Crops Bulletin
April 17, 2013
       Issue 1         


Prepared by

Paul Kassel

Extension Field Agronomist



Serving Clay, Buena Vista, Dickinson, Emmet, Hancock, Kossuth, Palo Alto, Pocahontas, Sac and Winnebago Counties



The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Many materials can be made available in alternative formats for ADA clients. To file a complaint of discrimination, write USDA, Office of Civil Rights, Room 326-W, Whitten Building, 14th and Independence Avenue, SW, Washington, DC 20250-9410 or call 202-720-5964.




Planting Progress: The USDA NASS weekly crop progress report shows 2013 corn planting at a stand still for the northern corn belt.


Optimum planting dates are still obtainable - since recent research  shows a 95 to 100 % yield potential if corn is planted by May 2 in north central Iowa and by May 9 in northwest Iowa.


Growing Degree Days (GDDs): The use of GDDs are not that useful in the early spring - except to estimate general heat accumulation. A recent check of the Iowa Mesonet shows some interesting March 1 to April 15 GDD accumulations. We are - just barely - warmer than 1993 for this time of year. Normal GDD is 88 for 3/1 to 4/15.


            Year                     GDDs - 3/1 to 4/15

            2013                                  29

            2012                                  336

            2011                                  95

            1993                                  8


Residual Nitrogen: There is potential for residual nitrate-N carryover from 2012 drought affected cornfields. Fields from 2012 that had drought reduced corn grain yields may be a place for residual soil nitrate sampling. Soil sample to a depth of two foot in one foot increments and have the samples analyzed for residual nitrate. An article by John Sawyer provides further detail on this topic.


Alfalfa: Check alfalfa fields for winter injury when the regrowth is about 3-4 inches tall. Select some random areas in the field and dig up all the plants in a one square foot area. Count the number of live plants per square foot. Also split the taproots and check their general health. You should 8-12 healthy plants per square foot if the field was seeded in 2012. Fields that were seeded in 2009 or 2010 and have less than 3-4 plants per square foot can be considered for replant. This article by Steve Barnhart has more information.


Pasture: Check cool season pastures for winter injury and growth this spring. A general guideline for pasture health is a 70% ground cover. Pastures with less than 70% cover may benefit from interseeding red, white or alsike clover. A separate approach may to fertilize with 30 to 50 lb/a of nitrogen. This YouTube video has more info.

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: