May 4, 2015 - 8:39am -- Anonymous

A lot of manure has been hauled onto and applied to crop fields in the past couple of weeks.  The nutrient value of that manure needs to be accounted for and subtracted from any planned commercial fertilizer applications.  In some cases, manure application may meet the total fertilizer needs of the 2015 crop.  In order to know, a nutrient analysis of the manure is needed.  Nitrogen values are harder to get a firm grasp on because nitrogen is present in manure in both ammonium and organic fractions.  Added to this is the fact that nitrogen can be lost in several different ways so it becomes difficult to account for the nitrogen in manure, but the following guidelines can be used.

The ammonium nitrogen and a portion of the organic nitrogen contained in spring applied manure are generally available for the growing crop. According to OSU Extension bulletin 604, 50 to 75 percent of the ammonia portion of the nitrogen could be captured if the manure is injected during application or incorporated within one day if surface applied. Approximately one-third of the organic portion of the manure nitrogen will be available regardless of whether the manure is incorporated or not.

One of the concerns sometimes expressed regarding manure application is the weight of the loaded manure tanks or spreaders and the resulting soil compaction.  The use of a drag hose where possible, to apply manure results in less soil compaction and generally greater application efficiency.  Glen Arnold, OSU Extension field specialist, in Manure Nutrient Management has been conducting research to evaluate the timing of side dressed manure to corn using a drag hose system.  

In 2014, at the OARDC Hoytville Research Station, a six inch diameter drag hose was pulled across each plot twice (going in opposite directions) at corn growth stages V1through V5. Tractor speed was approximately 4 miles per hour. Plots were replicated four times in a randomized block design.  The following table contains the results of the plant population and the harvest yield for each drag hose treatment:

 

Corn stage

Population

Yield bu/ac

No drag hose

30,166

145.1

V1

29,660

154.3

V2

30,166

157.9

V3

28,933

153.9

V4

29,264

149.7

V5

15,366

109.8

 

 

It is interesting to note that pulling a drag hose across corn up to the V4 stage of growth did not hurt the final plant stand or yield.  This is only 1 years’ worth of data and the experiment will be repeated again in 2015, but it suggests that there may be a wider window of opportunity to side dress manure on to corn with a drag hose than previously thought.

Rory Lewandowski is an OSU Extension Agriculture & Natural Resources educator and may be reached at 330-264-8722.