{"id":"https://openalex.org/W2005103174","doi":"https://doi.org/10.2134/agronj14.0392","title":"Using Canopy Indices to Quantify the Economic Optimum Nitrogen Rate in Spring Wheat","display_name":"Using Canopy Indices to Quantify the Economic Optimum Nitrogen Rate in Spring Wheat","publication_year":2015,"publication_date":"2015-01-05","ids":{"openalex":"https://openalex.org/W2005103174","doi":"https://doi.org/10.2134/agronj14.0392","mag":"2005103174"},"language":"en","primary_location":{"id":"doi:10.2134/agronj14.0392","doi":"https://doi.org/10.2134/agronj14.0392","is_oa":true,"landing_page_url":"https://doi.org/10.2134/agronj14.0392","pdf_url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.2134/agronj14.0392","source":{"id":"https://openalex.org/S139950591","display_name":"Agronomy Journal","issn_l":"0002-1962","issn":["0002-1962","1072-9623","1435-0645"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-c","jufo-1","ki-jl-1","norway-1","poland-100","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Agronomy Journal","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["crossref"],"open_access":{"is_oa":true,"oa_status":"bronze","oa_url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.2134/agronj14.0392","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5091746940","display_name":"Nahuel Ignacio Reussi Calvo","orcid":"https://orcid.org/0000-0002-4313-5226","observed_orcids":["https://orcid.org/0000-0002-4313-5226"]},"institutions":[],"countries":[],"is_corresponding":true,"raw_author_name":"Nahuel I. Reussi Calvo","raw_affiliation_strings":["Laboratorio de Suelos FERTILAB Moreno 4524, CP 7600 Mar del Plata Buenos Aires Argentina"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Laboratorio de Suelos FERTILAB Moreno 4524, CP 7600 Mar del Plata Buenos Aires Argentina","institution_ids":[]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5059724580","display_name":"Hern\u00e1n Rene Sainz Rozas","orcid":"https://orcid.org/0000-0002-6124-1639","observed_orcids":["https://orcid.org/0000-0002-6124-1639"]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"H. Sainz Rozas","raw_affiliation_strings":["Unidad Integrada Balcarce Route 226 km 73.5, CC 276, CP 7620 Balcarce Argentina"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Unidad Integrada Balcarce Route 226 km 73.5, CC 276, CP 7620 Balcarce Argentina","institution_ids":[]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5041238492","display_name":"Hern\u00e1n E. Echeverr\u00eda","orcid":"https://orcid.org/0000-0003-0031-3632","observed_orcids":["https://orcid.org/0000-0003-0031-3632"]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"H. Echeverr\u00eda","raw_affiliation_strings":["Unidad Integrada Balcarce Route 226 km 73.5, CC 276, CP 7620 Balcarce Argentina"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Unidad Integrada Balcarce Route 226 km 73.5, CC 276, CP 7620 Balcarce Argentina","institution_ids":[]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5084436751","display_name":"Natalia Ver\u00f3nica Diovisalvi","orcid":"https://orcid.org/0000-0002-4875-4819","observed_orcids":["https://orcid.org/0000-0002-4875-4819"]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"N. Diovisalvi","raw_affiliation_strings":["Laboratorio de Suelos FERTILAB Moreno 4524, CP 7600 Mar del Plata Buenos Aires Argentina"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Laboratorio de Suelos FERTILAB Moreno 4524, CP 7600 Mar del Plata Buenos Aires Argentina","institution_ids":[]}]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":["https://openalex.org/A5091746940"],"corresponding_institution_ids":[],"apc_list":{"value":1800,"currency":"USD","value_usd":1800},"apc_paid":null,"fwci":1.3359,"has_fulltext":true,"cited_by_count":18,"citation_normalized_percentile":{"value":0.79498447,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":88,"max":98},"biblio":{"volume":"107","issue":"2","first_page":"459","last_page":"465"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10111","display_name":"Remote Sensing in Agriculture","score":0.9970999956130981,"subfield":{"id":"https://openalex.org/subfields/2303","display_name":"Ecology"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10111","display_name":"Remote Sensing in Agriculture","score":0.9970999956130981,"subfield":{"id":"https://openalex.org/subfields/2303","display_name":"Ecology"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10616","display_name":"Smart Agriculture and AI","score":0.0007999999797903001,"subfield":{"id":"https://openalex.org/subfields/1110","display_name":"Plant Science"},"field":{"id":"https://openalex.org/fields/11","display_name":"Agricultural and Biological Sciences"},"domain":{"id":"https://openalex.org/domains/1","display_name":"Life Sciences"}},{"id":"https://openalex.org/T12294","display_name":"Agricultural Science and Fertilization","score":0.0003000000142492354,"subfield":{"id":"https://openalex.org/subfields/1111","display_name":"Soil Science"},"field":{"id":"https://openalex.org/fields/11","display_name":"Agricultural and Biological Sciences"},"domain":{"id":"https://openalex.org/domains/1","display_name":"Life Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/spring-wheat","display_name":"spring wheat","score":0.9760000109672546},{"id":"https://openalex.org/keywords/nitrogen-fertilizer-management","display_name":"nitrogen fertilizer management","score":0.5619999766349792},{"id":"https://openalex.org/keywords/economic-optimum-nitrogen-rate","display_name":"economic optimum nitrogen rate","score":0.9729999899864197},{"id":"https://openalex.org/keywords/normalized-difference-vegetation-index","display_name":"NDVI","score":0.6959999799728394},{"id":"https://openalex.org/keywords/spad-chlorophyll-meter","display_name":"SPAD chlorophyll meter","score":0.9769999980926514},{"id":"https://openalex.org/keywords/variable-rate-nitrogen-application","display_name":"variable rate nitrogen application","score":0.8220000267028809},{"id":"https://openalex.org/keywords/growth-stages","display_name":"growth stages","score":0.3880000114440918},{"id":"https://openalex.org/keywords/nitrogen-deficiency","display_name":"nitrogen deficiency","score":0.3959999978542328},{"id":"https://openalex.org/keywords/sensor-calibration","display_name":"sensor calibration","score":0.4970000088214874}],"concepts":[{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.691726803779602},{"id":"https://openalex.org/C1549246","wikidata":"https://www.wikidata.org/wiki/Q718775","display_name":"Normalized Difference Vegetation Index","level":3,"score":0.6547240018844604},{"id":"https://openalex.org/C165838908","wikidata":"https://www.wikidata.org/wiki/Q736777","display_name":"Calibration","level":2,"score":0.6025472283363342},{"id":"https://openalex.org/C48921125","wikidata":"https://www.wikidata.org/wiki/Q10861030","display_name":"Linear regression","level":2,"score":0.5140408277511597},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.5101080536842346},{"id":"https://openalex.org/C2780560099","wikidata":"https://www.wikidata.org/wiki/Q83323","display_name":"Fertilizer","level":2,"score":0.48656952381134033},{"id":"https://openalex.org/C101000010","wikidata":"https://www.wikidata.org/wiki/Q5033434","display_name":"Canopy","level":2,"score":0.48399993777275085},{"id":"https://openalex.org/C2780030769","wikidata":"https://www.wikidata.org/wiki/Q4968575","display_name":"Plateau (mathematics)","level":2,"score":0.42653176188468933},{"id":"https://openalex.org/C537208039","wikidata":"https://www.wikidata.org/wiki/Q627","display_name":"Nitrogen","level":2,"score":0.4263020157814026},{"id":"https://openalex.org/C152877465","wikidata":"https://www.wikidata.org/wiki/Q208042","display_name":"Regression analysis","level":2,"score":0.4251832962036133},{"id":"https://openalex.org/C137660486","wikidata":"https://www.wikidata.org/wiki/Q732240","display_name":"Growing season","level":2,"score":0.41874751448631287},{"id":"https://openalex.org/C6557445","wikidata":"https://www.wikidata.org/wiki/Q173113","display_name":"Agronomy","level":1,"score":0.3541114926338196},{"id":"https://openalex.org/C59822182","wikidata":"https://www.wikidata.org/wiki/Q441","display_name":"Botany","level":1,"score":0.22011220455169678},{"id":"https://openalex.org/C86803240","wikidata":"https://www.wikidata.org/wiki/Q420","display_name":"Biology","level":0,"score":0.19065633416175842},{"id":"https://openalex.org/C25989453","wikidata":"https://www.wikidata.org/wiki/Q446746","display_name":"Leaf area index","level":2,"score":0.15054166316986084},{"id":"https://openalex.org/C185592680","wikidata":"https://www.wikidata.org/wiki/Q2329","display_name":"Chemistry","level":0,"score":0.11817470192909241},{"id":"https://openalex.org/C134306372","wikidata":"https://www.wikidata.org/wiki/Q7754","display_name":"Mathematical analysis","level":1,"score":0.0},{"id":"https://openalex.org/C178790620","wikidata":"https://www.wikidata.org/wiki/Q11351","display_name":"Organic chemistry","level":1,"score":0.0}],"mesh":[],"locations_count":3,"locations":[{"id":"doi:10.2134/agronj14.0392","doi":"https://doi.org/10.2134/agronj14.0392","is_oa":true,"landing_page_url":"https://doi.org/10.2134/agronj14.0392","pdf_url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.2134/agronj14.0392","source":{"id":"https://openalex.org/S139950591","display_name":"Agronomy Journal","issn_l":"0002-1962","issn":["0002-1962","1072-9623","1435-0645"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-c","jufo-1","ki-jl-1","norway-1","poland-100","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Agronomy Journal","raw_type":"journal-article"},{"id":"pmh:oai:americanae.aecid.es:3888795","doi":null,"is_oa":true,"landing_page_url":"http://americanae.aecid.es/americanae/es/registros/registro.do?tipoRegistro=MTD&idBib=3888795","pdf_url":null,"source":{"id":"https://openalex.org/S4306400786","display_name":"Americanae (AECID Library)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-nc-sa","license_id":"https://openalex.org/licenses/cc-by-nc-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"reponame:CONICET Digital (CONICET)","raw_type":"http://purl.org/coar/resource_type/c_6501"},{"id":"pmh:oai:ri.conicet.gov.ar:11336/45681","doi":null,"is_oa":true,"landing_page_url":"http://hdl.handle.net/11336/45681","pdf_url":null,"source":{"id":"https://openalex.org/S4306402641","display_name":"LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Cient\u00edficas)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I4383465926","host_organization_name":"LA Referencia","host_organization_lineage":["https://openalex.org/I4383465926"],"host_organization_lineage_names":[],"type":"repository"},"license":"cc-by-nc-sa","license_id":"https://openalex.org/licenses/cc-by-nc-sa","version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"reponame:CONICET Digital (CONICET)","raw_type":"http://purl.org/coar/resource_type/c_6501"}],"best_oa_location":{"id":"doi:10.2134/agronj14.0392","doi":"https://doi.org/10.2134/agronj14.0392","is_oa":true,"landing_page_url":"https://doi.org/10.2134/agronj14.0392","pdf_url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.2134/agronj14.0392","source":{"id":"https://openalex.org/S139950591","display_name":"Agronomy Journal","issn_l":"0002-1962","issn":["0002-1962","1072-9623","1435-0645"],"is_oa":false,"is_in_doaj":false,"is_core":true,"listed_in":["anvur-scientific","cwts-core","dongbi-c","jufo-1","ki-jl-1","norway-1","poland-100","russia-white-list-1","vabb-shw"],"host_organization":"https://openalex.org/P4310320595","host_organization_name":"Wiley","host_organization_lineage":["https://openalex.org/P4310320595"],"host_organization_lineage_names":["Wiley"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Agronomy Journal","raw_type":"journal-article"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/2","display_name":"Zero hunger","score":0.991100013256073}],"study_designs":[],"awards":[],"funders":[],"has_content":{"pdf":true,"grobid_xml":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2005103174.pdf","grobid_xml":"https://content.openalex.org/works/W2005103174.grobid-xml"},"referenced_works_count":41,"referenced_works":["https://openalex.org/W90857671","https://openalex.org/W151021567","https://openalex.org/W186921001","https://openalex.org/W596053243","https://openalex.org/W1481351420","https://openalex.org/W1493624446","https://openalex.org/W1559233919","https://openalex.org/W1601287780","https://openalex.org/W1971138717","https://openalex.org/W1978828251","https://openalex.org/W1993874580","https://openalex.org/W1996146149","https://openalex.org/W2004675407","https://openalex.org/W2016376202","https://openalex.org/W2020507698","https://openalex.org/W2033816026","https://openalex.org/W2044023561","https://openalex.org/W2046551756","https://openalex.org/W2051377630","https://openalex.org/W2054010557","https://openalex.org/W2058213516","https://openalex.org/W2063362952","https://openalex.org/W2063462217","https://openalex.org/W2067923674","https://openalex.org/W2070813784","https://openalex.org/W2077576587","https://openalex.org/W2078777305","https://openalex.org/W2082833007","https://openalex.org/W2082928229","https://openalex.org/W2091160252","https://openalex.org/W2124656965","https://openalex.org/W2133325500","https://openalex.org/W2143105449","https://openalex.org/W2164831882","https://openalex.org/W2183297249","https://openalex.org/W2340014748","https://openalex.org/W2461585153","https://openalex.org/W2501784575","https://openalex.org/W2725974085","https://openalex.org/W2775362996","https://openalex.org/W3032559194"],"related_works":["https://openalex.org/W3045187909","https://openalex.org/W2290746210","https://openalex.org/W2070813784","https://openalex.org/W2051012853","https://openalex.org/W4402329053","https://openalex.org/W3042799690","https://openalex.org/W1987622292","https://openalex.org/W4414077115","https://openalex.org/W2367472502","https://openalex.org/W1971535458"],"abstract_inverted_index":{"In\u2010season":[0],"N":[1,14,46,60,67,134,216,241,246],"applications":[2],"to":[3,20,56,154,193],"spring":[4,232],"wheat":[5],"(Triticum":[6],"aestivum":[7],"L.)":[8],"may":[9],"increase":[10],"profits":[11],"and":[12,31,54,58,94,115,122,128,141,160,164,166,182,186,205],"improve":[13],"fertilizer":[15,68,247],"accuracy.":[16],"The":[17,89],"objectives":[18],"were":[19,109],"develop":[21],"a":[22,70],"calibration":[23,131,214],"tool":[24],"employing":[25],"normalized":[26],"difference":[27],"vegetative":[28],"index":[29],"(NDVI)":[30],"SPAD":[32,120],"502":[33],"chlorophyll":[34],"meter":[35],"(SPAD)":[36],"measurements":[37],"for":[38,63,177,184,202,215,244],"calculating":[39],"the":[40,43,112,130,137,143,146,195,203,212],"differential":[41],"from":[42],"economic":[44],"optimum":[45],"rate":[47,61,217,242],"(dEONR)":[48],"at":[49,69,111,162,168,173],"growth":[50,117,207],"stages":[51],"Z22,":[52],"Z24,":[53,113],"Z31":[55,140,163,204],"Z39":[57,116,206],"provide":[59],"algorithms":[62],"use":[64],"in":[65,231],"applying":[66,245],"variable":[71],"rate.":[72],"Sensing":[73],"was":[74,96,175,200],"conducted":[75],"trials":[76],"over":[77],"3":[78],"yr":[79],"encompassing":[80],"10":[81],"site\u2010years":[82],"across":[83],"Southeastern":[84],"Buenos":[85],"Aires":[86],"Province,":[87],"Argentina.":[88],"relationship":[90],"between":[91],"sensor":[92],"indices":[93],"dEONR":[95,196],"evaluated":[97],"by":[98],"fitting":[99],"quadratic":[100],"plateau":[101],"(QP)":[102],"regression":[103],"models.":[104],"Statistically":[105],"significant":[106],"QP":[107,191],"models":[108],"determined":[110],"Z31,":[114],"stages.":[118,208],"Relative":[119],"(rSPAD)":[121],"relative":[123],"NDVI":[124],"(rNDVI)":[125],"reduced":[126],"variation":[127],"improved":[129],"of":[132,149],"measured":[133],"stress":[135],"with":[136,197],"dEONR.":[138],"For":[139],"Z39,":[142,169],"rSPAD":[144,185,221],"had":[145],"best":[147],"goodness":[148],"fit":[150],"statistics":[151],"when":[152],"compared":[153],"rNDVI":[155,178,223],"[adjusted":[156],"R2":[157],"(adjR2)=":[158],"0.67":[159],"0.57":[161],"0.68":[165],"0.52":[167],"respectively].":[170],"However,":[171],"adjustment":[172],"Z24":[174],"higher":[176],"(adjR2":[179],"=":[180],"0.53":[181],"0.61":[183],"rNDVI,":[187],"respectively).":[188],"A":[189],"single":[190],"model":[192,235],"estimate":[194],"58%":[198],"confidence":[199],"adjusted":[201],"This":[209,234],"indicates":[210],"that":[211],"same":[213],"determination":[218],"based":[219],"on":[220],"or":[222],"values":[224],"can":[225,236],"be":[226,237],"used":[227,238],"during":[228],"stem":[229],"elongation":[230],"wheat.":[233],"as":[239],"an":[240],"algorithm":[243],"in\u2010season.":[248]},"counts_by_year":[{"year":2026,"cited_by_count":1},{"year":2025,"cited_by_count":3},{"year":2024,"cited_by_count":1},{"year":2023,"cited_by_count":1},{"year":2022,"cited_by_count":2},{"year":2020,"cited_by_count":3},{"year":2019,"cited_by_count":2},{"year":2017,"cited_by_count":4},{"year":2016,"cited_by_count":1}],"updated_date":"2026-11-04T10:54:05.112534","created_date":"2016-06-24T00:00:00"}