Adapting a Cloud-Based Irrigation Scheduler for Sugar Beets in the High Plains

Abstract

Highlights An existing sugar beet crop coefficient curve (K cr ) was modified to better represent canopy development in northeast Colorado conditions. The modified K cr curve improved the estimated soil water deficits (net irrigation requirements) calculated by the cloud-based Water Irrigation Scheduler for Efficient Application (WISE App). Feedback from sugar beet growers and agronomists helped expand WISE applicability in the northern High Plains with access to additional weather station networks and functionality to aggregate irrigation data across multiple sugar beet fields or regions. Abstract . The convergence of agrometeorological network, database, and cloud-computing technologies has enabled greater accessibility of irrigation management tools for growers. The goal of this research and outreach project was to adapt an existing cloud-based irrigation scheduler (WISE) for use by sugar beet (Beta vulgaris L.) producers in eastern Colorado and a wider area of a cooperative operating in Colorado, Nebraska, Wyoming, and Montana. Four center pivot sugar beet fields in northeast Colorado were monitored during the 2013 and 2014 growing seasons. Soil water, leaf area index (LAI), and weather data were used to estimate the soil water deficit (net irrigation requirement) and to modify a crop coefficient (Kcr) curve originally reported in the literature based on growing degree days (GDD). The average cumulative GDDs for sugar beets to mature (100% maturity) was 2,944°C·d. The localized Kcr had a peak value (Kcr,mid) occurring between 43% and 69% of maturity, which corresponded to effective full cover (LAI = 3) and start of leaf senescence, respectively. In contrast, the original Kcr curve from literature had a longer duration of Kcr,mid spanning 33% to 83% of maturity. Use of the modified Kcr curve in lieu of the original Kcr curve in WISE reduced the relative error of soil water deficits by 12% to 35%. Feedback and collaborations from representative sugar beet growers and agronomists in the Western Sugar Cooperative led to expansion of WISE weather data access in the High Plains to include sugar beet growing areas in western Nebraska, eastern and northern Wyoming, and southern Montana. Keywords: Crop coefficient, Evapotranspiration, Irrigation scheduling, Soil water balance, Soil water deficit, Sugar beets.