Development and evaluation of a phosphorus (P) module in RZWQM2 for phosphorus management in agricultural fields

Authors: SADHUKHAN, D - McGill University - Canada; QI, Z - McGill University - Canada; ZHANG, T - Agriculture And Agri-Food Canada; TAN, C - Agriculture And Agri-Food Canada; Ma, Liwang; ANDALES, A - Colorado State University

Submitted to: Journal of Environmental Modeling and Software
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2018
Publication Date: 12/19/2018
Citation: Sadhukhan, D., Qi, Z., Zhang, T.Q., Tan, C.S., Ma, L., Andales, A.A. 2018. Development and evaluation of a phosphorus (P) module in RZWQM2 for phosphorus management in agricultural fields. Journal of Environmental Modeling and Software. 113:48-58. https://doi.org/10.1016/j.envsoft.2018.12.007.
DOI: https://doi.org/10.1016/j.envsoft.2018.12.007

Interpretive Summary: Phosphorus (P) from manure and fertilizer may be lost to surface runoff and tile drainage, which eventually reaches fresh water bodies and causes eutrophication. However, there are few system models that can estimate P loss from tile drained agricultural fields. In this study, a P-module was developed based on the most recent scientific findings on the fate and transport of P from agricultural fields. The new P-module was then incorporated into the Root Zone Water Quality Model (RZWQM2). The combined RZWQM2-P model was evaluated for its performance on simulating both dissolved reactive phosphorus (DRP) and particulate phosphorus (PP) loss in surface runoff and subsurface drainage in a tile drained, inorganic P fertilizer treated, corn-soybean field located near Woodslee, Ontario from June 2008 to Dec 2012. Simulation results showed that the model was capable of simulating DRP and PP losses in both surface runoff and tile drainage. Its performance was better than that of the ICECREAM model, especially for P loss in tile drainage. This study concluded that the RZWQM2-P model is a promising tool for P management in subsurface drained fields although further test is needed to assess this model under different fertilization (manure), soil, climate, and crop conditions.

Technical Abstract: Phosphorus (P) applied in agricultural fields in terms of manure and fertilizer may be lost through surface runoff and tile drainage, which eventually reaches fresh water bodies to cause eutrophication. However, there are few system models that can simulate P loss from tile drained agricultural fields. In this study, a P-module was developed based on most recent scientific findings available regarding the fate and transport of P from agricultural fields, and was then incorporated into the Root Zone Water Quality Model (RZWQM2), a field scale agricultural management model. The developed P model simulates both dissolved reactive phosphorus (DRP) and particulate phosphorus (PP) loss through surface runoff and tile drainage. The RZWQM2-P model was evaluated for its performance in simulating P losses (DRP and PP) through surface runoff and subsurface drainage in a tile drained, inorganic P fertilizer treated, corn-soybean field located near Woodslee, Ontario from June 2008 to Dec 2012. The data from the year 2008 to 2010 were used to calibrate the model while the data of 2011 and 2012 were used to validate the model. The evaluation revealed that the developed P model was capable of simulating DRP and PP losses through both surface runoff and tile drainage with Nash-Sutcliffe model efficiency coefficient >0.65, percentage of biases within 5% and index of agreement > 0.75. Its performance was better than that of the ICECREAM model particularly in simulation of P loss in tile drainage. This study concluded that the RZWQM2-P model is a promising tool for P management in particular for subsurface drained field although further test is needed to assess this model under different fertilization (manure), soil, climate, and crop conditions.