I Can See the Difference, Can You See the Difference?

Ever made a change on your farm and wonder 'was it really worth it'? For instance, switch from one brand to another. Or maybe you are trying a new source of fertilizer or always wondered if that micro-nutrient supplement really all its cracked up to be.

Ultimately, you really want to know if what you changed was worth it. Were your yields higher? Or did it make a difference?

Let's take the example of applying a foliar micronutrient. If you spray the whole field with the product, you won't know if your good yields were due to the foliar spray or due to the nice timely rains. So like the old Tide commercial where they hold up two white t-shirts and ask 'I can't see the difference, can you see the difference?', you want to compare the old way of doing things to the new way. You want to know if yields were better, worse or not different.

This is where putting in a strip trial works really well. And it's as easy as 1,2,3. 1) get the worksheet 2) do the trial and 3) follow the calculation in the sheet to see if there was a difference.

The Practical Farmers of Iowa and Iowa State University have created a short worksheet that outlines all the information needed to do On-Farm Research, step by step. You can get the worksheet on the Iowa State University website, but it is probably easier to just google OFR design -for "on-farm research". So google OFR design. http://www.pfi.iastate.edu/ofr/OFR_worksheet.pdf The worksheet gives all instructions.

To set up the strip trial you want to compare two treatments: your normal practice with, let's say, the new foliar micronutrient spray. The two treatments, no spray and the foliar spray, with everything else the same, put out 6 pairs, or 12 strips total down the field. The strips should be randomized down the field.

The size of each strip depends on your equipment and the size of the field. So for the foliar micronutrients, each strip would be the size of your sprayer boom or half the boom if possible. Also consider the size of the strip when harvesting. How will you measure yield in the strips? - with a yield monitor? How big is the head on the combine, or weigh wagon, or counting baskets down a pepper field? Any of these methods are valid, just keep the strip wide enough to harvest.

With yield from the 6 foliar sprays and yield from the 6 no spray strips, follow the calculations in the worksheet. Once completed, it will clearly answer if there was a difference between your two treatments. And you'll know based on yield if it was worthwhile to apply that foliar micronutrient or not.

So, this spring set up an 'on-farm trial' to determine if there is a difference. To find the worksheet from the Practical Farmers of Iowa just Google 'OFR design' and you're on your way.

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