Managing excess water in Canadian prairie soils: A review

Can. J. Soil Sci. 89: 157-168. Excess water conditions develop when a soil is unable to transmit water, leading to the onset of saturated conditions harmful to soils and crops. Negative agricultural impacts include reduced trafficability, physical damage to crops under hypoxic or anoxic conditions, increased salinity or sodicity, reduced nutrient availability and uptake, and increased incidence of weeds and pests. There are two main objectives in managing landscapes prone to excess water, both of which must consider soil and landform characteristics. The first is to maximize infiltration and conductivity through tillage and residue management. The second is to remove water from the soil profile as quickly as possible through drainage or the adoption of high water use plants such as alfalfa (Medicago sativa), which increase water losses through transpiration. Changes to the overall cropping system can also be made, including selecting crops and forages that have shown reduced sensitivity to excess water, applying seed treatments that encourage the development of water-tolerant traits, timing fertilizer application to correspond with maximum plant uptake, and incorporating high water use crops into the rotation. Recent work from Australia suggests that management of excess water requires a multi-disciplinary approach; however, little research has been done on this problem in the semiarid to sub-humid Canadian Prairies.