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Nitrogen Response and Economics for Irrigated Corn in Nebraska

Dobermann, A.R. and Wortmann, C.S. and Ferguson, R.B. and Hergert, G.W. and Shapiro, C.A. and Tarkalson, D.D. and Walters, D.T. (2010) Nitrogen Response and Economics for Irrigated Corn in Nebraska. Agronomy Journal. 103(1):67-75. 3 November 2010.

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Nitrogen management recommendations may change as yield levels and efficiency of crop production increase. The mean yield with adequate nutrient availability in 32 irrigated corn (Zea mays L.) trials conducted across Nebraska to evaluate crop response to split-applied N was 14.8 Mg per ha. The mean economically optimal N rates (EONR) for irrigated corn varied with the fertilizer N to grain price ratio. At a fertilizer N:corn price ratio of 7, the EONR was 171, 122, and 93 kg per hectare, respectively, for cropping systems with corn following corn (CC), soybean (Glycine max L.) (CS), and drybean (Phaseolus vulgaris L.) (CD). At this price ratio the present University of Nebraska (UNL) recommendation procedure gave mean N recommendations that were 17.2, 0.3, and 68.1 kg per hectare higher than the mean EONR determined in this study for CC, CS, and CD, respectively. The UNL algorithm, adjusted for mean cropping system EONR gave more accurate prediction of site-year EONR than alternative N rate predictions for CC and CD with returns to applied N (RTN) of -$22 and -$13 per hectare compared with measured site-year EONR. Prediction of site-year EONR using mean EONR adjusted for soil organic matter was more accurate for CS than other methods with an RTN of -$6 per hectare compared with measured site-year EONR. Further research is needed to extend the results to: lower yield situations, alternatives to split application of N, and adjustment of EONR to protect against inadequate N in atypical seasons or for environmental protection.

Item Type: Article
NWISRL Publication Number: 1385
Subjects: Irrigated crops > Corn / maize
Soil > Chemistry > Nitrogen
Depositing User: Users 6 not found.
Date Deposited: 18 Mar 2011 19:36
Last Modified: 18 Mar 2011 19:36
Item ID: 1415