Southern Spotlight: Know Your Manure

James Banahan

James Banahan

I used to work for a grower who also raised chickens.  Year after year, he’d spread their manure over his fields, always in the same pattern.  And year after year, he’d run out in exactly the same place.  A full fifteen years after that man stopped raising chickens and spreading manure, you can still pick out that line where he always ran out, the corn looking good on the one side, and not so much on the other.

With our wheat off, those of you with cattle or hogs might be looking to make use of their byproducts on your own fields.  It’s an economical practice, a high-value way to provide your soil with important nutrients, but to truly use manure to your advantage, you need a little info.  Namely, you need to know what exactly it is that you’re spreading around out there and how much is needed.

The nutrient levels in manure are variable and depend on a few different factors, like what animal it came from, what type of feed those animals received, and what else might be mixed in with it, like bedding, for example.  To know the actual nutrient content of your manure then, you need to pull and test a sample.  With this info in hand, you’ll know exactly what you’re putting out there on your fields and what you’ll need to manage when you’re applying other fertilizers later on.IMG_6970

In addition to knowing the nutrient level of your manure, you need a few more pieces of info to best determine the spreading rate at which to apply it.  What crop you’re growing combined with your yield goal will give you your removal rate.  You’ll also benefit from having your particular crop rotation plan in mind.

These are your three big pieces of info—the nutrient level of your manure, your removal rate, and your rotation plan.  Knowing these things will help you determine the best spreading rate, which will ensure that you’re using this high-value resource to its greatest effectiveness.  With these pieces of info in place, you’ll be sure to spread liberally enough to endow your soil with nutrients, but not so liberally that you’re risking toxically high levels of nutrients or simply wasting a resource.

Which brings us back to the topic of last week’s article, VRT programs.  Your participation in such a program is highly useful when it comes to effective spreading of manure.  A VRT program essentially helps you know the nutrient landscape.  It provides you with a detailed vista of your fields in terms of the nutrient levels in the soil, so you’ll know exactly where spreading manure will be most helpful and can avoid spreading in places where it won’t be maximally beneficial.  As a VRT program helps to ensure where your money is best spent, it also helps to ensure where your other resources, like manure, are best spent as well.

To call manure a high-value resource (which I’ve done twice in this article) is perfectly accurate.  It is, essentially, a free resource with the potential to greatly benefit whatever crop you might be raising.  Like anything else though, it will make the greatest and most positive impact on your operation if it’s used correctly, which is easily done with just a little time and a few key pieces of information to guide your application.