Question:

I received a question today that hopefully one of you can help me to answer. I have a grower that wants to put chicken litter on a field that he had planned to put peanuts on. The farmer wants to make sure all rules and regulations are maintained. The question is are there any planting or harvest time restrictions between the litter application and the planting or harvesting of peanuts? I know some rules are in place for other food crops like cucumbers, but I do not know about peanuts and did not see anything online.

Kulesza:

Thanks for reaching out! First off, litter should be applied within 30 days of planting for any crop. However, manure cannot be applied directly to crops grown for human consumption without further processing. So, the peanuts could not be sold raw at a farmers market or grocery store if you apply manure after planting. This gives you a 30-day window for application prior to planting if no processing is involved. For crops that will be processed, you can apply manure up to 30 days prior to harvest. Though, I doubt they want to apply in-season anyways.

The grower should also consider whether the purchaser is willing to accept peanuts from manured fields. They might have additional requirements or restrictions.

You could also find out more from Christine Lawson at DEQ.

Jordan:

I am not aware of any rules relative to peanut.  But, it is absolutely critical to know the zinc concentration in the litter and how it will translate into zinc in soil.  The NCDA&CS index value is 250.  Peanuts are very sensitive.  Of course there may be a lot of N and P, but they are not an issue with peanuts (the N is perhaps a “waste” for peanuts - high P is not an issue.)  If K is high that could be an issue relative to calcium nutrition.  BUT step 1 is to make sure zinc is below 250.  That is a real issue.

Jordan:

Thanks Stephanie for that clarification.  The vast majority of peanuts go into the in-shell trade in our region with some processing in the form of roasting and adding salt.

Jordan:

As a general rule, I discourage direct application of litter to peanuts primarily due to concerns about zinc (and uniformity of application if one thinks zinc concentration is within reason.)  The N would be a waste on peanuts.