10 soil health tips to help tackle weed control this spring

Nutrient and weed control plans may end up looking different than usual this year due to supply challenges, notes Hans Kok of the Conservation Technology Information Center (CTIC) in West Lafayette, Indiana.

This makes it especially important to keep soil health in mind.

Kok points out that many growers are considering weed control regimes and tillage practices that they haven't used in years. He says that a little forethought can help protect the gains in soil health they have made over those years.

Consider these 10 tips as planting season approaches:

1. Start with a soil health mind-set.

"Consider the benefits you've gained if you have been able to reduce tillage, no-till your crops, and build up soil organic matter over the years," Kok says. "Keep them in mind as you consider your chemical and cultural options this spring and you'll have a better chance of minimizing your losses."

2. Use your cover crops to best advantage.

If you have cover crops, you're ahead of the game, Kok says, because cover crops can choke out weeds very effectively. "Our 2020 CTIC/SARE Cover Crop Survey found that about 40% of the respondents reported that cover crops reduced their herbicide bills in soybeans. For maximum effect, let them grow as much canopy as possible to compete with weeds, then roll them or terminate them with a herbicide appropriate for the species."

3. Check your herbicide options.

If you don't have cover crops, look at the range of herbicides that are available.

"You may not have access to every tool you normally would, but there are plenty of effective herbicides out there. Talk to your crop adviser or local crop protection supplier for a refresher on the product or combination that's best for your weed pressure," Kok advises.

4. Stay off wet soils.

"The instinct is going to be to get out and start doing fieldwork as quickly as possible," Kok says. "But it's important to take a deep breath and make sure you're not going out when soils are too wet to work. That would be the quickest way to create soil compaction — especially with today's heavy equipment — which could hold back your yields for years."

The more you can avoid working wet soil, the better off you are in the long run.

5. Minimize tillage.

"It's easy to just decide to disk it all, just to be sure," Kok admits. "But think it through. Does your weed pressure demand a maximum response, or can you get by with strip-till, a chisel, or field cultivator? How deep do you really need to go? Remember that the more aggressively you till, the more of your soil biology you disturb and the greater the disturbance to the soil structure. Here's another thing to notice the next time you drive past a road building site: road construction crews use disks to compact soils! That should be a strong reminder that disking can create long-term compaction problems in your fields."

6. Think narrow.

Talking about supply chains puts the focus on herbicides, but every corn or soybean field has a powerful ally built in from the start: the crop canopy.

Consider planting corn or soybeans in narrow rows to quickly shade out weeds, Kok suggests. "We've gotten great at thinking in terms of chemical weed control, but we've got cultural tactics, too. Plus, high populations on narrow rows will give you a lot of residue this fall to kick-start your effort to protect the soil surface and start rebuilding organic matter."

7. Seize the moment to incorporate P and K.

"There's nothing about being pushed into soil disturbance that's going to make no-tillers feel good about mechanical weed control," Kok notes. "But maybe the silver lining is the opportunity to incorporate some P and K into the soil. If you've got to do some tillage because you are short on weed control options, take heart in the fact that you could take advantage of this rare chance to get your non-mobile nutrients down below the soil surface."

8. Check your carbon contracts.

"Tillage stimulates aerobic activity in the soil and burns soil carbon," Kok explains. "It's bad enough when it causes you to lose soil organic matter. But it could be a problem if you're legally bound through a carbon credit contract to capture carbon in the soil. Check with the buyer of your carbon credits now to sort out your options."

9. Plan for your next cover crop.

"If you plan now on planting cover crops in the fall and winter of 2022, you can get a huge head start on rebuilding soil tilth and organic matter, putting the damage of this spring behind you," Kok says. "That should make you feel better about doing whatever it is you have to do this spring and getting you back into building your soils. And by thinking ahead, you might even be able to lock in cover crop seed at a more favorable price."

10. Most important, says Kok: Don't panic.

"We're hearing that this year's supply chain issues shouldn't be a long-term condition, so I'm confident we will have our full suite of tools back soon," he says. "We just need to keep a steady hand on the wheel, take a deep breath and keep the future in mind as we get through this spring. After all, sustainability is all about being in it for the long haul."

For more information on minimizing tillage, managing cover crops, and building soil health, visit ctic.org.