Navigating SFI – Improving soils

Across England and Wales, four million hectares of soils are currently at risk of compaction, and two million at risk of erosion – resulting in soil degradation that costs the agricultural industry at least £1 billion per year, according to Defra estimates1.

To help counteract this risk, every grower should be investing time in building a tailored soil management plan, aimed at improving long-term soil health, resilience and productivity.

Many farmers are already doing this to reap both environmental and business benefits. This is being made even easier to access as even more rewards available for sustainable soil management, through Defra’s Sustainable Farming Incentive (SFI) scheme.

The ‘SFI actions for soils’ include action SAM1, which incentivises farmers in England to carry out a soil assessment and produce a tailored soil management plan.

This blog explains SAM1 in more detail, and how actively improving soil health, structure and organic matter levels can benefit farming businesses.

What does SFI action SAM1 involve?

SAM1 offers farmers in England £6/ha and £97 per SFI agreement per year.

Eligible land must be below the moorland line, and includes:

  • Arable land (can be used as temporary grassland)
  • Permanent grassland (either improved or low input)
  • Land used for multi-annual/perennial crops (such as fruit and flower crops)

Completing the SAM1 action requires the following steps:

  1. Conduct a soil assessment across all land parcels entered into this action
  2. Produce a written soil management plan for this land
  3. Test soil organic matter (SOM) levels for all land entered into this action within the last five years

Farmers who have already produced a soil management plan for this land, based on soil assessment results in the last 12 months, can use the existing plan for evidence.

For example, a soil management plan produced for Red Tractor assurance can be used.

Existing SOM test results can also be used, as long as they have been captured within the last five years.

Soil assessment methods

Conducting a comprehensive soil assessment – the first stage of SAM1 – involves testing soil’s physical, chemical, and biological properties using a series of field assessment and soil analysis methods.

There is no standard format required, however the more data captured, the more accurately you can develop a bespoke soil management plan.

Field assessments should include:

  • Soil sampling to understand soil properties at various levels of each field
  • Visual assessments to examine compaction layers, root penetration, soil aggregation and erosion indicators
  • Slope and gradient analysis to help identify run-off patterns
  • Earthworm counts, which indicate healthy soil biology

More detailed soil analysis should also be carried out, including:

  • Texture analysis to determine soil particle size (sand, silt, clay)
  • Bulk density measurement to assess compaction levels
  • Water holding capacity tests
  • pH testing to measure soil acidity
  • Nutrient analysis to identify macronutrients and micronutrients present
  • Organic matter measurement using methods like loss on ignition (LOI) or dry combustion

These results and insights are essential to inform a bespoke soil management plan for each farm.

Find more practical advice on testing and analysing your soils in NIAB’s soil health assessment guide.

Creating a soil management plan

The second stage of SAM1 involves using the results of your soil assessments to create a tailored soil management plan. This must address the specific needs and conditions of each field, or land parcel within a field.

Key ways in which data from each assessment can be translated into actionable steps:

Improving soil structure

Understanding soil structure, which affects air and water movement, in more detail helps identify potential barriers to root growth and nutrient uptake.

This could be overcome by implementing deep tillage or subsoiling in areas with severe compaction, to improve root penetration and water infiltration.

Alternatively, an increasing proportion of farmers are planting cover crops as a less intensive method of enhancing soil structure and preventing future compaction.

Cover cropping can also help protect soil from erosion, reducing nutrient loss and preventing run-off from impacting water quality.

Encouraging microbial activity

When soil tests reveal low microbial activity or poor soil health indicators, such as reduced soil respiration, low organic matter content, or signs of nutrient deficiency, farmers should plan to increase organic matter within their soil management plan.

Organic matter can be added through composting or cover cropping to boost microbial activity.

Balanced fertiliser application also helps to support a healthy microbial population, by providing the essential macronutrients and micronutrients needed for a favourable environment for microorganisms.

In turn, this helps boost nutrient mineralisation and availability for crop growth.

Achieving optimal pH level

When soil pH falls below the optimal range (6.0 to 7.0 for most crops), essential nutrients such as nitrogen (N), phosphorus (P), and potassium (K) become less available to plants. Toxic elements like aluminium and manganese can also become more soluble and harmful to plant roots.

Depending on the specific soil’s magnesium needs, applying calcitic lime (calcium carbonate) or dolomitic lime (calcium magnesium carbonate) can help neutralise acidic soils.

On the other hand, soils with a pH above 7.5 can lead to deficiencies in micronutrients like iron, manganese, and zinc, as these become less soluble and less available to plants. This can result in poor crop growth and symptoms such as chlorosis (yellowing of leaves).

Fertilisers, such as ammonium sulphate or urea, can also help lower soil pH. When these fertilisers are nitrified by soil microbes, they release hydrogen ions, contributing to soil acidification and achieving the optimal pH level.

Enhancing nutrient levels

When scrutinising nutrient analysis results, growers should look for deficiencies and excesses of each nutrient, considering the specific requirements of each crop – different crops have varying nutrient demands.

N, P and K are the critical macronutrients to be aware of. These primary nutrients play a crucial role in biochemical processes, energy production and the overall health of crops.

Learn more about macronutrients and why they are so essential for optimal crop growth.

Micronutrients should not be overlooked either. For example, if soils are deficient in zinc, this can result in smaller, yellow leaves with shortened stem lengths – known as ‘little leaf’ syndrome.

Read more on the value of understanding micronutrients and their availability to crops.

Effective and sustainable soil management

There is no doubt that understanding your soil health in more detail, and implementing a targeted soil management plan, to maintain optimal nutrient levels, soil structure, microbial activity and pH level will benefit your productivity in the long run.

On top of this, accessing SFI rewards through SAM1 offers an extra incentive to invest time in completing thorough field assessments and soil analysis.

When doing this, it is essential to record all assessments, tests and management actions to comply with SFI requirements and ensure you are fully rewarded through the scheme.

It is also worth accessing support available for both conducting the soil assessments and developing a soil management plan – either through government guidance, agricultural advisers, or local farming groups.

Find more RPI advice, guidance and support on how to complete the SFI actions for soils.


  1. Defra, Government Statistical Service (2022) – Agriculture in the UK Evidence Pack

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