EDITOR’S NOTE — The Alabama Cooperative Extension System recently hosted a Planter Clinic at the E.V. Smith Research Center in the east-central part of the state. Presenters discussed the calibration and setup of planter units, new metering technology, and the impact of planter performance on crop yields. Beginning today, we will present a three-part series highlighting information presented at the clinic.
“The sins of planting will haunt you all season.”
Ozzie Luetkemeier, Purdue University
The ultimate goal of optimizing planter performance is to make high yields, but there are some factors that even the most finely tuned planter can’t overcome.
“You have to make sure you have adequate soil fertility and pH, manage any compaction problems to make a good zone in which plants can develop, use quality seed, plant in a timely fashion, and obviously you need a good stand,” says Kip Balkcom of the USDA-ARS National Soils Dynamics Lab in Auburn, Ala.
Planting is a critical component that affects everything else farmers do, says Balkcom. Considering the future demands on agriculture worldwide, the effects are far-reaching, he adds.
“World population continues to increase, growing exponentially in recent decades. We’re at 7 billion people now, and we’re expected to be at 9 billion by 2050. That’s a lot more mouths to feed. That problem is complicated by the fact that our arable land is decreasing.
“It’s not just a problem in the United States, but it’s one shared by countries throughout the world. This is a direct result of an increasing population and urban sprawl.
“Even if our arable land doesn’t decrease, we’ve still got to increase our efficiency, and we need to produce more than what we’ve produced previously,” he says.
One of the many factors that affect planting is the date, which depends upon soil temperature, says Balkcom.
“Our planting dates are, in a way, set for us. We can tweak those known dates or time periods. And many times, growers tweak them earlier to get the crop in as early as possible. This sometimes leads to cooler and wetter soils. You don’t want to plant in an environment that puts that seed at a disadvantage from the very beginning and increases the potential for disease.”
Planting dates must be managed carefully, says Balkcom. “With cotton, we know we need to have a soil temperature of around 65 degrees F. for four or five consecutive days. Then we have to take a look at the weather following the planting. Will we have enough heat units to get those plants out of the ground and get it off to a good start? These are all important considerations.”
Strip-tillage more of a challenge
Farmers who use strip-tillage have even more challenges when it comes to planting dates, he says.
“When you’re dealing with residues like with strip-tillage, you may have soils that are a little bit cooler. Some of the benefits of residue include cooler soils and less evaporative loss, and that’s great during the growing season, but it can be a hindrance at the beginning of the year when you’re trying to get a crop planted.”
Modifications can be made such as using row cleaners that will help move that residue away from the seed zone, says Balkcom.
“Row cleaners are one of the more popular planter attachments. There are fixed and floating row cleaners. If you’re working with heavy residue with a lot of cover in the field, fixed row cleaners are better because they’re closer to the disk openers.
“With lighter residue, a floating type might work better. The No. 1 thing to remember with a row cleaner is that you don’t want to move the soil — you want to move only the residue. You can operate some of these cleaners from the tractor and make adjustments on the fly.”
Other planting considerations include row patterns and widths, he says. “For many growers, it’ll be a standard 36-inch row. But there’s also a lot of interest in narrow-row patterns. The pros are that you have faster canopy closure that’ll help with weed suppression, more efficient moisture utilization, and more efficient light interception.
“Disadvantages are increased seed costs and the cost of modifying your equipment.”
A compromise between regular row widths and narrow rows is planting in twin-rows, says Balkcom. Many growers plant twin-row peanuts to minimize pressure from tomato spotted wilt virus.
“We’ve also looked at twin-row corn production. We looked at corn populations averaged over single and twin-rows, in dryland and irrigated environments, with 24,000, 30,000 and 36,000 plants per acre.
“Where our water was limited, we couldn’t support a high number of plants, and yields were decreased. But there was some separation when we looked at irrigated.
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“When we compared the single and twins, the twin-rows didn’t do much for us. We saw a bump with limited water, and I think in that case the twin-rows were more efficient. We still didn’t have enough water to support higher populations.
“Where we had unlimited water, we didn’t see a real advantage in the twin rows, and we had a slight yield decrease at the highest plant population.
“This research is continuing, but at this point it doesn’t justify someone going out and buying a twin-row planter. If you’re already planting twin-rows, I don’t think it’s going to hurt you.”
Variable seeding rate technology available
Technology is now available that allows growers to vary seeding rates on-the-go, says Balkcom.
If you have different soil types across the same field, it would be beneficial to reduce the seeding rates on some soil types and increase it on other types as opposed to using just one general seeding rate, he says.
Varieties also make a difference in how you plant, says Balkcom.
“When we think about varieties, we usually think about transgenic seed versus conventional seed, and we also think about varying maturity levels.
“But you’ve also got to be aware of different seed sizes, because it’ll make a difference when you’re calibrating the planter.
“If you’re planting peanuts, and you want to decrease the incidence of tomato spotted wilt virus, you need to be planted at six seed per foot of row. Based on the seed size, that could make a lot of difference in the actual number of seed you’ll be planting.”
As for planter performance, Balkcom says producers want to get good seed-to-soil contact, and there are simple attachments that can help you accomplish this.
“All planters now come with down-pressure springs and they can be adjusted. There are kits that allow you to put down-pressure springs on older planters.
“If you’re operating in rough ground, these are designed to help you maintain a consistent seed depth across the field. But you have to be careful with it. A little down pressure can be good, but more doesn’t always mean better. You could hurt yourself with compaction problems.”
Closing wheels represent the last contact your planter will have with the seed, he says.
“There are different styles, including rubber and spoke closing wheels. The rubber wheels work better in sandy soil types. If you use spoke closing wheels in sandy soils, it won’t seal as well and will dry much faster.
“Spoke wheels are designed more for heavy soil types, such as Decatur soils in the Tennessee Valley. If you use rubber closing wheels on those type soils, it’ll be difficult for the seed to emerge.”
If weather conditions are extremely dry and you’re trying to “dust in” cotton seed, he says, sometimes the closing wheel will kick up the seed because it is being planted so shallow. As a compromise, some growers use one rubber closing wheel and one spoke closing wheel.
“The name of the game with any planter is achieving uniform emergence,” says Balkcom. “When you get a good consistent stand across an entire field, you reduce yield variability.
Also, you want to optimize the plant spacing. Even-spaced plants will be able to take more advantage of sunlight and moisture than unevenly spaced plants.”
Tomorrow: Tuning Your Planter to Maximize Yield & Profit
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