In-Season Fertility Update

2021 Newsletter. Vol 1

by | Sep 27, 2021

Average K Leaf Test Value By Growth Stage
Average P Leaf Test Value By Growth Stage

If we are going to invest the time and money into making another fertility pass, it is beneficial to keep nutritional balance in mind when making decisions.

At Bio Ag Management, we are committed to what we have termed a “Hybrid” farming system. We are focused on using aspects of conventional and regenerative farming practices to be as efficient as possible. If you have followed our research from the last couple years, you will know that we see good things from split-applying nutrients to get more value per unit applied. Many growers are familiar with split applications on Nitrogen, but our data — collected over the last couple of years — has shown that Potassium and Sulfur are other critical nutrients we shouldn’t overlook. In our region of west central Illinois, we continually see potassium levels in leaf tests crash when rapid vegetative growth really kicks off — even if high rates of Potash have been applied. On the flip side, even if no Phosphate fertilizer was applied we consistently see Phosphorus levels in leaf tests stay in an adequate range, especially when using a a solid biological/biostimulant program at planting like Bio Ag E. This has led us to question the efficiency of single high rate applications of fertilizer in the fall. Our data this year is showing a similar trend. Above are graphs of the average P and K levels separated by growth stage in leaf tests that we have pulled so far in 2021. These data sets have over 50 individual sites per growth stage and are taken across a wide variety of soil types and fertility practices. As you can see — as we progress through the growing season, potassium levels drop and will fall outside the optimal range.

With a week of heavy rains, many growers may be thinking about Nitrogen loss and possibly applying more fertility. Our research last year showed benefits from applying more than just Nitrogen in a second pass when leaf test levels begin to fall, and this year appears to be similar to last year. To be as efficient as possible, we have to think about nutritional balance more than just fertilizer rate. If we are going to invest the time and money into making another fertility pass, it would be beneficial to keep balance in mind when making decisions. Another thing not to overlook is the importance of Sulfur. When we make in-season fertility passes, we highly recommend using Sulfur. Sulfur is critical when converting Nitrogen to protein in the plant. So as we apply Nitrogen, it is a good idea to also use Sulfur. At Bio Ag Management, we produce and source products to bring more balance to in-season fertility applications as well as quality biostimulants to keep fertilizer available as well as to aid in uptake. Please contact us if you want to learn more about this approach.

Visualizing Root Exudates

This is an interesting image that we took the other day while scouting the fields. After some heavy winds, the corn in the field had significant lodging but was still able to lift itself back up. In this process, corn will shoot brace roots off higher nodes to help hold the plant up after being lodged. When observing this, we got to take some images of actual root exudates. We hear a lot about root exudates in the soil health arena — about how they bring carbon into the soil and signal biology to help in the transfer of nutrients to the plant — but do we ever see root exudates? The corn in this field is extremely healthy and has Bio Ag E applied as well as an excellent split application fertilizer plan. As these brace roots are growing, they are also actively producing root exudates and we can actually see the exudates being pushed to form the roots because the brace roots have not made soil contact yet.


Contact Greg Tippey