Variable yields call for variable rates by Dr. Jason Weirich

And like the weather, crops were variable. In the combine seat this fall, more than likely you watched the yield monitor read-out dramatically rise and fall as you worked across the field. While I hope the overall yield was good, the acre-by-acre results probably looked like the picture at right.

With variable yields like we saw over much of MFA’s trade territory this year, the amount of nutrient removal will be variable, too. It’s all based where you are in the field and what yield you made there.

This variability can cause problems for growers as you think about how to replace the phosphorus and potassium your crop removed. The old standby of flat-rating fertilizer like my grandpa did hasn’t proved itself as the best use of your fertilizer dollar. Variable-rate technology allows you to replace and build your soil test levels in each field. You can target the optimal nutrient levels and make your fertilizer dollar go further. MFA’s Nutri-Track program is focused on putting nutrients where they are needed and avoiding over-application in areas that won’t perform.

While on the topic of nutrient management, and as we head into another application season, you need to take a step back and think about what practices you adopted on your farm.

The 4Rs promote the best management practices to achieve your yield goals while reducing nutrient loss and increasing nutrient use efficacy. So what are the 4Rs? Right source, right rate, right time, right place.

It’s important as a producer to pay attention to all the above. Not only from an expense standpoint, but from an environment standpoint.

Applying fertilizer while paying attention to the 4Rs will help growers produce more with less land. It will also help you retain nutrients where you intend for them to be—in the field instead of heading downstream.

There are increasing regulatory pressures zeroing in on your farm. Nutrient stewardship is just one of them. Out East, EPA has assigned 44 percent of the nitrogen and phosphorus loads to the Chesapeake Bay to agriculture. If that seems distant enough for comfort, look to the Des Moines Water Works issue. There is legal battling there over field runoff as I write this. Then there is Gulf hypoxia. These issues won’t just go away.

While you may be most interested in the 4Rs as a way to get the most efficient use of inputs, it is also important as a way to demonstrate our commitment to soil stewardship, proper fertilization practices and the economic benefit of using proper fertilization techniques.

I believe that the average non- farmer, the typical consumer, misunderstands the concept of fertilization in commercial agriculture. Hopefully, the 4R program can help dispel misconceptions by the general public. We know it can help you be more efficient.

For more information, please visit www.nutrientstewardship.org or stop by your local store for more information.