The State of Manure:  Spring 2021

How did your manure overwinter?  Of the 62 fields, we have sampled this spring, we have seen the highest levels in 5 years.  The graph below illustrates the results of this year’s deep nitrate samples.  Positive results this spring are likely a result of dry soil conditions last fall.  We are continuing to see this pattern carry into spring.  One thing that we have noticed is that on several samples, nitrogen is moving into the second foot earlier than it has in the past which is likely due to earlier applications last fall. The final observation we noticed is samples that fell short of the target threshold fall into one of three categories: light ground, very early application last fall or lower gallons per acre applied.

What Now?

If you have over 150 lbs of total nitrogen at this point in the season, you likely will have a sufficient level for the season.  Remember, however, there is generally 1 lb of sulfur per 1000 gallons of manure applied.  A good corn silage crop needs 24-30 lbs of sulfur to it.  This should be supplemented to make up the difference.  Many producers are planning on pulling some pre-sidedress soil samples to monitor nitrogen movement through the soil.  This will determine if additional nitrogen will be required to supplement the growing crop. Consult your agronomist on the next steps with your crop fertility.