The Hatch research farm, south of Declo, is where Amalgamated Sugar Co. operates some research and demonstration plots for sugarbeet growers. This year, field trials included nitrogen fertility, cropping systems, tillage, water sensor use and cover crops, in settings as close to actual field conditions as possible. Results were presented to growers at a midseason field day.
Tillage
Reid Bowen, crop consultant and senior agriculturist, presented demonstration plots where tillage practices were varied using strip-till, no-till and conventional tillage. Trials included:
- Fall strip-till into standing green cover crop
- Spring strip-till into fall-mowed cover crop
- No-till into fall-mowed cover crop
- No-till into standing winter-killed cover crop
“No-till outyielded and outsugared conventional tillage, but we’re still trying to figure out why,” Bowen said. “We also found that taller residue seems to work better than shorter residue. The taller stubble works better for the row cleaners to move more debris,” he said.
“So far, strip-till and no-till seem to be pretty much the same,” Bowen said. “But fall strip-till is looking a little better than spring strip-till, at least at this point.”
Soil moisture sensors installed at the site showed 4% less water used in the no-till and strip-tilled sugarbeets following cover crops. Trials next year will look at how much water can be saved in these systems across the season.
Cover crops
As far as cover crops go, the company is “looking at everything,” said Craig Findlay, including mustard, pea, rape, triticale, clovers, flax, chicory, sunn hemp, tillage radish, purple-top turnip, oats and vetch. In total, there were 24 different cover crops on display in the field demonstration.
Findlay said, “There’s still a lot of work to be done to find out what works best for sugarbeet growers and their various operations.”
Twenty-four different cover crops are being tested in sugarbeet production at the Hatch research farm. Photo by Lynn Jaynes.
Water and irrigation
Arianna Hege, a graduate student with University of Idaho, presented some data from the water and irrigation studies conducted at Hatch.
Included in the study were seven different sensors, differentiated by ease of use, cost, accuracy and other factors. The sensors are of two general types – those that read a percentage of water in the soil profile and those that measure water tension, or availability to the crop.
“Most water was extracted within the top 1 to 2 feet of the soil, so we put these sensors at 12- to 18-inch depths for irrigation scheduling, which worked for us,” Hege said.
“Each sensor is a little different, so it’s important to orient yourself to the sensor you choose,” Hege said. “We use the free Washington State University Irrigation Scheduler tool with sugarbeet-specific recommendations to help schedule our irrigations. Many irrigation schedulers don’t account for crop type, so it's best to pick one that does.”
As water moves through the soil, the first level – saturation – is during or immediately following an irrigation event. The next level is field capacity, which is reached when there is no runoff or drip from the irrigation event. The third level is maximum allowable depletion, and the lowest level is permanent wilting point. Hege recommended irrigating again sometime between field capacity and maximum allowable depletion. “You can do permanent damage to the plants if you wait too long and can’t catch up or refill the soil profile in time to help the plant,” she said.
This fall, her study will be looking at yield and sugar at harvest among the different water treatments.
Nurse crops
Davey Olsen, site manager of the Hatch research farm and research agronomist, presented the ongoing nurse-crops study findings, now in its second year.
“Many growers have issues with replants. There’s soil movement during spring, and small beet seedlings are susceptible to wind damage. So we’re looking at using nurse crops to anchor the soil and protect beets from the wind,” Olsen said.
Wheat, as a nurse crop, shields emerging sugarbeets from wind and also holds the soil in place to prevent erosion. While this practice can reduce replants, eventually the nurse crop competes with sugarbeets and must be terminated. The question is: What stage of growth is the best time for nurse crop termination?
In the study, a wheat nurse crop was planted in the spring three weeks ahead of sugarbeets. The wheat was about 2 inches tall by the time sugarbeets emerge.
In the wheat trials, when the wheat was sprayed down with an herbicide at 4, 6 and 8 inches tall, there was no impact on yield or quality in the sugarbeets at harvest. However, if the wheat was sprayed out at 10 inches tall, there was a 3-ton-per-acre yield penalty. If the wheat was never sprayed out, it resulted in a 13-ton yield penalty.
“Be on your game for spray-out timing,” Olsen said. “It’ll cost you if you’re not on time.”
“We found if we spray out the wheat at 4, 6 or 8 inches, there isn’t hardly any residue to deal with. It also sprays out weeds,” he said.
Seven different water sensors are being tested at the Hatch research farm to compare the efficacy, ease of use, cost and accuracy. Adrianna Hege, University of Idaho student, presented the study to growers at the field day. Photo by Lynn Jaynes.
Nitrogen recommendations
For many years, sugarbeet yield goals have been used to determine how much nitrogen fertilizer to apply. However, with yields increasing each year, we are now often applying more nitrogen than is needed. We are seeing that more nitrogen does not equal more yield, said Olsen. “Too much nitrogen in the system can lower sugar percentage and increase impurities in the sugar juice which creates problems for the factory,” he said. A new approach is needed.
With that in mind, other areas of the country in sugarbeet production have gone to a flat-rate recommendation. The question is whether a flat-rate recommendation is appropriate for Idaho growers in our soils and with our irrigation. This has been the subject of an eight-year collaborative research study between Amalgamated Sugar and the USDA Agricultural Research Service (ARS) in Kimberly.
Data across 26 sites from 2005 to 2021 now supports a new nitrogen approach. “What we’re finding is that yield flattens at about 180 pounds nitrogen per acre,” Olsen said. “So we can usually reduce nitrogen rates [from previous levels] without suffering yield or quality hits. We’re now recommending a flat-rate range of 180 to 193 pounds per acre of total available.”
The nitrogen application range (from 180 to 193 pounds per acre) to maximize yield was sufficient for yields that increased by 32% from 2005 to 2021. Olsen said a range of nitrogen application rate is recommended because site-specific conditions vary, and growers need to use site-specific data to determine if needs are greater or less than the ranges seen at the research site.
Western Idaho field day
Amalgamated Sugar also held a field day in western Idaho for growers in the Nampa area, where Clarke Alder presented on several studies regarding weed control. Highlights from his presentation included:
- Torero, a product seeking labeling in the U.S. for use in sugarbeets, is being analyzed for efficacy against kochia. It shows promise for controlling lamb's-quarters and pigweed. Use rates that provide the best balance between weed control and sugarbeet injury are still being tested.
- Another trial involved Eptam/Treflan, chemicals already registered in sugarbeets. The study is looking at using the two in combination much earlier in the season to possibly replace one application of glyphosate to help slow down the process of herbicide resistance to glyphosate.
- An herbicide carryover study was also presented, where seven different herbicides were applied that are typically harmful to sugarbeets if applied within 18 months prior to planting of sugarbeets. The object of the study was to quantify yield losses to the sugarbeets due to the carryover of these chemicals in the soil. Last year, results did not indicate that sugar was affected by these chemistries, but yield was severely reduced by some. Growers were able to see sugarbeet roots pulled from each of the plots to compare the effects of these herbicides.
- Herbicide drift onto sugarbeets was also demonstrated where sublethal doses were applied over the top of the beets. This showed the foliar effects on beets similar to when an applicator accidently drifts an herbicide from a non-beet crop onto sugarbeets.
Dr. Joel Felix of Oregon State University also spoke with growers about current studies regarding Truvera, a genetic trait from KWS that will make its commercial debut sometime in the next three to five years. Truvera will provide beets with resistance to not just glyphosate, but glufosinate and dicamba as well.
Oliver Neher, manager of sugarbeet quality improvement and plant health with Amalgamated Sugar Co., presented seven different cover crops available for sugarbeet cyst and stubby root nematode control. His presentation also included information on a rhizoctonia nursery where each variety claiming tolerance to the root rot rhizoctonia is planted, inoculated and evaluated for tolerance in relation to each other.
The day’s events also included a demonstration by Bill Ballantyne of Ballantyne Ag, who flew his sprayer drone over a triticale field at the site to demonstrate how well spraying with a drone works.
