Effects on irrigation patterns and management dates on silage corn and winter wheat yields in Northern Germany under climate change

Historically, there has not been major disputes over water rights between agriculture and domestic use in Northeastern Lower Saxony (NELS). In the 30-year mean from 1971 to 2000, the water balance national average was positive at 185 mm. According to the climate report for Lower Saxony, the water surplus will decrease by two-thirds for period 2070-2100 for RCP 8.5 scenario. NELS might be particularly vulnerable to more unstable precipitation patterns due to the sandy soil textures.

Frequency and intensity in drought events will intensify in the coming decades; irrigation investments might be the most promising option to attain stable yields for existing crops. Nevertheless, assessing feasible irrigation strategies requires consistent information on several crop processes and their impact by different weather conditions and irrigation strategies. EPIC crop model can generate data that allow testing of various irrigation options and their future implications. This offers an opportunity to save time resources, facilitating this way the decision-making processes.

In this study, we have simulated with EPIC crop model different irrigation levels changing application dates in regards to seasonal water deficit. The simulations use the crop rotation (potato – sugar beet – silage corn – soybean – winter wheat) under three RCPs scenarios (2.6, 4.5 and 8.5). With this research, we aim to advance the understanding of how irrigation influences soil quality and its contribution to the agriculture practices in Lower Saxony to emissions. Moreover, we investigated the effect of planting and harvesting dates on yield and soil quality.