6 Questions and Answers About Precision Planting's SmartFirmer

Over the last year, Precision Planting engineers say they've received a lot of questions about how SmartFirmer works.

Introduced in 2017 and rolled out to more farmers in 2018, SmartFirmer is a seed firmer that measures key factors in the furrow as it firms each seed into the bottom of the trench. The firmer's sensor measures temperature, moisture, furrow uniformity, residue, and organic matter. With this information, it's easier to begin variable rate applications. For example, based on the organic matter farmers can determine the best rate of seed or fertilizer to apply. This immediate feedback also helps farmers make tweaks during planting.

If you are using SmartFirmer or if you're debating purchasing the firmers for your planter, here are the six most common questions from farmers and answers from the Precision Planting team.

1. I'm already at 2.5 inches deep and SmartFirmer says I don't have enough moisture. Can this be right?

"SmartFirmer doesn't have an opinion," says Dale Koch, Precision Planting. "When Grandpa's digging behind the planter, he has an opinion about the moisture of the soil. This is not an opinion."

In the short-term, Koch recommends planting deeper. "Have you ever tried planting 2 ¾ inches deep?" asks Koch. "I'd rather be more on the moist side and a tiny bit deeper than be too dry and at a comfortable depth."

Another potential cause could be soil collapsing into the furrow. "You could have dry soil dropping in or gauge wheels that are dropping that in," says Koch, which means you need to tighten your gauge wheels.

For a long-term solution, you need to understand why your soil is dry. "The answers to that mostly lie in tillage," explains Koch. "Are there density layers in your soil? If there are, that density change from a hard pan to softer worked ground will stop moisture from moving up in the profile."

The timing of tillage can also make a difference. "If you wait 2-3 days behind spring tillage to plant, that's a lot of time that the soil has been in the sun and wind and may dry out," adds Koch.

2. SmartFirmer shows that most of my fields have good furrow moisture. Can this be right?

"Again, SmartFirmer doesn't have an opinion," says Koch. "Pat yourself on the back. You're doing a good job.

"But I'd also encourage you to ask some more why questions," he says.

Look at all of the row units and see if the moisture is consistent. If it's not, what's causing changes across the planter?

If you have different moisture levels in different fields, try to determine what is causing that. Is it the timing of weather events? The tillage practice for that specific field?

3. SmartFirmer shows my soil temperatures dipping below 50°F. What should I do?

"Many of you probably run into this scenario, especially those in the upper Midwest," says Koch. "Because you may only have one planting window and then you're going to be out for two weeks. You've got to make these hard decisions. I get that, but I want to make sure that we understand there is a cost."

Precision Planting shared results of independent experiments that demonstrated the impact temperature has on corn emergence. The experiments were run at two different temperature cycles: 50°F. to 68°F. and 59°F. to 77°F. to mimic night-to-daytime temps. The research team measured emergence from when it started (at 10% emerged) to complete (at 90%).

"When the temperature went up 9°F., there was a 47-hour improvement in the emergence window," says Koch. Precision Planting has long stressed the importance of corn emerging at the same time to set a high yield potential.

4. How different is the soil temperature at 1.5 to 2.5 inches? Does this affect germination?

"At 1.5 inches, the soil is going to be colder at night and warmer during the day. At 2.5 inches, it's a lot more buffered," says Koch, adding that when Precision Planting tested this in South Dakota the depth change didn't make a big difference in growing degree days. "There was only a half day difference in expected emergence timing. Our recommendation is not to put much weight on it. Depth decisions should be based on moisture."

However, there are three principles to keep in mind when it comes to temperature.

1. Lower temperatures equal lower uniformity. If you're planting in cooler temperatures, there's a cost. "But there are tradeoffs in planting when it's cold, depending on your location," says Koch.
2. Know the time it takes to bring moisture into the seed. With corn's harder seed coat, it takes 24 to 48 hours to get critical moisture into the seed. It only takes 6 to 12 hours for beans. "Watch when you're planting in the late evening. You can have a 25°F. temperature swing from noon to midnight. Those first 12 hours are when beans are going to take a drink, so watch the temperature in that timeframe," explains Koch.
3. Consider running a saturated cold germ test. "It's roughly $20 per hybrid. If you have 10 hybrids, that comes out to $200," says Koch. "This is a really inexpensive way to screen your hybrids" and can help you pick which field to plant first with a particular hybrid.

5. What is a clean furrow level to shoot for?

Aim for 95%, says Koch, adding that you're not going to accomplish that with every tillage system. But once again, there is a cost for not hitting that benchmark. "From our research, there is a 1-bushel yield loss for every 1% of residue," he says.

6. What do I do if my clean furrow measurement is low?

First of all, you need to determine what type of residue it is. "Is it surface residue? Do you have row cleaners?" asks Koch. "If you have fixed row cleaners, try floating ones."

The clean furrow indicator can also be triggered by roots, particularly in no-till situations. "You may need to make a shift in where you're planting," he explains. "Cover crops can also trigger this number."

There is a tradeoff when you have incorporated residue, Koch adds. The goal is to determine what the right amount of tradeoff is when you look at your clean furrow measurement, your tillage practices, and your use of cover crops.