Risk/opportunity:(from the Climate Change Risk Assessment for Scotland 2012):
AG25/AG51/AG52 Agricultural land classification and crop suitability. Cross-cutting (including changes in yields, human food supply)
Narratives: Suitability and productivity (agriculture)
SCCAP theme: Natural environment
N3: Sustain and enhance the benefits, goods and services that the natural environment provides
Crop diversity index (2015): 0.72
Crop portfolio (2015): see Figure 2
- Over half of Scotland’s arable land is used to grow barley, with the majority being winter rather than spring barley.
- Between 1988 and 2015 there was an overall decline in diversity largely due to annual fluctuations in the dominance of spring barley in the crop profile. An increase in diversity from 1988 to a peak in 1994 was due to an increase in both oilseed rape and wheat and a decline in the dominance of spring barley.
- Changes in agro-climate will not only impact on the sustainability of existing cropping but is likely to also create opportunities for new crops which may begin to alter the overall crop portfolio.
- Climate is likely to become increasingly important in influencing management options such as timing of operations and cultivar choice. However the main drivers of crop choice are likely to be based on market demands and prices
- European greening measures include crop diversification. The regulations impact on around 30% of Scotland’s farms, but it is estimated that only 800-900 will need to grow any additional crops to comply, with a larger number likely to need to reduce the dominance of their main crop.
- Significant changes in crop portfolio and overall diversity are likely to be in response to factors such as policy reform, global production and trade, and advances in research and technology.
Climate change can influence agricultural crop production, both positively and negatively, in a number of ways (Olesen et al, 2011):
- Increasing CO2 impacts on the growth and physiology of the plants
- Changes in temperature, rainfall, radiation etc. influence plant development and growth
- Damage due to extreme weather events
- Changing suitability for planting certain crops
- Changing occurrence of competitive weeds, pests and diseases
- Pollution (e.g. nitrate leaching) or degradation of the soil (e.g. erosion)
There is therefore a need to ensure that farmers are able to a) sustainably maximise potential opportunity, and b) ensure that resilience is built into Scotland’s agricultural system in order to be able to withstand shocks and adapt to future changes (Scottish Government, 2015b). Crop diversification has the potential to improve resilience in a number of ways e.g. increasing the ability to suppress pest outbreaks and reducing pathogen transmission; buffering impacts on crop production due to increased climate variability and/or extreme events (Lin, 2011; Abson et al, 2013).
The June Agricultural Census (Scottish Government, 2015a) collects annual data on land use, crop areas, livestock and the number of people working on agricultural holdings. This indicator uses the planted area data for 38 crops which have been consistently recorded since 20091.
The crop diversity index is based on Simpson’s Diversity Index which ranges from 0 to 1, where the greater the number the greater the level of diversity. Here the number of crops for which data has been included remains constant in order to maximise the number of years for comparison (due to changes in data collection methodology), and therefore any change in the index is as a result of a change in the evenness (relative abundance) rather than number of crops grown.
The latest diversity index for 2015 is 0.72 (Figure 1), but there has been no significant overall trend in diversity over the last 6 years with the index figure varying by +/- 0.02. The latest figures showed that over half of Scotland’s arable land was used to grow barley, with the majority being winter rather than spring barley2 (Figure 2). Approximately 20% of arable land was used to grow wheat, with oilseed rape (winter and spring), oats (winter and spring) and potatoes (ware3 and seed) being the other three single dominant crop types grown in Scotland’s crop portfolio.
Figure 1 Crop diversity index (2009-2015) for the whole of Scotland. Crop diversity calculated using the Simpson’s Diversity Index.
Figure 2 Comparison of major crop areas in Scotland4 (2015)
Between 1988 and 2015 there was an overall decline in the diversity of Scotland’s crop portfolio (Figure 3). This was largely dictated by the annual fluctuations in the dominance of spring barley in the crop profile. The increase in diversity from 1988 to a peak in 1994 was due to an increase in both oilseed rape and wheat and a decline in the dominance of spring barley (Figure 4).
Figure 3 Crop diversity index (1988-2015)5 for the whole of Scotland. Crop diversity calculated using Simpson’s Diversity Index6
Figure 4 Comparison of Scotland’s major crop portfolio (1982-2015)
Whilst the drivers of crop choice are likely to remain largely economic in origin (based on market demands and prices), climate influenced environmental drivers are projected to become increasingly important in influencing e.g. timing of operations and cultivar choice. These management changes may not, however, be able to adequately compensate for potential impacts on the yields of some crops and farmers as a result may need to consider altering crop choice itself. Changes in agro-climate will not only impact on the sustainability of existing cropping but is likely to also create opportunities for new crops which may also begin to alter the overall crop portfolio.
Impacts on viability and industry response are likely to be very crop (and location) specific e.g.:
- Although climate change is likely to affect the stability of barley yield through e.g. waterlogging in winter and water stress in drier summers, compared to other cereals, barley is an inherently resilient crop (Newton et al, 2013). Given it is of considerable economic importance for the whisky industry, it is highly likely that barley will therefore continue to be the dominant arable crop in Scotland.
- By contrast, potato production is far more vulnerable to projected climate change which is likely to expose Scotland’s potato crops to an increase in environmental stresses and a wide range of pests and diseases (Taylor & Stewart, 2013). As a consequence, in current research and breeding efforts there is a strong emphasis being placed on understanding and development of climate and pest resistance/ tolerance to better equip the Scottish potato industry to flourish in a changing climate.
Future indicator development may therefore also need to consider genetic and phenotypic (rather than crop) diversity which may be critical in order to ensure stability, resilience and enhanced system function (Newton, 2010).
The changing climate is also likely to result in significant shifts in land use. Analysis using both UKCIP02 (Brown et al., 2008) and UKCP09 (Brown et al., 2011) indicate a significant expansion of prime land, identified as being in the range of 20-40%. This is mainly a consequence of the shift towards warmer drier summers for the lowland agricultural areas of Scotland (in average years) evident in most climate change projections or scenarios. It is too early to determine whether this shift will also alter the overall crop portfolio and diversity of Scotland’s farming.
Until the mid-1950s, oats was the predominant cereal in Scotland and occupied around 75% of the arable land. The introduction of autumn-sown crops such as winter wheat, along with responses to changing market demands were largely responsible for these changes (Scotland’s Environment Web, 2011).
Arable crops, particularly barley, are often grown in rotation with grass or a break crop. Oilseed rape is often used as a break crop and has become the third most commonly grown crop in Scotland (after barley and wheat). The ban on the use of lindane, an organochlorine insecticide formerly used on up to 80% of Scotland’s rape crops, coincided with a significant drop in the production area of oilseed
rape in Scotland by almost a half (largely due to a drop in the planting of spring rather than winter oilseed), and the areal figures have generally remained at this lower figure since then (Scottish Government, 2016).
European greening measures, targeted at addressing a range of environmental challenges, includes crop diversification. This aims to ensure that a wider range of crops are grown, to try and limit monoculture cropping and to improve soil quality. As a consequence, farmers with between 10-30 ha of arable land will need to grow at least 2 different crops, those with more than 30 ha arable land must grow at least 3 different crops, with the main crop covering no more than 75% of the arable land. This impacts on around 30% of Scotland’s farms, but it is estimated that only 800-900 will need to grow any additional crops to comply (Scottish Government, 2013), though a larger number are likely to need to reduce the dominance of their main crop (NFU Scotland, 2014). Between 2014 and 2015 the area of cereal crops planted fell by approximately 4%, which is seen as a reaction to the new crop diversification rules (Scottish Government, 2015c). However, given the inter-annual variation in diversity (Figure 3) it is not yet possible to determine if the increase in diversity shown since 2013 is significant.
A large amount of farm-level adaptation (including diversification) is likely to arise autonomously as farmers make within year and more long term management decisions in response to fluctuations in yield (e.g. timing of field operations and choice of cultivars). However, it is likely that more significant changes in Scotland’s crop portfolio and overall diversity will be in response to other factors such as policy reform, global production and trade, and advances in research and technology (ACCSG, 2008).
From 2009, data on land use was obtained from the Single Application Form (SAF). In 2012 25,000 holdings claimed Single Farm Payments. This data has been combined with land use data from all the other holdings, collected through June Census forms, to generate overall 2012 June Census results.
The use of SAF data has resulted in a step change in some of the land use results from 2009, especially for rough grazing and grass. This means that trends between 2008 and 2012 for these land use categories do not represent genuine changes in land use, but do represent differences in the way this data has been reported between 2008 June Census and 2009 to 2012 SAF. These trends should be treated with caution (Scottish Government, 2015a).
Abson, D.J., Fraser, E.D.G., Benton, T.G. (2013) Landscape diversity and the resilience of agricultural returns: a portfolio analysis of land-use patterns and economic returns from lowland agriculture.
Agriculture & Food Security 2:2. DOI: 10.1186/2048-7010-2-2
Agriculture and Climate Change Stakeholder Group (ACCSG) (2008) Climate Change and Scottish Agriculture: Report and Recommendations of the Agriculture and Climate Change Stakeholder Group (ACCSG). Available online at: http://www.gov.scot/Publications/2008/05/15115150/0
Brown, I., Towers, W., Rivington, M. & Black, H. (2008) Influence of climate change on agricultural land- use potential: adapting and updating the land capability system for Scotland. Climate Research, 37, 43- 57.
Brown, I., Poggio, L., Gimona, A. & Castellazzi, M. (2011) Climate change, drought risk and land capability for agriculture: implications for land use in Scotland. Regional Environmental Change, 11, 503-518
Lin, B.B. (2011) Resilience in agriculture through crop diversification: Adaptive management for environmental change. BioScience 61 (3), 183-193. doi: 10.1525/bio.2011.61.3.4
Newton, A. (2010) Optimising composition and spatial deployment of diversity in agricultural crops for disease control and yield enhancement. Third Maths in Plant Sciences Study Group, University of Nottingham. Available online at: http://www.cpib.ac.uk/wp-content/uploads/MPSSG3_report_Newton.pdf
Newton, A. C., Thomas, B & Bingham, I. (2013) Breeding for Climate Change: Future-Proofing the Scottish Barley Industry. Policy brief for ClimateXChange. Available online
NFU Scotland (2014) Briefing note: CAP Greening –Crop Diversification. Available online at: http://www.nfus.org.uk/system/files/414ThreeCropRule%20briefing_1.pdf
J.E. Olesen,M. Trnka,K.C. Kersebaum,A.O. Skjelvåg,B. Seguin,P. Peltonen-Sainio,F. Rossi,J. Kozyra,F. Micale (2011) Impacts and adaptation of European crop production systems to climate change. European Journal of Agronomy 34, 2, 96-112. doi:10.1016/j.eja.2010.11.003
Scotland’s Environment Web (2011) Land use and management. Newsletter, November 2011. Available online at: http://www.environment.scotland.gov.uk/media/54767/Land-Land-Use-and-Management.pdf
Scottish Government (2013) Scottish Government consultation on Future CAP direct payments in Scotland from 2015. Available online at: http://www.gov.scot/Publications/2013/12/5922/0
Scottish Government (2015a) Abstract of Scottish Agricultural Statistics 1982 to 2015. Available online at: http://www.gov.scot/Topics/Statistics/Browse/Agriculture-Fisheries/PubAbstract/Abstract2015
Scottish Government (2015b) The Future of Scottish Agriculture: a Discussion Document. Available online at: http://www.gov.scot/Resource/0047/00479616.pdf
Scottish Government (2015c) Final estimates of the Scottish cereal and oilseed rape harvest 2015. Available online at: http://www.gov.scot/Publications/2015/12/5988/0
Scottish Government (2016) Survey of Scottish Winter Oilseed Rape Cultivation 2014/15: Impact of Neonicotinoid Seed Treatment Restrictions. Available online at: http://www.gov.scot/Publications/2016/02/7470
Taylor, M. & Stewart, D. (2013) Breeding For Climate Change: Future-Proofing The Scottish Potato Industry. Policy brief for ClimateXChange. Available online
Scottish agricultural statistics: http://www.gov.scot/Topics/Statistics/Browse/Agriculture-Fisheries
Farming for a Better Climate: http://www.gov.scot/Topics/farmingrural/Agriculture/Environment/climatechange/Advice