Checkoff-Funded Researchers Hope to Build on Existing Genetics, Sequenced Genome to Move National Yield Average to 60 Bu./A.
As U.S. soybean farmers continue their preparations for the coming growing season, they’re in the midst of making countless decisions that could impact the yields they’ll see on their combine monitors this fall. While farmers hold their yield destiny in their own hands to a great extent, the soy checkoff is spearheading a major project to bring about a significant boost in yields for U.S. soybean farmers.
“Yield research has been the center of checkoff research since the organization was established,” says Gregg Fujan, who leads the United Soybean Board’s (USB’s) focus on supply. “Checkoff-funded production research is incredibly important to U.S. soybean-farmer profitability. With the advancements we help bring to market, the national yield trend line should continue to grow at an even higher rate.”
The goal of this project is to increase the national soybean yield average to 60 bushels per acre, about 20 bushels higher than the current national average, by the year 2025. To do it, scientists are using soy-checkoff funding to harness the power of the sequenced soybean genome by using various genetic methods, such as nested association mapping (NAM), RNA sequencing and epigenetics.
While this might seem like an ambitious endeavor, farmers are achieving extremely high yields now – in some cases, more than 100 bushels per acre – which shows that the goal is achievable.
A Treasure Map of the Soybean Genes That Impact Yield
The project includes many researchers all working toward the same goal.
For example, two soy-checkoff-funded soybean researchers are using modern technology to locate key genes responsible for yield.
U.S. Department of Agriculture researcher Michelle Graham and her team are sequencing the genomes of 100 different soybean cultivars that have been heavily adopted by U.S. farmers over the past 90 years because of their high yield potential. This will help the team identify the genes and gene combinations that have been responsible for yield increases.
“This project will generate hundreds of thousands of new molecular markers that will be released to public and private researchers for use in soybean improvement,” says Graham.
At the University of Illinois, Brian Diers, Ph.D., uses a technique called NAM to find the location of important genes, which could help save time later in field trials.
“Once we know their locations, we can do a much better job of selecting these genes,” explains Diers. “Farmers want varieties with better yield and composition, and breeders want to deliver that. The more information we have about where genes controlling yield and composition are located, the better job we can do to deliver these varieties.”
Looking for a Key Yield Gene? Check the Soybean Atlas
In every cell that makes up a soybean plant, all of that plant’s genes are present. For example, a soybean leaf cell has the genes in it to be a flower or a pod or a stem. The difference is that only the genes relevant to that part of the plant – in this case, the leaf – get expressed. The expressed genes produce RNA, and scientists can sequence that RNA to find out which genes are expressed in each area of the plant.
Gary Stacey, Ph.D., works with a team of researchers at the University of Missouri to grow soybeans under various stressful conditions, such as heat, drought, pathogen infections and others. They then take samples of the different parts of these soybean plants and isolate the RNA. Next, they send the isolated RNA to the U.S. Department of Energy Joint Genome Institute for sequencing to show how the plants react under these environmental stresses.
This information is all recorded and mapped to provide what Stacey refers to as a “soybean genome atlas.” If a researcher has an idea of which gene might be responsible for a particular response, such as drought tolerance, that researcher can check the genome atlas and quickly narrow down where those genes are expressed in the plant. Stacey says this resource will save researchers time in finding the genes that are responsible for yield and other desirable traits.
Flip the Switch on Higher Yields
Other soybean scientists study a genetic component called epigenetics to learn how soybean plants respond to pathogens, pests and other yield robbers. Scientists hope to be able to predict those responses and use them to farmers’ advantage, such as by engineering plants for better protection against a virus.
Epigenetics serves as a switch that determines whether a soybean plant expresses certain genes, as well as the intensity with which those genes are expressed.
“The goal of the checkoff project is really to understand how many of those switches are there in the background that we don’t know about,” says University of Georgia soybean researcher Scott Jackson, Ph.D.
Another collaborator on the project, University of Delaware Professor Blake Meyers, Ph.D., says yield is a combination of genetics and the environment, and epigenetics could help determine which varieties to use in different situations.
“The environment is not easy to predict, if it can be predicted at all,” says Meyers. “So having soybeans that can respond to the widest range of environments in a beneficial way – drought tolerance, for example – will be critical to achieving that goal of 60 bushels an acre.”
Soybean Farmers Prove Triple-Digit Yield Potential Exists Today
A 60-bushels-per-acre national yield average might seem like a distant goal, but yield-contest winners in several states are proving that it’s actually closer than you might think.
For example, southeast Arkansas soybean farmer Nelson Crow became the first farmer in the state’s history to break the 100-bushels-per-acre barrier last year.
Crow planted a 3.9-maturity-group soybean, which he didn’t think had the ability to yield that high. However, proper management and some extra attention to this particular field went a long way. Here’s a look at his path to the Century Club:
- He used a fall burndown program on the field after his previous harvest in 2012 to keep weeds in check.
- He also samples soil from all of his fields on a two-year rotating basis. Based on the test results, he did not apply fertilizer on the record-breaking field last April.
- After emergence, Crow was vigilant about applying fungicides and benefited from the relatively cool weather in the South last summer.
- Then, Crow used another trick up his sleeve, applying non-food-grade sugar to the field twice. “Once you get over 80 bushels per acre, the additional sugar helps prevent the plants from dropping their pods.”
- He also applied urea to the field to increase available nitrogen in the soil.
- Crow’s successful equation included timely irrigation. He began irrigating the field 57 days after emergence and then irrigated every seven days after, assuming it had not rained.
Because of the time and cost investment needed to intensely manage the plot, Crow doesn’t plan to replicate his 2013 actions across all of his fields this year. However, he does plan to use the plot as a learning tool for what can be done to continue increasing yields.
“We plan to put some of the practices into effect on other fields to see what we can do to sustain yields at 80 to 90 bushels per acre,” he says.
Source : unitedsoybean.edu