Assessing on-farm water use efficiency in southern Ontario

In southern Ontario, irrigation is essential for high value horticultural crop production to overcome insufficient rainfall and achieve stabilized crop production. In a context where competition for limited water resources intensifies due to the expansion of the agricultural sector, increasing urban development and tourism, and potential climate change impacts, conserving water through efficient irrigation has become a key solution to address this growing challenge. The implementation of advanced soil water monitoring technologies and water budgeting for improved irrigation scheduling is explored to conserve water and thus cope with increasing competing demands for limited water supplies.;Soil moisture was measured by gravimetric sampling in conjunction with several modern soil water sensors over the course of the 2007 growing season at 15 field sites located in southern Ontario where high value horticultural crop production is predominant. Quantities of irrigation water used were measured by flow meters that were installed at three of these sites. In addition, two grower surveys were administered: the first to collect information on current irrigation scheduling practices, and another to determine the appropriateness of the soil moisture monitoring sensors. On-farm irrigation performance was assessed by comparing calculated crop water requirements (using the water budget method) with growers' estimates of irrigation water use with soil moisture measurements taken during the growing season.;In five out of six experimental zones, water was either excessively or insufficiently applied. In addition, the results demonstrated that although there was no "best" soil moisture monitoring sensor---all of them having advantages and drawbacks---growers recognized their usefulness and showed willingness to adopt the technology. Overall, the results of this research proved that by implementing advanced soil moisture monitoring technologies, growers could generally save water and reduce the uncertainty currently involved in their irrigation scheduling practices.