Filters








225 Hits in 4.0 sec

A global assessment of PT-JPL soil evaporation in agroecosystems with optical, thermal, and microwave satellite data

Lilin Zhang, Michael Marshall, Andy Nelson, Anton Vrieling
2021 Agricultural and Forest Meteorology  
Reliable estimates of ET for agricultural landscapes can facilitate water resources management and food security analysis.  ...  using atmospheric humidity limits its application in agroecosystems.  ...  Acknowledgements The work of first author (Lilin Zhang)  ... 
doi:10.1016/j.agrformet.2021.108455 fatcat:2jqkcej23jhjnpsvdmjvfayy7i

Scaling up of CO2 fluxes from leaf to canopy in maize-based agroecosystems

Timothy J. Arkebauer, Elizabeth A. Walter-Shea, Mark A. Mesarch, Andrew E. Suyker, Shashi B. Verma
2009 Agricultural and Forest Meteorology  
The agreement between estimated and observed values increases our confidence in the measured carbon pools and fluxes in these agroecosystems and enhances our understanding of biophysical controls on carbon  ...  Carbon dioxide fluxes are being measured in three maize-based agroecosystems in eastern Nebraska in an effort to better understand the potential for these systems to sequester carbon in the soil.  ...  We gratefully acknowledge the assistance of Dave Scoby, Brent Holmquist, and Brigid Amos in making the leaf-level and soil surface CO 2 flux measurements, Denise Gutzmer, Jacob Johnson, and Aaron Jensen  ... 
doi:10.1016/j.agrformet.2009.04.013 fatcat:awnjgwau7vel3l6qjnclybtxza

Modeling Regional Effects of Climate Change on Soil Organic Carbon in Spain

Asma Jebari, Agustin del Prado, Guillermo Pardo, José Antonio Rodríguez Martín, Jorge Álvaro-Fuentes
2018 Journal of Environmental Quality  
Qualitative Analysis of Uncertainty 480 Uncertainty related to this work may be ascribed to the model applied, the initial size 481 characterization of SOC fractions, and the nonavailability of some data  ...  Indeed, for most of the parameters (e.g., inputs of irrigation water, HI), 483 modeling was performed according to the most common practices of the study area. 484 Despite RothC performance shown in many  ... 
doi:10.2134/jeq2017.07.0294 pmid:30025039 fatcat:qxyamc7pozguhh3nh6hbbohnwy

Global sensitivity and uncertainty analysis of a dynamic agroecosystem model under different irrigation treatments

Kendall C. DeJonge, James C. Ascough, Mehdi Ahmadi, Allan A. Andales, Mazdak Arabi
2012 Ecological Modelling  
An uncertainty analysis was also conducted using model outputs from the Sobol' SA method.  ...  It is therefore desirable to quantify the effects of CERES-Maize input parameters on model output responses typically used for calibration and/or important in limited irrigation management, including vegetative  ...  It is a well-known fact that identifying influential model parameters, in a specific arena of application, is of primary importance for all types of models, in this case the agroecosystem (and specifically  ... 
doi:10.1016/j.ecolmodel.2012.01.024 fatcat:446pi5guizffjcj4qfbd5o4dui

Modeling Soil Water Dynamics and Pasture Growth in the Montado Ecosystem Using MOHID Land

Lucian Simionesei, Tiago Ramos, Ana Oliveira, Marjan Jongen, Hanaa Darouich, Kirsten Weber, Vânia Proença, Tiago Domingos, Ramiro Neves
2018 Water  
The purpose of this study was to determine whether the MOHID-Land model could adequately simulate soil water dynamics and pasture growth in the montado ecosystem.  ...  Water balance and dry biomass estimates were found to be significantly different between rainfed and irrigated pastures, as well as between the ten driest and ten wettest seasons, with the model responding  ...  observations and simulations to model formulations rather than structural uncertainties within the models.  ... 
doi:10.3390/w10040489 fatcat:kfhkozzsavd2fnumckhduemxju

Quantifying the link between crop production and mined groundwater irrigation in China

Danielle S. Grogan, Fan Zhang, Alexander Prusevich, Richard B. Lammers, Dominik Wisser, Stanley Glidden, Changsheng Li, Steve Frolking
2015 Science of the Total Environment  
Salinization due to diminished groundwater Large-scale surface water balance models can simulate the use of both surface water and groundwater for irrigation.  ...  Groundwater (both renewable and mined in excess of recharge) provides up to 40% of China's irrigation water, and model results from Wada et al. [2012] show that 20 km 3 yr −1 (5% of irrigation demand)  ...  Crop Yield Model The DeNitrification-DeComposition (DNDC) model, a process-based model of carbon and nitrogen biogeochemistry in agroecosystems, simulated irrigated and rainfed crop yields (kg C/ha/yr)  ... 
doi:10.1016/j.scitotenv.2014.11.076 pmid:25544335 fatcat:ryw7xfxasrcqtnxjib44xjiuhm

Regional scale cropland carbon budgets: Evaluating a geospatial agricultural modeling system using inventory data

Xuesong Zhang, Roberto C. Izaurralde, David H. Manowitz, Ritvik Sahajpal, Tristram O. West, Allison M. Thomson, Min Xu, Kaiguang Zhao, Stephen D. LeDuc, Jimmy R. Williams
2015 Environmental Modelling & Software  
the simulation of C budget components.  ...  However, we also detected notable differences in the magnitude of NPP and NEE, as well as in the spatial pattern of SOC change.  ...  The views expressed here are those of the authors and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.  ... 
doi:10.1016/j.envsoft.2014.10.005 fatcat:3s2aohhfcjc6lj2uvb7aj7jinq

Modeling the Impacts of Climate Change on Crop Yield and Irrigation in the Monocacy River Watershed, USA

Manashi Paul, Sijal Dangol, Vitaly Kholodovsky, Amy R. Sapkota, Masoud Negahban-Azar, Stephanie Lansing
2020 Climate  
To evaluate the effect of future climate projections, four global climate models (GCMs) and three representative concentration pathways (RCP 4.5, 6, and 8.5) were used in the SWAT model.  ...  Decision tree analysis indicated that corn and soybean yields are most influenced by soil moisture, temperature, and precipitation as well as the water management practice used (i.e., rainfed or irrigated  ...  Acknowledgments: The authors would like to thank all of the UMD Global STEWARDS fellows for their contributions in reviewing, language editing, and proofreading of this paper.  ... 
doi:10.3390/cli8120139 fatcat:z4ffgrvoebhezniwpv6dnbnakm

Mapping abiotic stresses for rice in Africa: Drought, cold, iron toxicity, salinity and sodicity

P.A.J. van Oort
2018 Field crops research (Print)  
Uncertainties in the mappings are discussed.  ...  In terms of relative importance, the study identified drought as the most important stress (33% of rice area potentially affected), followed by iron toxicity (12%) and then cold (7%) and salinity/sodicity  ...  The three crop maps are so uncertain in terms of their allocation of rainfed and irrigated rice that they were not used to differentiate these macro agroecosystems.  ... 
doi:10.1016/j.fcr.2018.01.016 pmid:29666552 pmcid:PMC5848050 fatcat:b2pzndq2vfgznehre5kguoqdje

Gross Primary Production of Rainfed and Irrigated Potato (Solanum tuberosum L.) in the Colombian Andean Region Using Eddy Covariance Technique

Fabio Ernesto Martínez-Maldonado, Angela María Castaño-Marín, Gerardo Antonio Góez-Vinasco, Fabio Ricardo Marin
2021 Water  
In this study, the net carbon ecosystem exchange (NEE) was measured using the Eddy Covariance (EC) method in two potato crops, one of them with an irrigation system, the other under rainfed conditions.  ...  In contrast, the irrigated crop showed higher GPP rate and acted as a carbon sink (NEE = −366.6 g C m−2 ± 50.30).  ...  in the equipment installation process, and farmers Santiago Forero and Alejandro Forero for providing a suitable lot for the study.  ... 
doi:10.3390/w13223223 fatcat:kvtwikly5bghxmgyastynk5rd4

An AgMIP framework for improved agricultural representation in integrated assessment models

Alex C Ruane, Cynthia Rosenzweig, Senthold Asseng, Kenneth J Boote, Joshua Elliott, Frank Ewert, James W Jones, Pierre Martre, Sonali P McDermid, Christoph Müller, Abigail Snyder, Peter J Thorburn
2017 Environmental Research Letters  
Diversity in climate responses underscores that crop model emulators must distinguish between regions and farming system while recognizing model uncertainty.  ...  gridded simulations, opening the door to accelerated development and a broad range of applications.  ...  Acknowledgements We are grateful for the tremendous effort and contributions provided by all modelers and leaders of all projects listed in table 1.  ... 
doi:10.1088/1748-9326/aa8da6 pmid:30881482 pmcid:PMC6417889 fatcat:na3v4xt7ona7fizkmitkntabia

Impacts of temperature and rainfall variation on rice productivity in major ecosystems of Bangladesh

Md Abiar Rahman, SuChul Kang, Nidhi Nagabhatla, Robert Macnee
2017 Agriculture & Food Security  
Inconsistency in climate regimes of rainfall and temperature is a source of biotic and abiotic stresses in agricultural systems worldwide.  ...  The multiple regression analysis identified a significant correlation between RPI, SPI and DTR accounting for 41, 45 and 49% of yield variability in dry, terrace and coastal ecosystems, respectively.  ...  The authors acknowledge the contribution of the members of APEC Climate Center (APCC) and Department of Agroforestry and Environment of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh  ... 
doi:10.1186/s40066-017-0089-5 fatcat:ti4iqyhd5ncjdhtjuqx755ujye

On parameterizing soil evaporation in a direct remote sensing model of ET: PT‐JPL

Michael Marshall, Kevin Tu, Veronica Andreo
2020 Water Resources Research  
LSWI and SMDI explained 18-33% of variance in 8-day soil evaporation. This led to a 3-11% increase in explained ET variance. LSWI and SMDI tended to perform better at the irrigated sites than RH.  ...  In this study, we compared soil evaporation parameterized with optical and thermal indices derived from MODIS to RH-based soil evaporation as implemented in the Priestley Taylor-Jet Propulsion Laboratory  ...  Department of Energy's Office of Science. We would also like to thank the staff of U.S. Geological Survey for their support in using the AρρEEARS tool.  ... 
doi:10.1029/2019wr026290 fatcat:lwsu4zqqtba77cvk7hpbpzxtle

The impact of agroforestry combined with water harvesting on soil carbon and nitrogen stocks in central Chile evaluated using the ICBM/N model

Osvaldo Salazar, Manuel Casanova, Thomas Kätterer
2011 Agriculture, Ecosystems & Environment  
The observed SOC and N stocks were bracketed by the uncertainty bands in 70% and 80% of the simulations, respectively.  ...  Sensitivity analysis showed the model to be most sensitive to C parameters, such as the humification coefficient (h).  ...  Acknowledgements The authors thank the Department of Soil and Engineering at the University of Chile and the Department of Soil and Environment at the Swedish University of Agricultural Sciences for supporting  ... 
doi:10.1016/j.agee.2010.11.019 fatcat:o5fmm3oxzfg6zneukapxuzqtjq

Designing efficient nitrous oxide sampling strategies in agroecosystems using simulation models

Debasish Saha, Armen R. Kemanian, Benjamin M. Rau, Paul R. Adler, Felipe Montes
2017 Atmospheric Environment  
Fertilization source, rate, and timing were site-specific. These simulated fluxes surrogated daily measurements in the analysis.  ...  We used outputs from simulations obtained with an agroecosystem model to design sampling strategies that yield accurate cumulative N 2 O flux estimates with a known uncertainty level.  ...  Acknowledgements Funding for this research was provided by the USDOT SunGrant #52110-9601, USDA NIFA grant #2012-68005-19703, and USDA NIFA grant #2015-51106-24237.  ... 
doi:10.1016/j.atmosenv.2017.01.052 fatcat:mvpvr6khgzdbtdloc7l2fdhpoi
« Previous Showing results 1 — 15 out of 225 results