Climatic and non-climatic drivers of spatiotemporal maize-area dynamics across the northern limit for maize production—A case study from Denmark

Abstract

It is expected that the ongoing anthropogenic climate change will drive changes in agricultural production and its geographic distribution. Here, we assess the extent to which climate change is already driving spatiotemporal dynamics in maize production in Denmark. We use advanced spatial regression modeling with multi-model averaging to assess the extent to which the recent spatiotemporal dynamics of the maize area in Denmark are driven by climate (temperature as represented by maize heating units [MHU] and growing-season precipitation), climate change and non-climatic factors (cattle density [in Denmark, maize is mainly grown for ensilage to feed livestock], and sandy soil [facilitates maize growing in cold areas due to higher soil temperature than loamy soils]). Our results indicate that there has been a geographical expansion of maize in Denmark from 1999 to 2008, with a strong link to rising MHU at the national scale. The geographic distribution of maize cultivation in Denmark was mainly related to the distribution of cattle-livestock farming followed by sandy soils and climate (MHU). Cattle density has increased in importance over time indicating an increasing coupling of maize cultivation and cattle farming, probably reflecting a change to a more favorable climate for maize cultivation: in the beginning of the study period, northern areas were mostly too cold for maize cultivation, irrespective of cattle density, but this limitation has been diminishing as climate has warmed, allowing maize production also in northern locations with high cattle density. Similarly, the association of maize cultivation with sandy soils has decreased over the study period, again consistent with a decreasing overall climatic limitation. Thereby, reflecting an interactive effect of climatic and non-climatic factors on the maize area dynamics. Our results show that even the relatively small climate changes that have been realized in the last decades have been partly driving the spatiotemporal dynamics of an important agricultural crop towards its northern cultivation limit in Europe.