Forecast evaluation of winter wheat productivity using topography

As demonstrated in this study of influence of climate, soils and topography on winter wheat productivity in the non-chernozem zone of Russia, the leading environmental factor was microclimate as defined by insolation of meso-slopes. Spatial variations of topography, climate and soils explained 74-76% of the variance in crop yields, while topography alone explained 40%. It was shown that yields are greater on more illuminated slopes by 1.6-1.9 times. Models of winter wheat productivity for the base period and by the year 2050 are constructed with the use of NASA’s climatic GISS Model E. A new variable, climatic invariant, was introduced for spatial models that describes a combination of February precipitation and spring temperature composed using certain rules. This variable describes a chronological consequence of climatic factors that is important for yields. The spatial heterogeneity of projected yields is essential and is defined not only by climate, but by slope insolation as well. Taking the later into account may be important for planning of field locations for the conditions of climate change by the year 2050.