Growing Knowledge

Read the latest insights from our experts as they cover agronomy issues that matter most to you and your operation.

Keep Nitrogen in the Root Zone

Tyler Steinkamp
Regional Agronomist
We all know that nitrogen is prone to leaching, especially in the spring when rain events can carry it straight from your fields into tile lines. I assumed that there would be less nitrate flow through tile lines during summer months when nitrogen uptake in the plant peaks. But after examining nitrate flow through tile lines in Iowa, we found peak losses occurred in June and July. This seemed counterintuitive, since that’s when we expect peak nitrogen uptake in plants to occur, so I conducted a modeling experiment to better understand how nitrogen moves in the soil as the season progresses.
 
My model was developed using corn root growth data from Iowa State University, average rainfall amounts and information on average nitrogen movement in soil based on rainfall. I ran three simulations to model nitrogen movement in soil.
 
Unstabilized nitrogen applied at planting
I used published data to estimate how quickly ammonium would convert to nitrate in the soil. Using this information I was able to track how long it would take 25, 50 and 75 percent of the ammonium nitrogen in soil to convert to nitrate as a basis for building a model. The graph below simulates nitrogen movement in soil compared to root growth when nitrogen is applied at planting. In order to maximize nitrogen uptake, we want the nitrogen depth lines to be right around the green depth of rooting line. It’s evident that some nitrogen has already made it into tile lines (at a depth of 48 inches) before rapid nitrogen uptake begins in the plant around 45 days after planting. The remaining nitrogen has also moved beyond the depth of the root zone by this time, making it unavailable for uptake.   

Graph1-(1).png 
Stabilized nitrogen applied at planting
Using data published by Dr. R. Jay Goos at North Dakota State University, I updated the model to reflect changes in nitrogen movement when a stabilizer was added to an at-planting application. As the graph below shows, applying a nitrogen stabilizer at planting helped keep more nitrogen in the root zone, so it was available during the peak uptake time prior to tasseling. Even when nitrogen was stabilized, some had still leached out of the root zone by peak uptake time.

Graph2-(1).png 
Side-dressed nitrogen application at V5
The final model simulated nitrogen movement in soil when it was side-dressed at V5. You’ll see that all of the nitrogen was available in the root zone during peak uptake time, an improvement over the previous two simulations. The problem with applying all the nitrogen at V5 is that there is none available to plants early in the season. For that reason, I recommend a split application where 50 percent of the total nitrogen is applied at planting with a stabilizer and the remaining nitrogen is applied via a side-dress application at the V5 growth stage.

Graph3-(1).pngThese simulations demonstrate that nitrogen mobility in soil is dynamic and is based on several variables that can change depending on conditions. Work with your local agronomist to develop a fertilization plan that will keep nitrogen in the root zone so it’s available during peak uptake around the time of tasseling.

It Really Is All About You

Kevin Eye
Vice President, WinField United
For 20 years, we’ve been focused on testing every agronomic concept that might make a difference for a farmer. The Answer Plot® program has looked at the good and the bad, the new and the assumed, the maybe-this-could-work and the crazy-but-possible. The program has grown to include nearly 200 sites across the United States, Canada, Mexico and South Africa that produce an incredible 6 million data points every year. And those millions of data points have led to some really valuable insights that are helping farmers get more from every field, every season.
 
But what all of us at WinField United are most proud of isn’t the big numbers; it’s the individual success stories Answer Plot insights have helped create. Every trial and every observation is managed by a local expert agronomy team driven to help their customers succeed. That’s what makes this program worthwhile and what can give you greater confidence in your agronomic decisions.
 
Putting Answer Plot data to work
You might be using Answer Plot insights without realizing it. If you are using response-to-fungicide scores to choose hybrids and plan in-season management, Answer Plot results helped shape the advice you’re getting from your local agronomy team.
 
When you’re discussing the pros and cons of increasing plant population with your agronomist, it’s a good bet Answer Plot data is adding context to those conversations.
 
When your team is helping you plan nitrogen applications throughout the season to get the most from your genetic investment, you can be sure Answer Plot trials helped fuel those recommendations.
 
If you have found the benefits of leveraging the R7® Tool on your farm, you have definitely been using Answer Plot data and insights.
 
Visit an Answer Plot site to see more
And we’re not done yet. We have our sights set on even more in-depth management insights and more localized data for better individual farm decision-making. Here are a few examples of what’s ahead for the Answer Plot program:
  • We’ll be evaluating seed care technology to give you the best opportunity to start the season with a strong, healthy stand.
  • We’ll be looking beyond general fungicide response to analyze how specific hybrids respond to specific fungicide products in more locations and accounting for more management strategies.
  • We’ll be testing new strategies for controlling herbicide-resistant weeds to help you choose the best solution for your specific challenges.
  • We’ll be tackling soil quality to help you maintain and improve the foundation of your crop production program.
You can be sure we will use everything we’ve learned from the last 20 years to inform the next 20 years and beyond – always focused on helping you make confident decisions for every field, every season.
 
Thanks for helping us recognize 20 years of insights and for inspiring us with your agronomic challenges. Let’s solve them together. I hope to see you at an Answer Plot event this summer!

Answer Plot Program Insights Reveal Yield Opportunities

WinField United
Agronomy Team
The Answer Plot® program was created to give farmers greater confidence in their agronomic decisions. Since 1988, we have been transforming data from test sites across the country into expertise you can use on your farm. Here’s a look at five key insights from the program in 2017 that can help you move your operation forward this year and in the years to come.

1. Don’t leave 90 bushels on the table.
Spending smarter beats spending more. Response-to scores help you manage input decisions with a clear understanding of potential ROI. Through the Answer Plot program, we measure crop response to management strategies, including plant population, nitrogen application, continuous corn and fungicide application. The bottom line: Nearly 90 bushels could be at risk on any acre every year.
 
The data below shows the range of yield response to four key decisions that affect productivity and profitability. The better you can predict the results of your management decisions, the less risk you will carry and the more yield opportunity you will realize.

Picture1-(1).png 

2. Plant with confidence.
The best results come from matching every seed to the right management practices. To improve your odds of choosing the right seed for each acre, we collect data on how a vast range of products perform on fields just like yours. Using those results on 240 corn hybrids and 360 soybean varieties at nearly 200 Answer Plot locations, we populate the R7® Tool Top 10 feature, which finds the best 10 products for your fields and the conditions you face, including geography, soil type, maturity and irrigation.

3. Let the fungicide data do the talking.
Effectively managing mid-season input costs can make the difference between profit and loss. But when disease strikes, you have to protect yield. Response-to-fungicide (RTF) scores help you with seed selection and indicate where to scout for conditions that favor disease growth, so you can decide whether you can expect a return on a fungicide application and when to take action.
 
The Answer Plot program gauges RTF scores on 240 corn products every year. In 2017, based on data from 41 locations, average yield response after fungicide application was 11.2 bushels per acre. And the higher the RTF score, the higher the yield response.
 
Picture2-(1).png

4. Keep nitrogen in its place.
Losing valuable nitrogen through air or soil is easy — and that’s not good for yield potential, the environment or your input budget. Nitrogen stabilizers slow the rate of nitrogen conversion so nutrients are ready and waiting for developing plants. The Answer Plot team is actively applying learnings from more than 400 independent research trials, which found treating fields with NutriSphere-N® Nitrogen Fertilizer Manager increased corn yield by an average of 10.0 bushels per acre compared to untreated plots.1,2

5. Seed treatment stops small pests from becoming big problems.
A well-chosen seed treatment can prevent damage from some of the biggest soybean yield threats, namely soybean cyst nematode (SCN) and sudden death syndrome (SDS). Based on testing at 25 Answer Plot locations with moderate to high SCN pressure, combining Warden® CX and ILeVO® seed treatments boosted soybean yield by 2.8 bushels per acre.
 
We hope you’ll join us in celebrating 20 years of insights — and bring your tough questions to an Answer Plot event this summer. See you at the plots!
 
Results may vary. Because of factors outside of Winfield Solutions’ control, such as weather, product application and any other factors, results to be obtained, including but not limited to yields, financial performance or profits, cannot be predicted or guaranteed by Winfield Solutions.
 
1. Koch Industries, 2018
2. Verdesian Life Sciences data on file

Spoon-Feed Crops for a Yield Advantage

George Watters
Agronomy Manager
Historically, many farmers have applied all their fertilizer in late fall or early spring. Although this practice can provide a sound foundation for crop growth, nitrogen and other key nutrients can be left vulnerable to environmental loss when applied all at once.   
 
Lost fertilizer results in wasted input and potential harm to the environment. Answer Plot® research suggests that spoon-feeding fertilizer throughout the growing season may result in a yield boost, because applying smaller amounts of nutrients when plants need them is more efficient from a plant uptake and use perspective.
 
Research backs the benefits
Data from 2016 Answer Plot® trials showed a 7.4 bushel per acre yield advantage in corn when a portion of the total nitrogen application was delayed until the V10 growth stage.1 The crop’s need for nitrogen increases rapidly toward the time of tasseling, so it makes sense that a later application would result in a yield bump as the plant begins shifting resources to fill out its ear.
 
A recent study by Purdue University found that modern corn hybrids have a higher demand for nitrogen later in the season, and thus may more likely benefit from a split application.2 Response-to-nitrogen scores from Answer Plot® trials can help identify corn hybrids that may benefit from spoon-feeding later in the season.
 
Start with sampling
Any sound fertilizer plan should be based on soil analysis from a quality laboratory. Soil testing guides application of crop nutrients and provides insight into the nutrient status of a field. Once you know what nutrient levels are in your soil, you can start optimizing your fertilization program.
 
Starter fertilizers like OptiStart® help provide a solid foundation for early plant growth by placing nutrients close to young roots for improved uptake. This promotes more vigorous early-season growth so plants are more tolerant to stress. Answer Plot® research has shown up to a 7 bushel per acre advantage in corn when starter fertilizers are used, especially in colder soils.3
 
An in-season tissue test will indicate real-time nutrient levels in the plant, which can guide additional fertilizer needs as the season progresses to help protect yield potential. Contact your local WinField United retailer to help develop a season-long fertilization program.  
 
With the growing season on the horizon, we’re here to help you with your holistic plant nutrition plan. Next, we’ll explore how modeling programs can help manage nutrients and the importance of micronutrients in your fertilization program. We’ll continue to dig into all aspects of plant nutrition throughout the year right here on the Growing Knowledge blog, so be sure to check back for more plant health tips.
 
1. Based on an average of 15 Answer Plot® locations.

2. Late Season Nitrogen Fertilizer Placement, Timing and Rate Responses in Modern Corn Hybrids; T. Vyn, et.al.; Purdue University; 2016 Indiana CCA Conference.

3. Based on an average from 37 Answer Plot® locations.

Let Hybrids Tell You What They Need

WinField United
Agronomy Team
Whether you’ve already chosen your corn hybrids for the year or still have purchasing decisions to make, one thing’s for sure: every dollar counts. Understanding how each hybrid reacts in various situations can lead to a clearer picture of how to allocate your resources.
 
Obtain Hybrid-Specific Data
From the moment your seed touches the soil, every decision you make affects the ROI potential of that seed. Response-To Scores can help you determine how a particular hybrid will perform under different management strategies. According to seven years of Answer Plot® data, there is a potential loss or gain of 90 bushels per acre based on these four factors:
  • Response to continuous corn
  • Response to population
  • Response to nitrogen
  • Reponse to fungicide
 
A 90-bushel-per-acre swing can be the difference between operating at a loss and having a banner year, so be sure to factor these scores into 2018 seed decisions if you haven’t finalized your purchases. If you’ve chosen your hybrids, you can still use this data to help ensure you give those hybrids what they need throughout the growing season.
 
Ensure Inputs Count
Response-To-Nitrogen and Response-To-Fungicide scores can help you determine how your hybrids will react to applications before you invest in these inputs, so you can weigh possible yield gain against application costs.
 
For example, Answer Plot® data, which tests the Reponse-To-Fungicide scores of 240 hybrids every year, shows that you’re more likely to see post-application yield increases from hybrids with high Response-To-Fungicide scores. In 2017, Answer Plot® data showed an average yield response of 11.2 bushels per acre following fungicide applications on fields with hybrids that had high Response-To-Fungicide scores; knowing the variance of each hybrid is important, which ranged from 0 to 37 bushels.
 
Work with your agronomist to review this information for each of your hybrids and use it to help guide management decisions now and throughout the growing season.

Displaying results 1-5 (of 19)
 |<  < 1 - 2 - 3 - 4  >  >| 

Subscribe to the Advisor Newsletter

Sign up for monthly agronomic insights and product information.