Introduction
A new planting season is here once again.  I’m sure one of the concerns on many produces minds is the lack of precipitation we’ve had over the past several months.  The soil profile has adequate moisture across most areas, yet moisture in the top few inches could become a problem if care is not taken prior to planting.  Dr. Elwynn Taylor stated that we may be in for a dryer than normal planting season followed by a normal precipitation pattern for the growing season.  A dryer than normal planting season is not all bad, it allows for timely planting and reduces the risk of soil compaction due to overly wet soils.  Oat seeding may well be under way as soil conditions allow.  There have been several predictions this winter that much of the anhydrous ammonia applied last fall has nitrified.  This does not mean that the nitrogen has been lost.  But it does indicate that the nitrogen is at a higher risk of being lost through the bottom of the rooting zone if we experience wet conditions over the next 2 to 3 months.  Make your nitrogen applications according to ISU’s recommendations.

Weather update
As we all know, weather conditions have a dramatic effect on crop production in western Iowa.  Elwynn Taylor (ISU Extension Climatologist) has some general comments on what may be expected for the upcoming planting and growing season.

As of March 15 the weather patterns that will determine the spring and summer conditions are not fully established.  Some of the leading weather indicators do give some clues for season: SOIL MOISTURE- the national Crop Moisture Index is normal to wetter than normal (positive yield potential factor).  WEATHER CYCLE- The 19-year Benner Cycle is nearing the end of the 13 high yield years, but there are 2 "likely high yield" years remaining in the cycle.  EL NINO- Scientists note that a "Kelvin Wave," warming water and cloud cover off Peru, and the SOI indicate that an El Nino is likely by August.  Accordingly, August may be less stressful than during the past 2 years.  PDO- May have influenced the "mild winter" conditions and could result in dry conditions in the western portion of the Corn Belt this year.  LONG-LEAD FORECAST- The National Weather Service forecast for April indicates possible wet conditions across Oklahoma-Arkansas.  Little or no signal is given for spring and summer Corn Belt Weather.  The Australian depiction of historical precipitation associated with SOI trends indicates planting season dryness in much of the Corn Belt and excessive moisture in the Gulf States.  Typical seasonal weather shifts could result in the wet pattern moving northward (a crop favorable but uncertain outlook).

                                                                                                                        -Elwynn Taylor

 You can find more weather information and facts from Elwynn Taylor at his website

http://www.extension.iastate.edu/cgi-bin/Notes/rnoteindex.pl?WEATHER

 To get information on weather conditions and climatic data for crop and insect development prediction for northwest Iowa, go to my weather web page at http://extension.iastate.edu/carroll/crops/weather_data.htm

Planting and Crop Development
Growing degree day accumulation   As we begin planting I will post accumulated growing degree units based on planting date for corn and will describe (in this section) current and forecasted developmental stages for corn and soybeans.  You can use this information to help plan crop management and protection activities throughout the season. 

Soil temperature is an important indicator to when you can begin planting corn and beans.  Corn germination is very slow below 50 F and soybean germination is greatly reduced at soil temperatures below 55 F.  Planting into cool soils slows germination and seedling development and increases the risk for seedling disease and stand loss.  Go to ISU’s NPKnowlege webpage ( http://extension.agron.iastate.edu/NPKnowledge/ ) to obtain the last three day’s soil temperature and the forecasted soil temperature for the next three days.  The current and 3-day forecasted 4-inch soil temperature ranges from 36 to 40 degrees for northwest Iowa.

Small Grain Planting has begun in some areas.   With depressed corn and soybean prices, small grains such as oats may be a good alternative crop.  Oat and wheat are an excellent alternative crop that can help break up the disease cycle of Phytophthora and Brown Stem Rot and is a good rotational crop to reduce SCN populations in fields.   In addition to the grain, straw can be a valuable commodity that can be utilized and marketed to livestock producers and hobby farmers.  It is also in demand as a mulch material for nurseries and road construction projects. 

To obtain small grain variety characteristic and yield information, go to IA Crop Improvement Association’s website http://www.agron.iastate.edu/icia/YieldTesting3.html or stop by your local Extension office.

Pest Management
Throughout the season I will be tracking insect growing degree days to predict when we need to start looking for certain insect pests, including black cutworm, common stalk borer, alfalfa weevil, western bean cutworm, European corn borer and bean leaf beetle.  If there are other pests that you would like me to track, please let me know by sending an email to vagts@iastate.edu .

Dr. Marlin Rice (ISU Extension Entomologist) has released information on new insecticides for 2002; you can view the article in the March 18, 2002 ICM newsletter also found at http://www.ipm.iastate.edu/ipm/icm/

Weed emergence for many species is not a random event and can be predicted to help in scouting, management and control.  Giant ragweed, lambsquarters, Pennsylvania smartweed and common sunflower are typically the first weeds to emerge and can be found in fields before corn and soybeans are planted.

Soils and Soil Fertility
The warm fall and winter may have increased the nitrification rate of anhydrous ammonia applied to 2002 corn fields.  Yet with the dryer than normal winter and spring so far, most for the Nitrogen should still be in the soil rooting profile.  If the spring turns wet, the nitrogen may be at high risk of being leached out of the rooting zone.  Utilizing the late spring nitrate test can be a useful tool to determine the status of nitrate in the upper soil profile.

 Refer to Table 1 for suggested nitrogen rates following a previous crop.

 Newsletters and Websites

Subscribe to these newsletters for more agricultural information.

• ISU Integrated Crop Management  http://www.ipm.iastate.edu/ipm/icm/

• Nebraska Crop Watch  http://cropwatch.unl.edu/

• The Ohio State University Extension C.O.R.N  http://corn.osu.edu/agcrops.html

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Todd Vagts
Iowa State University Extension
Field Crops Specialist
1240 D. Heires Avenue 
Carroll, IA 51401 
Office: 712-792-2364; Cell: 712-249-6025;  Fax: 712-792-2366
Email: vagts@iastate.edu  

For questions or comments please respond to vagts@iastate.edu