Author(s)

G. Parkin & S. Wang

Abstract

Irrigation is a vital part of agriculture in certain regions of Canada including the interior of British Columbia. In this study we examined the use of a soil water budget model for efficient irrigation management in two contrasting climatic regions of British Columbia: Abbotsford (AD) and Osoyoos (OS). The average annual precipitation at AD and OS are 1573 and 318 mm, respectively. The soil types (AD – silt loam and OS – sand) and major crops (AD – raspberry and OS – apple) are also quite different between the two regions. We used the Simultaneous Heat and Water (SHAW) model to estimate the amount of deep drainage and soil water content under different irrigation management strategies. The SHAW model integrates detailed physics of vegetative cover, snow, residue and soil into one simultaneous solution. The model was run on a daily basis for 28 and 32 years for AD and OS regions, respectively. Different combinations of crop and irrigation conditions were run for each region. Based on this study, the \“best” irrigation management strategy involves triggering every irrigation event when the soil water content (estimated by SHAW) in crop’s rooting zone reaches a prescribed amount below field capacity. At that time, 40 mm of irrigation is added as rainfall. Other strategies involved adding more irrigation and a constant weekly irrigation regardless of rainfall and soil water content. In conclusion, while most of deep drainage in the dormant seasons (no irrigation) cannot be controlled, it can be well controlled to a minimum level in the growing seasons by \“best” irrigation management practice. Keywords: irrigation modelling, minimize drainage, Canadian conditions.

Keywords

irrigation modelling, minimize drainage, Canadian conditions.