Now entering its second year, the Testing Ag Performance Solutions (TAPS) Farm Management Competition at the West Central Research and Extension Center is picking up steam, and is bringing a few updates to 2018.

In addition to the corn farm management competition held last year, the program is introducing a sorghum competition. This competition will have a total of eight farms competing. Two of them will be University of Nebraska-Lincoln teams — one for control with no water or nitrogen applied, and one a full management strategy.

Sorghum contest
For the most part, the sorghum competition will be similar, taking place under a Zimmatic variable-rate center pivot and involving the same six management decisions as the corn competition: crop insurance, marketing, hybrid selection, planting population, nitrogen and irrigation. However, there will be some differences when it comes to marketing.

"We'll have a 1,000-acre sorghum farm versus a 3,000-acre corn farm. Most who grow sorghum don't deal in that many acres," says Chuck Burr, Nebraska Extension crops and water educator, and one of the founders of the program. "We're pricing the basis on the sorghum determined at a co-op in McCook, which is in the heart of Nebraska sorghum country."

Corn competition
Meanwhile, the corn competition will largely stay the same except for a change to the mileage charges for hauling corn to market. The mileage charge will be reduced to three-quarters of a cent per bushel for 2018, compared to 2 cents per bushel in 2017.

This year, the corn competition has 20 farms: two University of Nebraska-Lincoln teams, and teams from state agencies, such as the Nebraska Department of Natural Resources and Nebraska Department of Environmental Quality. It also includes teams from out of state.

"We've got two different teams from Kansas competing, from the Groundwater Management District No. 1," Burr says. "They've been dealing with deficit irrigation for a long time, so it'll be interesting to see how they compete with our Nebraska growers."

This year, a subsurface drip irrigation system will be installed by Eco-Drip Irrigation Systems of Hastings. While the SDI system won't be available for the competition until 2019, it will provide some opportunities for workshops at the center this summer.

Year 1 takeaways
The 2017 competition saw some key takeaways. One was how hybrids responded to differences in irrigation amounts.

"If you look at yield versus irrigation applied, five farms with the same Dyna-Gro hybrid had a considerably different production function as compared to others, because that hybrid performed well and was exceeding others," says Daran Rudnick, Nebraska Extension irrigation management specialist. "Those are things we can't entirely answer in one year. But in two or three years, we will be able to more accurately know whether it's the hybrid, the year, or management. Oftentimes we're making management decisions without accounting for their potential interactions."

One of these UNL farms was a deficit management strategy, with 3.5 inches of water, or about half as much applied during the growing season compared to UNL's full management strategy farm.

"The deficit farm yielded about 250 bushels. It was in the upper third of the yield and had in the lower third in terms of water applied," says Rudnick. "That's why that farm did so well; it was the second highest in profitability."

The interaction between hybrid water-use efficiency and irrigation strategy showed up in the evapotranspiration measurements from last year's competition. The adjacent field to the TAPS field is equipped with a Li-Cor eddy covariance tower to measure actual ET, as well as tools to calculate reference ET through crop coefficients. Rudnick notes with the varying weather patterns seen in the 2017 growing season, competition participants often had to make in-season adjustments to their irrigation strategies.

"We had 100- to 105-degree [F] temperatures from mid-to-late July. The crop was developing exponentially, and we had a massive ramp-up of water use. We had a few periods between ⁴⁰/₁₀₀ to ⁵⁰/₁₀₀ inch of water use per day, which is extremely high. Interestingly, the first couple weeks of August were cool, with 70-degree days and quite a bit of rainfall. So, we saw a huge dip in crop water use," says Rudnick. "That's where people got creative, and we saw differences in how they managed their irrigation."

"We had a couple farms that applied more than they should have and were exceeding ET. Others took advantage of the full moisture profile and capitalized on the cooler weather and lower ET rates," he adds. "We're going to be able to see more of that this year with more teams competing."

Editor’s note: An earlier article stated the TAPS program would be adding a soybean competition this year. Plans for a soybean competition have been changed, and the program is adding a sorghum component instead.