Northwest Iowa Crop Update Newsletter by Todd Vagts ISU Extension Crops Specialist Counties Served:  Carroll, Calhoun, Crawford, Ida, Monona, Pocahontas and Sac.
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Volume 2, Number 29

Northwest IA Crop Update, November 05, 2002
(Word Document)

In this issue 
ISUE Extension Crop Advantage Conference
Soybean SCN Variety Publication
Organic Acreage
Soil Temperature On-Line
Fall Application of Anhydrous Ammonia

Introduction
The ground was once again white this morning as the weather just doesn’t want to cooperate in order to finish up fall activities in west-central IA.  Yet as we continue harvest and tillage operations, we need to be thinking ahead to next year for fertility, variety selection, crop rotation and pest management strategies.  To help make some of these decisions easier, please plan to attend ISU Extension’s Crop Advantage Conference in Carroll on January 15, or one of the other Crop Advantage conferences held around the state in early 2003.  Dr. Tylka has developed a new publication listing soybean varieties with SCN resistance, look to the included web-link to obtain that information.  Fall application of Anhydrous Ammonia, although time efficient, may be costly in terms of lost nitrogen and environmental degradation.   Application as late as possible in the fall and the use of nitrification inhibitors may reduce the risk of nitrogen loss.

Crop Advantage Series Conference
ISU Extension Crop Advantage Conference in Carroll, IA is set for January 15, 2003

Crop producers and agribusiness personnel are invited to attend the Iowa State University Extension Crop Advantage Series at the Carrollton Inn on January 15, 2002, registration beginning at 9:00 am, program beginning at 9:30.  Certified Crop Advisors can obtain up to 5 credits by attending the conference. This Integrated Crop Management conference is one of 10 being held in Iowa in January & February.

Featured speakers will be Dr. Mike Duffy, ISU Extension Economist, on the “Impact of the 2002 Farm Bill on Crop Management Decisions,” and Dr. Marlin Rice, ISU Extension Entomologist on “Bean Leaf Beetle & Bean Pod Mottle Virus:  Double Trouble for Soybean.”

Topics covered in the afternoon workshops will include:

·        “Thinking Outside the Insecticide Box:  The Future of Corn Rootworm control”

·        “Insuring N and P Recommendations”

·        “Quality Alfalfa Production Strategies; Management, Harvest, and Fertility”

·        “Revised ISU P and K Recommendations”

·        “Precision Agriculture Technologies: Local Perspective on Current and Future Successes”

The cost of the program is $25.  An additional $25 fee is charged for Certified Crop Advisors attending the conference for credit. To obtain a program brochure or for further information, contact Todd Vagts at the Carroll County Extension Service at 712-792-2364.

New ISU publication with listing of SCN resistant soybean varieties released
Dr. Greg Tylka, ISU Nematologist Specialist, has just released a new publication listing all SCN resistant soybean varieties (including the source of resistance) for Iowa.  Look for the next ISU Integrated Crop Management Newsletter for an article giving an overview of the publication's content. 

In summary, there's a little more than 650 varieties listed in maturity groups I, II, and III.  Approximately 80 percent of the varieties listed are Roundup Ready, and a few are tolerant to sulfonylurea herbicides. All but 27 of the varieties listed have SCN resistance derived solely from PI88788. One of the listed varieties has SCN resistance derived from PI209332, four have SCN resistance from Peking, 11 have SCN resistance from Hartwig, and 11 have a combination of two sources of SCN resistance.

The publication is available on-line at http://www.extension.iastate.edu/Publications/PM1649.pdf.

Look to the ISU publication PM 879 (http://www.extension.iastate.edu/Publications/PM879.pdf) for more detailed information on the soybean cyst nematode and its management options for Iowa.

Organic Acreage Available On-Line
2000 and 2001 U.S. organic acreage data for livestock and crops are now available online at www.ers.usda.gov/data/organic

Soil Temperature
Iowa current and 3-day forecasted soil temperatures available on-line on ISUE’s NPknowledge web site.  Go to the following web address http://extension.agron.iastate.edu/NPKnowledge/

Fall Application of Anhydrous Ammonia
For those that have finished crop harvest, fertility for the next crop may be on your mind; particularly with the application of Anhydrous Ammonia.  Fall application of AA may be conducive for some because of time considerations next spring, yet fall applications are often associated with an increased risk of nitrogen loss by leaching of nitrate through the soil profile.  In many cases, this lost nitrate is dumped into local ponds and rivers by way of tile lines.  The most efficient (least amount of lost nitrogen) method of nitrogen application is through split applications, the first application made just prior to planting and the second application made sometime in late spring to early summer.  If you are set on applying AA this fall, the later the application is made, typically resulting in cooler soil temperatures, there will be less risk for nitrogen loss this winter and early spring.  The addition of a nitrification inhibitor (N-Serve) with fall applied AA to reduce the rate of conversion of AA to nitrate may reduce nitrate loss and increase grain yields.  Following is a summary of a 7-year study in south-central MN with fall applied AA with and without N-serve and corresponding nitrogen loss and yield responses:

·        Corn grain yield was increased 8 bu/a by a fall N + N-Serve and spring N treatments compared to early to mid fall application without N-Serve 

·        Corn grain yield was increased by 14 bu/a for split N treatment compared to Fall N application without N-serve.  The split treatment was 40% spring pre-plant and 60% side-dress at V8. 

·        The data suggests that in a wetter than normal year, and in poorly drained soils, the application of AA in the spring or late Fall+N-Serve may reduce nitrate loss by about 15 to 20%  

Source:  Randall, G. “Nitrogen Management Influences on N Losses to Tile and Surface Water”.  Proceedings of the 13^th Annual Integrated Crop Management Conference, Ames IA.  Dec. 2001.

(Word Document)