Submitted to: Proceedings of American Chemical Society National Meeting
Publication Type: Abstract only
Publication Acceptance Date: 4/4/2008
Publication Date: 8/20/2008
Citation: Schmidt, J.P., Dellinger, A., Beegle, D. 2008. Developing nitrogen recommendations for corn with an on-the-go canopy reflectance sensor. Proceedings of American Chemical Society National Meeting. p. 115. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: Our objective was to compare the potential for developing N recommendations for corn based on crop reflectance with those developed from more traditional approaches. Corn yield response to N was determined for N applied at the 8-leaf growth stage. Crop reflectance (590 nm and 880 nm) was determined prior to sidedress N applications. Relative Green Normalized Difference Vegetation Index (RGNDVI) was determined, as GNDVI(0) / GNDVI(280), based on reflectance from corn receiving 280 kg per ha at planting. Traditionally used N recommendations deviated from EONR by: i) -68 to 126 kg per ha N when determined by a soil testing lab; ii) -49 to 162 kg per ha N when based on the Pre-Sidedress N test; and iii) -139 to 115 kg per ha N when based on a SPAD meter. Economic optimum N rate was strongly related to RGNDVI, which offers the potential to improve N recommendations for corn.