What is in this article?:
- Irrigation doesnâ€™t increase corn yield â€“ it captures it
- Apply enough water long enough
The proper use of irrigation can help corn producers capture the maximum amount of yield from improved hybrids.
IRRIGATION captures the maximum yield potential of improved corn hybrids.
When you’re planting corn hybrids with the potential of yielding more than 600 bushels per acre, your irrigation focus should not be on increasing yield but rather on capturing it.
“In the last two years in Georgia, we’ve averaged about 180 bushels of corn per acre,” says Dewey Lee, University of Georgia small grains agronomist. “And the reason that trend line is so sharp is because of irrigation.”
And while irrigation might not have been much of a factor during the rain-filled summer of 2013, it is in most years.
“With irrigation, we’re able to avoid some of the stresses that limit yield potential, and that’s what we have to do. Irrigation is a tool in managing the corn plant to capture maximum yield. We don’t increase yield, but we capture it,” says Lee.
It’s important, he says, the growers learn about the physiology and development of the corn plant. “When you know how this crop grows, you’ll actually learn what inputs are necessary, and what you can do to maintain yield potential. It’s up to us how to use water.”
One-inch of water in the life of a crop can easily return 8 or 9 bushels of corn, says Lee. “Even with $4 corn, we’re talking about a $32 return per inch of water that we apply. That’s a no-brainer since it doesn’t cost us nearly that much. Water is literally an investment,” he says.
The basic strategy for corn production is “what you do, when you do it, and how you do it,” he continues.
“It’s all about understanding growth and development, and then balancing the costs of production. We can throw the kitchen sink at it, but is it profitable? One of the things about irrigation is learning how to use this tool – and it goes along with learning to use the planter, the plow, the sprayer and the combine. It’s just one of several tools, but it is all about reducing plant stress.”
Growers should understand the stages of a corn crop, he says, and the water use requirements at each stage. “By the time you get a plant that’s 13 to 14 inches tall, you’re at a V6 stage, and that crop is no longer making leaves. It’s done, and now you’re making a tassel and the ear.”
Lee sees a few common irrigation mistakes each year, including allowing the plants to stress. “How many times have you heard this before – ‘I want the crop to stress a little bit, and I want those roots to go down and find that water.’ But it doesn’t find water, it grows through water. It doesn’t grow through dry dirt.”
The V6 stage is determined by looking at the upper most leaf that has a visible collar.
“This light green collar is just like the collar on a shirt – the neck or stalk of the plant is nested within it. If you see this collar, that’s where your stages begin, from there up. All of these leaves and cells are expanding, and we want to think about that timeline. Because at this point, you have a tassel, an ear and kernels are growing until you get to the silking stage.”