Don’t Pinch Pennies on Potassium!

by Peter Bixel, Seed-2-Soil

With commodity prices lower, it’s certainly prudent for farmers to rethink each input expense. Crop inputs are certainly one big investment! I’m a farmer myself, so I understand the value in evaluating investments.

Analyzing investments is really an exercise in managing expectations. We might settle for returns of 2 to 5% on our bank savings accounts and 401K, right? We don’t want to skimp on investments that will help us in the future. So why skimp on your Phosphorus (P) & Potassium (K) fertilizer investments? After all, an investment in P & K has the potential to return 100-700%!

Phosphorus aids in healthy root growth, as well as flower and seed production. Potassium is responsible for improving overall health and disease.

Local data is critical for analyzing where your fertilizer dollars are best spent. Our data shows that across 400,000 acres, phosphorous values continue to be in the High category of soil test values with an average of 28ppm. This is more than likely because of manure history, fertilizer application and soil types in our area. However, potassium levels continue to be an area that needs to be addressed in order for us to not mine what we have invested in building up. Potassium levels are in the medium category with an average of 160ppm, while we are trying to reach 200ppm and higher.

Take a look at the Potassium Calibration Curve below. With low soil test K values, your potential for high yielding crops dramatically decreases. Take your 2013 Local Data, looking at Corn on Corn Yield to Soil Test K, as soil test levels go from Low to High categories, yield increased 20bu/ac. How do these returns look to you?

Potassium plays an important role in the utilization and uptake of Nitrogen and in turn meaning improved N use and higher yields. Higher rates of K allow for efficient use of more N, which resulted in better early vegetative growth and higher yields. K fertility is another important piece of the puzzle for high yielding crops.

With tighter margins moving into 2015 crop year, it is important to remember to use YOUR data to help make the best investment decisions and to make sure you don’t mine your soil fertility.

Make sure you’re not losing a dollar by trying to save a penny!