The Devil Is In The Details:
Why Claims For High Organic Yields Require Careful Study
Jim Prevor’s Perishable Pundit, October 27, 2015
With local being all the rage, organic has taken a back seat — at least for the moment. Yet organic advocates, of course, continue their work. Quite frequently in fact, we receive notice that some research project or other shows organic produce having some superior nutritional benefit or taste benefit over conventionally grown produce or that the assumption that organic yields are lower is incorrect.
We rarely publish these things because, in general, the research doesn’t stand up to scrutiny. For example, we just received a piece trumpeting that a particular variety of wheat is yielding exceptionally well when grown organically, What a Revelation as organic wheat yields 9.9t/ha:
An organic crop of Revelation wheat has yielded an astounding 9.9t/ha proving the value of robust agronomics in protecting and fulfilling yield potential.
This is the highest yielding crop we have ever had, and we are thrilled with it, says Anna McCowan at seed producers and merchants LC Smales & Son, near Berwick-upon-Tweed.
Most of the piece gives agronomic detail about how the wheat was raised:
“As the crop began to grow in the spring, it got 2.4t of granulated lime to improve the pH and an application of liquid manganese and sulphur to combat deficiencies. We also ran the sheep over it for a few days to encourage tillering, which really got the crop growing.”
We are certainly not experts on wheat, but, to us, the startling line in the piece was this:
The 9ha field of Revelation was drilled at 220kg/ha at the beginning of October, following two years of white clover. “The clover was ploughed up on 22nd August and we then ran a Kvik-up through the fields twice to reduce the dock population before the crop went in.”
In other words, in order to obtain this yield, the land had to be kept fallow for two years! That means that the yield is not really 9.9 tons per hectare; it is a third of that, because you are using the land for three years to get that yield of wheat.
Of course, we can’t be sure that is the cause of the yield increase. The release credits sunlight, which, of course, is not reliable at all:
Ms McCowan believes that the high yields from this effectively ‘untreated’ crop, have probably come about because the crop got sufficient sunshine at the right time, adding that Revelation is a later maturing crop, so the extra days of sunshine at the end of August -- beginning of September will have paid off as this crop was harvested on 10th September.
The point, though, is that much of the research results reported about organics is highly questionable. Understanding requires attention to the subtext and, all too often, these things get reported in the consumer press based just on the headline.