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1. Evaluating the APEX model for alternative cow-calf grazing management strategies in Central Texas
- Author:
- R.D. Harmel, et al. ; Q.X. Fang; L. Ma; P.N.S. Bartling; J.D. Derner; J. Jeong; J.R. Williams; R.B. Boone; Show all 8 Authors
- Source:
- Agricultural systems 2022 v.195 pp. 103287
- ISSN:
- 0308-521X
- Subject:
- aboveground biomass; agricultural policy; algorithms; calves; data collection; energy; feed intake; hay; hydrology; models; soil; vegetation; weight gain; Texas
- Abstract:
- ... Simulation tools are increasingly used to inform grazing management decisions by assessing livestock performance, as well as environmental and economic impacts. Ability to represent the grazing of multiple pastures (i.e., paddocks) that differ in soil, hydrology, vegetation, and management is critical for reliable grazing management decision support.The main objectives of this study were to: 1) mo ...
- Handle:
- 10113/7530340
- DOI:
- 10.1016/j.agsy.2021.103287
- https://doi.org/10.1016/j.agsy.2021.103287
- Author:
- R.D. Harmel, et al. ; Cheng G.; L. Ma; J.D. Derner; D.J. Augustine; P.N.S. Bartling; Q.X. Fang; J.R. Williams; C.J. Zilverberg; R.B. Boone; Q. Yu; Show all 11 Authors
- Source:
- Rangeland ecology & management 2022 v.82 no. pp. 1-11
- ISSN:
- 1550-7424
- Subject:
- administrative management; animal performance; dry matter intake; forage; herds; issues and policy; models; range management; rangelands; stakeholders; uncertainty; weight gain; yearlings
- Abstract:
- ... Rotational grazing studies have produced mixed results related to animal performance (weight gain), which has contributed to producer uncertainty regarding grazing management decisions. To enhance decision-support for producers, we improved algorithms in the Agricultural Policy/Environmental eXtender (APEX) model to better represent cattle weight gain in real-world rangeland conditions under two g ...
- Handle:
- 10113/7664766
- DOI:
- 10.1016/j.rama.2022.01.005
- https://doi.org/10.1016/j.rama.2022.01.005
- Author:
- R.D. Harmel, et al. ; A. Hertzberger; C.M. Pittelkow; L.E. Christianson; Show all 4 Authors
- Source:
- Agricultural water management 2019 v.216 pp. 113-117
- ISSN:
- 0378-3774
- Subject:
- United States Environmental Protection Agency; Weibull statistics; arithmetics; databases; drainage; drainage systems; eutrophication; freshwater; land use; maximum contaminant level; nitrate nitrogen; nitrogen; nutrient content; nutrient transport; pollution; probability; reactive phosphorus; surface water
- Abstract:
- ... Artificially drained agricultural systems can be a primary contributor of non-point source nitrogen (N) and phosphorus (P) pollution to ground and surface waters; therefore, it is imperative to understand the mechanisms responsible for nutrient transport from this land use. Here, 79 drainage nutrient-related studies were used to compile 1564 site-years of agricultural drainage N and P concentratio ...
- DOI:
- 10.1016/j.agwat.2019.01.021
- https://doi.org/10.1016/j.agwat.2019.01.021
- Author:
- R.D. Harmel, et al. ; G. Cheng; L. Ma; J.D. Derner; D.J. Augustine; P.N.S. Bartling; Q.X. Fang; J.R. Williams; C.J. Zilverberg; R.B. Boone; D. Hoover; Q. Yu; Show all 12 Authors
- Source:
- Agricultural systems 2021 v.191 pp. 103139
- ISSN:
- 0308-521X
- Subject:
- adaptive management; agricultural policy; animals; ecosystems; forage; forage production; herds; pastures; perennial grasses; range management; rangelands; stakeholders; warm season; water stress; Western United States
- Abstract:
- ... Understanding how grazing management decisions influence the productivity and composition of rangeland plant communities is essential for the development of effective strategies to sustainably produce multiple ecosystem goods and services. Informed with experimental measurements, simulation models can advance our understanding and stewardship of rangeland ecosystems.Our main objective was to evalu ...
- DOI:
- 10.1016/j.agsy.2021.103139
- https://doi.org/10.1016/j.agsy.2021.103139
- Author:
- R.D. Harmel, et al. ; L.E. Christianson; Show all 2 Author
- Source:
- Agricultural water management 2015 v.159 pp. 277-289
- ISSN:
- 0378-3774
- Subject:
- administrative management; agriculture; agronomy; atmospheric precipitation; biofuels; crop yield; cropping systems; databases; drainage; drainage systems; drainage water; energy crops; environmental impact; farming systems; fiber crops; food crops; journals; plant fibers; pollution load; textile fibers; tillage; water quality; North America
- Abstract:
- ... As agriculture in the 21st century is faced with increasing pressure to reduce negative environmental impacts while continuing to efficiently produce food, fiber, and fuel, it becomes ever more important to reflect upon more than half a century of drainage water quality research to identify paths forward. This work provided a quantitative review of the water quality and crop yield impacts of artif ...
- Datasets:
- Measured Annual Nutrient loads from AGricultural Environments (MANAGE) database
- Handle:
- 10113/61281
- DOI:
- 10.1016/j.agwat.2015.06.021
- https://doi.org/10.1016/j.agwat.2015.06.021
- Author:
- R.D. Harmel, et al. ; L.F. Gregory; R. Karthikeyan; J.A. Aitkenhead-Peterson; T.J. Gentry; K.L. Wagner; Show all 6 Authors
- Source:
- Water research 2017 v.126 pp. 442-449
- ISSN:
- 0043-1354
- Subject:
- Escherichia coli; algae; aquatic environment; bacteria; decision making; fate and transport models; indicator species; plate count; pollution load; raceways; sediments; streams; water quality; Texas
- Abstract:
- ... Understanding fecal indicator bacteria persistence in aquatic environments is important when making management decisions to improve instream water quality. Routinely, bacteria fate and transport models that rely on published kinetic decay constants are used to inform such decision making but may not adequately represent instream conditions. The objective of this work was to evaluate bacterial resp ...
- DOI:
- 10.1016/j.watres.2017.09.043
- https://doi.org/10.1016/j.watres.2017.09.043
- Author:
- R.D. Harmel, et al. ; J.M. Hathaway; K.L. Wagner; J.E. Wolfe; R. Karthikeyan; W. Francesconi; D.T. McCarthy; Show all 7 Authors
- Source:
- Journal of hydrology 2016 v.534 pp. 524-533
- ISSN:
- 0022-1694
- Subject:
- Escherichia coli; birds; bridges (infrastructure); decision making; fate and transport models; indicator species; issues and policy; microbial contamination; monitoring; nesting; nutrients; quality control; sediments; stormwater; stream flow; streams; surface water; uncertainty; uncertainty analysis
- Abstract:
- ... Microbial contamination of surface waters, a substantial public health concern throughout the world, is typically identified by fecal indicator bacteria such as Escherichia coli. Thus, monitoring E. coli concentrations is critical to evaluate current conditions, determine restoration effectiveness, and inform model development and calibration. An often overlooked component of these monitoring and ...
- Handle:
- 10113/61984
- DOI:
- 10.1016/j.jhydrol.2016.01.040
- https://doi.org/10.1016/j.jhydrol.2016.01.040
- Author:
- R.D. Harmel, et al. ; P.M. Allen; J.A. Dunbar; J.G. Arnold; Show all 4 Authors
- Source:
- Journal of hydrology 2011 v.407 no.1-4 pp. 1-11
- ISSN:
- 0022-1694
- Subject:
- drought; erodibility; highlands; landscapes; monitoring; planning; prairies; rain; rain intensity; runoff; sediment transport; sediment yield; sediments; water reservoirs; water supply; watersheds; Texas
- Abstract:
- ... The 1950s drought severely impacted a 1.1millionkm² area in the central US. This drought, along with the famous 1930s drought, was among the most severe of the 20th century for large areas and is the drought of record for water supply planning in Texas. At the USDA-ARS Riesel Watersheds during the drought, average annual rainfall was reduced 27%, which produced 75% less runoff and 35% less sedimen ...
- Handle:
- 10113/54534
- DOI:
- 10.1016/j.jhydrol.2011.04.039
- https://doi.org/10.1016/j.jhydrol.2011.04.039