Downforce – The Unseen Yield Robber
As growers become more and more aware of needing to focus on the agronomics of planting, many find out that downforce is a crucial aspect that affects emergence and yield, yet is typically overlooked. Proper downforce settings on the row units create a proper amount of weight on the gauge wheels. It is this weight on the gauge wheels that determines if the row unit is planting at the correct depth, as well as determining if the row unit is causing compaction which will rob yield from the plants. A correct gauge wheel weight firms soil under the gauge wheels to allow the disk openers to create a trench and then hold that trench open while the seed is placed in it, and then lets the closing system do it’s job of closing the furrow. Too little gauge wheel weight and depth is lost and sidewalls of the furrow collapse: too much weight and compaction is created. Compaction can cause delayed emergence, but also has a bigger, typically unseen yield impact- restricted root growth. As roots grow, they need to grow unrestricted and uninhibited. Compaction created by too much gauge wheel weight will cause roots to turn, become smaller, and when that happens in growth stages V4-V8 of corn, it causes the kernels long and kernels around on the ear to be reduced. This reduction in ear size is a significant loss in yield, but many times unknown to a grower because the plant looks healthy, even though the root system underground is sick. Getting the correct amount of weight on the gauge wheels is challenging, because fields have so much variability in them from the lay of the land to manmade variability like wheel traffic
