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Dissolving uncertainty: A comprehensive evaluation of dissolved P in tile drainage

As major phosphorus-related water impairments continue to generate headlines and stir regulatory interest, there is an increasing need to better understand factors impacting phosphorus (P) transported from areas where agriculture is heavily underpinned by tile drainage. Substantial opportunities to reduce Illinois’ point-source P loads exist, but the agricultural sector will nevertheless need to play a role in meeting P reduction targets.

This work, funded starting in 2016 by the Illinois Nutrient Research and Education Council, builds on the momentum of the previously established and publicly available “Measured Annual Nutrient loads from AGricultural Environments” (MANAGE) database to answer questions about how and why P is transported in subsurface drainage. Original support from the 4Rs Research Fund in 2014 led to the development of a “Drain Load” component in the database. In 2016-2018, more than 400 publications were reviewed and a total of 1,564 site-years were entered into a new MANAGE “Drain Concentration” database component. Drainage dissolved phosphorus and nitrate concentrations compiled in the database have been analyzed against variables including crop type, location, soil type, nutrient management, and tillage factors (Figure 1).

Christianson Hertzberger UIUC_2018_Draft of MANAGE Drain Conc

Figure 1. Draft characteristics of the MANAGE Drain Concentration database

Dr. R. Daren Harmel, USDA ARS, is a collaborator on this work.  Mr. Allan Hertzberger is the graduate student project lead.

Project results were previously presented at the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America 2017 International Annual Meeting, “Managing Global Resources for a Secure Future,” on Oct. 22-25, 2017, in Tampa, Florida (Paper #105221 and #105220). Mr. Hertzberger defends his thesis on Feb. 6, 2018 in the Department of Crop Sciences at the University of Illinois. 

Peer-reviewed outputs from these projects include:

  1. Christianson, L., and R. D. Harmel. 2015. The MANAGE Drain Load database: Review and compilation of more than fifty years of North American drainage nutrient studies. Ag. Water Manage. 159:277-289.
  2. Christianson, L., and R. D. Harmel. 2015. 4R water quality impacts: An assessment and synthesis of forty years of drainage nitrogen losses. J. Environ. Qual. 44(6):1852-1860.
  3. Christianson, L., R. D. Harmel, D. Smith, M. Williams, and K. King. 2016. Assessment and synthesis of 50 years of published drainage phosphorus losses. J. Environ. Qual. doi:10.2134/jeq2015.12.0593.
  4. Harmel, R.D., L.E. Christianson, M. McBroom, D.R. Smith, and K.D. Higgs. 2016 (Accepted). Expansion of the MANAGE database with forest and drainage studies. J. Am. Water Res.  Association.


The MANAGE database is published via the National Agricultural Library: DOI: 10.15482/USDA.ADC/1372907