Recent warming across the North Atlantic region may be contributing to an expansion in barley cultivation

Peter Martin,Jens Ivan Í Gerdinum,Mette Thomsen,Ólafur Reykdal,Joanne Russell,Saemundur Sveinsson,Katrin Mackenzie,John Wishart,Hilde Halland,Vanessa Kavanagh,Jónatan Hermannsson,Sigridur Dalmannsdottir

doi:10.1007/s10584-017-2093-y

Abstract

Although grass dominates most agricultural systems in the North Atlantic region (NAR), spring barley is the most important cereal and is used for animal feed and food and drink products. Recent changes in climate have resulted in warmer conditions across the NAR which have major implications for crop production. In this paper, we investigate the thermal requirement of spring barley in the region and use the results to examine the effects of recent trends in temperature and rainfall on barley cultivation, based on 11 regional meteorological sites. At these sites, between 1975 and 2015, we found significant warming trends for several months of the cropping season and significant trends for increases in the cropping season degree days (CSDD). In recent years, this has resulted in an increased proportion of years when the estimated minimum thermal requirement for barley has been met at sites above about 60°N. However, annual variations in CSDD are large and years still occur at these sites where this is insufficient. While warming could potentially allow an earlier start and later end to the cropping season, it is likely that high rainfall at maritime sites, and low rainfall at continental sites, will limit the ability of growers to benefit from this. Warming is considered to have been one of the main factors contributing to the large expansion of the area of barley cultivated in Iceland since the 1990s.

Highlights

In most of the North Atlantic region (NAR), defined here as Newfoundland, Greenland, Iceland, coastal Norway, the Faroes, and the Scottish archipelagos of Shetland, Orkney and the Western Isles, grassland or rough grazing dominate the agricultural area (Peltonen-Sainio 2012)
Using a range of sources (Table 1), we found large differences in Day requirement (DR) and thermal requirement (TR) of spring barley in northern regions when grown for dry grain
Temperature and day length, in particular, have a strong positive effect on the rates of crop phenological phases which tend to be shorter at high latitudes, resulting in shorter cropping seasons

Summary

Introduction

In most of the North Atlantic region (NAR), defined here as Newfoundland, Greenland, Iceland, coastal Norway (from Rogaland to Finnmark), the Faroes, and the Scottish archipelagos of Shetland, Orkney and the Western Isles, grassland or rough grazing dominate the agricultural area (Peltonen-Sainio 2012). In more continental parts of the region, late frosts and dry weather after sowing can result in poor establishment (Peltonen-Sainio 2012). Considering these challenges, it is likely that the main driver for barley cultivation in the past was the isolation of this region and the need for selfsufficiency. With renewed interest in sustainability and a growing tourist market across the region for high provenance food and drink products, there has been a resurgence of interest in growing barley for these markets (Martin 2016)

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Discussion

Conclusion