Impact of climate changes on crop yields of winter rye in Halle (southeastern Germany), 1901 to 1980

Abstract

This study attempts to answer the question whether observed recent climatic changes have had an impact on the crop yields of winter rye in this century, using grain yields from a long-term fertilization experiment in Halle (southeastern Germany). Using the statistical method of factor analysls it was possible to show that the long-term yield variations in Halle were associated with recent climate changes (i.e. on a time scale from years to decades) between 1901 and 1980. During this period annual climate fluctuations from October (sowing) to August (harvest) were significantly correlated with crop yields. A clear difference between years with high and low yields was discernible with respect to the corresponding annual climatic anomalies. Generally it was easier to explain high yields than low ones. because there are various possible reasons for low yields. The results of this study show that relatively small climate changes in this century have affected crop yields; it is therefore probable that the expected clinlate change due to the increase of trace gases in the atmosphere will have a substantial impact on crops and therefore on agriculture, unless new crop varieties become available which are well adapted to the new climatic situation.