We are in operation Monday - Friday 8:00 AM to 4:30 PM EDT. End of season corn stalk nitrate should be taken 1 to 3 weeks after black layer has formed on 80% of the kernels on most ears. The portion of each plant sampled is the 8-inch segment of stalk found between 6 and 14 inches above the soil. 15 segments required.
Spectrum Analytic Inc.
1087 Jamison Rd NW
Washington Court House, OH 43160-8748