{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/37386"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/37386","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Long-term Effects of Fertilization on Phosphorus Biogeochemical Pools in Forest Soils","abstract":"Southern pines are typically limited by nitrogen (N) and phosphorus (P) availability in the soil environment. While the absolute quantities of P in forests soils may be large, the concentration of inorganic P in the soil solution is typically very small (< 0.01 mg L²-1). A onetime application of just 56 kg P ha²-1 can substantially increase growth of pine stands over a 20 year rotation (Pritchett and Comerford, 1982; Allen et al., 1990). Phosphorus fertilization of Pinus radiata in New Zealand has also shown long-term effects on labile P pools in the soil which improved stand growth during the subsequent rotations (Ballard, 1978; Gentle et al., 1986). Identifying and quantifying the biologically available P pools in the soil environment will help foresters in making site-specific P fertilizer prescriptions. I examined soil phosphorus pools using the Hedley sequential fractionation procedure and Mehlich-3 soil tests in a long-term loblolly pine (Pinus taeda L.) fertilization trial from four sites in the Atlantic and Gulf Coastal Plains. After 22 years, fertilization effects were limited to the surface depths. Mehlich-3 extractable P was largest in the soil surface (0-10 cm) of the fertilized treatments plots. Hedley labile and moderately labile P pools were also largest in the soil surface and decreased with depth. Results from the Hedley fractionation procedure suggested that the Virginia site has a large pool of organic P in the soil surface. Organic P pools can represent 20-90% of the total P present in most mineral soils increasing with the age of the soil (Condron et al., 2005). This increase in organic P pool suggests that biological cycling becomes more important as the stand develops (Wells and Jorgensen 1975). I used solution 31P nuclear magnetic resonance (NMR) spectroscopy to characterize organic P extracted with NaOH-EDTA in the surface of a Paleaquults from coastal Virginia. Total NaOH-EDTA extractable P was significantly larger in the fertilized treatment. Concentrations ranged from 0.1 mg P L²-1 in the control plots to 5.1 mg P L²-1 in fertilized plots. The surface soils in both treatments were dominated by inorganic orthophosphate. Monoester P compounds were the only organic P compounds detected and were present in very low quantities. The significant increase of NaOH/EDTA extractable P in the soil surface of the VA site suggested there has been a beneficial long-term effect of fertilization similar to the observations from the Mehlich-3 soil test. Results from oxalate loading experiments on ligand exchangeable versus dissolvable P pools in the bulk soil suggested that the long-term effect of P fertilization increased oxalate dissolvable P pools. Plants and microbes have evolved a variety of mechanisms to increase P uptake in low P soil environments. These mechanisms include changes in root morphology and architecture, preferential root growth into high P microsites, the secretion of low-molecular-mass organic acids (LMMOA), and uptake via symbiotic relationships (Fox and Comerford, 1992b; Raghothama, 1999; Hinsinger, 2001; Raghothama, 2005). Results from soil samples taken from the ectomycorrhizal rhizosphere found that loblolly pine mycorrhizal roots modified the soil environment, possibly making recalcitrant P more available. In addition, the long-term effect of fertilization was a 396% increase in biologically available P. Fertilization increased loblolly pine volume growth by 57 m¹3 ha and increased the P content in the litter layer by 118%. After the stand was harvested and replanted, mineralization of the litter layer may also increase soil P pools. Results from this long-term fertilization experiment in the Coastal Plain province of Virginia have demonstrated that there has been a significant increase in soil (33.6 kg P ha²-1) and biologically available P pools (3.0 kg P ha²-1).","abstract_html":"Southern pines are typically limited by nitrogen (N) and phosphorus (P) availability in the soil environment. While the absolute quantities of P in forests soils may be large, the concentration of inorganic P in the soil solution is typically very small (&lt; 0.01 mg L²-1). A onetime application of just 56 kg P ha²-1 can substantially increase growth of pine stands over a 20 year rotation (Pritchett and Comerford, 1982; Allen et al., 1990). Phosphorus fertilization of Pinus radiata in New Zealand has also shown long-term effects on labile P pools in the soil which improved stand growth during the subsequent rotations (Ballard, 1978; Gentle et al., 1986). Identifying and quantifying the biologically available P pools in the soil environment will help foresters in making site-specific P fertilizer prescriptions. I examined soil phosphorus pools using the Hedley sequential fractionation procedure and Mehlich-3 soil tests in a long-term loblolly pine (Pinus taeda L.) fertilization trial from four sites in the Atlantic and Gulf Coastal Plains. After 22 years, fertilization effects were limited to the surface depths. Mehlich-3 extractable P was largest in the soil surface (0-10 cm) of the fertilized treatments plots. Hedley labile and moderately labile P pools were also largest in the soil surface and decreased with depth. Results from the Hedley fractionation procedure suggested that the Virginia site has a large pool of organic P in the soil surface. Organic P pools can represent 20-90% of the total P present in most mineral soils increasing with the age of the soil (Condron et al., 2005). This increase in organic P pool suggests that biological cycling becomes more important as the stand develops (Wells and Jorgensen 1975). I used solution 31P nuclear magnetic resonance (NMR) spectroscopy to characterize organic P extracted with NaOH-EDTA in the surface of a Paleaquults from coastal Virginia. Total NaOH-EDTA extractable P was significantly larger in the fertilized treatment. Concentrations ranged from 0.1 mg P L²-1 in the control plots to 5.1 mg P L²-1 in fertilized plots. The surface soils in both treatments were dominated by inorganic orthophosphate. Monoester P compounds were the only organic P compounds detected and were present in very low quantities. The significant increase of NaOH/EDTA extractable P in the soil surface of the VA site suggested there has been a beneficial long-term effect of fertilization similar to the observations from the Mehlich-3 soil test. Results from oxalate loading experiments on ligand exchangeable versus dissolvable P pools in the bulk soil suggested that the long-term effect of P fertilization increased oxalate dissolvable P pools. Plants and microbes have evolved a variety of mechanisms to increase P uptake in low P soil environments. These mechanisms include changes in root morphology and architecture, preferential root growth into high P microsites, the secretion of low-molecular-mass organic acids (LMMOA), and uptake via symbiotic relationships (Fox and Comerford, 1992b; Raghothama, 1999; Hinsinger, 2001; Raghothama, 2005). Results from soil samples taken from the ectomycorrhizal rhizosphere found that loblolly pine mycorrhizal roots modified the soil environment, possibly making recalcitrant P more available. In addition, the long-term effect of fertilization was a 396% increase in biologically available P. Fertilization increased loblolly pine volume growth by 57 m¹3 ha and increased the P content in the litter layer by 118%. After the stand was harvested and replanted, mineralization of the litter layer may also increase soil P pools. Results from this long-term fertilization experiment in the Coastal Plain province of Virginia have demonstrated that there has been a significant increase in soil (33.6 kg P ha²-1) and biologically available P pools (3.0 kg P ha²-1).","abstract_has_math":false,"creators":["Miller, Bradley W."],"institution":"Virginia Tech","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Forestry","degree_department":"Forestry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Fox, Thomas R."],"committee_members":["Aust, W. Michael","Burger, James A.","Sanchez, Felipe G.","Zelazny, Lucian W.","Allen, H. Lee"],"year":2009,"date_issued":"2009-02-02","date_published":"2009-02-02","updated_at":"2026-07-22T22:20:18Z","subjects":["rhizosphere","organic phosphorus","ectomycorrhiza","oxalate"],"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-02202009-042129"],"render_values":[{"text":"etd-02202009-042129","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/37386","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Fox, Thomas R."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Aust, W. Michael","Burger, James A.","Sanchez, Felipe G.","Zelazny, Lucian W.","Allen, H. Lee"]},{"key":"dc:contributor.department","label":"Department","values":["Forestry"]},{"key":"dc:creator","label":"Author","values":["Miller, Bradley W."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:09:38Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:09:38Z","2009-03-18"]},{"key":"dc:date.issued","label":"Date","values":["2009-02-02"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Forestry"]},{"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":["rhizosphere","organic phosphorus","ectomycorrhiza","oxalate"]}]},{"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-02202009-042129"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/37386"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Southern pines are typically limited by nitrogen (N) and phosphorus (P) availability in the soil environment. While the absolute quantities of P in forests soils may be large, the concentration of inorganic P in the soil solution is typically very small (< 0.01 mg L²-1). A onetime application of just 56 kg P ha²-1 can substantially increase growth of pine stands over a 20 year rotation (Pritchett and Comerford, 1982; Allen et al., 1990). Phosphorus fertilization of Pinus radiata in New Zealand has also shown long-term effects on labile P pools in the soil which improved stand growth during the subsequent rotations (Ballard, 1978; Gentle et al., 1986). Identifying and quantifying the biologically available P pools in the soil environment will help foresters in making site-specific P fertilizer prescriptions. I examined soil phosphorus pools using the Hedley sequential fractionation procedure and Mehlich-3 soil tests in a long-term loblolly pine (Pinus taeda L.) fertilization trial from four sites in the Atlantic and Gulf Coastal Plains. After 22 years, fertilization effects were limited to the surface depths. Mehlich-3 extractable P was largest in the soil surface (0-10 cm) of the fertilized treatments plots. Hedley labile and moderately labile P pools were also largest in the soil surface and decreased with depth. Results from the Hedley fractionation procedure suggested that the Virginia site has a large pool of organic P in the soil surface. Organic P pools can represent 20-90% of the total P present in most mineral soils increasing with the age of the soil (Condron et al., 2005). This increase in organic P pool suggests that biological cycling becomes more important as the stand develops (Wells and Jorgensen 1975). I used solution 31P nuclear magnetic resonance (NMR) spectroscopy to characterize organic P extracted with NaOH-EDTA in the surface of a Paleaquults from coastal Virginia. Total NaOH-EDTA extractable P was significantly larger in the fertilized treatment. Concentrations ranged from 0.1 mg P L²-1 in the control plots to 5.1 mg P L²-1 in fertilized plots. The surface soils in both treatments were dominated by inorganic orthophosphate. Monoester P compounds were the only organic P compounds detected and were present in very low quantities. The significant increase of NaOH/EDTA extractable P in the soil surface of the VA site suggested there has been a beneficial long-term effect of fertilization similar to the observations from the Mehlich-3 soil test. Results from oxalate loading experiments on ligand exchangeable versus dissolvable P pools in the bulk soil suggested that the long-term effect of P fertilization increased oxalate dissolvable P pools. Plants and microbes have evolved a variety of mechanisms to increase P uptake in low P soil environments. These mechanisms include changes in root morphology and architecture, preferential root growth into high P microsites, the secretion of low-molecular-mass organic acids (LMMOA), and uptake via symbiotic relationships (Fox and Comerford, 1992b; Raghothama, 1999; Hinsinger, 2001; Raghothama, 2005). Results from soil samples taken from the ectomycorrhizal rhizosphere found that loblolly pine mycorrhizal roots modified the soil environment, possibly making recalcitrant P more available. In addition, the long-term effect of fertilization was a 396% increase in biologically available P. Fertilization increased loblolly pine volume growth by 57 m¹3 ha and increased the P content in the litter layer by 118%. After the stand was harvested and replanted, mineralization of the litter layer may also increase soil P pools. Results from this long-term fertilization experiment in the Coastal Plain province of Virginia have demonstrated that there has been a significant increase in soil (33.6 kg P ha²-1) and biologically available P pools (3.0 kg P ha²-1)."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:title","label":"Title","values":["Long-term Effects of Fertilization on Phosphorus Biogeochemical Pools in Forest Soils"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Fox, Thomas R."],"dc:contributor.committeemember":["Aust, W. Michael","Burger, James A.","Sanchez, Felipe G.","Zelazny, Lucian W.","Allen, H. Lee"],"dc:contributor.department":["Forestry"],"dc:creator":["Miller, Bradley W."],"dc:date.accessioned":["2014-03-14T21:09:38Z"],"dc:date.available":["2014-03-14T21:09:38Z","2009-03-18"],"dc:date.issued":["2009-02-02"],"dc:description.abstract":["Southern pines are typically limited by nitrogen (N) and phosphorus (P) availability in the soil environment. While the absolute quantities of P in forests soils may be large, the concentration of inorganic P in the soil solution is typically very small (< 0.01 mg L²-1). A onetime application of just 56 kg P ha²-1 can substantially increase growth of pine stands over a 20 year rotation (Pritchett and Comerford, 1982; Allen et al., 1990). Phosphorus fertilization of Pinus radiata in New Zealand has also shown long-term effects on labile P pools in the soil which improved stand growth during the subsequent rotations (Ballard, 1978; Gentle et al., 1986). Identifying and quantifying the biologically available P pools in the soil environment will help foresters in making site-specific P fertilizer prescriptions. I examined soil phosphorus pools using the Hedley sequential fractionation procedure and Mehlich-3 soil tests in a long-term loblolly pine (Pinus taeda L.) fertilization trial from four sites in the Atlantic and Gulf Coastal Plains. After 22 years, fertilization effects were limited to the surface depths. Mehlich-3 extractable P was largest in the soil surface (0-10 cm) of the fertilized treatments plots. Hedley labile and moderately labile P pools were also largest in the soil surface and decreased with depth. Results from the Hedley fractionation procedure suggested that the Virginia site has a large pool of organic P in the soil surface. Organic P pools can represent 20-90% of the total P present in most mineral soils increasing with the age of the soil (Condron et al., 2005). This increase in organic P pool suggests that biological cycling becomes more important as the stand develops (Wells and Jorgensen 1975). I used solution 31P nuclear magnetic resonance (NMR) spectroscopy to characterize organic P extracted with NaOH-EDTA in the surface of a Paleaquults from coastal Virginia. Total NaOH-EDTA extractable P was significantly larger in the fertilized treatment. Concentrations ranged from 0.1 mg P L²-1 in the control plots to 5.1 mg P L²-1 in fertilized plots. The surface soils in both treatments were dominated by inorganic orthophosphate. Monoester P compounds were the only organic P compounds detected and were present in very low quantities. The significant increase of NaOH/EDTA extractable P in the soil surface of the VA site suggested there has been a beneficial long-term effect of fertilization similar to the observations from the Mehlich-3 soil test. Results from oxalate loading experiments on ligand exchangeable versus dissolvable P pools in the bulk soil suggested that the long-term effect of P fertilization increased oxalate dissolvable P pools. Plants and microbes have evolved a variety of mechanisms to increase P uptake in low P soil environments. These mechanisms include changes in root morphology and architecture, preferential root growth into high P microsites, the secretion of low-molecular-mass organic acids (LMMOA), and uptake via symbiotic relationships (Fox and Comerford, 1992b; Raghothama, 1999; Hinsinger, 2001; Raghothama, 2005). Results from soil samples taken from the ectomycorrhizal rhizosphere found that loblolly pine mycorrhizal roots modified the soil environment, possibly making recalcitrant P more available. In addition, the long-term effect of fertilization was a 396% increase in biologically available P. Fertilization increased loblolly pine volume growth by 57 m¹3 ha and increased the P content in the litter layer by 118%. After the stand was harvested and replanted, mineralization of the litter layer may also increase soil P pools. Results from this long-term fertilization experiment in the Coastal Plain province of Virginia have demonstrated that there has been a significant increase in soil (33.6 kg P ha²-1) and biologically available P pools (3.0 kg P ha²-1)."],"dc:description.degree":["Ph. D."],"dc:identifier.other":["etd-02202009-042129"],"dc:identifier.uri":["http://hdl.handle.net/10919/37386"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["rhizosphere","organic phosphorus","ectomycorrhiza","oxalate"],"dc:title":["Long-term Effects of Fertilization on Phosphorus Biogeochemical Pools in Forest Soils"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Forestry"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:18Z"}