It looks like corn is coming around from the dry weather we had this spring, and since it requires the most nitrogen between the ninth leaf stage and just before tasseling, now is the perfect time to side dress to ensure adequate nitrogen is available to maximize yield.

While many apply the majority of their nitrogen at planting, heavy spring rains and soil types can leach nitrogen away prior to crop utilization, while even more is lost to weeds and bound in the soil.

To combat this, a split application is best for the environment and the wallet, but just like applying everything at planting, you're still not sure what the plant is actually capturing.

Crop rotations, biological activity, manure application, organic matter and weather patterns all play a role in nitrogen availability and content, so testing the corn plant is the only accurate way to determine the true nitrogen need.

A plant tissue test or chlorophyll meter is an excellent way to test for nitrogen and gives you the ability to make adjustments to what's happening in the field early in the season.

Plant tissue tests can measure all macro and micronutrients for the plant, giving the best overall picture of plant growth and helping pinpoint disguised problems.

These tests require harvesting several leaves throughout the crop field and then sending off the samples to an analytical lab where results and recommendations are made.

A chlorophyll meter is an in-the-field tool that checks the light penetration through the plant leaf and then extrapolates the findings to nitrogen need.

To obtain accurate results from the meter, a test strip where nitrogen was over applied is used as a check strip and the difference between the controlled area and the rest of the field is used to determine the nitrogen needed.

Alternately you can apply no more than 15 pounds of actual at planting and the meter reading will determine the remaining requirement.

This is an excellent option where a legume crop or manure applications account for most of the crops' nitrogen. Since this is an organic form, it is far more stable in the soil and typically is metered out at a slower rate as the plant requires feeding than nitrate nitrogen from a synthetic source.

Chlorophyll meters are expensive, but planting a few hundred acres of corn and having the ability to safely reduce fertilizer application will quickly pay for the meter.

On the other hand, the Butler County Conservation District has a meter available to rent and can make recommendations on the spot. This is a convenient way to check your fertilization program to make sure you're not over or under applying nitrogen.

Anyone interested in trying the meter can contact the conservation district at 724-284-5270. Plant tissue tests and instruction on how to sample are available from the Penn State Analytical Lab.

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