Does climate change affect period, available field time and required capacities for grain harvesting in Brandenburg, Germany?

Grain harvesting is one of the most weather-dependent processes in agriculture. Grain moisture contents decide on machinery use and costs and determine the necessary grain harvesting and preservation capacities of farms. The objective of this work is to investigate whether and how recent climate changes in the German state of Brandenburg affect the available field time and the required combine harvester capacity. Weather data, the beginning of harvesting, available hours with defined grain moisture contents and total required harvesting capacity are analyzed for the years 1961-2013 for winter wheat, winter rye, winter barley and spring barley. The trends found differ for the four cereal crops. Compared with 53 years ago, today harvesting starts significantly earlier for two cereal crops (−16 days for spring barley and −11 days for winter wheat). The available harvesting hours show a clear and highly significant increase for winter wheat (up to +9%), a distinct and highly significant decrease for winter barley (up to −20%), as well as a slight and significant decrease for winter rye (up to −3%). Inter-annual variability decreases for winter wheat and increases for winter barley. The unfavorable changes for winter barley do not ultimately affect the total required machinery capacity due to the separate harvesting period and relatively small cropping area for winter barley. In contrast, the primarily favorable trends for winter wheat lead to an increase in the total required combine harvester capacity, since the earlier harvesting period overlaps with the rye harvesting period.