|BEAN, G - Lincoln University Of Missouri|
|CAMBERATO, J - Purdue University|
|FERGUSON, R - University Of Nebraska|
|FERNANDEZ, F - University Of Minnesota|
|FRANZEN, D - North Dakota State University|
|LABOSKI, C.A. - University Of Wisconsin|
|NAFZIGER, E - University Of Illinois|
|SAWYER, J - Iowa State University|
|SHANAHAN, J - Fortigen|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2018
Publication Date: 11/4/2018
Citation: Bean, G.M., Kitchen, N.R., Camberato, J.J., Ferguson, R.B., Fernandez, F.G., Franzen, D.W., Laboski, C.M., Nafziger, E.D., Sawyer, J.E., Shanahan, J., Veum, K.S. 2018. Using USDA-NRCS soil hydrologic groups to enhance corn nitrogen fertilizer recommendations [abstract]. ASA-CSSA Meeting, November 4-7, 2018, Baltimore, Maryland. Paper 112268.
Technical Abstract: Uncertainty exists with corn (Zea mays L.) N management partially due to site-specific variability in soil nitrogen (N) supply and N loss. The objective of this research was to determine if integrating soil respiration measurements taken from samples early in the growing season with USDA-NRCS defined soil hydrologic groups could improve the ability to estimate the economical optimal N fertilizer rate (EONR). A total of 49 corn N response trials were conducted across eight different US Midwest states over three growing seasons (2014 – 2016). Using the 4-day “Cornell Method”, soil respiration was linearly regressed against site-level EONR. Without classifying sites into defined soil hydrologic groups, soil respiration weakly correlated to EONR (R^2 = 0.18). After classifying sites by defined soil hydrologic groups, soil respiration highly correlated to EONR for one defined group (15 sites; R^2 = 0.70). This research suggests using early-season soil respiration testing to estimate EONR was useful under certain site hydrologic characteristics.