Farmers' investment in more efficient irrigation systems represents a primary adaptation strategy when confronting climate change. However, the regional benefits of these investments and their influence on the conflicting demands... more
Farmers' investment in more efficient irrigation systems represents a primary adaptation strategy when confronting climate change. However, the regional benefits of these investments and their influence on the conflicting demands among different water dependent stakeholders for intensely irrigated regions remains an open question. Using the Pacific Northwest of the United States as an illustrative region of focus, we show that higher irrigation efficiency has diverse effects across stakeholders that are contingent on many local climatic, institutional and infrastructural factors such as the availability of water storage, the location of hydropower generators, and water rights. These complexities limit simple abstractions of irrigation efficiency as broader policy challenge and are central to its inclusion within the class of "wicked problems". Additionally, we argue that the widely used rebound effect concept, which implicitly discourages irrigation efficiency supporting policies, should not be assumed to fully capture the nuances of the complex suite of regional impacts that emerge from irrigation efficiency investments. Consequently, the evaluation of irrigation efficiency investments requires a broader framing across a diversity of perspectives. policies and actions that are pluralistic, context-specific, and closely engage various groups of stakeholders in the policymaking process.
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With the decline of operational river gauges monitoring sediments, a viable means of quantifying sediment transport is needed. In this study, we address this issue by applying relationships between hydraulic geometry of river channels,... more
With the decline of operational river gauges monitoring sediments, a viable means of quantifying sediment transport is needed. In this study, we address this issue by applying relationships between hydraulic geometry of river channels, water discharge, water-leaving surface reflectance (SR), and suspended sediment concentration (SSC) to quantify sediment discharge with the aid of space-based observations. We examined 5490 Landsat scenes to estimate water discharge, SSC, and sediment discharge for the period from 1984 to 2017 at nine gauging sites along the Upper Mississippi River. We used recent advances in remote sensing of fluvial systems, such as automated river width extraction, Bayesian discharge inference with at-many-stations hydraulic geometry (AMHG), and SSC-SR regression models. With 621 Landsat scenes available from all the gauging sites, the results showed that the water discharge and SSC retrieval from Landsat imagery can yield reasonable sediment discharge estimates al...
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As shown in Figure 1, NT management leaves residue biomass on the ground, while CT mostly incorporates these residues into the soil. Residue biomass is partially incorporated in RT, depending on tillage intensity. Thus, a key difference... more
As shown in Figure 1, NT management leaves residue biomass on the ground, while CT mostly incorporates these residues into the soil. Residue biomass is partially incorporated in RT, depending on tillage intensity. Thus, a key difference between CT and RT practices is that the former redistributes residues within the soil depth affected by tillage, while the latter concentrates residue accumulation on the topsoil. In addition, NT and RT reduce disturbance of the tilled soil layer, which reduces oxidation of SOC and carbon dioxide (CO2) emissions.
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This study evaluated evapotranspiration (ET) estimated using the Earth Engine Evapotranspiration Flux (EEFlux), an automated version of the widely used Mapping Evapotranspiration at High Spatial Resolution with Internalized Calibration... more
This study evaluated evapotranspiration (ET) estimated using the Earth Engine Evapotranspiration Flux (EEFlux), an automated version of the widely used Mapping Evapotranspiration at High Spatial Resolution with Internalized Calibration (METRIC) model, via comparison with ET measured using eddy covariance flux towers at two U.S. sites (St. John, WA, USA and Genesee, ID, USA) and for two years (2018 and 2019). Crops included spring wheat, winter pea, and winter wheat, all grown under rainfed conditions. The performance indices for daily EEFlux ET estimations combined for all sites and years dramatically improved when the cold pixel alfalfa reference ET fraction (ETrF) in METRIC was reduced from 1.05 (typically used for irrigated crops) to 0.85, with further improvement when the periods of early growth and canopy senescence were excluded. Large EEFlux ET overestimation during crop senescence was consistent in all sites and years. The seasonal absolute departure error was 51% (cold pixe...
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Site-specific irrigation management for perennial crops such as grape requires water use assessments at high spatiotemporal resolution. In this study, small unmanned-aerial-system (UAS)-based imaging was used with a modified mapping... more
Site-specific irrigation management for perennial crops such as grape requires water use assessments at high spatiotemporal resolution. In this study, small unmanned-aerial-system (UAS)-based imaging was used with a modified mapping evapotranspiration at high resolution with internalized calibration (METRIC) energy balance model to map water use (UASM-ET approach) of a commercial, surface, and direct-root-zone (DRZ) drip-irrigated vineyard. Four irrigation treatments, 100%, 80%, 60%, and 40%, of commercial rate (CR) were also applied, with the CR estimated using soil moisture data and a non-stressed average crop coefficient of 0.5. Fourteen campaigns were conducted in the 2018 and 2019 seasons to collect multispectral (ground sampling distance (GSD): 7 cm/pixel) and thermal imaging (GSD: 13 cm/pixel) data. Six of those campaigns were near Landsat 7/8 satellite overpass of the field site. Weather inputs were obtained from a nearby WSU-AgWeatherNet station (1 km). First, UASM-ET estim...
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Water scarcity is one of the most important problems of agroecosystems in Mediterranean and semiarid areas, especially for species such as vineyards that largely depend on irrigation. Actual evapotranspiration (ET) is a variable that... more
Water scarcity is one of the most important problems of agroecosystems in Mediterranean and semiarid areas, especially for species such as vineyards that largely depend on irrigation. Actual evapotranspiration (ET) is a variable that represents water consumption of a crop, integrating climate and biophysical variables. Actual evapotranspiration models based on remote sensing data from visible bands of Sentinel-2, including Penman-Monteith–Stewart (RS-PMS) and Penman-Monteith–Leuning (RS-PML), were evaluated at different temporal scales in a Cabernet Sauvignon vineyard (Vitis vinifera L.) located in central Chile, and their performance compared with independent ET measurements from an eddy covariance system (EC) and outputs from models based on thermal infrared data from Landsat 7 and Landsat 8, such as Mapping EvapoTranspiration with high Resolution and Internalized Calibration (METRIC) and Priestley–Taylor Two-Source Model (TSEB-PT). The RS-PMS model showed the best goodness of fit...
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Geospatial crop water use mapping is critical for field-scale site-specific irrigation management. Landsat 7/8 satellite imagery with a widely adopted METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration)... more
Geospatial crop water use mapping is critical for field-scale site-specific irrigation management. Landsat 7/8 satellite imagery with a widely adopted METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration) energy balance model (LM approach) estimates accurate evapotranspiration (ET) but limits field-scale spatiotemporal (30 m pixel−1, ~16 days) mapping. A study was therefore conducted to map actual ET of commercially grown irrigated-field crops (spearmint, potato, and alfalfa) at very high-resolution (7 cm pixel−1). Six small unmanned aerial system (UAS)-based multispectral and thermal infrared imagery campaigns were conducted (two for each crop) at the same time as the Landsat 7/8 overpass. Three variants of METRIC model were used to process the UAS imagery; UAS-METRIC-1, -2, and -3 (UASM-1, -2, and -3) and outputs were compared with the standard LM approach. ET root mean square differences (RMSD) between LM-UASM-1, LM-UASM-2, and LM-UASM-3 were in the...
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A recent innovation in assessment of climate change impact on agricultural production has been to use crop multi model ensembles (MMEs). These studies usually find large variability between individual models but that the ensemble mean... more
A recent innovation in assessment of climate change impact on agricultural production has been to use crop multi model ensembles (MMEs). These studies usually find large variability between individual models but that the ensemble mean (e-mean) and median (e-median) often seem to predict quite well. However few studies have specifically been concerned with the predictive quality of those ensemble predictors. We ask what is the predictive quality of e-mean and e-median, and how does that depend on the ensemble characteristics. Our empirical results are based on five MME studies applied to wheat, using different data sets but the same 25 crop models. We show that the ensemble predictors have quite high skill and are better than most and sometimes all individual models for most groups of environments and most response variables. Mean squared error of e-mean decreases monotonically with the size of the ensemble if models are added at random, but has a minimum at usually 2-6 models if bes...
Research Interests: Mathematics, Environmental Science, Statistics, Climate Change, Agriculture, and 13 moreGlobal Change Biology, Medicine, Biological Sciences, Triticum Aestivum, Environmental Sciences, Cambio climático, Theoretical Models, Triticum, Ensemble Forecasting, Simulation Models, Environment, Crop models, and Mean Squared Error
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Research Interests: Law, Environmental Law, Climate Change, Ecosystem Services, Corporate Governance, and 15 morePolicy, Adaptation, Human Capital, Environmental Planning, Multidisciplinary, Policy Change, Global Warming, Global change, Environmental Resource Management, Political Economy of Climate Change, Climatic Change, Climate change impact, Climate impacts, Climate Warming, and Environment
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Research Interests: Environmental Science, Climate Change, Hydrology, Irrigation, Adaptation, and 15 moreAgriculture, Multidisciplinary, Human Right to Water, Climate Models, Policy Planning, Climatic Change, Climate Model, Climate change impact, Economic Loss, Economic Impacts, Irrigated Agriculture, ENVIRONMENTAL SCIENCE AND MANAGEMENT, Cumulant, hydrologic model, and Drainage basin
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Research Interests: Computer Science, Relational Database, Agronomy, Cropping Systems, Crop management, and 13 moreSpatial Variability, Data Model, Farming Systems, Precision Farming, Relational databases, Entity Relationship Diagram, Simulation Models, Database, Sustainability, Simulation Model, Cropping System, Simulation Modeling, and Cropping
Research Interests: Mathematics, Earth Sciences, Environmental Science, Biophysics, Biomass, and 15 moreEcophysiology, Biometeorology, Biological Sciences, Air, Vapor Pressure, Crop Production, Atmospheric Pressure, Transpiration, Water Use, Gramineae, Field Data, Vapor Pressure Deficit, Cumulant, Hordeum vulgare L, and Triticum aestivum L
ABSTRACT This paper discusses the estimated impact of climate warming on irrigated crops grown in the Yakima Valley of Washington State, both at today's concentration of CO2 and at 560 ppm, which is roughly double the... more
ABSTRACT This paper discusses the estimated impact of climate warming on irrigated crops grown in the Yakima Valley of Washington State, both at today's concentration of CO2 and at 560 ppm, which is roughly double the pre-industrial level and also approximately equal to the CO2 component of an equivalent doubling of today's level. The integrated assessment involves traditional crop modeling using the CropSyst model, but also discusses impacts for crops where models are not currently available, impacts on farm profitability, and impacts on the regional economy (with and without impacts on food processing) using the IMPLAN model. Two key climate questions concern the impact of climate change on relative humidity (which strongly regulates water demand) and on future availability of water to fulfill junior water rights. At roughly constant relative humidity and modest changes in water availability, the regional economic impact is positive. For severe changes in water availability, the regional impact is negative.
Research Interests: Environmental Science, Climate Change, Irrigation, Water Availability, Integrated assessment, and 15 moreRegional Economics, Food Processing, Travel Management and Tour Operations, Water Cycle, Production economics, Water Supply, Water Demand, Profitability, Crop Production, Human Right to Water, Relative Humidity, Regional Economy, Washington State, Climate Warming, and Crop Model
Research Interests: Environmental Science, United States, Pacific Northwest, THERMAL DIFFUSIVITY, Reduced Tillage, and 15 moreWater Use, Soil Temperature, Tillage, Mediterranean Climate, Water Content, Bulk Density, Field Data, Soil Water Content, Soil Water, Cropping System, Crop Residue, Other Engineering, Triticum aestivum L, Modeling Tool, and Soil Depth
Research Interests: Agronomy, Biology, Canopy, Crop Science, Field Experiment, and 15 moreNitrogen, Cultivar, Life Cycle, Hordeum vulgare, Poaceae, Solar radiation, Aboveground biomass, Irradiance, Management Practice, Gramineae, Photosynthetic Rate, Radiation Use Efficiency, Seeding, Solar Irradiance, and Plant density
An important aspect that determines the ability of crop growth models to predict growth and yield is their ability to predict the rate of water consumption or evapotranspiration (ET) of the crop, especially for rain-fed crops. If, for... more
An important aspect that determines the ability of crop growth models to predict growth and yield is their ability to predict the rate of water consumption or evapotranspiration (ET) of the crop, especially for rain-fed crops. If, for example, the predicted ET rate is too high, the simulated crop may exhaust its soil water supply before the next rain event, thereby causing growth and yield predictions that are too low. In a prior inter-comparison among maize growth models, ET predictions varied widely, but no observations of actual ET were available for comparison. Therefore, another study has been initiated under the umbrella of AgMIP (Agricultural Model Inter-Comparison and Improvement Project). This time observations of ET using the eddy covariance technique from an 8-year-long experiment conducted at Ames, IA are being used as the standard. Simulation results from 29 models have been completed. In the first “blind” phase for which only weather, soils, and management information ...
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Managing shared data is becoming increasingly important as we move towards an open data world. For sharable data to be actionable, it needs to be FAIR: findable, accessible, interoperable and re-usable. In applied interdisciplinary... more
Managing shared data is becoming increasingly important as we move towards an open data world. For sharable data to be actionable, it needs to be FAIR: findable, accessible, interoperable and re-usable. In applied interdisciplinary research, data from many different sources are used. Socio-economic data is often referred to as being of relatively low quality. In part, this is due to a lack of standardization. Socio-economic data is messy. Data sets tend to be a mix of structured semi-structured, and unstructured data. The community of practice on socio-economic data (#CoP_SED) , which is part of the CGIAR Platform for Big Data in Agriculture aims at providing the tools to make socioeconomic data FAIR. In this presentation, we will address some of the latest developments in managing actionable open data, touching on issues such as ontologies, metadata schemas, key indicators, data curation and confidentiality. This is ongoing work, which has the potential of revolutionizing the way w...
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Wheat grain protein concentration is an important determinant of wheat quality for human nutrition that is often overlooked in efforts to improve crop production. We tested and applied a 32-multi-model ensemble to simulate global wheat... more
Wheat grain protein concentration is an important determinant of wheat quality for human nutrition that is often overlooked in efforts to improve crop production. We tested and applied a 32-multi-model ensemble to simulate global wheat yield and quality in a changing climate. Potential benefits of elevated atmospheric CO concentration by 2050 on global wheat grain and protein yield are likely to be negated by impacts from rising temperature and changes in rainfall, but with considerable disparities between regions. Grain and protein yields are expected to be lower and more variable in most low-rainfall regions, with nitrogen availability limiting growth stimulus from elevated CO . Introducing genotypes adapted to warmer temperatures (and also considering changes in CO and rainfall) could boost global wheat yield by 7% and protein yield by 2%, but grain protein concentration would be reduced by -1.1 percentage points, representing a relative change of -8.6%. Climate change adaptation...
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Nature Plants 3, 17102 (2017); published online 17 July 2017; corrected online 27 September 2017.
Increasing the accuracy of crop productivity estimates is a key element in planning adaptation strategies to ensure global food security under climate change. Process-based crop models are effective means to project climate impact on crop... more
Increasing the accuracy of crop productivity estimates is a key element in planning adaptation strategies to ensure global food security under climate change. Process-based crop models are effective means to project climate impact on crop yield, but have large uncertainty in yield simulations. Here, we show that variations in the mathematical functions currently used to simulate temperature responses of physiological processes in 29 wheat models account for >50% of uncertainty in simulated grain yields for mean growing season temperatures from 14 °C to 33 °C. We derived a set of new temperature response functions that when substituted in four wheat models reduced the error in grain yield simulations across seven global sites with different temperature regimes by 19% to 50% (42% average). We anticipate the improved temperature responses to be a key step to improve modelling of crops under rising temperature and climate change, leading to higher skill of crop yield projections.
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A potato crop multi-model assessment was conducted to quantify variation among models and evaluate responses to climate change. Nine modeling groups simulated agronomic and climatic responses at low- (Chinoli, Bolivia and Gisozi, Burundi)... more
A potato crop multi-model assessment was conducted to quantify variation among models and evaluate responses to climate change. Nine modeling groups simulated agronomic and climatic responses at low- (Chinoli, Bolivia and Gisozi, Burundi) and high- (Jyndevad, Denmark and Washington, United States) input management sites. Two calibration stages were explored, partial (P1), where experimental dry matter data were not provided, and full (P2). The median model ensemble response outperformed any single model in terms of replicating observed yield across all locations. Uncertainty in simulated yield decreased from 38% to 20% between P1 and P2. Model uncertainty increased with inter-annual variability, and predictions for all agronomic variables were significantly different from one model to another (p < 0.001). Uncertainty averaged 15% higher for low- versus high- input sites, with larger differences observed for evapotranspiration (ET), nitrogen uptake, and water use efficiency as com...
Research Interests: Environmental Science, Climate Change, Biomass, Crop Modeling, Bolivia, and 14 moreGlobal Change Biology, Climate Change Impacts, Potato, Biological Sciences, Denmark, Environmental Sciences, Potatoes, Crops, Climate Change and Food Security, Washington, Theoretical Models, Solanum Tuberosum, Crop Ecophysiology, and Simulation Models
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... REFERENCES. 1. Alva, AK 2004. Effects of pre-plant and in-season nitrogen management practices on tuber yield and quality of two potato cultivars. J. Veg. ... Oct1999 . Edited by: Tomer, M., Robinson, M. and Gielen, G. pp.19–28.... more
... REFERENCES. 1. Alva, AK 2004. Effects of pre-plant and in-season nitrogen management practices on tuber yield and quality of two potato cultivars. J. Veg. ... Oct1999 . Edited by: Tomer, M., Robinson, M. and Gielen, G. pp.19–28. 14–15. New Zealand: New Plymouth. 12. ...