U N I V E R S I T Y O F A A R H U S Faculty of Agricultural Sciences Climate change impact on winter wheat yield and nitrogen leaching Preliminary analysis Tove Heidmann & Jørgen E. Olesen Department of Agroecology

Methods Daisy model Simulations for selected regions in Europe Baseline climate data from MARS/STAT database at JRC ( ) Future climate data from ENSEMBLES Two crops: winter wheat and spring barley

MARS/STAT grid

Thresholds 20 % decrease in yield 10 % decrease in yield Nitrogen leaching > 25 kg N/ha

Example - preliminary work Future climate data from perturbed physics experiment ( ) Two locations: Denmark and South Germany Crop: winter wheat Fertilisation: optimum N rate Soil type: same soil type at both sites (14 % clay in top soil)

Cumulative probability plot of temperature change and precipitation change

Changes in climate South Germany: Precipitation: -15, -10, -5, 0, +5, +10, +15 % Temperature: +1, +2, +3, +4, +5, +6 o C Denmark Precipitation: -10, -5, 0, +5, +10, +15, +20, +25 % Temperature: +1, +2, +3, +4, +5, +6 o C

Changes in climate Two different situations Precipitation evenly distributed on all months Seasonal variation in precipitation included

Seasonal variation in climate (from Ruosteenoja et al., 2003)

Including seasonal variation in precipitation distribution South Germany Decrease: Decrease in precipitation during May – Nov. (larger decrease during Jul. – Aug.) Unchanged precipitation during Dec. – Feb. Increase Unchanged precipitation during Jun. – Aug. Increase in precipitation during the rest of the period (larger increase during Dec. – Feb.)

South Germany, 20% yield decrease

South Germany, 10 % yield decrease

South Germany, Leaching > 25 kg N/ha

Seasonal variation in climate (from Ruosteenoja et al., 2003)

Including seasonal variation in precipitation distribution Denmark Increase: Increase in precipitation during Sep. – May Decrease in precipitation during Jun. – Aug. Decrease: All the decrease in Jun. – Aug. The rest of the months unchanged

Denmark, 20 % yield decrease

Denmark, 10 % yield decrease

Denmark, leaching > 25 kg N/ha

Response surfaces in combination with probabilistic information on future climate

Remarks Baseline climate from , should be CO 2 concentration not included in simulations

Preliminary conclusion Calculations of nitrogen leaching is more sensitive to seasonal variation in climate data than the calculations of crop yields.

Future work Seasonal relationships between meteorological variables in future climate data will be investigated Include CO 2 -concentrations, fixed for each time period Include the seasonal variation in climate in the calculations Simulations with two crops: winter wheat and spring barley Simulations for more locations and local soil types