Studies of the surface and subsurface fate and transport

of nitrogen and phosphorous from poultry litter

© 2000, 2001, D. Baker & D. Scott

  Poultry litter is often used and disposed, wittingly or not, as fertilizer. In the Mid-South and elsewhere, animal waste is becoming a detrimental addition to surface and ground waters. These web pages, papers and tutorials represent a continuing effort to understand and model the transformation and movement of organic and inorganic fertile materials in poultry litter from the surface of agricultural fields down to the ground water.

   This is a work in progress, albeit slowly. These pages should be considered drafts and preprints of current and past work. Hopefully, as the work progresses, and time and money permit, more will be added to this site, and existing material updated and improved. The dates on the topic links below indicate when the material was last updated. Some of the html files are lengthy and take longer than usual to download due to the large numbers of tutorial graphs and equations. Patience is its own reward.

Topics

• 11/21/2000 - Calibration to field data. A draft Word 97 document (not html) describing the calibration the flow code to 1990 and 1991 field data, using a unique minimal-parameterization approach, Fletcher-Reeves optimization and an objective function based on the probability that model estimates fit the mean values of replicate field sensor readings.
• 9/19/2000 - Soil data fitting. A draft description of how soil hydraulic saturation and conductivity data were fitted from field and laboratory data for a field of tall fescue in northwest Arkansas, with a downloadable DOS program for fitting saturation relation data with simulated annealing.
• 9/19/2000 - POULIT flow code. A draft description of the subsurface water flow modeling code in POULIT, with downloadable example files. Flow code only, no temperature or transport compenents. A good tutorial on the application of a second-order Runge-Kutta time stepping method to rapid infiltration
• 9/19/2000 - POULIT I/O specification. A draft description of the program variables, and input and output files.
• 9/13/1998 - Modeling the mineralization and volitilization of nitrogen in poultry litter applied to tall fescue. A draft paper by H.D. Scott, D.L. Baker, M.J. Cochran and J. Smartt. Primarily a description of the separation of surface litter decomposition mechanisms into separate numerical compartments. Uses the analogy of chemical processing tanks.
• 9/13/2000 - Map of the University of Arkansas Agricultural Research and Extension Center where the field experiments were performed that produced the data used here (farmap02.pdf 76k).

References

• Scott, H.D., A. Mauromoustakos and J.T. Gilmour. 1995. Fate of inorganic nitrogen and phosphorous in broiler litter applied to tall fescue, University of Arkansas Agricultural Experiment Station, Bulletin 947, Fayetteville, AR 72701, 55p.
• Thiesse, B.R., 1984, Variability of the physical properties of the Captina soils, M.S. Thesis, Department of Agronomy, University of Arkansas, Fayetteville, AR USA, 91 p.