By Ricardo Costa
When it comes to corn production, nitrogen (N) is the most commonly applied nutrient and one of the most expensive inputs, ranging from 13 to 18% of the variable costs of production. On the other hand, the nitrogen cost-to-benefit ratio usually exceeds that of other fertilizer inputs. Growers seek to use nitrogen efficiently to maximize its value and minimize nitrogen losses by applying the nutrient at the appropriate rate and timed to coincide with the need of the crop. The goal is to make sure crop yield is not limited by lack of nitrogen throughout the crop life cycle.
Lenawee County growers Blaine Baker and Tim Stutzman have been using crop nitrogen sensing technology for over a decade. With this technology, variable nitrogen rates (based on the NDIV field map based on a well-fertilized reference strip) can be applied up to corn growth state V9, minimizing losses and supplying the nitrogen when it is most crucial to the plant.
According to Baker and Stutzman, since the sensors read the corn on the go, they are applying about 30% less nitrogen when compared with the conventional “1 bushel per 1 pound of nitrogen” recommendation and still getting the same yields. They also stated that nitrogen sensing technology saves them a lot of time when compared to conventional soil samples procedures such as the PSNT (pre-sidedress nitrate test).
Baker believes the technology does an excellent job in conventional tillage systems with lower soil organic matter, but still can be improved in no-till situations where the percent of soil organic matter tends to be higher.
Stutzman thinks many farmers fear they aren’t applying enough nitrogen, and a possible corn yield reduction is one of the reasons why more farmers don’t use this technology. He believes farmers that have been applying nitrogen in the same way for the past several years (based on bushels) might find it challenging to switch to a new technology such as nitrogen sensing. Baker’s recommendation to farmers wary of trying the technology is to start small (10 acres or so) and compare it to their current way of applying nitrogen. According to both farmers, they have had excellent results throughout the years, and “there is money to be made with this technology.”