By Brian Hefty

When the corn was rolled up in June on some of our ground due to lack of moisture, I really questioned how good 2016 could be, but when all was said and done we finished with both record corn and soybean yields on our farm.  Whether you hit a record or not this year, we can all agree that yields seem to be trending higher.  This is great for net income, but one of the downsides is the huge pull on soil nutrition.

Look below at what big yields can cost you in terms of grain removal of nutrients.

corn and soybean nutrient removal

Assuming you leave all the residue in the field, removing only the grain, these numbers are what just left your field forever.  My point is unless you find a way to replace this much fertility, your ground is becoming depleted.

When the average farmer complains about cost, you know what comes up number one for most people?  It’s cash rent.  How does the average farmer fertilize ground he owns versus ground he cash rents?  We all know the answer to that, and it’s something I’ve been trying to address with landlords over the last few years.  What I encourage landlords to do is look at the total cost to replace the nutrients the farmer is removing.

If the farmer can’t afford to put that fertilizer back, the rent needs to come down.  On the flip side, if the farmer can afford to replace what he’s removed, what discussions are being had to make sure this is done?

Whether you own your ground or rent it, you need to soil test to find out what your ground needs, and in most cases, we suggest at least applying what you’ve removed.  Use the free Ag PhD Fertilizer Removal app on your smartphone to figure out exactly how many pounds of each nutrient you need.  While replacing what you removed is usually good advice, we run into many situations where you don’t need to follow that rule.  For example, if your ground currently has excess phosphorus, but is deficient in potassium, we would suggest applying no more phosphorus and loading up on K.

Now that we’ve had some full corn fields in the 250 range on our farm, we’re going to smaller grids (zones work great, too), to help identify where we need fertilizer and where we don’t.  5-acre grids are a great place to start, but try a field at 2.5 or even 1-acre grids, and see what you find for a difference.  Here’s my hope.  If we run with smaller grids for say 4 years, we can even a lot of things out in that time and then go back to larger grids or come up with a better zone plan to reduce our soil testing cost.

If you have a lot of variability or if you are making drastic changes, you should soil test more often and in smaller grids or zones, at least for a few years.  It’s fun to get big-time yields, but how do you get to the next level?  One of the most important things we’ve learned from some of the top farmers in the country is to improve your fertility program.  Once you have soil test data, you can manage most things.  Add some plant tissue analysis in-season to take it a step further.