Perceived Causes and Solutions to Soil Degradation in the UK and Norway

Soil quality is declining in many parts of the world, with implications for the productivity, resilience and sustainability of agri-food systems. Research suggests multiple causes of soil degradation with no single solution and a divided stakeholder opinion on how to manage this problem. However, creating socially acceptable and effective policies to halt soil degradation requires engagement with a diverse range of stakeholders who possess different and complementary knowledge, experiences and perspectives. To understand how British and Norwegian agricultural stakeholders perceived the causes of and solutions to soil degradation, we used Q-methodology with 114 respondents, including farmers, scientists and agricultural advisers. For the UK, respondents thought the causes were due to loss of soil structure, soil erosion, compaction and loss of organic matter; the perceived solutions were to develop more collaborative research between researchers and farmers, invest in training, improve trust between farmers and regulatory agencies, and reduce soil compaction. In Norway, respondents thought soils were degrading due to soil erosion, monocultures and loss of soil structure; they believed the solutions were to reduce compaction, increase rotation and invest in agricultural training. There was an overarching theme related to industrialised agriculture being responsible for declining soil quality in both countries. We highlight potential areas for land use policy development in Norway and the UK, including multi-actor approaches that may improve the social acceptance of these policies. This study also illustrates how Q-methodology may be used to co-produce stakeholder-driven policy options to address land degradation.

Soil Erosion Susceptibility Prediction in Railway Corridors Using RUSLE, Soil Degradation Index and the New Normalized Difference Railway Erosivity Index (NDReLI)

This study presents a remote sensing-based index for the prediction of soil erosion susceptibility within railway corridors. The empirically derived index, Normalized Difference Railway Erosivity Index (NDReLI), is based on the Landsat-8 SWIR spectral reflectances and takes into account the bare soil and vegetation reflectances especially in semi-arid environments. For the case study of the Botswana Railway Corridor (BRC), the NDReLI results are compared with the RUSLE and the Soil Degradation Index (SDI). The RUSLE model showed that within the BRC, the mean annual soil loss index was at 0.139 ton ha−1 year−1, and only about 1% of the corridor area is susceptible to high (1.423–3.053 ton ha−1 year−1) and very high (3.053–5.854 ton ha−1 year−1) soil loss, while SDI estimated 19.4% of the railway corridor as vulnerable to soil degradation. NDReLI results based on SWIR1 (1.57–1.65 μm) predicted the most vulnerable areas, with a very high erosivity index (0.36–0.95), while SWIR2 (2.11–2.29 μm) predicted the same regions at a high erosivity index (0.13–0.36). From empirical validation using previous soil erosion events within the BRC, the proposed NDReLI performed better that the RUSLE and SDI models in the prediction of the spatial locations and extents of susceptibility to soil erosion within the BRC.

Soil, Water, and Climate Change Integrated Impact Assessment on Yields

This article describes the potential yields of maize, wheat and barley which were modeled with climate change, soil degradation and water balance scenarios in central Mexico. Two adaptation measures were also evaluated. To estimate yields the AquaCrop-FAO model was applied. Three study cases were chosen and their climate, soil, phenological and management information was compiled. Once calibrated, the authors tested the response in yields for 28 climate change scenarios: five General Circulation Models, two RCP and three-time horizons. Two adaptation actions were evaluated: changing planting date and increase of organic mulches. Results show that yield of maize in the near future (2015-2039) would fall 50% average, barley and wheat yields would decrease in 40% and 25% respectively. If soil degradation and loss is considered, the yield will reduce considerably. Adaptation measure based on changing planting date was as effective as increasing mulches. It is necessary to consider soil together with climate change scenarios in yield modeling. It is possible to suggest wrong adaptation measures if only the climate is considered and not all the variables involved.

Environmental Consequences of Soil Erosion

Soil is one of the most valuable natural resources. Despite soil importance, the pressures on soil have increased in recent decades. Soil degradation is a critical and growing problem, whereby soil erosion presents a prevailing process compared to other degradative processes. The intensity of erosion depends on the topography, climate conditions, soil characteristics, human activities, and the presence of vegetation. In this chapter, the diverse factors that cause soil erosion have been evaluated. The level of damage associated with soil erosion has been analyzed, with emphasis on the impacts they may have on the global carbon cycle, phosphorus loss, dust emissions, eutrophication, and soil biodiversity.

Wind Erosion, Climate Change, and Shelterbelts

Wind erosion is a widespread phenomenon causing serious soil degradation. It is estimated that about 28% of the global land area suffers from this process. Global climate changes are expected to accelerate land degradation and significantly affect the intensity of wind erosion. Shelterbelts are linear multi-row planting strips of vegetation (trees or shrubs) established for numerous environmental purposes. Shelterbelts are a specific type of agroforestry system which could reduce soil degradation (soil erosion). Shelterbelts mitigate greenhouse gas through trees storing carbon (C) in their above- and below-ground biomass, wherefore they are highlighted as one of the potential ways to mitigate climate change. The purpose of this chapter is to present wind erosion as a land degradation problem, especially in line with climate changes and the present concept of vegetation establishment in the form of shelterbelts for long-term multi-functional provision of ecosystem services, in particular carbon sequestration.