New Website for Regional Corn Nitrogen Rate Calculator

Posted on 05/16/2016 by Lynn Laws

AMES, Iowa – The regional Corn Nitrogen Rate Calculator website, which has been helping farmers determine profitable nitrogen rates since 2005, now has a new URL (cnrc.agron.iastate.edu) and a revised nitrogen response trial database, and is more user friendly for mobile devices.

The largest changes to the website are the updated individual state nitrogen rate response trial database and, for Iowa, the addition of the southeast Iowa region. Nitrogen response trial sites for Iowa are grouped by two geographic regions, which now matches guidelines in the publication Nitrogen Use in Iowa Corn Production (CROP 3073). The publication can be downloaded for free at the online extension store.

“The site revisions allow users to have access to the latest nitrogen rate research, and it offers more tailored rate guidelines in Iowa,” said John Sawyer, professor and extension soil fertility and nutrient management specialist at Iowa State University.

While suggested nitrogen rates may have changed somewhat due to the update, the concept and calculation process of the online tool remains the same. The method continues to be based on a regional approach, providing nitrogen rate guidelines in six states across the Corn Belt: Iowa, Illinois, Michigan, Minnesota, Ohio and Wisconsin.

“The corn nitrogen rate calculator benefits farmers so they can understand needed nitrogen application rates, adjust for different crop rotations, and provide guidance and flexibility in choice of application rate,” said Sawyer. “More importantly, it allows adjustment in rate for changing nitrogen and corn prices.”

Using the Maximum Return to Nitrogen concept within the CNRC also helps farmers implement the most economical nitrogen rate inputs, which helps moderate water quality issues.

For more information about the CNRC, visit cnrc.agron.iastate.edu.

Saturated Buffers Improving Iowa Water Quality

Posted on 04/27/2016 by Lynn Laws

AMES, Iowa – Using science-based research, Iowa State University Extension and Outreach specialists are working to improve the quality of water throughout the state of Iowa. The use of saturated buffers in watersheds has proven to be a successful nitrate management practice.

ISU Extension and Outreach has been forging partnerships with private land-owners in Iowa watersheds to establish saturated buffers. These buffers reduce the movement of sediment, phosphorus and nitrogen into surface water while redirecting water into the root zone of the buffer.

Click on the infographic below to enlarge…

Corn Project Findings

Posted on 01/27/2016 by Lynn Laws

Researchers with the Climate and Corn-based Cropping Systems Coordinated Agricultural Project (commonly known as the Sustainable Corn Project) have documented 130 findings, some of which will be explored during a Feb. 11 webinar, open to the public through Iowa State University

The five-year USDA-National Institute of Food and Agriculture research project is nearing completion, led by Lois Wright Morton, a professor of sociology at Iowa State University. In 2011, Morton convened 140 researchers from 10 land-grant universities in the Corn Belt and USDA Agricultural Research Service, to begin a study of farmers’ perceptions and farm management practices.

The practices had the potential to provide resilience in times of drought, reduce soil and nutrient losses under saturated soil conditions, decrease field nitrogen losses, retain carbon in the soil and ensure crop and soil productivity. The researchers collected measurements at 35 field sites with diverse landscapes and soils, and from surveys of thousands of Midwestern farmers, entering all the data into one database for the team’s use. Continue reading →

Corn SplitN Decision Support Tool Now Available in All 12 Corn Belt States

Posted on 11/03/2015 by Lynn Laws

img_cornsplitn_banner2

Now farmers and advisors in all 12 Corn Belt states can use the free Corn-Split N decision support tool, developed by the USDA-funded Useful to Useful climate initiative. The tool helps farmers and advisors manage nitrogen application for efficiency and profit. Corn yield response data from seven new states, together with statistical modeling of days suitable for field work in those states, has recently been added.

Farmers in Illinois, Iowa, Indiana, Missouri, Kansas, Wisconsin, Minnesota, South Dakota, North Dakota, Nebraska, Ohio and Michigan can get customized results based on their planting and fertilization schedule, local costs and available equipment. A summarized fieldwork table and crop calendar makes it easy for farmers to see how schedule adjustments might affect their ability to fertilize on time.

Continue reading →

Split Nitrogen (N) Decision Support Tool (DST) – Evaluating the Economics of Conservation

Posted on 03/19/2015 by Hans Schmitz

Farmers can conserve nitrogen by applying it when corn can most benefit from its application, reducing nitrogen in the water supply by keeping it in the growing crop. How can they do so? By applying some to get the crop started and the rest after the corn is out of the ground and actively growing.

The Useful to Usable initiative has developed a new tool for use by farmer, farm managers, and crop advisors that evaluates the feasibility of transitioning to or continuing use of split applications of nitrogen during the growing season.

Farmers who do not sidedress nitrogen on an active crop often do so for multiple reasons. One main concern lies in the uncertainty around having the time to get across all those acres when the weather allows one to do so, before the corn grows too large to put machinery in the field. The Split N DST helps with this risk by using local weather data and fieldwork days compiled by the National Agriculture Statistics Service (NASS), to estimate how likely a farmer can apply nitrogen at sidedress across all his or her acres. Continue reading →

There’s still time to collect samples for the cornstalk nitrate nitrogen test

Posted on 10/29/2014 by Chad Ingels

Fall is the time to evaluate corn nitrogen use efficiency by using the end-of-season cornstalk nitrate test. The test measures nitrate-nitrogen left in the corn plant following maturity.

According to the most recent USDA Crop Progress report released on October 27 just 46% of the nation’s corn was harvested so there is still time to collect samples for analysis. Ideally samples should be collected 1 to 3 weeks after maturity (black layer), however, over the course of 15 years of utilizing the test I have collected samples up to, and immediately after harvest. Post harvest samples can be collected if the corn header is raised high enough to allow an 8-inch stalk segment to be collected starting 6 inches above the ground. If using a head with shredders samples will need to be collected before harvest. Don’t allow stalks that have been harvested to get rained on before collection or nitrates will start washing out of the stalks.

The video provides a demonstration of sample collection and preparation in order to send to a lab for analysis.

Days suitable for field work in the Corn Belt

Posted on 04/02/2014 by Ben Gramig

Tillage, planting, fertilizer application and harvest all require field work to be completed. The timing and sequencing of these activities are critical for crop development, field dry down and farm profitability. Members of the Useful-to-Usable team have compiled weekly reports of days suitable for field work and planting and harvest progress from the state offices of the National Agricultural Statistics Service to understand the historical trend in days suitable during planting and harvest. An important objective of this research is to construct a predictive model of days suitable as a function of weather and soil type at a given location. We are using historical field work and weather data, together with soil information, to construct a statistical model that explains as much of the variation in historical field work days as possible so that we can use this information in the development of decision support tools to aid farmers in:

Selecting what size of machinery to purchase,
Determining the risks and rewards of alternative fertilizer application timing, and
Predicting how we expect field work days to be different in the future based on predicted climate change.

Over the period from 1980-2010, there is an overall trend towards fewer days suitable per week during the planting period and more days suitable during the harvest period. There are differences across states, as is shown in the table below.

Table UPDATED 8/30/2017

Table 2 Mean Weekly Days Suitable for Fieldwork, 1980-2010

	Entire growing season	Planting Period¹		Harvest period¹
State	Mean (S.D.)	Mean (S.D.)	Difference between 1980-1994 and 1995-2010	Mean (S.D.)	Difference between 1980-1994 and 1995-2010
Illinois	4.8 (1.8)	3.7 (1.9)	( – )***	5.2 (1.5)	( + )***
Indiana	4.6 (1.8)	3.5 (1.9)	( – )***	5.1 (1.5)	( + )***
Iowa	4.6 (1.8)	3.8 (1.9)	( – )***	5.0 (1.5)	( + )***
Kansas	4.7 (1.9)	4.1 (1.8)	( + )***	5.0 (1.8)	( + )***
Missouri	4.6 (1.9)	3.5 (1.9)	( + ) **	4.7 (1.8)	( + )***

Table notes: All values are weekly reports of the number of days between 0 and 7, averaged over all USDA Crop Reporting Districts in a given state. ** and *** denote <5% and <0.1% confidence levels for t-tests of the directional (+, -) difference in means between time periods.
¹ Weeks when planting and harvest take place each year based on USDA-NASS weekly crop progress and condition reports issued by state NASS offices.

Farmers weigh in on Nitrogen management in a changing climate

Posted on 03/24/2014 by Marilyn Thelen

Climate and weather greatly impact a farmer’s day-to-day operations as well as their livelihood. To gain perspective on farmers’ production practices and how they are changing, Michigan State University Extension educators and specialist invited farmers from across Michigan to participate in one of three discussions on sustainable corn production held at locations in the north central, central and south central part of the state during mid-March. Climate and nitrogen were two of the topics discussed.

Concerns over heavy spring rains prompts Michigan corn growers to split N-applications throughout growing season.

We found that producers have already decreased the amount of nitrogen applied per bushel of yield. Cost of nitrogen, concern of environmental impacts, improved technology and better information were all given as reasons for the change. The source of nitrogen used is also changing. Most producers indicated that they will or have already moved away from using anhydrous mostly due to availability. Continue reading →

State Nutrient Reduction Strategy: Information Midwestern Farmers Can Use

Posted on 02/10/2014 by Lynn Laws

Dick Sloan, an Iowa farmer in Buchanan County, recently wrote to his local newspaper to bring attention to the portion of Iowa’s Nutrient Reduction Strategy that provides tables that assist farmers in making nutrient management decisions. Table 2, for example, on page 6 of the strategy shows the potential impact of certain practices, like cover crops, on reducing nitrate loss and on corn yield based on literature review. Farmers can see which practices have been shown to be most effective. His article can be found at http://thegazette.com/2014/02/02/good-options-to-choose-from/. The document to which he refers – Iowa’s nutrient reduction strategy – can be found online at http://www.nutrientstrategy.iastate.edu/sites/default/files/documents/NRS2-130529.pdf.

Scientists Team Up to Keep Nitrates on Fields

Posted on 12/11/2013 by Lynn Laws

Matthew Helmers is an associate professor of agriculture and biosystems engineering at Iowa State University and a Principal Investigator with the Sustainable Corn project. He is working with teams of scientists who are field testing promising strategies to keep nitrogen fertilizer on farm fields, using a systems approach. The following is a news release about some of his findings…

AMES, Iowa – Keeping nitrogen fertilizer on farm fields, to support optimum crop growth, and out of streams and rivers is no simple formula. It’s complex.

“Think ‘writing a novel’ versus ‘writing a recipe,’” said Matthew Helmers, an associate professor of agriculture and biosystems engineering at Iowa State University, where he is working with teams of scientists who are field testing promising strategies, using a systems approach. Continue reading →

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