Little Ice Age Farming in Finland: Preindustrial Agriculture on the Edge of the Grim Reaper's Scythe

This study examines potential climatic influences on historical agrarian populations in Finland by means of historical weather diaries, rye phenology, and rye and barley grain-figure (ratio between sown and harvested grain) data from the sixteenth to the nineteenth centuries. Crops exhibited great temporal variation. During the poorest years, the amount of harvested grain was less than that sown whereas during the better years the sown grain was harvested more than tenfold. Depending on the locality, 37-84% of this variability could be explained by monthly variables of growing season temperature and precipitation over the latter half of the eighteenth century. Although the grain-figure data showed clear spatial synchrony, it was found that this synchrony was much weaker than that of temperature, precipitation or rye phenology. Consequently, individual crop failure years should not be extrapolated over widely extended areas from spatially restricted data. Further, it was found that the desertion of farms in the sixteenth and the seventeenth centuries occurred coterminously with long-term summer temperature cooling, indicating that the desertion may have resulted from climatic deterioration that significantly impeded agriculture as a means of subsistence.