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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #230789
Title: Utilizing existing sensor technology to predict spring wheat grain nitrogen concentration

Author
item Qualm, Ann
item Osborne, Shannon
item GELDERMAN, RON - SOUTH DAKOTA STATE UNIV

Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2010
Publication Date: 9/15/2010
Citation: Qualm, A.M., Osborne, S.L., Gelderman, R. 2010. Utilizing existing sensor technology to predict spring wheat grain nitrogen concentration. Communications in Soil Science and Plant Analysis. 41:2086-2099.

Interpretive Summary: Obtaining optimum grain protein and yield in spring wheat can be problematic without proper nitrogen fertilizer management. Sensor-based technologies have been used for an accurate and precise application of fertilizers. This technology has also been used to predict yield in wheat although little has been done in the prediction of grain protein. Field studies were conducted in South Dakota in 2006 and 2007. There were five N treatments applied pre-plant with a second N application being applied foliar at anthesis to half the plots. Sensor readings were taken at growth stages Feekes 10, anthesis, and post-foliar application using the GreenSeeker Hand Held optical sensor. The sensor measures reflectance in the red and near infrared region of the electromagnetic spectrum. Grain samples were taken at maturity and analyzed for total N. Using similar information collected in 2003 and 2005, a critical normalized difference vegetation index (NDVI) value was determined using the Cate-Nelson procedure. The critical NDVI value needed to ensure optimum grain protein was 0.70. In 2006 and 2007, the plots that received an application of nitrogen at anthesis had higher grain protein than the plots not receiving nitrogen. There was also a significant response between applied nitrogen and grain yield. The results show that with further studies, the Greenseeker could be used to apply nitrogen to maximize yield and grain protein in a precise and accurate manner.

Technical Abstract: Obtaining optimum grain N concentration and yield in spring wheat (Triticum aestivum L.) can be problematic without proper nitrogen (N) fertilizer management. Sensor-based technologies have been used for an accurate and precise application of fertilizers. This technology has also been used to predict yield in wheat although little has been done in the prediction of grain N. Field studies were conducted in South Dakota in 2006 and 2007. There were five N treatments (0, 56, 112, 168, and 224 kg N ha-1) applied pre-plant with a second N application being applied foliar at anthesis to half the plots. In 2006, experimental locations included Gettysburg, Bath and Cresbard while in 2007 experimental locations included Gettysburg, Aurora, Leola and Artas, South Dakota. Sensor readings were taken at growth stages Feekes 10, anthesis, and post-foliar application using the GreenSeeker Hand Held optical sensor. The sensor measures reflectance in the red and near infrared (NIR) region of the electromagnetic spectrum. Grain samples were taken at maturity and analyzed for total N. Using similar information collected in 2003 and 2005, a critical normalized difference vegetation index (NDVI) value was determined using the Cate-Nelson procedure. The critical NDVI value needed to ensure optimum (to receive the protein premium) grain N was 0.70. In 2006 and 2007, the plots that received an application of N at anthesis had higher grain N than the plots not receiving N. There was also a significant response between applied N and grain yield. The results show that with further studies, the Greenseeker could be used to apply N to maximize yield and grain N in a precise and accurate manner.