84% to 92%; Missing the Mark
By: Katie McWhirter, Precision Ag Specialist
84% to 92% of individual fields are being over fertilized or under fertilized. As a former high school teacher, this is astounding to even think about! Because the flip-side of the 84% to 92% is only 8% to 16% accuracy rate on getting every area of a field what it needs. If this was a letter grade, we know what it would be (a big, fat F)! I can tell you from experience if this was my class average, I could conclude as the teacher, I had not done my job. This means it’s time to go back and figure out what went wrong.
In the past, we’ve been okay with saying that we are going to put back on removal only. So, what do we do? We look at last year’s yield map and see that magic number of the whole field average. Let’s say our field averaged 212.91 bu/acre last year. Here is where the problem lies; if we break that down and see how much of that whole field ACTUALLY averaged 207.91 to 217.91, we see that only 8% of our entire field received the right amount of fertilizer! To look at it this way, we now understand why even in our own sampling area, many acres being grid sampled are below critical levels (<21 ppm for Phosphorus and <201 ppm for Potassium)!
Better genetics have brought us better yields. Technology, like yield monitors, have brought us the ability to make better fertilizing decisions. We are here to digest the infinite amounts of data, research and suggested practices to help you better maximize your success. Grid sampling and utilizing actual yield data versus yield goals will continue to be key factors in turning that 8% to 16% accuracy rate into 84% and 92%.
Although your P & K fertilizer decisions for the 2017 crop year have probably already been made, it’s never too early to start thinking about ways to keep improving for 2018. Click here to chat.