable landscape features or demonstrating adherence to an Integrated Pest Management (IPM) plan. Some tasks can be completed by the land manager themselves, while others, like soil and nutrient management actions, require plans created by a qualified professional, such as a FACTS-registered adviser.

Fortunately, Agrii’s team of FACTS-qualified crop input specialists and agronomists are well-versed in these requirements and are ideally placed to assist.

Soil Health

Figure 1: The average pH of UK soils has fallen below the optimal score of 6.5

Central to both the soil and nutrient management actions is the emphasis on maintaining the long-term health of the soil while supporting broader environmental goals, such as improving surface water and air quality. Although not outlined as a specific action, soil acidity (pH) and its critical role in sustaining healthy, functional soils are integral to these modules.

Following a challenging season, many soils are likely to require remedial attention. In cases where soils have suffered from prolonged waterlogging, compaction is often the most evident form of damage. This is particularly true for those transitioning to reduced tillage systems, which are more vulnerable to such issues. Waterlogging can also exacerbate soil acidity, making it essential to address both compaction and soil pH as part of a comprehensive soil management plan.

Analysis of soil sample data shows that the health of UK soils has been declining for decades. Findings from the 2023 British Survey of Fertiliser Practice reinforce this trend, revealing that only around 5% of fields are limed annually. This rate is insufficient to maintain pH values within the desired range, a critical factor for soil functionality.

Soil acidity is just one indicator of soil health, but it is a valuable proxy. Over the past 20 years, the average pH of UK soils has fallen by more than 0.4 units (see Figure 1). When high-pH brash or calcareous soils are excluded, the decline is even steeper, with average pH dropping from an optimal 6.7 to a sub-optimal 6.3. Given the logarithmic nature of the pH scale, this change is significant: a one-unit drop represents a tenfold increase in soil acidity, making effective soil pH management a vital part of maintaining soil health and productivity.

 Soil acidity must be addressed. As pH levels drop closer to 6, essential nutrients like phosphorus and calcium, along with important micronutrients such as magnesium and molybdenum, become increasingly unavailable to crops – see Figure 2.

Soil pH also affects nutrient utilisation, whether nutrients are applied through organic manures and wastes or mineral fertilisers  – see Table 1.

The impact of acidic soils extends far beyond nutrient availability. For loamy soils, a soil management plan requires actions to ‘encourage earthworms,’ while for clay soils, it aims to ‘maintain earthworm activity and water infiltration.’

However, as soil acidity increases, earthworm populations decline significantly, with survival becoming unlikely at pH levels below 4.5. Similarly, the activity of microorganisms essential for breaking down organic matter and converting nutrients into plant-available forms is directly influenced by soil pH. Neglecting to address soil acidity could potentially constitute a breach of the actions specified in a soil management plan.

Restoring soil pH is a relatively straightforward process. The SFI includes payment for soil organic matter testing as part of a soil management plan. Adding a basic nutrient analysis (P, K, Mg, and pH) is a cost-effective addition and is also a requirement for Nutrient Management Planning, ensuring most land managers already have up-to-date data on their soils.

This data can be easily uploaded to RHIZA’s Contour platform, enabling a digital record, nutrient map visualisation, and access to planning tools like the new Lime Planner module. Once soil sample data is integrated into the Lime Planner, users can set a target pH, generate a job sheet report, and produce an application file (in shapefile format) for either variable rate or flat-rate application. This file can then be sent directly to the machinery controller, simplifying the process of restoring soil health.

Adopting technology that enhances the performance and resilience of agriculture is a key objective of the SFI. Demonstrating compliance with its actions goes beyond a simple tick-box exercise. RHIZA has a number of new technologies that can help support SFI claims, including ClearSky imagery.