Effects of erosion control practices on runoff, soil loss, and yield of strawberries in the Lower Fraser Valley

Erosion control practices were evaluated for their ability to reduce soil loss and runoff and for their effects on strawberry (Fragaria x ananassa Duch,) yield on a silt loam soil in the uplands area of the Lower Fraser Valley. Three treatments (underdrainage, winter cover cropping of barley [Hordeum vulgare L.] and cross slope planting) were compared to a control. Soil and runoff losses from natural rainfall were measured on replicated experimental plots (0.01375 ha) from 1991 to 1994. Soil and runoff losses were significantly lower with the winter cover crop and cross-slope planting treatments than the control. Results for the underdrainage treatment were not significantly different from the control and non-representative of proper underdrainage due to too deep an installation under wet conditions. Soil protection by the barley cover crop reduced mean annual soil loss and runoff by 78 and 43%, respectively. Cross slope planting reduced soil and runoff losses by 97 and 84%, respectively, compared with the control. Annual runoff coefficients of up to 21% were observed for the control, while coefficients of 40% were not uncommon for single storm events. Except for the cross slope treatment, strawberry yields were not compromised by the erosion control practices. Winter cover cropping is the preferred erosion control practice for strawberries grown on upland soils, since cross slope planting may cause depressed yields from root rot disease resulting from stagnant water between the rows.