Climatic conditions for crop production in Nordic countries

Climate is today a more determinant factor for yield level than it was in the past, when soil fertility was more important. The regional variation in radiation during the growing season in Nordic countries is less than that in temperature conditions. A combined plant growth-related index of these climatic factors accumulated during the growing season decreased from an annual value of 106 at 56°N (Ødum, East Jutland) to about 90, 60 and 44 at 60°N, 67°N and 70°N, respectively. The difference between coastal areas in Norway and the Finnish interior was either negligible or about 10% in disfavour of the coast at 67°N. When the moisture conditions of an imaginary pasture crop on a sandy soil were taken into account, the combined accumulated growth index of radiation, temperature and soil moisture was 71 at Ødum. On the Norwegian coast, the values were 72, 49 and 37, whilst in Finland, up to northeastern Norway, they were 56, 43 and 35 at 60°N, 67°N and 70°N, respectively. Plant production potential may be directly related to the accumulated growth index