A bright future for sorghum
LEAD Comment: With its weed control and soil health benefits, sorghum in rotation is due for a comeback.
Oct 05, 2017
By Lynn Belitz
Nebraska has seen a renewed interest in sorghum in recent years, including for grain and forage, and as an energy crop. Moving forward, what challenges are there in treating sorghum as a primary crop and what steps can growers take to address those challenges? What reasons might a grower consider sorghum in their rotation?
Driving through Nebraska in the 70s and 80s, one didn't have to travel far to see acre after acre of grain sorghum. Rainy, wet summers and improved corn genetics that allow it to better tolerate drought, combined with herbicide-tolerant traits in corn and soybeans, worked together to reduce sorghum acres. Grain sorghum has also been treated as the red-headed stepchild. It has been planted on marginal, rougher land and has been treated as a second-class crop.
Farmers also believed in the philosophy of using less fertilizer on milo than other crops, and as a result, we harvested lower yields. Crop rotations that were common practice in those days were forgotten and put aside for our zeal to farm bigger and faster.
When you combine some or all of these practices, one can see why sorghum acres have declined. However, today we are seeing better results from using improved practices, and grain sorghum is carving out a niche for itself. Glyphosate-resistant weeds are popping up, and it isn't as easy to keep corn and bean fields as clean as we would like, so farmers in Nebraska are taking another look at crop rotation and especially crops that don't rely as heavily on glyphosate.
Lower seed costOne of sorghum's advantages is a lower seed cost. Sorghum seed cost per acre is around $10 for non-irrigated and slightly more for irrigated, compared to $50 to $100-plus for beans and corn. Rootworm can't winter over in sorghum stalks, so when planting corn after sorghum, insecticide is not necessary.
Traditionally, farmers rotated between corn and milo, only realizing the final yield for each crop, and comparing that data. If grain sorghum's yield fell below that of corn, they assumed it was sorghum not keeping up with corn and moved away from growing sorghum.
Research data from Rick Kochenower, agronomist for Sorghum Partners seed company, compares yields of crops planted in rotation between corn, soybeans and sorghum. The results show corn-following-corn yields to be the lowest, but when soybeans and sorghum were in the rotation, all the crops benefited and resulted in higher yields for all the crops. Corn planted in rotation with grain sorghum yielded from 20 to 30 bushels more than when corn was planted continuously. The exact reasons why cannot be definitively determined, but some explanations could be better root worm control, improved water management and better weed control that comes from crop rotation.
Another well-kept secret of milo is it is considered to be a compaction-breaking crop. The roots on sorghum grow out and down, and can grow through hard soils. As the roots grow, they help open up the soil, which allows water to run in and down, and the compaction starts to break down.
Gluten-free alternativeAs more people show concerns with gluten sensitivity, grain sorghum flour is gluten-free and is a viable alternative. Sorghum was once solely used for animal feed, but today it is increasingly being used for human consumption. Grain sorghum is also used for ethanol production, and the yield is equivalent to corn.
For decades grain sorghum has had very little money spent on research, and so the genetics have not been improved as rapidly as corn and soybeans, but that is changing. The United Sorghum Checkoff Program has invested wisely in grain sorghum genetics and it is paying off. Within three or four years, we will hopefully have herbicide-resistant sorghum that would work well in a corn rotation and will allow farmers to control glyphosate-resistant weeds.
When farmers implement the same management practices on grain sorghum that they use on other crops, they can realize a 20% yield increase over a four-year time frame.
When considering crop rotations for better weed control, especially with glyphosate-resistant weeds, the yield benefits, the advantages of soil improvement and all the uses of grain sorghum, its future is so bright that "you gotta wear shades!"
Belitz is a sorghum grower near Fullert
