Water Movement in Some Southern Quebec Irrigated Histosols.

Histosols are highly productive soils and intensively cropped in Southern Quebec.  These soils are highly porous, with a moderate to a high hydraulic conductivity. Water management is of special concern in these soils as they appear prone to leaching. It is managed with limited knowledge on the mechanisms controlling water exchange with the rooting zone and on appropriate management tools to follow water movement. Two years of field studies showed that the capillary rise to the root zone is limited in these soils and showed the occurrence of perched water table and fingering, due to textural/structural discontinuity. Direct measurements of leaching using pan lysimeters showed that an indirect assessment of this process using different tools (TDR, tensiometers or ETP/water balance models) was of limited accuracy, most likely because of the complex nature of water exchange in these soils.