Scoping Study of Soil Loss Through Wind Erosion, Tillage Erosion and Soil Co-Extracted

National Soil Resources Institute (NSRI) Report for DEFRANSRI, CranfieldUniversity

DEFRA project SP08007

Scoping study of soil loss through wind erosion, tillage erosion and soil co-extracted with root vegetables.

Objective 3 deliverable:

Review of how appropriate current mechanisms and advice on best practice for control and mitigation of erosion is to wind, tillage co-extraction with root vegetables in England and Wales, and consideration ofalternative methods and advice.

Owens, P.N., Rickson, R.J. and Clarke, M.A.

FINAL REPORT

April 2006

Contact:

Dr Philip N. Owens

National Soil Resources Institute (NSRI)

CranfieldUniversity

North Wyke Research Station

Okehampton

Devon EX20 2SB

Tel: 01837 883524

Fax: 01837 82139

E-mail:

Website:

CONTENTS

EXECUTIVE SUMMARY 4

1 Introduction 5

2Recommendations and advice based on present

agri-environment schemes in England 6

2.1Introduction6

2.2Cross Compliance and the Single Payment Scheme7

2.2.1Introduction 7

2.2.2Advice and recommendations according to soil texture 9

2.2.3Advice and recommendations according to land use and crop type 14

2.2.4Evaluation 19

2.3Environmental Stewardship: Entry Level Stewardship 20

2.3.1Introduction 20

2.3.2ELS Step 3: Identification of fields where soil erosion and runoff occur 23

2.3.3ELS options and advice 23

2.3.4ELS Soil Management Plan 36

2.3.5Evaluation 43

2.4Environmental Stewardship: Higher Level Stewardship 44

2.4.1Introduction 44

2.4.2HLS management options 46

2.4.3Joint Character Areas within HLS 52

2.4.4Evaluation 54

2.5Conclusions 54

2.6Bibliography and references 55

3Critique of current “best practice” recommendations in

DEFRA documents on controlling soil erosion in England 56

3.1Introduction and assessment 56

3.2Alternative advice and guidance 63

3.3Bibliography and references 64

4Best practice advice and recommendations for Wales 65

4.1 Introduction 65

4.2Cross Compliance 65

4.3Agri-environment schemes in Wales 68

4.3.1 Tir Cynnal 68

4.3.2Tir Gofal 68

4.3.3Catchment Sensitive Farming 69

4.4Limitations and recommendations 69

4.5Bibliography and references 70

LIST OF FIGURES

Figure 2.1Relationship between Single Payment Scheme and

Environmental Stewardship 6

Figure 2.2Relationship and increasing level of detail between a Soil

Protection Review completed under Cross Compliance and a

Soil plan prepared for Environmental Stewardship 7

Figure 2.3Steps required for ELS 22

Figure 2.4Hedgerow management for ELS 25

Figure 2.5Buffer strips on cultivated land 28

Figure 2.6Example map as part of a Soil Management Plan 37

LIST OF TABLES

Table 2.1Summary table of options and points available for ELS 23

Table 2.2Risk of soils to water erosion for a Soil Management Plan 40

Table 2.3Risk of soils to runoff or soil wash for a SMP 41

Table 2.4Payments for HLS 45

Table 2.5Steps for HLS 46

Table 2.6Management options for HLS 47

Table 2.7Woodland trees and scrub options for HLS 47

Table 2.8Orchard options for HLS 47

Table 2.9Historic environments options for HLS 48

Table 2.10Arable options for HLS 48

Table 2.11Resource protection options for HLS 49

Table 2.12Grassland protection options for HLS 50

Table 2.13Moorland and upland grazing options for HLS 51

Table 2.14Lowland heathland options for HLS 52

Table 2.15Wetland options for HLS 52

Table 3.1Summary of recommended practices for soil erosion control 57

Table 4.1Soil assessment guidance table for Wales 66

Acknowledgements

We would like to thank Sue Rodway-Dyer of South West Environmental Stewardship Surveys, and our partners on the project – Marc Dresser, Bob Jones, Tim Quine, Kristof Van Oost and Gavin Wood– for helpful discussions during the preparation of this report.

Please reference this document as:

Owens, P.N., Rickson, R.J. and Clarke, M.A.(2006). Review of how appropriate current mechanisms and advice on best practice for control and mitigation of erosion is to wind, tillage co-extraction with root vegetables in England and Wales, and consideration of alternative methods and advice.National Soil Resources Institute (NSRI)Report to DEFRA, Project SP08007, NSRI, Cranfield University, UK.

Executive summary

This report presents the current state of advice and recommendations for controlling soil erosion in England and Wales. The advice and recommendations and associated measures to control soil erosion are contained in DEFRA reports and documents either specific to erosion or as part of larger agri-environment schemes such as Single Payment Scheme and Environmental Stewardship. In Wales, such advice is more limited, much of which is contained in documents by the Welsh Assembly Government.

There are various types of agri-environment schemes presently available to farmers and landowners, with a tiered level of complexity and measures. The advice and recommendations given within documents for achieving the aims of the schemes relates to several criteria of which good soil (and environmental) management is one. Information and advice on soil erosion largely aimed at controlling soil erosion by water processes, particularly as these are reasonably well understood, relatively easy to identify and have implications for the wider environment, such as watercourses. Information and advice for other forms of erosion is generally very limited, although wind erosion is usually recognized, especially as a risk for sandy and peaty soils. Soil loss by tillage is only very rarely mentioned and soil loss by co-extraction with root vegetables and farm machinery is not considered.

The advice and recommendations offered for erosion, mainly water erosion, is good and consistent, and covers a wide range of options, including creation of buffer features, reducing grazing pressures and making soils less erodible. In many cases, the advice given in erosion control documents and the management options available within the agri-environment schemes should also help to indirectly control erosion by non-water processes. There are a few cases where advice and options offered for water erosion could potentially increase the risk of erosion by another process. However, the knowledge base and understanding of the interaction of different forms of erosionis lacking. This makes it difficult to derive appropriate advice and recommendations that would limit and control soil erosion and sediment delivery to watercourses, and other impacts, for all erosion processes.

One of the key issues that should be addressed is education and awareness of forms of soil erosion other than water. In some parts of the county, farmers and landowners may be aware of soil loss by other erosion processes (e.g. wind) but generally most farmers and landowners will be unaware of the full suite of soil erosion processes, and thus may not be able to assess the risk of their land to these erosion processes.This may also apply to those required to manage such schemes and offer advice to farmers and landowners. In addition, as many of the non-water erosion processes are more relevant to some forms of agriculture and some parts of the country than others, then there is perhaps a need to assess regional variations in advice and recommendations to prevent soil erosion.

1.Introduction

The aim of this report is to identify and evaluate current advice and recommendations of “best practice” for controlling soil loss by wind, tillage and co-extraction with root vegetables and farm machinery processes. These practices are defined in policies such as agri-environment schemes and CAP reform. This report reviews the information on soil loss given in the main policies(including Environmental Stewardship) and reviews information and advice contained in specific MAFF/DEFRA documents on soil erosion. The effectiveness of the advice in controlling soil losses due to the processes reviewed in Objective 1 (Owens et al., 2006) is considered, followed by recommendations as to how the efficacy of the advice and methods suggested might be improved further.

2. Recommendations and advice based on present agri-environment schemes in England

2.1 Introduction

This section considers some of the recommendations and advice based on the main current agri-environment schemes within England. This includes Cross Compliance and the Single Payment Scheme, as part of the Common Agricultural Policy, and Environmental Stewardship, specifically Entry and Higher Level Stewardship. The relationships between these types of schemes in terms of the level of detail required and their management are illustrated in Figures 2.1 and 2.2.Most of the text, figures and tables in the sections below are synthesized from existing DEFRA documents such as handbooks and leaflets.Most of these sections(i.e. sections 2.2) include the majority of the advice and recommendations given, as opposed to just those specific to soil erosion, as some of these are also relevant to non-water erosion even though they do not necessarily state this.In some sections (i.e. section 2.3), however, the advice reviewed mainly related to soil erosion. This section also evaluates the advice and recommendations given in terms of the potential effects in reducing soil loss due to wind, tillage and co-extraction with root vegetables and farm machinery (i.e. non-water) processes.

Figure 2.1. Relationship between Single Payment Scheme and Environmental Stewardship and their management (from DEFRA, 2005a).

Figure 2.2. Relationship and increasing level of detail between a Soil Protection Review completed under Cross Compliance and a soil plan prepared for Environmental Stewardship (from DEFRA, 2005b).

2.2 Cross Compliance and the Single Payment Scheme

2.2.1 Introduction

The Single Payment Scheme (SPS) replaced most existing crop andlivestock payments from 1 January 2005. The new scheme breaksthe link between production and support. In SPS farmers and land owners are asked todemonstrate that they are:

• keeping land in Good Agricultural and EnvironmentalCondition (GAEC); and
• are complying with a number of specified legal requirements relatingto the environment, public health, plant health, animal health andwelfare, and livestock identification and tracing (StatutoryManagement Requirements).

Meeting these requirements is described in the Common AgriculturalPolicy legislation as ‘cross compliance’. The farmer requirements forCross Compliance are set out in the Cross Compliance Handbook forEngland 2006 edition.

The document Single Payment Scheme: Cross Compliance Guide for Soil Management (DEFRA, 2006) provides guidance that aims to help farmers and landowners to manage their soils so as to improve theiragricultural potential while at the same time reducing the scope fornegative impacts on the environment. It also provides information for farmers to understandother soil-related problems that they may find on farms and whatgood practice measures they can put in place to minimise theseproblems, and also help them meet the soils standards.

Good soil management (i.e. GAEC) means better productivity as well asimproved environmental standards; it is vital to achieving goodagricultural practice on farms. Preventing soil eroding from fieldsand maintaining soil organic matter and a good soil structure arecentral for meeting the soil standards of GAEC.For Cross Compliance, a simple risk-based soilmanagement plan (the Soil Protection Review: SPR), must be prepared before 1 September 2006 (GAEC level 1). The SPRinvolves selecting measures that will help to avoid any problems observed on a farm, and, for future years, the actions to betaken to help remedy problems if selected measures do not work.The Soil Protection Review must be put into practice on landfrom 1 January 2007 onwards and is reviewed annually.GAEC 2–4involves compliance with the three simple soilprotection standards set out in the handbook DEFRA (2006), and these are:

• GAEC 2 – post-harvest management of land after combinablecrops (from harvest to 1 March);
• GAEC 3 – waterlogged soil; and
• GAEC 4 – burning of crop residues.

Although the impact of these standards may be greatest in thearable sector, they are relevant to all agricultural land. There are also requirements under the GAECstandards to protect soils for the maintenance of habitats and landscape features. For example, farmers with livestock must complywith the overgrazing and unsuitable supplementary feedingrequirement (GAEC 9).

During 2007 and in subsequent years farmers must:

• continue to comply with the three simple standards(GAEC 2–4); and
• implement the actions identified in the SRP and updatethe SPR each year according to experiences on the farm.

For implementing Cross Compliance and assisting with the development of a Soil Protection Review, DEFRA (2006) identifies advice and recommendations for good soil management through a series of both general and specific“principles” of good soil husbandry. The principles specific to broad soil groups (defined by texture) and land use and crop type are considered in the sections below. The general principles are:

• Prepare and follow a soil management plan and, for Cross Compliance,complete a Soil Protection Review.
• Prepare and follow a nutrient management plan.
• Wet soils are more easily damaged by cultivation, harvesting, trafficking andlivestock. Timeliness of activities and not overworking soils are critical tomaintaining soils in good condition.
• Drainage extends the season for field operations and grazing, especially inautumn and spring periods.
• Soil organic matter improves soil stability and increases workability.
• Look at soils during and after rain to identify areas of poor drainage andsurface soil stability.
• If you have to travel on or work wet soils, reduce the load with low groundpressureset-ups, or set tyre pressures at the lowest pressure that is compatiblewith the load and tyre type.
• Regular use of a spade to look for any compaction in the topsoil or subsoilhelps you make decisions on cultivations, loosening and subsoiling. Deepercultivation is often needed on tramlines, headlands and gateways to removesoil compaction.
• Grow crops that match the capability of the land. When growing crops thatrequire late harvesting, be prepared to correct any compaction or structuralproblems if they occur. Out-wintering of stock should be carried out on landthat has good drainage. Stocking rates should be adjusted to minimize compaction and any runoff to watercourses caused by poaching.
• Operating machines on sloping ground increases the possibility of overturnand likely injury. When carrying out your soil management planning, it is goodpractice to consider the limitations of the equipment you have available andavoid unnecessary risks to your safety.
• Consider the risks of runoff and erosion when planning what to grow oryour stocking on sloping land and which management practices to adopt.
• Where severe erosion occurs, earth banks or other physical barriers may beused as a last resort to check the flow of water and reduce off-site impacts.They must be carefully designed and installed.

2.2.2 Advice and recommendations according to soil texture

Using DEFRA (2006), for the development of a SRP it is suggested that farmers understand the managementrequirements of different soils, and the report classifies soils into five broad groups:

• sandy and light silty soils;
• medium soils;
• heavy soils;
• chalk and limestone soils; and
• peaty soils.

Sandy and light silty soils

When in good condition, these soils are naturally free-draining anddo not lie wet for long periods (unless there is a high water table inthe subsoil). There are usually long periods in the year when thesesoils may be worked without damaging them.However, their structure is often weak because of the low clay andorganic matter content. The soil surface is easily broken up by rainand forms a cap when it dries. The topsoil may fall apart, causingthe soil to slump. The soil may then set solid when it dries out.Water gets into soils more slowly if they are capped, slumped orhave poor soil structure. This leads to runoff and erosion duringrainfall.Although sandy and light silty soils are usually well drained andpresent good opportunities for land-work, they can suffer fromcompaction – particularly when used to grow vegetable crops.Compaction can be caused by harvesting in wet conditions or bydeep cultivation in a wet spring.When they are dry and have little or no vegetation to protect them,these light soils are also prone to wind erosion.

The main problems associated with sandy and lightsilty soils are:

• low organic matter;
• capping, surface sealing and slumping;
• runoff and soil wash; and
• soil erosion by water and wind.

The principles of good soil husbandry for sandy and light silty soils are:

• For winter cereals in particular, avoid a very fine, smooth seedbed. A coarseseedbed is less likely to form a cap that will lead to runoff.
• Crop cover protects the soil from the battering action of the rain, and a goodroot structure holds the soil together. Therefore, sow winter cereals earlyenough to achieve a good crop cover before winter.
• Correct any deep compaction problems caused by harvesting of potatoes,vegetables and forage crops by subsoiling when conditions are suitable.
• Where it is safe and practical, sow crops and establish tramlines acrossthe slope.
• Sandy and light soils are not well suited to direct drilling because they tend toslump and will need regular loosening.
• Aim to increase the organic matter content and improve the stability of thetopsoil by retaining crop residues, by applying manures or by using grassbreaks or green manures.
• Avoid growing potatoes, vegetables, maize and other forage crops on slopesif runoff problems are likely to cause soil erosion.
• Avoid out-wintering stock on slopes if runoff problems are likely to cause soilerosion.
• Sow nurse crops such as barley to prevent wind erosion, particularly invegetable crops or sugar beet grown on unsheltered land that is exposed tostrong winds.

Medium soils

“Medium” refers to a range of soils that are widespread across thecountry. Some of the most productive soils are in this category.Medium soils tend not to lie as wet as heavy soils and in general areat lower risk of structural damage. However, compaction can occurbecause, although conditions in the topsoil may be suitable, thesubsoil may stay wet for longer, particularly where the water tableis high or the subsoil is heavier than the topsoil. Timeliness ofoperations is essential to prevent damage to soil structure.Medium soils contain enough clay to make them stick together,so they are at less risk of capping or slumping after rain. However,those with a high content of silt or fine sand are not as stable,particularly where organic matter content is low, and they may cap.Even on medium soils, capping, compaction or poor drainage cancause excessive runoff leading to erosion, particularly on sloping landin wetter areas of the country.