{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/82659"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/82659","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"The fate of applied phosphorus on a piedmont soil and its effect on loblolly pine growth twenty years after application","abstract":"A loblolly pine phosphorus fertilization trial was evaluated 20 years after establishment on a Tatum silt loam in the Virginia Piedmont. Triple superphosphate (TSP) was applied at 160 kg P/ha and ground rock phosphate (GRP) was applied at both 160 kg P/ha and 670 kg P/ha. Lime (4.48 T/ha) was applied with and without the TSP treatment. Tree growth was not significantly affected by treatment and foliar phosphorus levels were above 0.10% indicating that a deficiency was not the immediate growth limiting factor. Double-acid-extractable soil phosphorus critical levels established for the Coastal Plain do not appear useful for diagnosing tree requirements for this Piedmont soil. A critical level of 1.0 ppm double-acid-extractable phosphorus would be more applicable to this soil. GRP was more effective than TSP after 20 years at increasing phosphorus uptake, probably due to a slower dissolution rate and the inclusion of F-ions which reacted with soil Al to reduce phosphorus fixation. Although an increase in the A horizon pH persisted for 20 years, there was no increase in phosphorus uptake as a direct response to this higher pH. Liming may have some long-term merit when applied in conjunction with a water soluble phosphorus fertilizer such as TSP by reducing the transformations of applied phosphorus to unavailable forms.","abstract_html":"A loblolly pine phosphorus fertilization trial was evaluated 20 years after establishment on a Tatum silt loam in the Virginia Piedmont. Triple superphosphate (TSP) was applied at 160 kg P/ha and ground rock phosphate (GRP) was applied at both 160 kg P/ha and 670 kg P/ha. Lime (4.48 T/ha) was applied with and without the TSP treatment. Tree growth was not significantly affected by treatment and foliar phosphorus levels were above 0.10% indicating that a deficiency was not the immediate growth limiting factor. Double-acid-extractable soil phosphorus critical levels established for the Coastal Plain do not appear useful for diagnosing tree requirements for this Piedmont soil. A critical level of 1.0 ppm double-acid-extractable phosphorus would be more applicable to this soil. GRP was more effective than TSP after 20 years at increasing phosphorus uptake, probably due to a slower dissolution rate and the inclusion of F-ions which reacted with soil Al to reduce phosphorus fixation. Although an increase in the A horizon pH persisted for 20 years, there was no increase in phosphorus uptake as a direct response to this higher pH. Liming may have some long-term merit when applied in conjunction with a water soluble phosphorus fertilizer such as TSP by reducing the transformations of applied phosphorus to unavailable forms.","abstract_has_math":false,"creators":["Torbert, John L."],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Forestry and Forest Products","degree_department":"Forestry and Forest Products","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1982,"date_issued":"1982","date_published":"1982","updated_at":"2026-07-22T22:19:41Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/82659","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Forestry and Forest Products"]},{"key":"dc:creator","label":"Author","values":["Torbert, John L."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2018-03-26T19:54:10Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2018-03-26T19:54:10Z"]},{"key":"dc:date.issued","label":"Date","values":["1982"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Forestry and Forest Products"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"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.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/82659"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A loblolly pine phosphorus fertilization trial was evaluated 20 years after establishment on a Tatum silt loam in the Virginia Piedmont. Triple superphosphate (TSP) was applied at 160 kg P/ha and ground rock phosphate (GRP) was applied at both 160 kg P/ha and 670 kg P/ha. Lime (4.48 T/ha) was applied with and without the TSP treatment. Tree growth was not significantly affected by treatment and foliar phosphorus levels were above 0.10% indicating that a deficiency was not the immediate growth limiting factor. Double-acid-extractable soil phosphorus critical levels established for the Coastal Plain do not appear useful for diagnosing tree requirements for this Piedmont soil. A critical level of 1.0 ppm double-acid-extractable phosphorus would be more applicable to this soil. GRP was more effective than TSP after 20 years at increasing phosphorus uptake, probably due to a slower dissolution rate and the inclusion of F-ions which reacted with soil Al to reduce phosphorus fixation. Although an increase in the A horizon pH persisted for 20 years, there was no increase in phosphorus uptake as a direct response to this higher pH. Liming may have some long-term merit when applied in conjunction with a water soluble phosphorus fertilizer such as TSP by reducing the transformations of applied phosphorus to unavailable forms."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["The fate of applied phosphorus on a piedmont soil and its effect on loblolly pine growth twenty years after application"]}]}],"canonical_facts":{"dc:contributor.department":["Forestry and Forest Products"],"dc:creator":["Torbert, John L."],"dc:date.accessioned":["2018-03-26T19:54:10Z"],"dc:date.available":["2018-03-26T19:54:10Z"],"dc:date.issued":["1982"],"dc:description.abstract":["A loblolly pine phosphorus fertilization trial was evaluated 20 years after establishment on a Tatum silt loam in the Virginia Piedmont. Triple superphosphate (TSP) was applied at 160 kg P/ha and ground rock phosphate (GRP) was applied at both 160 kg P/ha and 670 kg P/ha. Lime (4.48 T/ha) was applied with and without the TSP treatment. Tree growth was not significantly affected by treatment and foliar phosphorus levels were above 0.10% indicating that a deficiency was not the immediate growth limiting factor. Double-acid-extractable soil phosphorus critical levels established for the Coastal Plain do not appear useful for diagnosing tree requirements for this Piedmont soil. A critical level of 1.0 ppm double-acid-extractable phosphorus would be more applicable to this soil. GRP was more effective than TSP after 20 years at increasing phosphorus uptake, probably due to a slower dissolution rate and the inclusion of F-ions which reacted with soil Al to reduce phosphorus fixation. Although an increase in the A horizon pH persisted for 20 years, there was no increase in phosphorus uptake as a direct response to this higher pH. Liming may have some long-term merit when applied in conjunction with a water soluble phosphorus fertilizer such as TSP by reducing the transformations of applied phosphorus to unavailable forms."],"dc:description.degree":["Master of Science"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/82659"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["The fate of applied phosphorus on a piedmont soil and its effect on loblolly pine growth twenty years after application"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Forestry and Forest Products"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:41Z"}