Wallaces Farmer

Planting corn after anhydrous ammonia application

Every year someone asks "how long to wait after anhydrous ammonia is applied before a field can be tilled or planted?"

Rod Swoboda 1, Editor, Wallaces Farmer

April 29, 2015

3 Min Read
Farm Progress logo in a gray background | Farm Progress

How long should you wait after applying anhydrous ammonia before you plant corn? Or before you can do tillage to the field? Brian Lang, Iowa State University Extension crop specialist at Decorah, gives the following answer.

Related: Improved ag sprayer technology pays off

"Regarding tillage, this is not a concern as long as the tillage is more shallow than the anhydrous ammonia is injected," he says.

"However, if the soil is inverted soon after anhydrous ammonia is injected, such as with a chisel plow, some volatilization of the ammonia could occur if a zone of concentrated ammonium is exposed at the surface. By waiting at least one day before tilling, the chance for nitrogen loss would be minimized. Having normal soil moisture conditions further minimizes the potential problem, whereas dry soil conditions increase risk."

Regarding when to plant, "There is no specific "wait time" for planting after applying anhydrous ammonia," says Lang. "What is important is that the seed does not come in contact with the ammonia zone. As long as the anhydrous is injected at a proper depth and soil sealing behind the knives is "normal", this is not a problem."

However, sometimes the anhydrous is not being injected as deep as it should, or the soil doesn't seal behind the knife as good as anticipated, points out Lang. "This can bring the ammonia zone closer to the seed zone. An additional "safety factor" often used is to inject the anhydrous at an angle to the way the corn rows will be planted so that if there is a problem, the anhydrous zone won't affect entire rows of corn," he says.

Best Practices For Spraying: Get The Most Out Of Your Sprayer
Are you confident you know the best ways to prepare your sprayer for the season ahead? Are you sure you know the best practices for minimizing herbicide spray drift? Read through these best practices to make sure you are on the right track.

Use rhizobia inoculants on soybeans?
Soybean bacteria inoculants for nitrogen fixation were evaluated in the mid-1990's on 44 no-till trials across eight Midwest states (IA, IL, IN, MI, MN, OH, SD, WI). In the more southern states (IA, IL, IN, OH), inoculation had little effect on yield. But in the more northern states (MI, MN, SD, WI), inoculated soybeans yielded 3.8 bushels per acre more than uninoculated soybeans (8.6% yield increase).

~~~PAGE_BREAK_HERE~~~

ISU's Brian Lang notes that the following are general recommendations for use of inoculants in Midwest states:

•No inoculants are needed on silt loam and loam soils where well-nodulated soybeans have been grown in the last three to five years, and where soil pH has been maintained above 6.

•Seed should be inoculated every year for fields with no soybean history in the last three to five years.

•Seed should be inoculated every year when planted on sandy soils, regardless of field history of soybean production.

•Updated recommendations for the "northern" mid-west states included: consider inoculation where soils tend to be cooler and soybeans are planted using reduce-till and no-till, regardless of field history of soybean production.

Save money on soybean seeding rates
"Recent research by both ISU and major seed companies indicates we can keep seeding rates in the more affordable ranges, lower than we may have been planting in the past," says Clarke McGrath, ISU area crop specialist at Lewis in southwest Iowa. "With the cost of seed, this is timely information."

Harvest stands of 110,000 and above produce similar soybean yields in Iowa. Studies have shown that field stand losses of 15% to 30% are common, depending on planter performance, soil conditions, type (if any) of seed treatment, weather and pest pressure. These field losses are due to lack of seed germination, insect and disease damage, barren plants, lodging, and many other factors. To make it more complex, each field will likely have a different stand loss.

"So, if we shoot the average, if we want to harvest 130,000 plants and we average a 23% stand loss before harvest, the seeding rate should be 159,900 seeds per acre.

About the Author

Rod Swoboda 1

Editor, Wallaces Farmer

Rod, who has been a member of the editorial staff of Wallaces Farmer magazine since 1976, was appointed editor of the magazine in April 2003. He is widely recognized around the state, especially for his articles on crop production and soil conservation topics, and has won several writing awards, in addition to honors from farm, commodity and conservation organizations.

"As only the tenth person to hold the position of Wallaces Farmer editor in the past 100 years, I take seriously my responsibility to provide readers with timely articles useful to them in their farming operations," Rod says.

Raised on a farm that is still owned and operated by his family, Rod enjoys writing and interviewing farmers and others involved in agriculture, as well as planning and editing the magazine. You can also find Rod at other Farm Progress Company activities where he has responsibilities associated with the magazine, including hosting the Farm Progress Show, Farm Progress Hay Expo and the Iowa Master Farmer program.

A University of Illinois grad with a Bachelors of Science degree in agriculture (ag journalism major), Rod joined Wallaces Farmer after working several years in Washington D.C. as a writer for Farm Business Incorporated.

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like