Comparing an Annual and a Daily Time-Step Model for Predicting Field-Scale Phosphorus Loss.
J Environ Qual
; 46(6): 1314-1322, 2017 Nov.
Article
in En
| MEDLINE
| ID: mdl-29293849
ABSTRACT
A wide range of mathematical models are available for predicting phosphorus (P) losses from agricultural fields, ranging from simple, empirically based annual time-step models to more complex, process-based daily time-step models. In this study, we compare field-scale P-loss predictions between the Annual P Loss Estimator (APLE), an empirically based annual time-step model, and the Texas Best Management Practice Evaluation Tool (TBET), a process-based daily time-step model based on the Soil and Water Assessment Tool. We first compared predictions of field-scale P loss from both models using field and land management data collected from 11 research sites throughout the southern United States. We then compared predictions of P loss from both models with measured P-loss data from these sites. We observed a strong and statistically significant ( < 0.001) correlation in both dissolved (ρ = 0.92) and particulate (ρ = 0.87) P loss between the two models; however, APLE predicted, on average, 44% greater dissolved P loss, whereas TBET predicted, on average, 105% greater particulate P loss for the conditions simulated in our study. When we compared model predictions with measured P-loss data, neither model consistently outperformed the other, indicating that more complex models do not necessarily produce better predictions of field-scale P loss. Our results also highlight limitations with both models and the need for continued efforts to improve their accuracy.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Phosphorus
/
Models, Theoretical
Type of study:
Prognostic_studies
/
Risk_factors_studies
Country/Region as subject:
America do norte
Language:
En
Journal:
J Environ Qual
Year:
2017
Document type:
Article