October 10, 2018   
  Issue 4   

Prepared by

Paul Kassel

Extension Field Agronomist



(712) 262-2264

Email: kassel@iastate.edu 



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.


The Iowa State University Extension and Outreach Policies Page.  


























Soybean drying.    Soybeans can be dried with low temperature natural air drying equipment.  It will take about two weeks of 50 degree outside air temperature at 50% humidity to dry 16% moisture soybeans to 13%.  This assumes a 1.0 cubic foot/minute (CFM) air flow per bushel.  Fan air delivery can be estimated at about 1000 CFM per fan horsepower (5 HP fan produces about 5000 CFM). Fall weather conditions will vary enough that soybean drying time will be longer than what is expected.   
Soybean can be dried with added heat as well.  It is recommended that air temperatures do not exceed 140 degrees.  This website has more info. 
Soybean shrink.   Grain elevators will charge shrink on soybean grain that exceeds 13% grain moisture. Elevators may assign 3% shrink per bushel per point (or more) as a dock on high moisture soybean.  The water loss represents 1.2% of that 3%. The remaining 1.8% is a handling shrink and represents a loss in actual saleable bushels. 
Example 1 assumes 65 bu/a at 14% moisture and a 3% shrink.
Example 2 assumes 65 bu/a at 14% moisture, 2% shrink and $0.0375/point drying cost.
moisture loss/a            shrink loss/a     drying cost/a    net yield/a
Ex 1      0.8 bu                          2 bu                  $0.00               62.2
Ex 2      0.8 bu                          1.3 bu              $2.46               62.9
There is some consolation to know that soybeans harvested below 13% moisture also have 0.8 bu/a/point hidden loss - because of the loss of the weight in the water loss in each bushel that is sold. 
Rainfall in 2018.   The following are some rainfall totals since April 1 for selected weather stations - arranged in order of departure from normal.   
Location          inches rainfall                          departure
Britt                 46.0                                         +21.9
Forest City       45.9                                         +21.1
Milford            42.8                                         +20.3
Sioux Rapids    40.2                                         +17.0
Algona             40.7                                         +16.9
Pocahontas       40.4                                         +16.7
Estherville        38.0                                         +15.4
Sac City           35.2                                         +11.1
Emmetsburg     32.6                                         +8.7
Storm Lake      26.9                                         +2.2

Prepared by Paul Kassel, Extension Field Agronomist

Phone: (712) 262-2264, Email: kassel@iastate.edu