Corn Yield Response to Drainage and Subirrigation in the Canadian Prairies

Abstract

Subsurface drains are commonly used in humid regions to deal with high water tables. However, corn (Zea mays L.) could benefit from subsurface drainage even under semi-arid conditions where high-intensity rainfall causes the water table to rise within the root zone for short periods. In southern Manitoba, seasonally high water tables with high salinity have led to salinization of the root zone, making subsurface drainage an attractive option to increase yields. The objective of this research was to evaluate agronomic performance of corn under water table management using subirrigation and tile drainage. Four treatments were tested in this experiment: (1) controlled drainage with subirrigation (CDSI), (2)no drainage with overhead irrigation (NDIR), (3) free drainage with overhead irrigation (FDIR), and (4) no drainage with no irrigation (NDNI) as control. The impacts of these treatments on crop performance, measured by yield, kernel quality, plant biomass, and plant height, were evaluated over two growing seasons. In the first year, which was 57% wetter than the 30-year average, yields were 8.48 (NDNI), 10.36 (NDIR), 10.10 (FDIR), and 9.22(CDSI) Mg ha-1 with only the mean yield difference for the NDIR and the CDSI treatments being statistically significant (p = 0.014). In the second year, which was 16% drier than normal, yields were 9.25 (NDNI), 10.47 (NDIR), 11.28 (FDIR), and 9.49 (CDSI) Mg ha-1 with no statistically significant differences in yield.