9 Chapters
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6: Valuing the Neglected: Lessons and Methods from an Organic, Anthropic Soil System in the Outer Hebrides

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6 

Valuing the Neglected: Lessons and

Methods from an Organic, Anthropic Soil

System in the Outer Hebrides

Mary Norton Scherbatskoy,1* Anthony C. Edwards2 and Berwyn L. Williams3

1

Blackland Centre, Grimsay, North Uist, Scotland, UK; 2SRUC,

Craibstone, Aberdeen, Scotland, UK; 3formerly Macaulay

Land Use Research Institute, Aberdeen, Scotland, UK

It is too simple to say that the ‘marginal’ farms of New England were abandoned because they were no longer productive or desirable as living places. They were given up for one very practical reason: they did not lend themselves readily to exploitation by fossil fuel technology . . . Industrial agriculture sticks itself deeper and deeper into a curious paradox: the larger its technology grows in order to ‘feed the world’, the more potentially productive ‘marginal’ land it either ruins or causes to be abandoned.

(Wendell Berry, 1979)

6.1  Introduction

Small-scale abandoned agricultural systems can be found worldwide: throughout Europe (MacDonald et al., 2000; Marini et al., 2011), on American prairie and hill farms (Manning, 1995; Berry,

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5: Choosing and Evaluating Soil Improvements by Subsoiling and Compaction Control

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5 

Choosing and Evaluating Soil

Improvements by Subsoiling and Compaction Control

Richard J. Godwin1* and Gordon Spoor2

Harper Adams University, Newport, UK; 2Model Farm, Maulden, UK

1

5.1  Introduction

Soil compaction can seriously affect crop

­production, soil quality and biological activity, and considerable time and energy are often expended in attempts to alleviate it. Problems arise through increased mechanical impedance restricting water availability, root development and air and water movement, increasing the risk of anoxic conditions. Figure 5.1 illustrates how alleviating the compaction layer or pan in a sandy loam soil has transformed the root development of sugarbeet.

The influence of compaction on crop production depends on the thickness, location, macroporosity and moisture status of the compact layer, together with the prevailing weather conditions and soil management techniques.

Compaction can also significantly influence soil infiltration rates and the efficiency of sub-surface drainage. These are important locally at farm level, but also at catchment level through their influence on soil erosion and surface flooding, concerns likely to increase in these times of increasing extremes of weather. Visual soil assessment (VSA) has an important part to play in identifying all such potential problems (Ball et al.,

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4: Visual Evaluation of Grassland and Arable Management Impacts on Soil Quality

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4 

Visual Evaluation of Grassland and Arable Management Impacts on Soil Quality

Lars J. Munkholm1* and Nicholas M. Holden2

Aarhus University, Tjele, Denmark; 2University College Dublin, Dublin, Ireland

1

4.1  Introduction

Soil management has a profound influence on soil quality1 through land use, crop rotation, manure spreading, fertilization, irrigation, liming, tillage and traffic. Management effects on soil quality are in many cases complex interactions, and therefore extensive research has been carried out to describe, quantify and understand these effects. Visual soil evaluation (VSE) is one of the tools developed over the last century to specifically evaluate management impact on soil quality.

During the early days of modern farming there was a focus on soil nutrients and mineral fertilizer; however by the mid-20th century

Görbing realized that factors like soil compaction, crusting or drainage also caused poor growth.

Görbing and others recognized that there was a need to supplement assessment of chemical properties with visual assessment of soil structure, root growth and biological activity. His visual assessment spade method (Görbing, 1947) has since been refined by Preuschen (1983), Beste (1999),

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9: The Expanding Discipline and Role of Visual Soil Evaluation

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9 

1

The Expanding Discipline and Role of Visual Soil Evaluation

Bruce C. Ball1* and Lars J. Munkholm2

SRUC, Edinburgh, Scotland, UK; 2Aarhus University, Tjele, Denmark

9.1  Introduction

Drawing on the conclusions of previous chapters, our objective here is to show that methods of visual soil evaluation (VSE) are key aids to the management of soils. They can identify and quantify soil degradation, particularly compaction. These methods can be used to monitor soil quality and thus to maintain its cropping potential. We also identify the future roles of VSE in soils and the environment and suggest improvements in the methods to support these roles.

The prominence of the role of soils for food security and environmental sustainability is likely to increase as the area of land available shrinks and the quality of what is left decreases. Soil is basically a non-renewable resource and, with limited scope to bring new land into cultivation, degradation needs to be decreased or negated by conservation and by restoration of prior degraded land (Lal, 2013). New technologies such as genetic modification are restricted in their ability to increase crop yields by limitations in soil water and/or nitrogen supply (Sinclair and Rufty, 2012) and the constraints of photosynthetic efficiency.

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8: Soil Structure under Adverse Weather/Climate Conditions

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8 

Soil Structure under Adverse

Weather/Climate Conditions

Rachel M.L. Guimarães,1* Owen Fenton,2

Brian W. Murphy3 and Cássio A. Tormena4

1

Department of Agronomy, Federal University of Technology – Paraná,

Brazil; 2Teagasc, Environmental Research Centre, Johnstown Castle,

Co. Wexford, Ireland; 3Honorary Scientific Fellow with the New South Wales

Office of Environment and Heritage, Cowra, Australia; 4Department of Agronomy, Universidade Estadual de Maringá, Paraná, Brazil

8.1  Introduction

The use of the Earth’s natural resources in a sustainable manner has increased in importance over the past few decades. This is particularly true for soil, with soil degradation likely to continue being a serious problem throughout the

21st century, due to its impact on food security and environment quality (Eswaran et al., 2001).

Soil degrades by losing its actual or potential productivity or its function as a result of natural or anthropogenic factors (Lal, 1997). Soil degradative processes include physical, chemical and biological processes. The most important of the physical processes is the deterioration of soil structure leading to crusting, compaction, erosion, anaerobism, salinization, acidification, decrease in cation exchange capability, leaching, volatilization, nutrient imbalance, reduction in soil biodiversity and a decrease in soil organic carbon. The main degradative processes are

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