Climate change is causing increased temperatures and changing the distribution of precipitation. However, it remains elusive how climate change will affect regions and what intensity they will have.
Recently, scientists at the Technical University of Munich have investigated the effects of various weather parameters on the long-term yields of winter barley. They also evaluated the parameters that have a decisive impact on plant development throughout the year and during specific growth phases.
They found that the weather conditions in the winter and during the transitional phases from fall to winter and winter to spring have a significant influence on the yield level of key cereal crops, such as winter barley and winter wheat.
Past studies only focused on the water supply (drought stress) and Temperature (heat) during the growing season. This new study determines the weather parameters outside the growing season – a topic to have received less attention to date.
The first author, Dr. Kurt Heil, said, “Our continuous field trials in Dürnast near Freising (Bavaria) have provided a very comprehensive archive of data for studying the relationships between climate change and yields. The soil available here consists of very fertile Pleistocene Loess.”
“Late frosts can sometimes occur in our area as late as May. As winter periods end earlier nowadays on a perennial average, late frosts of this kind have a significant impact on plant health, as the plant already begins to grow at a temperature of a few plus degrees, so late frosts damage the young shoots.”
With higher rates of nitrogen fertilization, however, weather patterns become increasingly significant during growing seasons, which has also caused plants to become more sensitive to extreme weather conditions. When more fertilizer is used, plants grow more strongly, which means they consume more water and, in the absence of precipitation, are hit harder by drought than when they grow less strongly.
Urs Schmidhalter, Professor of Plant Nutrition at TUM, said, “Temperature and precipitation are of importance with all calculations in all variants, but to a lesser extent when they are considered as totals or averages. Specific indices such as frost change days, temperature thresholds, the precipitation intensity, rain-free days, the early or late frost index, and the drought index are of greater relevance in this context.”
Scientists mainly determined the annual variations in crop yields due to prevailing climatic conditions in the winter and the transition periods from the warmer season to the winter and vice versa.
Temperature thresholds, frost change days, and precipitation intensity are critical in the winter. During the main growing seasons, only the intensity of the rainfall was of considerable importance.
Heil said, “These results can be attributed to the high availability of the available field water capacity at this location, which significantly reduces the need for summer precipitation when the stores of groundwater are replenished in the winter.”
The potential effects of climate change are transferable to high-yield locations in Western Europe, which are among the world’s most fertile and high-yield places of cultivation and therefore predestined and essential for food production. The continuation of long-term experiments also suggests essential insights and predictions concerning the effects of climate change in the future.
- Heil, K.; Gerl, S.; Schmidhalter, U. Sensitivity of Winter Barley Yield to Climate Variability in a Pleistocene Loess Area. Climate 2021, 9, 112 – DOI: 10.3390/cli9070112
- Heil, K.; Lehner, A.; Schmidhalter, U. Influence of Climate Conditions on the Temporal Development of Wheat Yields in a Long-Term Experiment in an Area with Pleistocene Loess. Climate 2020, 8, 100 – DOI: 10.3390/cli8090100