Driving around the area I see a lot of corn making good progress and, while there are some guys finishing up planting for those who have corn coming into the 6- and 8-leaf stage, now is the proper time to test fields for a split application of nitrogen.

By utilizing a chlorophyll meter or leaf tissue test you can determine the amount of nitrogen still needed by the crop.

A split application of nitrogen is not only environmentally friendly, it’s also economical to the farm. By using book values for the nitrogen use of corn and applying that early in the spring, there are a lot of factors that can affect the actual uptake by the plant.

Weather is probably the biggest factor affecting the uptake of nitrogen throughout the year. Excessive amounts of rain early in the year can leach a lot of available nitrogen away, just as a humid spring with surface applied nitrogen can cause a lot of volatility too. Losing this nitrogen early can have huge impacts on the plant during ear-filling when nitrogen uptake is critical.

By doing a tissue or chlorophyll test you can measure that actual nitrogen still required by the plant as it grows into ear production. The chlorophyll meter works by cross referencing a test strip where nitrogen was purposely over-applied then checked against the rest of the field to determine how much more nitrogen needs to be added to the crop.

Tissue tests work similarly in the sense you harvest a specific leaf from the plant and mail it to an lab for analysis. By providing the lab with your fertilizer history it can then determine how much, if any, nitrogen would be required by the plant.

The common complaint by doing a split application is the time it takes to make an extra trip over the field; however with the cost of nitrogen and the potential yield loss, it’s well worth the time and any damage caused by the application.

While Penn State and other major universities make standard nitrogen recommendations for nitrogen by crop, no-till, previous crops and covers all play a factor into what a corn crop actually needs.

Research has shown that in the long term no-till nitrogen can be reduced by 25 percent; add in cover crops to increase organic matter and that number can be even higher, and without a test it’s hard to say what’s actually needed in that year’s crop.

Chlorophyll meters are expensive — $2,000 to $2,500 — and unless you are planting a large acreage of corn, they are hard to justify the expense.

The Butler County Conservation District has a meter available for use, or alternatively you can use an analytical lab like Midwest Laboratories to do a leaf test.

For more information on the availability of the chlorophyll meter you can contact Ryan Harr at the Butler County Conservation District at 724-284-5270, or Midwest Laboratories services can be found online at www.midwestlabs.com.

Andy Gaver is a conservationist with the USDA Natural Resources Conservation Service in Butler County.