We are often approached by clients looking to develop large areas of land for Solar Farms, Battery Storage and residential developments. Whether looking to satisfy a planning condition or inform feasibility, we often recommend taking a staged approach to Agricultural Land Classifications (ALCs).

In this blog, we will discuss what a staged approach to ALCs is and why it is beneficial to developers.

What is a Staged Approach to Agricultural Land Classifications?

Stage 1: Desk-Based Agricultural Land Classification

A Desk Based Agricultural Land Classification provides a preliminary assessment of the likely ground conditions, soil types and grades at the site which is being assessed.

In order to do so we require data to be collected across multiple criteria to infer the likely ALC grade. The data sources reviewed include:

• Published BGS Geology Maps – to determine likely soil constituents;
• Climate data provided by the Met Office – to determine climate limitations on crop variety and growth;
• Flood Risk Mapping and previous Flood Risk Assessments – to determine how frequently the site may be flooded, limiting productivity and crop yields;
• Historical Mapping – to determine previous site uses and whether they may result in adverse ground conditions;
• Pre-1988 Agricultural Land Classification Grade Mapping – for a high-level assessment of indicative ALC grading;
• Post-1988 Agricultural Land Classification Grade Mapping – for a more detailed assessment of likely grading; and
• Likelihood of Best and Most Versatile (BMV) Agricultural Land Mapping.

Following a review of the above data, the information can be collated to provide a report including a detailed preliminary assessment of the likely soil grades present at the site.

Stage 2: Intrusive Agricultural Land Classifications

Once the likely areas of non-BMV land (Grades 3b-5) have been identified, these can be targeted and subject to intrusive investigation. Typically, a sample is collected using an hand auger at 100m centers across the site and at a minimum one per hectare.

A hand pit is dug for each encountered soil type to examine its structure. These pits can be up to 1m x 1m square in size and reach a maximum depth of 1.20 meters.

After excavation, the soils encountered within the auger and pit locations are logged and sampled (where necessary) before being reinstated.

In some cases, laboratory analysis may be required to corroborate in-fieldhand textures and analyse soil organic matter content.

Following the completion of the investigatory works, a comprehensive report is generated. This report includes a site description, the Agricultural Land Classification grades and justifications for land grades determined on-site. It also includes observation logs and separate colour maps illustrating soil types and ALC grades.

‍What are the benefits of a Staged Approach to Agricultural Land Classifications?

Effective Planning and Resource Management

ALCs are often required as part of the feasibility assessment during the early development planning process, identifying which areas of the site can and cannot be developed. Furthermore, an ALC can inform development decision-making by providing early identification of mitigation measures, such as avoiding key or sensitive habitats e.g. areas of deep peat or watercourses.

By adopting a staged approach and offering Desk Based Agricultural Land Classifications, REL enables informed decisions to be made as early as possible in the build programme. The additional information gathered improves the accuracy of feasibility studies. In addition, by understanding the likely ALC Grade types at the site, REL can ensure that resources are not invested in intrusive investigations within areas which may not be suitable for the proposed use.  

Saving Time and Money

Desk Based assessments can normally be completed in less than half the time required to undertake intrusive investigations and reporting.

Once complete, the preliminary assessment of the soil grades at a site enables a more effective investigation strategy to be developed.

Consideration can be given to remove areas which are highly likely to be BMV land (Grades 1- 3a) from future intrusive investigation, reducing the timescales on-site during soil sampling and therefore developer costs.

Conclusions

By adopting a staged approach to Agricultural Land Classifications developers can obtain critical information on the likely soil grades at their site, enabling effective planning and resource management during feasibility studies. In addition, the information provided by Desk Based Agricultural Land Classifications allows for the development of a more effective investigation strategy, reducing timescales on site and associated costs.

At Roberts Environmental Ltd we have considerable experience in carrying out ALCs to aid in the planning process and overall strategy of developers and planners.