EFFECTS OF DIFFERENT CROPPING SYSTEMS ON SOIL-WATER PROPERTIES OF A BORALF SOIL

A long-term field experiment utilizing five different cropping systems was established on a Boralf soil in 1968 in the Peace River region of Alberta, Canada. The cropping systems consisted of: continuous barley (CB), barley/forage (Bf) (3 y of barley followed by 3 y of forage), forage/barley (Fb) (3 y of forage followed by 3 y of barley), continuous grass (CG) as bromegrass and continuous legume (CL) as red clover. The saturated conductivity (K-sat) was improved by growing forage crops as the CG acid CL cropping systems had a higher K-sat (1.20x10(-2) and 1.57x10(-2) cm h(-1)) than the Fb, Bf, and CB cropping systems (4.41x10(-3), 5.01x10(-3) and 4.50x10(-4) cm hr(-1), respectively) for the 15-30 cm depth. At the 30-45 cm depth the CL cropping system K-sat was a hundred fold greater, at 10(-2) compared to 10(-4) cm hr(-1). The infiltration and the depth of accumulated water over time also reflected forage production cropping practices as the CG and CL cropping systems had the highest infiltration rates at 30 min of 9.7 and 9.4 mm hr(-1) while the Fb, Bf, and CB cropping systems had infiltration rates of 4.8, 7.1 and 8.3 mm hr(-1). The ratio of the infiltration rate at the beginning versus the end of the infiltration period (30 to 480 min) of 4.0, 5.6, 6.4, 6.4; and 7.0 although not significant indicated decreasing structural stability in the order of CG > CL > Bf > Fb > CB cropping systems, respectively. It was observed that differences in soil water properties due to cropping history were reflected.