Drought risk to agricultural land in Northeast and Central Germany

Aim of the study was the evaluation of the present state and further development of drought risk to agricultural sites in Northeast (NE) and Central Germany in consideration of climate changes. Based on the Medium Scale Agricultural Site Map, soil-hydrological data were derived for heterogeneous soil areas. They refer to the landscapes in NE and Central Germany characterized by low precipitation, marked spatial soil heterogeneity, and a high share of hydromorphic soils. The soil data were linked with long-term climate records of 368 stations for the period 1951–2000 as well as a climate scenario for the period 2001–2055. The plant water supply was calculated for three crop groups: cereals, root crops, and grass. The current and future development of drought risk of agricultural land of NE and Central Germany was evaluated. Starting in 1951, the water supply over the vegetation period has been decreasing with time for all crop groups up to now and may continue up to the year 2055 at most sites. However, there are also regions with increased plant water supply. The federal states of Brandenburg and Saxony-Anhalt showed the strongest water deficit. Especially in these states, the plant water supply is strongly limited for cereals already today and probably may get worse for all crops in the future. On an average of the years, drought may limit plant growth in parts at >40% of agricultural land. In the federal states Mecklenburg-Western Pomerania, Saxony, and Thuringia, the plant water supply mostly will stay in an approximately sufficient range due to higher precipitation and more favorable soil quality. The results are a background for the assessment of land-use planning and evaluation of current and future soil- and site-specific crop growing suitability on a medium scale.