Respect for the Law

Two Laws from Central Valley Ag on Vimeo.

by Mike Zwingman

by Mike Zwingman

Or laws, that is. And I’m not talking about no manmade laws here—no speed limits or no smoking zones.  I’m talking about eternal laws. Laws imposed on us by time, and science, and math. You can’t break them, so you might as well learn to use them to your advantage.

So, two of them for you today, friends: the law of the minimum and the law of diminishing incremental yield. Both have much for us in terms of our management and decision making.

To begin, the law of the minimum tells us that no matter how excellent our total picture looks, our yield is constrained by our most restricted nutrient. Consider a whiskey barrel with just one stave too short.  Unless you fix that stave, you can never fill that barrel. You will always only be able to fill it to the height of that shortest stave.

The law of diminishing incremental yield isn’t quite the same punch in the nose, but means just as much to us. It is essentially the law of diminishing returns for agriculture. Taking N for example: every unit we add to our fields (above adequacy) results in decreasing additional yield.

Taken together, these two laws speak to the constraints in our operations. The question du jour is if you know the constraints in your operation.

Because you might not.

If we really unleash the law of the minimum and broaden it to apply to everything from nutrients to compaction to our ability to water and etc., do you really know which factor is most limiting your yield?  Do you actually know your greatest weakness? That’s never really an easy question to answer…

Which is why things like soil sampling and crop scouting remain ever important in our down economy: these activities reveal constraint to us and thus allow us to address factors that are limiting our production.

I’m going to press on this this season. What are our constraints? To investigate, we’re going to have some “learning blocks” in place in some fields this season. They’ll be small plots—just 75-100 feet in length—but we’re going to have a little fun with them. Like subjecting some to a zero N Rate test. Or a zero P rate. Or a plant population dropped down to a minimum. Or jacked up to a maximum.

None of which is actually for fun. Any and all of these tests will tell us something about constraint as each test will probe into the sufficiency of one factor or another.

We talk very often about our goals and not so often about our boundaries. But the key to efficiency is knowing our boundaries.

Which includes those in your head. Because while we’ll push on biology and chemistry to discover our boundaries, we’ll push on your comfort level too as, theoretically, there will come a time when your constraint is your comfort with risk.