{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/101217"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/101217","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Late-split application of nitrogen on corn","abstract":"The practice of applying a portion of N fertilizer during late vegetative growth of corn using high-clearance equipment has grown rapidly in the last few years, despite the absence of evidence supporting the profitability of this practice. We conducted trials at fifteen Illinois sites – six in which corn followed corn and nine in corn following soybean in 2016-2017. In each trial, six N rates ranging from 0 to 280 kg N ha-1 in increments of 56 kg N ha-1 were assigned to main plots. Two subplot treatments were 1) each rate applied as UAN solution injected at or near the time of planting, and 2) late-split N application with a portion applied at or near planting and the remaining 56 kg N ha-1 hand-applied near the base of the plants at tasseling. Grain protein content, grain N content, and chlorophyll concentration measurements were collected in the trials conducted at Urbana. Grain protein and N content were found to be very similar between application timings. Chlorophyll concentrations in late-split plots were found to be lower prior to application at VT compared to plots receiving all N early, however, readings taken after application indicated plants were capable of increasing chlorophyll concentration during reproductive growth stages. Appropriate curves were fitted to the data, and economically optimum N rates (EONR), the yields at those rates (EOY), and return to nitrogen (RTN) values were calculated. EONR values ranged from 125 to 214 kg N ha-1 in S-C trials conducted during 2016 with EOY values ranging from 14.6 to 15.0 Mg ha-1. EONR values in C-C trials conducted in 2016 ranged from 144 to 196 kg N ha-1 with yields at the EONR ranging from 14.3 to 14.7 Mg ha-1. EONR values in the S-C trials conducted during the 2017 growing season ranged from 135 to 233 kg N ha-1 with EOY values ranging from 9.2 to 16.6 Mg ha-1. EONR values ranged from 143 to 181 kg N ha-1 in the 2017 C-C trials with yields at these rates ranging from 12.9 to 14.5 Mg ha-1. RTN values ranged from $489 to $687 ha-1 in S-C 2016 trials, $690 to $1,1129 ha-1 in C-C 2016 trials, $387 to $730 ha-1 in S-C 2017 trials, and $180 to $933 ha-1 in C-C 2017 trials. The average RTN over the four S-C trials conducted in 2016 was $556 ha-1 when all N was applied early compared to $560 ha-1 when N was late split. The average RTN over the three C-C trials conducted in 2016 was $978 ha-1 when all N was applied at planting while the average RTN when N was late-split was found to be $983 ha-1. The average RTN for 2017 S-C trials when all N was applied early was $496 ha-1 compared to $476 ha-1 when N was late-split. The average RTN for 2017 C-C trials was $488 ha-1 when all N was applied early versus $463 ha-1 when N was late-split. While the 56 kg N ha-1 applied late was utilized to increase yields in some cases (at the lower N rates), it did not increase the return to N; with higher application costs, late-split N was less profitable than application of all of the N at planting. It appears that late-split application of the last increment of N is unlikely to be profitable in comparison to early application of all of the N, at least in productive soils.","abstract_html":"The practice of applying a portion of N fertilizer during late vegetative growth of corn using high-clearance equipment has grown rapidly in the last few years, despite the absence of evidence supporting the profitability of this practice. We conducted trials at fifteen Illinois sites – six in which corn followed corn and nine in corn following soybean in 2016-2017. In each trial, six N rates ranging from 0 to 280 kg N ha-1 in increments of 56 kg N ha-1 were assigned to main plots. Two subplot treatments were 1) each rate applied as UAN solution injected at or near the time of planting, and 2) late-split N application with a portion applied at or near planting and the remaining 56 kg N ha-1 hand-applied near the base of the plants at tasseling. Grain protein content, grain N content, and chlorophyll concentration measurements were collected in the trials conducted at Urbana. Grain protein and N content were found to be very similar between application timings. Chlorophyll concentrations in late-split plots were found to be lower prior to application at VT compared to plots receiving all N early, however, readings taken after application indicated plants were capable of increasing chlorophyll concentration during reproductive growth stages. Appropriate curves were fitted to the data, and economically optimum N rates (EONR), the yields at those rates (EOY), and return to nitrogen (RTN) values were calculated. EONR values ranged from 125 to 214 kg N ha-1 in S-C trials conducted during 2016 with EOY values ranging from 14.6 to 15.0 Mg ha-1. EONR values in C-C trials conducted in 2016 ranged from 144 to 196 kg N ha-1 with yields at the EONR ranging from 14.3 to 14.7 Mg ha-1. EONR values in the S-C trials conducted during the 2017 growing season ranged from 135 to 233 kg N ha-1 with EOY values ranging from 9.2 to 16.6 Mg ha-1. EONR values ranged from 143 to 181 kg N ha-1 in the 2017 C-C trials with yields at these rates ranging from 12.9 to 14.5 Mg ha-1. RTN values ranged from $489 to $687 ha-1 in S-C 2016 trials, $690 to $1,1129 ha-1 in C-C 2016 trials, $387 to $730 ha-1 in S-C 2017 trials, and $180 to $933 ha-1 in C-C 2017 trials. The average RTN over the four S-C trials conducted in 2016 was $556 ha-1 when all N was applied early compared to $560 ha-1 when N was late split. The average RTN over the three C-C trials conducted in 2016 was $978 ha-1 when all N was applied at planting while the average RTN when N was late-split was found to be $983 ha-1. The average RTN for 2017 S-C trials when all N was applied early was $496 ha-1 compared to $476 ha-1 when N was late-split. The average RTN for 2017 C-C trials was $488 ha-1 when all N was applied early versus $463 ha-1 when N was late-split. While the 56 kg N ha-1 applied late was utilized to increase yields in some cases (at the lower N rates), it did not increase the return to N; with higher application costs, late-split N was less profitable than application of all of the N at planting. It appears that late-split application of the last increment of N is unlikely to be profitable in comparison to early application of all of the N, at least in productive soils.","abstract_has_math":true,"creators":["Rapp, Derek"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Crop Sciences","degree_department":null,"school":null,"contributors":["Nafziger, Emerson D."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-09-04T20:36:53Z","date_published":"2018-09-04T20:36:53Z","updated_at":"2026-07-22T22:24:38Z","subjects":["Late-split, nitrogen, corn"],"languages":["en"],"rights":["Copyright 2018 Derek Rapp"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/101217","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Nafziger, Emerson D."]},{"key":"dc:creator","label":"Author","values":["Rapp, Derek"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018-09-04T20:36:53Z","2020-09-05T09:15:16Z","2018-04-24","2018-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Crop Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Late-split, nitrogen, corn"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2018 Derek Rapp"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/101217"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The practice of applying a portion of N fertilizer during late vegetative growth of corn using high-clearance equipment has grown rapidly in the last few years, despite the absence of evidence supporting the profitability of this practice. We conducted trials at fifteen Illinois sites – six in which corn followed corn and nine in corn following soybean in 2016-2017. In each trial, six N rates ranging from 0 to 280 kg N ha-1 in increments of 56 kg N ha-1 were assigned to main plots. Two subplot treatments were 1) each rate applied as UAN solution injected at or near the time of planting, and 2) late-split N application with a portion applied at or near planting and the remaining 56 kg N ha-1 hand-applied near the base of the plants at tasseling. Grain protein content, grain N content, and chlorophyll concentration measurements were collected in the trials conducted at Urbana. Grain protein and N content were found to be very similar between application timings. Chlorophyll concentrations in late-split plots were found to be lower prior to application at VT compared to plots receiving all N early, however, readings taken after application indicated plants were capable of increasing chlorophyll concentration during reproductive growth stages. Appropriate curves were fitted to the data, and economically optimum N rates (EONR), the yields at those rates (EOY), and return to nitrogen (RTN) values were calculated. EONR values ranged from 125 to 214 kg N ha-1 in S-C trials conducted during 2016 with EOY values ranging from 14.6 to 15.0 Mg ha-1. EONR values in C-C trials conducted in 2016 ranged from 144 to 196 kg N ha-1 with yields at the EONR ranging from 14.3 to 14.7 Mg ha-1. EONR values in the S-C trials conducted during the 2017 growing season ranged from 135 to 233 kg N ha-1 with EOY values ranging from 9.2 to 16.6 Mg ha-1. EONR values ranged from 143 to 181 kg N ha-1 in the 2017 C-C trials with yields at these rates ranging from 12.9 to 14.5 Mg ha-1. RTN values ranged from $489 to $687 ha-1 in S-C 2016 trials, $690 to $1,1129 ha-1 in C-C 2016 trials, $387 to $730 ha-1 in S-C 2017 trials, and $180 to $933 ha-1 in C-C 2017 trials. The average RTN over the four S-C trials conducted in 2016 was $556 ha-1 when all N was applied early compared to $560 ha-1 when N was late split. The average RTN over the three C-C trials conducted in 2016 was $978 ha-1 when all N was applied at planting while the average RTN when N was late-split was found to be $983 ha-1. The average RTN for 2017 S-C trials when all N was applied early was $496 ha-1 compared to $476 ha-1 when N was late-split. The average RTN for 2017 C-C trials was $488 ha-1 when all N was applied early versus $463 ha-1 when N was late-split. While the 56 kg N ha-1 applied late was utilized to increase yields in some cases (at the lower N rates), it did not increase the return to N; with higher application costs, late-split N was less profitable than application of all of the N at planting. It appears that late-split application of the last increment of N is unlikely to be profitable in comparison to early application of all of the N, at least in productive soils.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-05-01","The student, Derek Rapp, accepted the attached license on 2018-04-24 at 10:39.","The student, Derek Rapp, submitted this Thesis for approval on 2018-04-24 at 11:16.","This Thesis was approved for publication on 2018-04-24 at 17:11.","DSpace SAF Submission Ingestion Package generated from Vireo submission #12442 on 2018-08-31 at 17:21:22","Made available in DSpace on 2018-09-04T20:36:53Z (GMT). No. of bitstreams: 2 RAPP-THESIS-2018.pdf: 677961 bytes, checksum: de573277047fd26b296f2d3347652c6e (MD5) LICENSE.txt: 4207 bytes, checksum: f2df682fd4009c7dc7411d0f03238ad9 (MD5) Previous issue date: 2018-04-24","Embargo set by: Seth Robbins for item 107301 Lift date: 2020-09-04T20:37:00Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 107301 Lift date: 2020-09-04T20:42:08Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 107301 on 2020-09-05T09:15:16Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Late-split application of nitrogen on corn"]}]}],"canonical_facts":{"dc:contributor":["Nafziger, Emerson D."],"dc:creator":["Rapp, Derek"],"dc:date":["2018-09-04T20:36:53Z","2020-09-05T09:15:16Z","2018-04-24","2018-05"],"dc:description":["The practice of applying a portion of N fertilizer during late vegetative growth of corn using high-clearance equipment has grown rapidly in the last few years, despite the absence of evidence supporting the profitability of this practice. We conducted trials at fifteen Illinois sites – six in which corn followed corn and nine in corn following soybean in 2016-2017. In each trial, six N rates ranging from 0 to 280 kg N ha-1 in increments of 56 kg N ha-1 were assigned to main plots. Two subplot treatments were 1) each rate applied as UAN solution injected at or near the time of planting, and 2) late-split N application with a portion applied at or near planting and the remaining 56 kg N ha-1 hand-applied near the base of the plants at tasseling. Grain protein content, grain N content, and chlorophyll concentration measurements were collected in the trials conducted at Urbana. Grain protein and N content were found to be very similar between application timings. Chlorophyll concentrations in late-split plots were found to be lower prior to application at VT compared to plots receiving all N early, however, readings taken after application indicated plants were capable of increasing chlorophyll concentration during reproductive growth stages. Appropriate curves were fitted to the data, and economically optimum N rates (EONR), the yields at those rates (EOY), and return to nitrogen (RTN) values were calculated. EONR values ranged from 125 to 214 kg N ha-1 in S-C trials conducted during 2016 with EOY values ranging from 14.6 to 15.0 Mg ha-1. EONR values in C-C trials conducted in 2016 ranged from 144 to 196 kg N ha-1 with yields at the EONR ranging from 14.3 to 14.7 Mg ha-1. EONR values in the S-C trials conducted during the 2017 growing season ranged from 135 to 233 kg N ha-1 with EOY values ranging from 9.2 to 16.6 Mg ha-1. EONR values ranged from 143 to 181 kg N ha-1 in the 2017 C-C trials with yields at these rates ranging from 12.9 to 14.5 Mg ha-1. RTN values ranged from $489 to $687 ha-1 in S-C 2016 trials, $690 to $1,1129 ha-1 in C-C 2016 trials, $387 to $730 ha-1 in S-C 2017 trials, and $180 to $933 ha-1 in C-C 2017 trials. The average RTN over the four S-C trials conducted in 2016 was $556 ha-1 when all N was applied early compared to $560 ha-1 when N was late split. The average RTN over the three C-C trials conducted in 2016 was $978 ha-1 when all N was applied at planting while the average RTN when N was late-split was found to be $983 ha-1. The average RTN for 2017 S-C trials when all N was applied early was $496 ha-1 compared to $476 ha-1 when N was late-split. The average RTN for 2017 C-C trials was $488 ha-1 when all N was applied early versus $463 ha-1 when N was late-split. While the 56 kg N ha-1 applied late was utilized to increase yields in some cases (at the lower N rates), it did not increase the return to N; with higher application costs, late-split N was less profitable than application of all of the N at planting. It appears that late-split application of the last increment of N is unlikely to be profitable in comparison to early application of all of the N, at least in productive soils.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-05-01","The student, Derek Rapp, accepted the attached license on 2018-04-24 at 10:39.","The student, Derek Rapp, submitted this Thesis for approval on 2018-04-24 at 11:16.","This Thesis was approved for publication on 2018-04-24 at 17:11.","DSpace SAF Submission Ingestion Package generated from Vireo submission #12442 on 2018-08-31 at 17:21:22","Made available in DSpace on 2018-09-04T20:36:53Z (GMT). No. of bitstreams: 2 RAPP-THESIS-2018.pdf: 677961 bytes, checksum: de573277047fd26b296f2d3347652c6e (MD5) LICENSE.txt: 4207 bytes, checksum: f2df682fd4009c7dc7411d0f03238ad9 (MD5) Previous issue date: 2018-04-24","Embargo set by: Seth Robbins for item 107301 Lift date: 2020-09-04T20:37:00Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 107301 Lift date: 2020-09-04T20:42:08Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 107301 on 2020-09-05T09:15:16Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/101217"],"dc:language":["en"],"dc:rights":["Copyright 2018 Derek Rapp"],"dc:subject":["Late-split, nitrogen, corn"],"dc:title":["Late-split application of nitrogen on corn"],"dc:type":["text"],"thesis:degree_discipline":["Crop Sciences"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:38Z"}