| Title: | Simulating behavioral heterogeneity in watershed models: A systematic review of fertilizer use in SWAT studies |
| Authors: | Arrueta, L., D. Jackson-Smith and M. Kalcic |
| Year: | 2022 |
| Journal: | Journal of Soil and Water Conservation |
| Volume (Issue): | 77(3) |
| Pages: | 249-260 |
| Article ID: | |
| DOI: | 10.2489/jswc.2022.00055 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | review/history |
| Primary Application Category: | BMP and/or cropping system assessment |
| Secondary Application Category: | bibliometric analysis |
| Watershed Description: | None |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Nonpoint source pollution is the primary cause of reduced water quality in the
United States. This pollution results primarily from fertilizer and manure application in farmland.
One of the hydrological models most widely used to predict the effect of nitrogen (N)
and phosphorus (P) fertilizer application on nutrient loadings is the Soil and Water Assessment
Tool (SWAT). While important advances have been made to improve the representation of
biophysical processes within SWAT, modelers often fail to capture the complexity of human
land management behaviors. Meanwhile, decades of social science research have demonstrated
that farmers are not a homogeneous group, but rather exhibit complex and diverse
behaviors. In this paper we present a systematic review of recently published papers that use
SWAT to document how the modeling community typically represents fertilizer application
behaviors. We compare these representations with findings from recent farmer surveys that
captured information about fertilizer application rates. We found that most SWAT model
applications assume that farmer field management behaviors are relatively homogeneous (e.g.,
all farmers behave in the same way), and that farmers generally apply fertilizer using rational
agronomic or economic criteria. These simplifying assumptions conflict with the reality of
farmers’ fertilizer behavior. Farmer surveys in Minnesota and Ohio show considerable variability
in N and P fertilizer application rates on corn (Zea mays L.) fields following soybeans
(Glycine max [L.] Merr.). The disconnect between SWAT modeling approaches and results
of farmer surveys point to opportunities to better represent the heterogeneity of farmers’
fertilizer behavior in SWAT and other hydrologic models, which could improve our ability
to link changes in land use and management to water quality and increase the effectiveness of
conservation program interventions. |
| Language: | English |
| Keywords: | conservation, farmer behavior, fertilizer use, Soil and Water Assessment Tool (SWAT), water quality—watershed modeling |