Kaizzi, C.K., J. Byalebeka, C.S. Wortmann, and M. Mamo. 2007. Low input approaches for soil fertility management in semi-arid eastern Uganda. Agron. J. 99:847-853 [Full Paper]

Wortmann, C.S., M. Mamo, and A. Dobermann. 2007. Nitrogen response of grain sorghum in rotation with soybean. Agron. J. 99:808-813 [Full Paper]

Shapiro, C.A. and C.S. Wortmann. 2006. Corn response to nitrogen rate, row spacing and plant density in eastern Nebraska. Agron. J. 98:529-535. [Full Paper]

Shapiro, C.A. and C.S. Wortmann. 2006. Corn Response to Nitrogen Rate, Row Spacing and Plant Density in Eastern Nebraska. Agronomy Journal 98:529-535. [Full paper]

Walters, D.T. 2005. Fertilizer nitrogen source and management impacts on greenhouse gas emissions. North central Extension-Industry soil Fertility Conference. Des Moines, IA. [Full paper]

Walters, D.T., A. Dobermann, K.G. Cassman, R. Drijber, J. Lindquist, J. Specht,
and H. Yang. 2004. Changes in nitrogen use efficiency and soil quality after five years of managing for high yield corn and soybean. North Central Extension-Industry soil Fertility Conference. Des Moines, IA. [Full paper]

Ferguson, R.B., A. Dobermann, C.S. Wortmann, D.T. Walters, C.A. Shapiro, D. Tarkalson, and D.D. Baltensperger. 2004. Developing recommendations for site-specific nitrogen management of irrigated maize. In Proceedings of the 7th International Conference on Precision Agriculture and Other Resource Management, July 25-28, 2004, Bloomington, MN. CD-ROM. ASA, CSSA, SSSA, Madison, WI [CD-ROM]. [Full paper]

Walters, D.T. 2003. Diagnosis of nitrogen deficiency in maize and the influence of hybrid and plant density. North central Extension-Industry soil Fertility Conference. Vol. 19, Des Moines, IA. [Full paper]

Shapiro, C.A. 1999. Using a Chlorophyll Meter to Manage Nitrogen Applications to Corn with High Nitrate Irrigation Water. Commun. Soil Sci. Plant Anal. 30:1037-1049. [Abstract]