By Darren Hefty

If you haven’t harvested your wheat yet, the last thing you are probably thinking about is the nutrient needs of your next wheat crop.  Here’s why it should be on the top of your mind.

Crop fertility is perhaps the single largest yield limiting factor in wheat production in our country and around the world.  Either there’s too much of one or more nutrients, and it’s hurting yields, OR more commonly, there is not enough of one or more essential plant nutrients, which stops your yield potential in its tracks.  The challenge is most of us don’t know enough about the fertility needs of our crops to first determine what the problem is and secondly to decide how to fix it.  However, there are new easy-to-use tools available to help us diagnose and solve fertility problems.  Are you ready to maximize the return on your input costs?

Notice I didn’t say “lower your input costs.”  Personally, I’m not interested in lowering the input costs for our farm.  I want to spend as much money as possible on input costs as long as they provide me a positive and predictable return on my investment.  You see, on the Hefty farm, we don’t look at crop inputs as costs.  We see them as investments, and no investment on our farm is bigger in size than our investment in crop fertility.  Here’s how we develop our plan for wheat:

  1. Determine what fertility is in the soil by taking a complete soil test.
  2. Estimate what the field will yield based on field history, but add a reasonable yield increase goal.
  3. Apply fertility to account for at least what the crop will remove from the field.  Apply more if the soil test won’t cover what the stover will take from the soil.
  4. Plant tissue test during the season to evaluate the program.

SOIL TEST

We recommend taking a complete soil test to see what there is to work with.  Go to www.midwestlabs.com and look at what’s included in their S3C test.  That’s what we feel is the minimum to learn what’s going on in your soils.  That test includes micronutrients, cation exchange capacity, soil pH, base saturation, and more.  The cost was $26.50 per sample the last time I checked.  We typically “zone” sample our fields based on topography, where we sample hilltops separate from sidehills separate from valleys, etc.  We’re doing more grid sampling than we have in the past because some of our newer ground is quite variable and needs more attention, but also because of how easy it is to take your own samples using your smartphone and the soil sampling app from FarmLogic.

YIELD ESTIMATE

If we raised 100 bushel wheat last year, we’re shooting for at least that much again this year.  Adding 5% to 10% to that estimate, meaning 105 to 110 bushels for the yield goal, is reasonable.  Some look at this as a soil fertility build program.  I consider it putting the fertility out there for future success.  If I fix more of the yield limiting factors in my fields, I want to make sure I have the fertility out there for my crop to reach my ever-increasing yield goals.  Just make sure you keep your fertility in balance.  If you want to put on a whole bunch of K, for example, be sure to get corresponding levels of P, S, micronutrients, etc. in your soil.

CROP NUTRIENT REMOVAL

When it comes to fertility, this is probably the most common question – How much fertility does my crop actually remove from the soil and take out of the field?  We developed a phone app for this specific question.  At the iTunes Store, search “fertilizer removal by crop” or just “Ag PhD” to find our free app.  You can also just CLICK HERE.   We plan to have the Android version out very soon, as well.  You can type in your yield goal and the app will tell you how many nutrients will leave your field when you harvest the grain.  It also has a measure of what the stover will need to remove from the soil to grow a healthy plant during the year.  You can view an example to the right.

PLANT TISSUE TEST

We pull plant tissue samples in a couple areas of one or more fields each season.  We typically shoot for a 2 to 3 month time period where we pull samples every Monday morning to learn which nutrients are short.  That way the fertility plan can be adjusted for the next crop.

Follow these steps and you’ll become a crop fertility expert in no time.   You’ll also feel more confident in your fertility investments as you maximize your returns with your crop inputs.