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Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws
School of Natural Resources: Dissertations, Theses, and Student Research
Marginal cropland is suboptimal due to historically low and variable productivity and limiting biophysical characteristics. To support future agricultural management and policy decisions in Nebraska, U.S.A, it is important to understand where cropland is marginal for its two most economically important crops: corn (Zea mays) and soybean (Glycine max). As corn and soybean are frequently planted in a crop rotation, it is important to consider if there is a relationship with cropland marginality. Based on the current literature, there exists a need for a flexible yet robust methodology for identifying marginal land at different scales, which …
Maize Leaf Appearance Rates: A Synthesis From The United States Corn Belt, Caio L. Dos Santos, Lori J. Abendroth, Jeffrey A. Coulter, Emerson D. Nafziger, Andrew E. Suyker, Jianming Yu, Patrick S. Schnable, Sotirios V. Archontoulis
Maize Leaf Appearance Rates: A Synthesis From The United States Corn Belt, Caio L. Dos Santos, Lori J. Abendroth, Jeffrey A. Coulter, Emerson D. Nafziger, Andrew E. Suyker, Jianming Yu, Patrick S. Schnable, Sotirios V. Archontoulis
School of Natural Resources: Faculty Publications
The relationship between collared leaf number and growing degree days (GDD) is crucial for predicting maize phenology. Biophysical crop models convert GDD accumulation to leaf numbers by using a constant parameter termed phyllochron (°C-day leaf−1) or leaf appearance rate (LAR; leaf oC-day−1). However, such important parameter values are rarely estimated for modern maize hybrids. To fill this gap, we sourced and analyzed experimental datasets from the United States Corn Belt with the objective to (i) determine phyllochron values for two types of models: linear (1-parameter) and bilinear (3-parameters; phase I and II phyllochron, and transition …
Two Source Energy Balance Maize Evapotranspiration Estimates Using Close-Canopy Mobile Infrared Sensors And Upscaling Methods Under Variable Water Stress Conditions, A. Katimbo, D. Rudnick, W. Liang, K. Dejonge, T. Lo, T. Franz, Y. Ge, X. Qiao, H. Kabenge, H. N. Nakabuye
Two Source Energy Balance Maize Evapotranspiration Estimates Using Close-Canopy Mobile Infrared Sensors And Upscaling Methods Under Variable Water Stress Conditions, A. Katimbo, D. Rudnick, W. Liang, K. Dejonge, T. Lo, T. Franz, Y. Ge, X. Qiao, H. Kabenge, H. N. Nakabuye
School of Natural Resources: Faculty Publications
No abstract provided.
Chaco Canyon, New Mexico: A Caretaker City And A Pilgrimage Destination, Larry Benson, Deanna N. Grimstead, John R. Stein, David A. Roth, Terry I. Plowman
Chaco Canyon, New Mexico: A Caretaker City And A Pilgrimage Destination, Larry Benson, Deanna N. Grimstead, John R. Stein, David A. Roth, Terry I. Plowman
United States Geological Survey: Staff Publications
Some Southwestern archaeologists continue to ascribe to the hypothesis that Chaco was agriculturally productive to the point that it could support at least a few thousand full-time residents. This paper suggests an alternative hypothesis; i.e., Chaco was marginally productive and could only support a few hundred permanent residents. Isotopic analysis of mammal teeth found in trenches cut through platform mounds fronting Pueblo Bonito indicate the possibility that much of the meat consumed by Chacoan residents and visitors came from higher elevation sites bordering the San Juan Basin. We suggest that resident population estimates based on great house room numbers and …
Prehistoric Chaco Canyon, New Mexico: Importation Of Meat And Maize, Larry Benson, Deanna Grimstead, John R. Stein, David A. Rith, Terry L. Plowman
Prehistoric Chaco Canyon, New Mexico: Importation Of Meat And Maize, Larry Benson, Deanna Grimstead, John R. Stein, David A. Rith, Terry L. Plowman
United States Geological Survey: Staff Publications
In a recent paper, Benson and Grimstead (2019) determined that only minimal amounts of maize could have been grown in Chaco Canyon due to its aridity, short growing season, and frequent summer flooding of the valley floor. In this paper it is shown that deer and rabbit densities within semiarid regions such as the Canyon are such that 2300 Canyon residents would eliminate essentially all small and large mammals within a year. This implies that food (meat and maize) must have been imported from one or more outlying areas to feed the Canyon's residential population. This would have entailed ~18,000 …
Validation Of A Process-Based Agro-Ecosystem Model (Agro-Ibis) For Maize In Xinjiang, Northwest China, Tureniguli Amuti, Geping Luo, Gang Yin, Qi Hu, Elizabeth A. Walter-Shea
Validation Of A Process-Based Agro-Ecosystem Model (Agro-Ibis) For Maize In Xinjiang, Northwest China, Tureniguli Amuti, Geping Luo, Gang Yin, Qi Hu, Elizabeth A. Walter-Shea
School of Natural Resources: Faculty Publications
Agricultural oasis expansion and intensive management practices have occurred in arid and semiarid regions of China during the last few decades. Accordingly, regional carbon and water budgets have been profoundly impacted by agroecosystems in these regions. Therefore, study on the methods used to accurately estimate energy, water, and carbon exchanges is becoming increasingly important. Process-based models can represent the complex processes between land and atmosphere among agricultural ecosystems. However, before the models can be applied they must be validated under different environmental and climatic conditions. In this study, a process-based agricultural ecosystem model (Agro-IBIS) was validated for maize crops using …
Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani
Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani
Department of Geography: Dissertations, Theses, and Student Research
The gross primary production (GPP) metric is useful in determining trends in the terrestrial carbon cycle. Models that determine GPP utilizing the light use efficiency (LUE) approach in conjunction with biophysical parameters that account for local weather conditions and crop specific factors are beneficial in that they combine the accuracy of the biophysical model with the versatility of the LUE model. One such model developed using in situ data was adapted to operate with remote sensing derived leaf area index (LAI) data and gridded weather datasets. The model, known as the Light Use Efficiency GPP Model (EGM), uses a four …
Feasibility Analysis Of Using Inverse Modeling For Estimating Field-Scale Evapotranspiration In Maize And Soybean Fields From Soil Water Content Monitoring Networks, Foad Foolad, Trenton E. Franz, Tiejun Wang, Justin Gibson, Ayse Kilic, Richard Allen, Andrew Suyker
Feasibility Analysis Of Using Inverse Modeling For Estimating Field-Scale Evapotranspiration In Maize And Soybean Fields From Soil Water Content Monitoring Networks, Foad Foolad, Trenton E. Franz, Tiejun Wang, Justin Gibson, Ayse Kilic, Richard Allen, Andrew Suyker
School of Natural Resources: Faculty Publications
No abstract provided.
Quantification And Mapping Of Surface Residue Cover For Maize And Soybean Fields In South Central Nebraska, Vivek Sharma, Suat Irmak, Ayse Kilic, Vasudha Sharma, John E. Gilley, George Meyer, Stevan Z. Knezevic, D. B. Marx
Quantification And Mapping Of Surface Residue Cover For Maize And Soybean Fields In South Central Nebraska, Vivek Sharma, Suat Irmak, Ayse Kilic, Vasudha Sharma, John E. Gilley, George Meyer, Stevan Z. Knezevic, D. B. Marx
School of Natural Resources: Faculty Publications
The area cultivated under conservation tillage practices such as no-till and minimal tillage has recently increased in Midwestern states, including Nebraska. This increase, consequently, resulted in changes in some of the impacts of cropping systems on soil, such as enhancing soil and water quality, improving soil structure and infiltration, increasing water use efficiency, and promoting carbon sequestration. However, there are no methods currently available to quantify the percent crop residue cover (CRC) and the area under conservation tillage for maize and soybean at large scales on a continuous basis. This research used Landsat-7 (ETM+) and Landsat-8 (OLI) satellite data to …
Informative Spectral Bands For Remote Green Lai Estimation In C3 And C4 Crops, Oz Kira, Anthony L. Nguy-Robertson, Timothy J. Arkebauer, Raphael Linker, Anatoly A. Gitelson
Informative Spectral Bands For Remote Green Lai Estimation In C3 And C4 Crops, Oz Kira, Anthony L. Nguy-Robertson, Timothy J. Arkebauer, Raphael Linker, Anatoly A. Gitelson
School of Natural Resources: Faculty Publications
Green leaf area index (LAI) provides insight into the productivity, physiological and phenological status of vegetation. Measurement of spectral reflectance offers a fast and nondestructive estimation of green LAI. A number of methods have been used for the estimation of green LAI; however, the specific spectral bands employed varied widely among the methods and data used. Our objectives were (i) to find informative spectral bands retained in three types of methods, neural network (NN), partial least squares (PLS) regression and vegetation indices (VI), for estimating green LAI in maize (a C4 species) and soybean (a C3 species); (ii) to assess …
Modeling Gross Primary Production Of Maize And Soybean Croplands Using Light Quality, Temperature, Water Stress, And Phenology, Anthony L. Nguy-Robertson, Andrew E. Suyker, Xiangming Xiao
Modeling Gross Primary Production Of Maize And Soybean Croplands Using Light Quality, Temperature, Water Stress, And Phenology, Anthony L. Nguy-Robertson, Andrew E. Suyker, Xiangming Xiao
School of Natural Resources: Faculty Publications
Vegetation productivity metrics, such as gross primary production (GPP) may be determined from the efficiency with which light is converted into photosynthates, or light use efficiency (ϵ). Therefore, accurate measurements and modeling of ϵ is important for estimating GPP in each ecosystem. Previous studies have quantified the impacts of biophysical parameters on light use efficiency based GPP models. Here we enhance previous models utilizing four scalars for light quality (i.e., cloudiness), temperature, water stress, and phenology for data collected from both maize and soybean crops at three Nebraska AmeriFlux sites between 2001 and 2012 (maize: 26 field-years; soybean: …
Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang
Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang
School of Natural Resources: Faculty Publications
Accurate estimates of gross primary production (GPP) for croplands are needed to assess carbon cycle and crop yield. Satellite-based models have been developed to monitor spatial and temporal GPP patterns. However, there are still large uncertainties in estimating cropland GPP. This study compares three light use efficiency (LUE) models (MODIS-GPP, EC-LUE, and VPM) with eddy-covariance measurements at three adjacent AmeriFlux crop sites located near Mead, Nebraska, USA. These sites have different croprotation systems (continuous maize vs. maize and soybean rotated annually) and water management practices (irrigation vs. rainfed). The results reveal several major uncertainties in estimating GPP which need to …
Gross Primary Production And Ecosystem Respiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems Over 8 Years, Andrew E. Suyker, Shashi B. Verma
Gross Primary Production And Ecosystem Respiration Of Irrigated And Rainfed Maize–Soybean Cropping Systems Over 8 Years, Andrew E. Suyker, Shashi B. Verma
School of Natural Resources: Faculty Publications
The objective of this study is to examine interannual variability of carbon dioxide exchange and relevant controlling factors in irrigated and rainfed maize–soybean agroecosystems. The mean annual gross primary production (GPP) of irrigated and rainfed maize was 1796 ± 92 g C m−2 y−1 (±standard deviation) and 1536 ± 74 g C m−2 y−1, respectively. Mean annual GPP of soybean (average of irrigated and rainfed crops) was about 56% that of maize. Light use efficiency of maize and soybean during clear sky conditions were 1.96 ± 0.10 and 1.37 ± 0.06 g C MJ−1 …
Coupling Of Carbon Dioxide And Water Vapor Exchanges Of Irrigated And Rainfed Maize–Soybean Cropping Systems And Water Productivity, Andrew E. Suyker, Shashi B. Verma
Coupling Of Carbon Dioxide And Water Vapor Exchanges Of Irrigated And Rainfed Maize–Soybean Cropping Systems And Water Productivity, Andrew E. Suyker, Shashi B. Verma
School of Natural Resources: Faculty Publications
Continuous measurements of CO2 and water vapor exchanges made in three cropping systems (irrigated continuous maize, irrigated maize–soybean rotation, and rainfed maize–soybean rotation) in eastern Nebraska, USA during 6 years are discussed. Close coupling between seasonal distributions of gross primary production (GPP) and evapotranspiration (ET) were observed in each growing season. Mean growing season totals of GPP in irrigated maize and soybean were 1738 ± 114 and 996 ± 69 g C m−2, respectively (±standard deviation). Corresponding mean values of growing season ET totals were 545 ± 27 and 454 ± 23 mm, respectively. Irrigation affected GPP …
The Cleaning Of Burned And Contaminated Archaeological Maize Prior To 87sr/86sr Analysis, L.V. Benson, H. E. Taylor, T. I. Plowman, D. A. Roth, R. C. Antweiler
The Cleaning Of Burned And Contaminated Archaeological Maize Prior To 87sr/86sr Analysis, L.V. Benson, H. E. Taylor, T. I. Plowman, D. A. Roth, R. C. Antweiler
United States Geological Survey: Staff Publications
Accurate trace-metal and strontium-isotope analyses of archaeological corn cobs require that metal contaminants be removed prior to chemical analysis. Archaeological cobs are often coated with construction debris, dust, or soilwhich contains mineral particles. In addition, most archaeological cobs are partially or completely burned and the burned parts incorporate mineral debris in their hardened residual structures. Unburned cobs are weak ion exchangers and most metals within a cob are not firmly bound to cob organic matter; therefore, immersing cobs in acids and rinsing them in deionized water to remove mineral contaminants may result in the undesirable loss of metals, including strontium, …
Possible Sources Of Archaeological Maize Found In Chaco Canyon And Aztec Ruin, New Mexico, Larry Benson, J. R. Stein, H. E. Taylor
Possible Sources Of Archaeological Maize Found In Chaco Canyon And Aztec Ruin, New Mexico, Larry Benson, J. R. Stein, H. E. Taylor
United States Geological Survey: Staff Publications
Maize played a major role in Chaco’s interaction with outlying communities in the southern Colorado Plateau. This paper seeks to determine where archaeological corn cobs brought to Chaco Canyon were grown. Strontium-isotope and trace-metal ratios of 180 soil-water and 18 surface-water sites in the Southern Colorado Plateau have revealed possible source areas for some of 37 archaeological corn cobs from Chaco Canyon and 10 archaeological corn cobs from Aztec Ruin, New Mexico. The most probable source areas for cobs that predate the middle-12th-century drought include several Upper Rio Chaco sites (not including Chaco Canyon). There are many potential source areas …
Test Of An Extended Mathematical Approach To Calculate Maize Leaf Area Index And Leaf Angle Distribution, Elizabeth A. Walter-Shea, Mark A. Mesarch
Test Of An Extended Mathematical Approach To Calculate Maize Leaf Area Index And Leaf Angle Distribution, Elizabeth A. Walter-Shea, Mark A. Mesarch
School of Natural Resources: Faculty Publications
No abstract provided.