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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #394951
Research Project: Development of Enhanced Tools and Management Strategies to Support Sustainable Agricultural Systems and Water Quality

Location: Grassland Soil and Water Research Laboratory

Title: Plant parameterization and APEXgraze model calibration and validation for U.S. land resource region H grazing lands

Author
item MEKI, MANYOWA - Texas Agrilife Research
item OSORIO-LEYTON, JAVIER - Texas Agrilife Research
item STEGLICH, EVELYN - Natural Resources Conservation Service (NRCS, USDA)
item Kiniry, James
item PROPATO, MARCO - Stone Environmental Consulting
item WINCHELL, MIKE - Stone Environmental Consulting
item RATHJENS, HENDRIK - Stone Environmental Consulting
item Angerer, Jay
item NORFLEET, LEE - Natural Resources Conservation Service (NRCS, USDA)

Submitted to: Agricultural Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2023
Publication Date: 3/16/2023
Citation: Meki, M.N., Osorio-Leyton, J., Steglich, E.M., Kiniry, J.R., Propato, M., Winchell, M., Rathjens, H., Angerer, J.P., Norfleet, L.M. 2023. Plant parameterization and APEXgraze model calibration and validation for U.S. land resource region H grazing lands. Agricultural Systems. 207. Article 103631. https://doi.org/10.1016/j.agsy.2023.103631.
DOI: https://doi.org/10.1016/j.agsy.2023.103631

Interpretive Summary: Some of the main resource concerns on grazing lands are soil erosion, water quality and conservation. Computer simulation models using daily climatic data can be used to assess management options. We parameterized, calibrated and validated the APEXgraze model. This model was developed from the APEX model and simulates conservation practices on grazing lands. With the high plant variability in grazing lands, APEXgraze was calibrated using plant functional groups (FGs). Sixty four FGs were incorporated into the model. These functional group parameters realistically simulated plant species growth dynamics. The model realistically simulated evapotranspiration and plant biomass. This demonstrated the potential of using APEXgraze and FGs to simulate grazing management practices to address natural resource concerns on grazing lands.

Technical Abstract: Soil erosion, water quality and conservation have been identified as primary resource concerns on grazing lands. Biophysical models driven by daily climatic variables can enable assessment of natural resource management options. We parameterized, calibrated and validated the APEXgraze model, an offshoot from the APEX model adapted to simulate the effects and benefits of conservation practices on grazing lands. Because of the high plant species variability in grazing lands, APEXgraze was calibrated using plant functional groups (FGs). A total of 64 FGs were identified and incorporated into the APEXgraze model. Overall, the FG parameters gave a good representation of the plant species growth dynamics, and model evaluation metrics indicated satisfactory performance by APEXgraze during calibration and validation against evapotranspiration data and biomass yields. The results presented here are a demonstration of the potential of using APEXgraze and FGs to simulate grazing management practices to address natural resource concerns on grazing lands.