Save with SoyWater
University of Nebraska-Lincoln experts have developed a website, called “SoyWater,” that promises to make it easier for soybean growers to schedule irrigation during the growing season.
The SoyWater Internet-based program has been in development for about two years, says James E. Specht, professor of agronomy and horticulture at UNL and one of several collaborators on the project. It was tested by a few soybean growers and UNL Extension experts during the 2009 growing season.
At press time, the website was expected to be fully functional and available in late April. To reach the site, type www.hprcc3.unl.
edu/soywater into your Internet browser. Contact Specht via e-mail at email@example.com or phone him at 402-472-1536 for more information.
“In the past, it has been difficult to schedule irrigation to any crop because you have had to use a checkbook approach,” says Specht. “This required you each day to update that checkbook by first deducting yesterday’s withdrawal of soil water by the crop — evaporation from the soil surface and transpiration from the leaves, collectively known as ET. Then you had to deposit yesterday’s rainfall and/or irrigation amounts, if any. Doing so allowed you to discover where the crop stood today with respect to the soil water.”
It’s very difficult for producers to obtain daily ET amounts for their specific area every day during the growing season, Specht says.
As more growers have obtained fast Internet connections, it’s become more feasible to develop a website, such as SoyWater, that can gather those daily ET values and then do the checkbook calculations, he says. Using the website, growers or consultants only need to input their planting dates or crop emergence dates for a given field, and thereafter input the rainfall and irrigation amounts when these occur.
“Soybean growers just need to go to the website and see a table for each field that tracks the crop’s withdrawals from the stored soil water in the crop root zone,” Specht says. “Yellow highlighting in the table tells them when the first — or next — irrigation should occur.”
SoyWater goal: easier scheduling
The goal of SoyWater is to make it easier for producers to schedule irrigation in a just-in-time manner, whether the irrigation event is the first or the last of the growing season.
“We think if they use SoyWater for irrigation scheduling, they could potentially save up to an inch of water or more per year,” says Specht. That would be significant because nearly half of the state’s 4.5 million acres of soybeans are irrigated to some extent.
Even soybean growers who don’t irrigate can benefit from SoyWater. “This website, although it is designed more for the producer who irrigates, predicts the date of your soybean growth stages, too,” says Specht. “Producers who rely solely on rainfall to grow soybeans could use it to help determine what stage their soybeans are today or at some point in the future. This would allow them to plan to apply particular sprays that require specific growth-stage timing, such as herbicides or canopy-applied fungicides.”
Jessica A. Torrion and Tri Setiyono, postdoctoral research associates, have spent considerable time developing and refining the SoyWater website to make it as producer-friendly as possible, says Specht.
Other collaborators in this project included Kenneth G. Cassman, Nebraska Center for Energy Sciences Research at UNL; Suat Irmak, UNL Biosystems Engineering; Ken Hubbard, senior scientist at the UNL High Plains Regional Climate Center; and Martha D. Shulski, director of the UNL High Plains Regional Climate Center, who along with HPRCC programmers Bill Sorensen and Jun Li provided the links needed for SoyWater to acquire daily data from the state’s automated weather stations.
Carlton writes from Lincoln.
This article published in the May, 2010 edition of NEBRASKA FARMER.