FELD 01/2019

Many people in Tanzania suffer from malnutrition. Together with local communities, a research team is working on solutions that could be used as an example for wide parts of Africa. // The more intensive the work on the fields, the more frequently agriculture and nature come into conflict. ZALF research shows that there are ways to better protect amphibians living in fields. // Kettle holes: small water bodies in the middle of our fields, with over 150.000 of them existing in Northern Germany alone. ZALF researchers are studying these biotopes, also looking at the indications they can give about the state of the landscape. // Summer heat waves like in 2018 might become more frequent in the future. An international research team finds out how exactly heat and drought affect crops and how agriculture can adapt.

Climate change Climate

Climate change Climate change LESS MAIZE, MORE WHEAT The results of the simulations make it clear: “It is above all drought stress in maize cultivation that leads to high yield losses”, says Heidi Webber. For the future, the models also predict declining maize yields with increasing demands for water. However, this is not the case to this extent for winter wheat. Here the team was not able to explain the yield fluctuations with drought. It is evidently less sensitive to drought stress than maize. Winter wheat may benefit from its sowing date. While summer wheat is sown in spring, winter wheat is sown in fall. If temperatures are mild, the seeds begin to germinate. During winter, the young plants barely suffer from drought stress, can form strong roots and in the warmer, drier season can also tap deeper water reserves. On the other hand, things can soon become critical for maize seedlings if too little rain falls after sowing in spring. “According to the model results, winter wheat yields could even rise”, explains Webber, explaining this with rising concentrations of CO2. “CO2 stimulates the growth of wheat and partially compensates for the negative effects of stress.” Thanks to their metabolism, cereals seem to be well prepared for climate change, at least in most European growing regions. However, this characteristic does not help in years of severe drought such as 2018. “In extremely dry years, the yields of wheat also decline”, Webber emphasizes. DROUGHT IS THE GREATEST RISK In other words, drought is the greatest risk factor in European agriculture. How can farmers react? “There is no single answer”, says Heidi Webber, “because conditions vary from place to place.” To prevent drought years like 2018 from resulting in massive crop failures, agricultural actors have to react on many levels. In future, they will have to give more thought to irrigation, alternative methods of cultivation and approaches to breeding, which will above all increase the drought resistance of the plants. Too hot and too dry: In the summer of 2018 there were crop losses of up to 50 percent in some regions of Germany. An important strategy for adapting agriculture to climate change is breeding more resistant crops. www.zalf.de/feld/en 32 33