{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/29249"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/29249","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Development of Nitrogen rate Recommendations for No-till Dryland Grain Sorghum in Virginia","abstract":"Little research has been done in the humid mid-Atlantic region to develop full-season N fertilizer recommendations for dryland no-tillage grain sorghum (Sorghum bicolor L. Moench) production. The objectives of this study were: (i) to determine the optimum rate of band-placed starter N fertilizer needed in combination with side-dress N applications to achieve economic grain yields, (ii) to investigate if pre-plant broadcast N applications are as efficient as band-placed plus side-dress N applications, (iii) to evaluate the response of grain sorghum yield to partitioned side-dress N applications, and (iv) to study the influence of residual soil profile mineral-N (nitrate and ammonium) on sorghum response to applied N fertilization. Multi-location field studies were conducted over three years. A range of N treatments of various starter-band and side-dress N rates were applied. The experimental data indicate that an optimum rate of N fertilization depends on residual soil mineral-N. Little or zero starter-band-N in conjunction with side-dress-N applications of 130 kg of N ha-1 for soils testing high in mineral-N ( 50 kg N ha-1 in the top 0.3m of surface soil) at planting, and a starter-band-N supplement of 40 kg N ha-1 in conjunction with 130 kg N ha-1 side-dress N for soils testing low in mineral-N at planting, optimized the grain sorghum yields in these experiments. Broadcast N applications were observed to be as efficient as band placed N applications when followed by rainfall soon after application. Grain sorghum yields did respond to the partitioned side-dress N applications. However, partitioning of side-dress N application again depends on the residual mineral-N level present in the soil. In order to consider residual soil mineral-N in making N fertilizer recommendations \"Associated Nitrogen Fertilizer Equivalency\" (ANFE) values were calculated. ANFE is the amount of applied N that has potential to produce the same yield as that produced by the residual soil mineral-N. The N fertilizer recommendations based on ANFE values were quite close for two out of four sites as compared to the N rates at which the maximum yields were obtained in this study.","abstract_html":"Little research has been done in the humid mid-Atlantic region to develop full-season N fertilizer recommendations for dryland no-tillage grain sorghum (Sorghum bicolor L. Moench) production. The objectives of this study were: (i) to determine the optimum rate of band-placed starter N fertilizer needed in combination with side-dress N applications to achieve economic grain yields, (ii) to investigate if pre-plant broadcast N applications are as efficient as band-placed plus side-dress N applications, (iii) to evaluate the response of grain sorghum yield to partitioned side-dress N applications, and (iv) to study the influence of residual soil profile mineral-N (nitrate and ammonium) on sorghum response to applied N fertilization. Multi-location field studies were conducted over three years. A range of N treatments of various starter-band and side-dress N rates were applied. The experimental data indicate that an optimum rate of N fertilization depends on residual soil mineral-N. Little or zero starter-band-N in conjunction with side-dress-N applications of 130 kg of N ha-1 for soils testing high in mineral-N ( 50 kg N ha-1 in the top 0.3m of surface soil) at planting, and a starter-band-N supplement of 40 kg N ha-1 in conjunction with 130 kg N ha-1 side-dress N for soils testing low in mineral-N at planting, optimized the grain sorghum yields in these experiments. Broadcast N applications were observed to be as efficient as band placed N applications when followed by rainfall soon after application. Grain sorghum yields did respond to the partitioned side-dress N applications. However, partitioning of side-dress N application again depends on the residual mineral-N level present in the soil. In order to consider residual soil mineral-N in making N fertilizer recommendations "Associated Nitrogen Fertilizer Equivalency" (ANFE) values were calculated. ANFE is the amount of applied N that has potential to produce the same yield as that produced by the residual soil mineral-N. The N fertilizer recommendations based on ANFE values were quite close for two out of four sites as compared to the N rates at which the maximum yields were obtained in this study.","abstract_has_math":false,"creators":["Khosla, Rajiv"],"institution":"Virginia Tech","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Crop and Soil Environmental Sciences","degree_department":"Crop and Soil Environmental Sciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Alley, Marcus M."],"committee_members":["Brann, Daniel E.","De Datta, Surajit K.","Dillaha, Theo A. III","Martens, David C.","Zelazny, Lucian W."],"year":1998,"date_issued":"1998-10-26","date_published":"1998-10-26","updated_at":"2026-07-22T22:19:49Z","subjects":["Side-dress","Soil mineral-N","Sorghum","Nitrogen","Broadcast","Starter-band."],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-101198-103006"],"render_values":[{"text":"etd-101198-103006","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/29249","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Alley, Marcus M."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Brann, Daniel E.","De Datta, Surajit K.","Dillaha, Theo A. III","Martens, David C.","Zelazny, Lucian W."]},{"key":"dc:contributor.department","label":"Department","values":["Crop and Soil Environmental Sciences"]},{"key":"dc:creator","label":"Author","values":["Khosla, Rajiv"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:17:18Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:17:18Z","1999-11-12"]},{"key":"dc:date.issued","label":"Date","values":["1998-10-26"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Crop and Soil Environmental Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Side-dress","Soil mineral-N","Sorghum","Nitrogen","Broadcast","Starter-band."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-101198-103006"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/29249"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Little research has been done in the humid mid-Atlantic region to develop full-season N fertilizer recommendations for dryland no-tillage grain sorghum (Sorghum bicolor L. Moench) production. The objectives of this study were: (i) to determine the optimum rate of band-placed starter N fertilizer needed in combination with side-dress N applications to achieve economic grain yields, (ii) to investigate if pre-plant broadcast N applications are as efficient as band-placed plus side-dress N applications, (iii) to evaluate the response of grain sorghum yield to partitioned side-dress N applications, and (iv) to study the influence of residual soil profile mineral-N (nitrate and ammonium) on sorghum response to applied N fertilization. Multi-location field studies were conducted over three years. A range of N treatments of various starter-band and side-dress N rates were applied. The experimental data indicate that an optimum rate of N fertilization depends on residual soil mineral-N. Little or zero starter-band-N in conjunction with side-dress-N applications of 130 kg of N ha-1 for soils testing high in mineral-N ( 50 kg N ha-1 in the top 0.3m of surface soil) at planting, and a starter-band-N supplement of 40 kg N ha-1 in conjunction with 130 kg N ha-1 side-dress N for soils testing low in mineral-N at planting, optimized the grain sorghum yields in these experiments. Broadcast N applications were observed to be as efficient as band placed N applications when followed by rainfall soon after application. Grain sorghum yields did respond to the partitioned side-dress N applications. However, partitioning of side-dress N application again depends on the residual mineral-N level present in the soil. In order to consider residual soil mineral-N in making N fertilizer recommendations \"Associated Nitrogen Fertilizer Equivalency\" (ANFE) values were calculated. ANFE is the amount of applied N that has potential to produce the same yield as that produced by the residual soil mineral-N. The N fertilizer recommendations based on ANFE values were quite close for two out of four sites as compared to the N rates at which the maximum yields were obtained in this study."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:title","label":"Title","values":["Development of Nitrogen rate Recommendations for No-till Dryland Grain Sorghum in Virginia"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Alley, Marcus M."],"dc:contributor.committeemember":["Brann, Daniel E.","De Datta, Surajit K.","Dillaha, Theo A. III","Martens, David C.","Zelazny, Lucian W."],"dc:contributor.department":["Crop and Soil Environmental Sciences"],"dc:creator":["Khosla, Rajiv"],"dc:date.accessioned":["2014-03-14T20:17:18Z"],"dc:date.available":["2014-03-14T20:17:18Z","1999-11-12"],"dc:date.issued":["1998-10-26"],"dc:description.abstract":["Little research has been done in the humid mid-Atlantic region to develop full-season N fertilizer recommendations for dryland no-tillage grain sorghum (Sorghum bicolor L. Moench) production. The objectives of this study were: (i) to determine the optimum rate of band-placed starter N fertilizer needed in combination with side-dress N applications to achieve economic grain yields, (ii) to investigate if pre-plant broadcast N applications are as efficient as band-placed plus side-dress N applications, (iii) to evaluate the response of grain sorghum yield to partitioned side-dress N applications, and (iv) to study the influence of residual soil profile mineral-N (nitrate and ammonium) on sorghum response to applied N fertilization. Multi-location field studies were conducted over three years. A range of N treatments of various starter-band and side-dress N rates were applied. The experimental data indicate that an optimum rate of N fertilization depends on residual soil mineral-N. Little or zero starter-band-N in conjunction with side-dress-N applications of 130 kg of N ha-1 for soils testing high in mineral-N ( 50 kg N ha-1 in the top 0.3m of surface soil) at planting, and a starter-band-N supplement of 40 kg N ha-1 in conjunction with 130 kg N ha-1 side-dress N for soils testing low in mineral-N at planting, optimized the grain sorghum yields in these experiments. Broadcast N applications were observed to be as efficient as band placed N applications when followed by rainfall soon after application. Grain sorghum yields did respond to the partitioned side-dress N applications. However, partitioning of side-dress N application again depends on the residual mineral-N level present in the soil. In order to consider residual soil mineral-N in making N fertilizer recommendations \"Associated Nitrogen Fertilizer Equivalency\" (ANFE) values were calculated. ANFE is the amount of applied N that has potential to produce the same yield as that produced by the residual soil mineral-N. The N fertilizer recommendations based on ANFE values were quite close for two out of four sites as compared to the N rates at which the maximum yields were obtained in this study."],"dc:description.degree":["Ph. D."],"dc:identifier.other":["etd-101198-103006"],"dc:identifier.uri":["http://hdl.handle.net/10919/29249"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Side-dress","Soil mineral-N","Sorghum","Nitrogen","Broadcast","Starter-band."],"dc:title":["Development of Nitrogen rate Recommendations for No-till Dryland Grain Sorghum in Virginia"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Crop and Soil Environmental Sciences"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:49Z"}