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oai:www.ideals.illinois.edu:2142/85036 2023-07-11 col_2142_5131 col_2142_14798 com_2142_5130 com_2142_686 com_2142_397

Fred E. Below Wessel, Jeffrey Ronald 2015-09-25T22:33:32Z 2015-09-25T22:33:32Z 10000-01-01 2007 2007 Production and profitability of corn (Zea mays L.) is highly dependent on fertilizer nitrogen (N) use. The efficiency of fertilizer N use and the capacity of the soil to supply N are the two main components determining the corn N requirement. The cropping management system can also affect N use efficiency and soil N supply. A better understanding of the impact of management practices on corn N requirements is needed due to high N costs and increasing environmental scrutiny over fertilizer N use. The overall objective of this work was to characterize how cultural practices influence corn N requirements, and to develop strategies to adjust for any differences. The approach was to vary the N supply using different management practices over multiple sites and years. Practices evaluated included time of N application, degree of tillage, and varying levels of corn rootworm (Diabrotica spp.) larval damage. Results showed that management practices such as reduced tillage and/or fall or winter applied N can have a greater N requirement compared with more conventional production methods. The economic return to fertilizer N increased with increasing root injury and with decreasing tillage. Fall and winter N applications can cause large yield losses when compared to spring, however these losses can be predicted with spring rainfall and corrected with in-season N based on predicted loss. Management practices that increase the economic response to N, such as reduced tillage and increased root injury, have a greater likelihood of causing N stress and lower yield when other management practices, or environmental conditions decrease the availability of N. Made available in DSpace on 2015-09-25T22:33:32Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3301247.pdf: 1553324 bytes, checksum: 223cdc01c3a263814b652923eae9cfc4 (MD5) Previous issue date: 2007 Embargo set by: Seth Robbins for item 86317 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 87 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. http://hdl.handle.net/2142/85036 (MiAaPQ)AAI3301247 eng Agriculture, Agronomy Value of Cultural Practices for Improving Nitrogen Management in Corn text Crop Sciences Crop Sciences University of Illinois at Urbana-Champaign Dissertation Ph.D.