INFLUENCE OF INTERCROPPING AND SUBIRRIGATION ON SOIL MOISTURE AND WATER TABLES UNDER MAIZE IN QUEBEC

Abstract

Intercropping and water table management have become important tools in reducing nitrate leaching from fields under maize production in Quebec. However, the effects and interactions between these two management practices and soil moisture and water table fluctuations in the region have not been investigated. A water table management study was conducted in Soulanges County, Quebec during the summer of 1994. Three water table levels freely drained (1.0 m) and subirrigated to 0.5 m and 0.75 m from the ground surface; and two cropping systems; monocropped maize (Zea mays L.) and maize with ryegrass (Lolium multiflorum Lam.), were factorially combined. Soil moisture content (SMC) at three depths (0–0.15, 0.15–0.30, and 0.3–0.5 m), and water table depths (WTD) were monitored twice a week, and meteorological data were collected at the site. The 0.5 m and 0.75 m subirrigated plots provided the same SMC trends in both cropping systems, but the SMC in freely drained plots was always lower than in the subirrigated plots. The cropping system did not affect SMC in either water table management system. WTDs were greater in the freely drained plots than in the subirrigated plots. These results are discussed in the context of best management practices for corn production in Quebec.