Module 5: Phosphorus Storage and Release from P-impacted Soils

Lecture 1: Long-term contribution of phosphorus from agricultural lands: “legacy” P

View on YouTube

Describes P loss from Spodosols, explains the relationship between SPSC and water quality, and examines various P-impacted soils in the Lake Okeechobee Basin, with emphasis on what happens to P after a dairy is abandoned, what soil factors should be considered for sustainable dairy farming, and the role of the SPSC as a tool to indicate the amount of P that can be added before the soil becomes an environmental risk.

  • Graetz, D.A., and V.D. Nair. 1995. Fate of phosphorus in Florida Spodosols contaminated with cattle manure. Ecol. Eng. 5:163-181.
  • Nair, V.D., W.G. Harris, and D. Chakraborty. 2010. An Indicator for Risk of Phosphorus Loss from Sandy Soils. SL 333.
  • Nair, V.D. W.G. Harris, D. Chakraborty, and M. Chrysostome. 2010. Understanding Soil Phosphorus Storage Capacity. SL 336.
  • Nair, V.D., D.A. Graetz, and K.M. Portier. 1995. Forms of phosphorus in soil profiles from dairies of South Florida. Soil Sci. Soc. Am. J. 59:1244-1249

Lecture 2: Inorganic vs organic sources of P

View on YouTube

Describes how different P sources affect P storage and release from impacted soils, which in turn affects water quality of nearby water bodies. Discusses the relationship between manure components and P release, including P source characteristics such as P solubility that must be accounted for when evaluating P loss risk during land application of organic amendments. Details examples of P losses from different P sources and the relationships between the amounts of P leached and WSP and TP concentrations.

  • Harris, W.G., V.D. Nair, R.D. Rhue, and D.A. Graetz. 2007. Deliverable 2. Progress report on source materials characterization and implications for effects. Site-specific determination of soil capacity to assimilate or release P applied as manure, fertilizer, compost, or biosolids. Report to FDACS. Contract number 0061873. Tallahassee, FL.
  • Nair, V.D. and W.G. Harris. 2011. Phosphorus Sources and Risk Potential: Organic and Inorganic Fertilizers. SL 358.
  • Rew, T.J., D.A. Graetz, M.S. Josan, V.D. Nair, and W.G. Harris. 2007. Phosphorus Mobility from Organic and Inorganic Soil Amendments: Rainfall Simulation Studies. ASA/CSSA/SSSA 2007 International Annual Meetings. CD Rom Publication.

Lecture 3: Reduction of soil P loss through amendment additions

View on YouTube

Discusses how to reduce P loss from soils though addition of amendments, with a focus on water treatment residues (WTRs) and biochar amendments.

  • Dari, B. 2015. Predicting soil phosphorus loss and its potential remediation through biochar application. Ph.D. diss., University of Florida., Gainesville, Florida, USA.
  • Oladeji, O.O., G.A. O’Connor, J.B. Sartain, and V.D. Nair. 2007. Controlled Application Rate of Water Treatment Residual for Agronomic and Environmental Benefits. J Environ. Qual. 36:1715-1724.

Lecture 4: Natural and anthropogenic sources of P

View on YouTube

Examines differences in P loss risk from natural and anthropogenic sources of P (e.g., dairies or inorganically-fertilized soils), paying particular attention to some of the other components of the P source.

  • Chakraborty, D., V.D. Nair, and W.G. Harris. 2012. Compositional differences between Alaquods and Paleudults affecting phosphorus sorption-desorption behavior. Soil Sci. 177:188–196.
  • Osborne, T.Z., V.D. Nair, L.R. Ellis, D. Chakraborty, W.G Harris, and K. R. Reddy. 2012. Kissimmee River Sediment and Floodplain Soil Nutrient Assessment. Final Report to the South Florida Water Management District, West Palm Beach, FL.

Lecture 5: Risk assessment of wetland soils

View on YouTube

Discusses phosphorus storage and release from P-impacted wetland soils and describes conventional risk assessment techniques and the use of SPSC for wetland soils.

  • Nair, V.D., M. W. Clark, and K.R. Reddy. 2015. Evaluation of legacy phosphorus storage and release from wetland soils. J. Environ. Qual. 44: 1956 – 1964. doi:10.2134/jeq2015.03.0154.
  • Nair, V.D., and K.R. Reddy. 2013. Phosphorus sorption and desorption in wetland soils. pp 667 – 678. In: DeLaune, R., Reddy, K.R., Richardson, C.J., and Megonigal, P. (ed). Methods on biogeochemistry of wetlands. Soil Science Society of America Publication.
  • Reddy, K.R., S. Grunwald, V.D. Nair, and Y. Wang, 2006. Baseline Characterization of the Taylor Creek Pilot Storm Treatment Areas (STA) in the Lake Okeechobee Watershed, West Palm Beach, Florida: South Florida Water Management.