Zeroing In

ReachOut: Zeroing In from Central Valley Ag on Vimeo.

by Mike Zwingman

by Mike Zwingman

I’ve already made my case that among the four Rs, rate is best considered last as we can improve our efficiency with the careful and thoughtful handling of the other three Rs.  The question that keeps popping up since is exactly how different treatments of the remaining Rs affect rate.  The answer, as you might guess, isn’t exactly short…

So, let me focus here on the other R that’s garnered the most questions lately: right placement.  The strip tillers out there have become a choir and they want to know what their good placement practice means for their rate.

So let’s start here: a plant’s nutrient requirement doesn’t change according to whatever method of placement.  Whether you’re strip tilling, fertigating, or tossing handfuls of Nitrogen into your neighbor’s field, that corn plant needs what that corn plant needs.  How placement can affect your rate is by increasing (with good placement—thus decreasing with poor placement) the probability that every pound of nutrient you apply will be used by your plants.  In short, good placement minimizes loss.

Let’s add this too, before we go on: what “good” placement means depends on what nutrient we’re talking about.  Plants take different nutrients in differently.  For example, to take in Phosphorus, a plant’s roots must intercept Phosphorous molecules.  Nitrogen, however, doesn’t need to be intercepted by roots because it travels easily in water and can so be carried to the roots.  As you proceed thinking about good placement practices, keep in mind that you’re dealing with a very complex biological entity in your corn plant and beware the urge to oversimply.

Now, onward though.  We still haven’t answered the question as to exactly how placement practices can affect rate.  So let’s continue with Nitrogen as our example nutrient, since it’s kind of the biggie:

“Good” placement in terms of Nitrogen is within seven inches of the stalk.  Research shows that 63% of a plant’s Nitrogen uptake occurs within that range.  As the Nitrogen within seven inches of the stalk has a high probability of being used by the plant, Nitrogen placed within that range is less subject to loss and soil tie-up.

But yes, yes—to the question at hand.  So you place Nitrogen within seven inches of stalk.  Great.  What’s that mean for your rate?

Here’s the thing: I don’t quite know.

I’m sure that’s not the answer you wanted to hear, but give me a moment.  I’ve said before that when we talk like this, we’re talking about a cutting edge approach to nutrient management and I meant it.  I don’t quite know because that’s how innovative this is.  The research that science and industry has done so far suggests that strip tilling probably increases Nitrogen efficiency by at least 5% and Potassium and Phosphorous efficiency by more than 10%.  Those are numbers that tell us we’re on the right path, but they’re not specific enough to tell us we’ve arrived at our destination.  The exact numbers still need to be worked into.

Blue-Box-e1409667504172So, to my friends wondering so intensely about how y-dropping, or strip tilling, or starter fertilizing, or insert-another-good-placement-practice-here might affect your rate: stay tuned.  The question you are asking is one of the questions pushing the frontier of our science ever further.   If the idea of being a pioneer isn’t quite going to keep you coming back though, stay tuned for the good of your own bottom line: those initial numbers I dropped earlier regarding increased efficiency suggest an additional $80 profit per acre when we take a good placement practice into our accounting of rate.