Calculate water needs
David Nielsen and his research team sat down and burned the midnight oil pouring over long-term field data that showed a relationship between crop yields and irrigation applications. The trends they discovered confirmed what Nielsen had suspected: It was possible for farmers to calculate water needs in advance of crop needs.
The ARS team, based in Akron, Colorado, went on to create a compact disk or Web downloadable program called the MultiCalculator. The program has proven to be a hit. Nearly a thousand copies have been obtained by central Great Plains farmers, while downloads have been brisk, Nielsen reports.
The reason for this popularity stems from the fact that the MultiCalculator is not only based on realistic field information but also is easy to use. Nielsen says the MultiCalculator uses three simple Excel spreadsheets that include a yield calculator, water calculator, and ethanol-water calculator. Plus, it can be used to predict nonirrigated crop yields.
Using The Program
To begin to use the program, first estimate how much available soil water your fields have. This information can be obtained from soil-moisture probes in respective fields. Or, for your general area, you can contact your land-grant university or state metrological service.
With current moisture content in hand, tab to a table on a different screen that helps make this estimate, giving multiplication factors for various soil types.
For example, fields predominantly consisting of silty loam, you would multiply the depth of the wet soil by 2.2 to get the number of inches of soil water available for the crop at planting time.
Next, going to step three of the program, select the crop to be irrigated, your fields’ locations (currently the program only provides locations for eastern Colorado, western Kansas, and western Nebraska), and then guess the percentage of average precipitation expected during the growing season. You can get historic precipitation data for your specific area from your state’s meteorological website.
After inputting this information, the program will instantly project yields for your fields based on actual field data. The calculator provides this for 18 crops, including cereal grains, seed legumes, oilseeds, and forages.
The water calculator also works in reverse, beginning with choosing a crop and then selecting the target yield. It tells how much water you’ll need to achieve that target yield.