Effects of row-spacing and stubble height on soil water content and water use by canola and wheat in the dry prairie region of Canada

Studies were conducted to examine the effects of row spacing and stubble height on surface soil water content, water use, yield, and water use efficiency of canola and wheat in the drier regions of the Canadian prairies. For this purpose, randomized complete block design trials were implemented separately in canola and wheat fields at Central Butte and Swift Current in the Brown soil zone of southwestern Saskatchewan. At each experimental site, two factors and two levels for each factor, i.e., 30- and 60-cm row spacing and 15- and 30-cm stubble heights, were included. Wider row spacing and taller stubble generally increased soil water content for the surface 0–30cm soil depth, and taller stubble often had greater spatial variability of surface soil water content at both locations. Row spacing or stubble height had minimal effect on water use for both crops at both locations over the two years (2012 and 2013). Yield and water use efficiency of 30-cm row spacing were 1.3–1.6 (Central Butte) and 1.0–1.2 (Swift Current) times greater than those of 60-cm row spacing. Stubble height had little effects on yield and water use efficiency. There were no interactions of row spacing and stubble height on water use, yield, and water use efficiency for either crop. Overall, 30-cm row spacing and 30-cm stubble tended to increase surface soil water content, yield, and water use efficiency for most crop type, year, and site combinations.