Climatic Suitability for Plant Production in Switzerland

Solar radiation, temperature and precipitation are important climatic factors driving crop yield potentials. Consequently, climate change has implications for the regional suitability to cultivate specific crops. To make optimal use of regional site potentials, it is important to quantify crop-specific climatic suitability and its variation in time and space.

For this purpose, Agroscope developed a modelling approach, which evaluates climatic yield potentials for main arable crops on the basis of growth-phase specific climate indicators. Results can serve as a basis for planning climate adaptation measures such as irrigation infrastructure.

Average climate suitability and water-availability-related limitations for the cultivation of grain maize in Switzerland (1983–2010; from Holzkämper et al. 2014 Regional Environmental Change).

So far, climate potentials and limitations were quantified for maize and winter wheat, allowing us to understand which climatic factors are most limiting to yield potentials, and which limitations gain in importance as climate change progresses (e.g. heat and drought stress).

Results show that the productivity of winter wheat is mainly limited by waterlogging, frost, heat and insufficient solar radiation under current climate conditions. With rising temperatures, we must thus expect an increase in heat stress limitations.

Current grain maize productivity is mostly limited by sub-optimal growth temperatures and solar radiation. This implies that production potentials for grain maize could increase with temperatures approaching the optimum.

Temperature effects on the acceleration of phenological development were found to play an important role: shifting the vulnerable flowering stage to an earlier period of the year can reduce the adverse effects of drought and heat stress. On the other hand, accelerated phenological development also leads to a shortened grain-filling period, which in turn reduces yield.