Study: Sensors Outdo Farmers At Choosing Nitrogen Rates

Corn Field

Choosing how much nitrogen (N) to put on corn fields isn’t something farmers take lightly. Many factors go into the decision, including past experiences, the timing of application, yield goals, and results from soil tests.

Nevertheless, crop sensors can select N rates for corn that outperform those chosen by farmers, according to more than 50 on-farm demonstration projects conducted in Missouri from 2004 to 2008. Compared to producers’ N rates, sensor-selected rates increased yield by almost 2 bushels per acre, on average, while reducing by 25% the amount of excess N that was applied to fields but not removed in grain.

As concerns about N pollution continue to mount, the sensors offer a way to cut fertilizer inputs without hurting yield or profits. “The most important thing, I think, is that we were able to make progress on both fronts: The technology slightly improved production and slightly improved environmental outcome,” says the study’s leader, Peter Scharf, a University of Missouri extension agronomist. “There has been talk about win-win, but really there have not been a lot of approaches that have actually [achieved] that.”

Funded by the USDA-NRCS Conservation Innovation Grants program, the Missouri DNR Nonpoint Source Pollution Control program, and the U.S. EPA Special Grants program, the study appears in the November-December issue of Agronomy Journal.

Scharf explains that although optimal N rates can vary substantially within and between fields, most U.S. corn growers still apply the same rates to entire fields or even entire farms. Many farmers in Missouri and elsewhere also spread N fertilizer months before planting, often the November before.

As fertilizer and seed costs keep climbing, however, corn producers are feeling financial pressure to apply N more precisely — in amounts that satisfy crop requirements but don’t exceed them. To help farmers with this, in 1997 Scharf began studying methods for predicting where to put more N in fields and where to put less before sowing crops, since that’s the system most people use. But he and his colleagues eventually turned to crop sensors, employed after plants start growing, as a more accurate means to diagnose N deficiency and sufficiency.

The sensors take advantage of what farmers know already from experience and common sense, Scharf says: Crops with enough N are darker green and taller, while N-deficient crops are lighter and shorter. After developing a technique for translating sensor output into a suitable N rate within a few seconds — work that was published in 2009 — Scharf and his collaborators began taking the technology to farms.

Fifty five demonstrations were eventually conducted across a broad swath of Missouri’s corn-growing region. In most cases, two or three sensors were attached to N applicators already owned by farmers or their service providers, and then used to side-dress N at variable rates to corn in growth stages ranging from V6 and V16. At the same time, fixed N rates chosen by farmers were applied in other areas, allowing comparison of the two techniques.

An average of 14 pounds/acre less N was applied when sensors chose the rates, the researchers found, without affecting yields. In fact, during the exceptionally wet spring of 2008, sensor use actually boosted grain yield by 8 bushels/acre, on average, over what producer rates achieved–a significant bump that brought the overall yield gain with the sensors to 2 bushels/acre over all 55 fields.

Scharf believes yield increased significantly in 2008 because the sensors actually chose higher N rates than farmers did that year, better compensating for fertilizer lost through heavy rainfall. And this yield bump, coupled with an overall reduction in N fertilizer from 2004-2007, ended up increasing partial profit by an average of $17/acre across all farms.

Despite the sensors’ benefits, however, “the adoption numbers are still quite small,” Scharf says. Complete systems currently range in price from $10,500 to $16,500, and learning to use them involves time and expense, as well. Still, these aren’t the main hurdles to wider adoption, he adds.

The bigger one is getting farmers to side-dress N during the growing season, rather than fertilizing in spring before planting or even the fall before.

The unusually heavy rains of the past four years may change that. Because applying N months in advance gives it more time to leach and run off, many farmers have lost loads of it — and, therefore, money and yield — in recent rain-soaked years. That leaves one option: Applying the nutrient during the growing season.

“If this weather keeps up, I think we’ll see more people going toward in-season N application,” he says. “And that will be a big obstacle out of the way to using the sensors.”

Leave a Reply

Fertilizer Stories

Iowa waterways
FertilizerDow AgroSciences Recognizes Ag Retailers’ Role in Protecting Iowa Water Quality
April 6, 2017
The state of Iowa and its agriculture community have worked for decades to preserve soil health, protect water quality and Read More
Yara West Sacramento Ribbon Cutting
Crop InputsYara West Sacramento Is Newest Addition
March 27, 2017
Yara’s West Sacramento Terminal was officially welcomed March 21 as the newest Yara North America facility in the U.S. While continually Read More
Nutrients for Life Foundation Teacher
FertilizerNutrients For Life Foundation Celebrates 10 Years Teaching Fertilizer Education
March 23, 2017
Those in agriculture know fertilizer is a vital ingredient to grow strong, productive crops. In fact, fertilizer is responsible for Read More
Growing corn
Crop InputsLock Down Nitrogen For 2017 Profits
March 5, 2017
Managing nutrient programs to snuff out the three types of nitrogen loss — leaching, volatilization, and denitrification — is crucial Read More
Trending Articles
Young Corn Plants
Crop NutritionStill Hunting Yields
April 1, 2017
There’s no denying it — the agricultural marketplace today is undergoing a fundamental shift in fortunes. Not too many years Read More
Nutrients for Life Foundation Teacher
FertilizerNutrients For Life Foundation Celebrates 10 Years Teaching Fertilizer Education
March 23, 2017
Those in agriculture know fertilizer is a vital ingredient to grow strong, productive crops. In fact, fertilizer is responsible for Read More
AdjuvantsA New Weed-Control Era Begins: But First, One Last Obstacle
March 4, 2017
There is trepidation, there is reluctance, and there is excitement. Ag retailers feel it all about the new dicamba and Read More
LIFT Academy video screenshot
Crop InputsLIFT Agriculture Academy: A Q&A With West Central Distribution’s Dean Hendrickson
March 1, 2017
West Central Distribution recently launched its LIFT Agriculture Academy, a new, premiere training and professional development resource for West Central’s ag Read More
Farmer and aptop
Matt Hopkins10 Warning Signs Your Website Is Grossly Outdated
February 8, 2017
Your Website is often a visitor’s first impression of your ag retail business. A positive first impression can set the Read More
AgriSync
Matt Hopkins17 Agriculture Apps That Will Help You Farm Smarter In 2017
December 9, 2016
Ag professionals are working smarter, not harder, than ever before. Smart farming technologies have enabled them to reduce costs, maximize Read More
Latest News
ManagementAn Inside Look at Award Winning Ag Retailer Gar Tooteli…
April 20, 2017
CropLife Editor Eric Sfiligoj discusses An Inside Look at Award Winning Ag Retailer Gar Tootelian Read More
Students Soybean Field
Industry NewsMACA Announces 2017 Young Leader Scholarship Recipients
April 19, 2017
The Mid America CropLife Association (MACA) Board of Directors selected 11 college students to receive the MACA Young Leader Scholarship Read More
Growmark FS Outlet
SoftwareKnoa Software Solution Helps GROWMARK Boost System Perf…
April 19, 2017
Knoa Software, a leading provider of user experience management (UEM) software, has announced that GROWMARK, Inc., a regional agricultural cooperative Read More
Crop InputsFBN Publishes ‘Voice of the Farmer’ Agricul…
April 17, 2017
Farmer’s Business Network (FBN) released today its “The Voice of the Farmer”, which the company is describing as “a special Read More
ManagementTalking Responsible Ag
April 13, 2017
CropLife Editor Eric Sfiligoj discusses the Responsible Ag program with director Bill Qualls. Read More
Crop InputsFlying Under the Radar No More, FMC Goes Big
April 13, 2017
Describing FMC as “under the radar,” admittedly, is probably a stretch. But in a snap of the fingers, FMC upped Read More
Crop InputsWhat do Roundup and Mickey Mouse Have in Common? Califo…
April 13, 2017
(SOURCE: East Valley Times) Glyphosate, the active ingredient in Monsanto Co.’s Roundup and many other weed killers, is being added Read More
Syngenta headquarters in Basel, Switzerland
Crop InputsSource: ChemChina to Divest Assets to Adama Following S…
April 11, 2017
China National Chemical Corp. plans to redistribute agrochemical assets to its Adama unit after the $43 billion takeover of Syngenta Read More
Farming drone air
Eric SfiligojThe Interest in UAVs for Agriculture Grows
April 10, 2017
At times, it seems as if experts have been predicting “big things” for unmanned aerial vehicles (UAVs) for several years Read More
OpinionOpinion: Taking On The Farmers Business Network
April 8, 2017
Well, another round of venture capital funding has come to Farmers Business Network (FBN), followed up with the obligatory feature Read More
Drone
EquipmentFarming Drones: The Future Of Agriculture?
April 7, 2017
Chances are, you already know drones are amazing. After all, this is something DroneLife readers just understand. But if you’re Read More
ManagementFMC-DuPont, Crop Plantings, and UAV Updates
April 6, 2017
Editors Eric Sfiligoj and Jackie Pucci discuss the purchase agreement between DuPont and FMC, the 2017 crop acreage mix and Read More
Falcon soil sampler
EquipmentSerious Soil Sampling Rigs
April 6, 2017
The industry has seen an increase in automation in sampling equipment, and consultants now often pull cores with an automated Read More
Iowa waterways
FertilizerDow AgroSciences Recognizes Ag Retailers’ Role in Prote…
April 6, 2017
The state of Iowa and its agriculture community have worked for decades to preserve soil health, protect water quality and Read More
Farmer Scouting Weeds in Soybean Field
EquipmentSoil, Scouting Programs Continue To Gain Value
April 5, 2017
How much growers and their retailers utilize soil testing and scouting varies greatly. But they should step up their game Read More
Forbes Mixing Bowl NYC
Precision Ag6 Key Takeaways from Forbes Mixing Bowl NYC
April 5, 2017
Advisory investment group The Mixing Bowl teamed up with Forbes for its New York-based event this year to discuss technology’s Read More
Pam Marrone
Crop InputsQ&A With Pam Marrone On The World’s First All-Biolo…
April 4, 2017
Marrone Bio Innovations Inc. and Israel-based Ground­work BioAg in February announced successful field trials of the world’s first all-biological comprehensive Read More
Corn soil
Crop NutritionBiostimulants Clamor For A Piece Of The Row Crop Market
April 3, 2017
The question these days isn’t who is venturing into biostimulants — it’s who isn’t. Or more to the point: The Read More