ONLINE IRRIGATION SCHEDULING WITHIN THE BELLE FOURCHE IRRIGATION DISTRICT

Online irrigation scheduling consultant software is being developed for producers within the Belle Fourche Irrigation District (BFID). This project, which is funded for 3 years by a Conservation Innovation Grant through the Natural Resources Conservation Service (NRCS), is entering its third and final irrigation season. The BFID is a gravity-fed, canal-based system located in western South Dakota. Recurring droughts often limit the amount of water available for irrigation in the BFID. The purpose of this project is to provide producers with a reliable, easy-to-use means to monitor and schedule irrigations that will conserve water and reduce the amount of sediment-laden irrigation return flows that are discharged into the adjacent Belle Fourche River, historically listed as impaired for total suspended solids by the South Dakota Department of Environment and Natural Resources.

The online irrigation scheduling consultant software allows producers with Internet access to create a secure, personalized Web page that provides irrigation scheduling advice for a particular field. The software collects daily weather data and uses it to estimate rainfall and calculate crop evapotranspiration (ET) using the American Society of Civil Engineers (ASCE) Penman method and locally adapted crop coefficients. Irrigation delivery amounts entered online by the producer are added to the rainfall estimates for that location. The irrigation scheduling software then calculates a soil water balance and irrigation schedule for soil types in the field. Soil moisture sensors installed at two depths are recorded to provide online tracking of relative soil water changes throughout the irrigation season. The producer has the option to adjust the calculated soil water balances or measured rainfall amounts based on observations at the field.

The results of the first 2 years of irrigation scheduling were used to evaluate the online software and methods. User feedback is also being collected to fine-tune the online user interface. The third season of irrigation will continue to expand the user base and be used to further evaluate the software.