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ARS Home » Research » Publications at this Location » Publication #234637
Title: Corn as a Nitrogen Scavenger Crop Following Onion in Rotation

Author
item Halvorson, Ardell
item BARTOLO, MICAHEL - CSU, ROCKY FORD, CO
item REULE, CURTIS - ARS, RETIRED
item BERRADA, ABDEL - CSU, ROCKY FORD, CO

Submitted to: Agricultural Experiment Station Publication
Publication Type: Experiment Station
Publication Acceptance Date: 12/2/2008
Publication Date: 11/30/2010
Citation: Halvorson, A.D., Bartolo, M., Reule, C., Berrada, A. 2010. Corn as a Nitrogen Scavenger Crop Following Onion in Rotation. Agricultural Experiment Station Publication. p. 8-13.

Interpretive Summary: We evaluated the effectiveness of corn in recovering residual soil and fertilizer N resulting from N fertilizer of onion crops in 2005 and 2006. Six N fertilizer rates (0 to 120 lb N/a) were applied in 2007 to a 2nd corn crop following a 2005 onion crop (N Management I study) and to a 1st corn crop following a 2006 onion crop (N Management II study). Corn grain yields and corn N uptake were measured, as well as residual soil N levels in the 0- to 6-ft depth. In the N Management I study, residual soil N levels in the 0- to 6-ft soil profile at planting in 2007 ranged from 27 to 85 lb N/a where furrow irrigation was used and 31 to 186 lb N/a where drip irrigation was used in 2005. Corn grain yields increased from 74 bu/a with no N applied to 237 bu/a with 120 lb N/a applied on the 2005 drip irrigated onion plots and from 69 bu/a with no N applied to 200 bu/a with the application of 120 lb N/a on the 2005 furrow irrigated onion plots. The second corn crop responded to the higher level of residual soil N present in drip irrigated onion plots. Residual soil NO3-N levels were relatively low in both the furrow and drip irrigated onion plots after harvest of the 2nd corn crop in 2007. In the N Management II study, corn yields following onions ranged from 195 bu/a with no N applied to 271 bu/a with 120 lb N/a applied to the drip irrigated onion plots and from 160 bu/a with no N applied to 255 bu/a with 120 lb N/a applied to the furrow irrigated plots in the 2006. Residual soil NO3-N levels following corn harvest in 2007 ranged from 28 to 248 lb N/a in the drip irrigated plots and 20 to 148 in the furrow irrigated 2006 onion plots. These two studies showed that corn after onion effectively utilized residual soil and fertilizer N from the root zone. Using corn to recover residual fertilizer N applied to a previous onion crop will help reduce the potential of NO3-N contamination of the groundwater in the lower Arkansas River Valley in Colorado and improve N use efficiency.

Technical Abstract: In 2007, we evaluated the effectiveness of corn in recovering residual soil and fertilizer N resulting from N fertilizer application to onion crops in 2005 and 2006. Conservative N fertilizer rates (6 N rates, 0 to 120 lb N/a) were applied in 2007 to the second corn crop following the 2005 onion crop (N Management I study) and to the first corn crop following the 2006 onion crop (N Management II study). Corn grain yields and corn N uptake were measured, as well as residual soil N levels in the 0- to 6-ft depth of both studies. In the N Management I study, residual soil N levels in the 0- to 6-ft soil profile at corn planting in 2007 increased as the previous N rates increased, ranging from 27 to 85 lb N/a where furrow irrigation was used in 2005 and 31 to 186 lb N/a where drip irrigation was used in 2005. Corn grain yields in 2007 increased from 74 bu/a with no N applied to 237 bu/a with 120 lb N/a applied on the 2005 drip irrigated onion plots and from 69 bu/a with no N applied to 200 bu/a with the application of 120 lb N/a on the 2005 furrow irrigated onion plots. Thus, the second corn crop responded to the higher level of residual soil N present in the 2005 drip irrigated onion plots. Residual soil NO3-N levels were relatively low in both the 2005 furrow and drip irrigated onion plots after harvest of the second corn crop in 2007. In the N Management II study, corn yields following the 2006 onions ranged from 195 bu/a with no N applied to 271 bu/a with 120 lb N/a applied in the 2006 drip irrigated onion plots and from 160 bu/a with no N applied to 255 bu/a with 120 lb N/a applied in the 2006 furrow irrigated plots. Residual soil NO3-N levels in the 2006 onion plots following corn harvest in 2007 ranged from 28 to 248 lb N/a in the 2006 drip irrigated plots and 20 to 148 in the 2006 furrow irrigated onion plots. Therefore, corn will be grown on these same plots in 2008 to recover additional residual soil N. The N Management I and II studies showed that both the first and the second year of corn after onion effectively utilized the residual soil and fertilizer N from the root zone. Using corn to recover residual fertilizer N applied to a previous onion crop will help reduce the potential of NO3-N contamination of the groundwater in the lower Arkansas River Valley in Colorado and improve N use efficiency.