Soybean tips: rotation, subsoiling, fertility and beds
Jan 29, 2008 10:58 AM,
By David Bennett
Farm Press Editorial Staff
Martin Walker farms soybeans outside the Stoneville Research Station near Leland, Miss. There are many fans of his work.
SPEAKING AT the recent Tri-State Soybean Forum, Martin Walker explained how he’d strengthened soybean yields.
“If you’re looking for someone who knows raised-bed/twin-row production and makes it work year after year, I encourage you to talk to Martin,” said Dan Poston, Mississippi State University weed scientist, who introduced Walker at the recent Tri-State Soybean Forum in Dumas, Ark.
“We used to grow a lot of cotton,” Walker told the crowd. “In 1999, we began reducing our cotton acres, growing more soybeans. We found a lot of the cotton production practices also work with soybeans. At least 60 percent of our land is sandy and the other 40 percent is rice/soybean land.”
The four main factors that help Walker make soybean yields:
• Rotating crops.
• Subsoil land, or some form of deep tillage.
• Maintain a good fertility plan.
• Plant on beds.
Walker had soybeans on some of his land for 15 or 20 straight years. Within four years of going with a bean/corn rotation, “we were able to raise bean yields by 20 bushels. And that was planting the same varieties with the same planting dates. That yield bump was due to rotation and grain sorghum would probably work just as well.”
Walker subsoils his sandy dryland acres every year. On some of the heavy ground, “we till every other year. The last two years, when it grew dry during the growing season, we’ve seen a tremendous benefit in doing this.”
To have his soil fertility checked regularly, Walker has a contract with a local agriculture service.
“They use GPS and have a grid sampling system for every 2.5 acres. This is our ninth year of doing that. They test a field and provide a three-year maintenance program to apply variable-rate fertilizer on.”
If you’re going to plant soybeans, “instead of just putting out a (consistent) blend of P and K (across the whole field), you may apply 200 pounds in one little part, none next to it, and 20 pounds somewhere else. That takes a lot of variability out of the soil and provides more consistent yields across the entire field.”
For years, said Walker, his operation didn’t “row up and plant cotton on beds and our bean land was flat. We’d try to water down the middles and around the outside.”
Some of his cotton fields go from sand to buckshot very quickly. “When we began planting soybeans in those fields, we found yields were lower.
“Then, we starting rowing up every acre, even on the heaviest ground we’ve got. Once you do that, as long as you don’t harvest when it’s wet, you can maintain those beds and re-use them.”
Now with beds, the irrigation efficiency is much better and yields have risen tremendously.
“We use a Monosem twin-row planter on 38-inch beds. There’s a 30-inch gap between the rows. We plant about 2.3 seed per foot — all Group 4s — for around 140,000 plants per acre.”
On irrigated land, “we consistently make 70-plus bushels per acre. That isn’t the yield from a small field but across the farm.”
How does Walker deal with corn residue in the rotation? “Several ways. Next to the highway, we shred it. Some we disk several times.”
But the vast majority of the residue is burned. “I know some people say that’s the wrong thing to do. But I don’t think when you burn it, as much (material is) lost as some claim. After burning, lots of cobs and stalks are still there. The leaves and light tissue are burned away but the roots are still in the ground.
“We just drop in, subsoil, re-hip and we’re ready for the next season.”
What’s Walker’s normal planting window? “I’ll plant some of our dryland soybeans around April 1. Normally, though, we plant between April 10 and April 25. I like to be done by April 25.”
Does Walker rip down the row? “I do both. I don’t have a set system. We bought a Great Plains in-line subsoiler. It goes down the top of the row with a straight shank. We’ve done that on a few hundred acres. On irrigated land, I normally subsoil after the beans more so than corn. On dryland acres, I subsoil every year.”
e-mail: dbennett@farmpress.com
