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https://www.readbyqxmd.com/read/29153528/modeling-greenhouse-gas-emissions-from-dairy-farms
#1
C Alan Rotz
Dairy farms have been identified as an important source of greenhouse gas emissions. Within the farm, important emissions include enteric CH4 from the animals, CH4 and N2O from manure in housing facilities during long-term storage and during field application, and N2O from nitrification and denitrification processes in the soil used to produce feed crops and pasture. Models using a wide range in level of detail have been developed to represent or predict these emissions. They include constant emission factors, variable process-related emission factors, empirical or statistical models, mechanistic process simulations, and life cycle assessment...
November 15, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/29148964/twenty-five-years-of-the-binary-power-law-for-characterizing-heterogeneity-of-disease-incidence
#2
Laurence V Madden, Gareth Hughes, Wanderson Bucker Moraes, Xiangming Xu, William W Turechek
Spatial pattern, an important epidemiological property of plant diseases, can be quantified at different scales using a range of methods. The spatial heterogeneity (or overdispersion) of disease incidence among sampling units is an especially important measure of small-scale pattern. As an alternative to Taylor's power law for the heterogeneity of counts with no upper bound, the binary power law (BPL) was proposed in 1992 as a model to represent the heterogeneity of disease incidence (number of plant units diseased out of n observed in each sampling unit, or the proportion diseased in each sampling unit)...
November 17, 2017: Phytopathology
https://www.readbyqxmd.com/read/29142024/a-model-of-leaf-coordination-to-scale-up-leaf-expansion-from-the-organ-to-the-canopy
#3
Pierre Martre, Anaelle Dambreville
Process-based crop growth models are popular tools to analyze and understand the impact of crop management, genotype by environment interactions, or climate change. The ability to predict leaf area development is critical to predict crop growth, particularly under conditions of limited resources. Here, we aimed at deciphering growth coordination rules between wheat plant organs, i.e. between leaves within a stem, between laminae and sheaths, and between the mainstem and axillary tillers, to model the dynamics of canopy development...
November 15, 2017: Plant Physiology
https://www.readbyqxmd.com/read/29139077/spatiotemporal-patterns-and-source-attribution-of-nitrogen-pollution-in-a-typical-headwater-agricultural-watershed-in-southeastern-china
#4
Wenjun Chen, Bin He, Daniel Nover, Weili Duan, Chuan Luo, Kaiyan Zhao, Wen Chen
Excessive nitrogen (N) discharge from agriculture causes widespread problems in aquatic ecosystems. Knowledge of spatiotemporal patterns and source attribution of N pollution is critical for nutrient management programs but is poorly studied in headwaters with various small water bodies and mini-point pollution sources. Taking a typical small watershed in the low mountains of Southeastern China as an example, N pollution and source attribution were studied for a multipond system around a village using the Hydrological Simulation Program-Fortran (HSPF) model...
November 14, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29136323/increasing-canopy-photosynthesis-in-rice-can-be-achieved-without-a-large-increase-in-water-use-a-model-based-on-free-air-co2-enrichment
#5
Hiroki Ikawa, Charles P Chen, Martin Sikma, Mayumi Yoshimoto, Hidemitsu Sakai, Takeshi Tokida, Yasuhiro Usui, Hirofumi Nakamura, Keisuke Ono, Atsushi Maruyama, Tsutomu Watanabe, Tsuneo Kuwagata, Toshihiro Hasegawa
Achieving higher canopy photosynthesis rates is one of the keys to increasing future crop production; however, this typically requires additional water inputs because of increased water loss through the stomata. Lowland rice canopies presently consume a large amount of water, and any further increase in water usage may significantly impact local water resources. This situation is further complicated by changing environmental conditions such as rising atmospheric CO2 concentration ([CO2 ]). Here we modeled and compared evapotranspiration of fully developed rice canopies of a high-yielding rice cultivar (Oryza sativa L...
November 14, 2017: Global Change Biology
https://www.readbyqxmd.com/read/29121579/a-process-oriented-hydro-biogeochemical-model-enabling-simulation-of-gaseous-carbon-and-nitrogen-emissions-and-hydrologic-nitrogen-losses-from-a-subtropical-catchment
#6
Wei Zhang, Yong Li, Bo Zhu, Xunhua Zheng, Chunyan Liu, Jialiang Tang, Fang Su, Chong Zhang, Xiaotang Ju, Jia Deng
Quantification of nitrogen losses and net greenhouse gas (GHG) emissions from catchments is essential for evaluating the sustainability of ecosystems. However, the hydrologic processes without lateral flows hinder the application of biogeochemical models to this challenging task. To solve this issue, we developed a coupled hydrological and biogeochemical model, Catchment Nutrients Management Model - DeNitrification-DeComposition Model (CNMM-DNDC), to include both vertical and lateral mass flows. By incorporating the core biogeochemical processes (including decomposition, nitrification, denitrification and fermentation) of the DNDC into the spatially distributed hydrologic framework of the CNMM, the simulation of lateral water flows and their influences on nitrogen transportation can be realized...
November 6, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29120779/9-10-anthraquinone-deposit-in-tea-plantation-might-be-one-of-the-reasons-for-contamination-in-tea
#7
Xuan Wang, Li Zhou, Fengjian Luo, Xinzhong Zhang, Hezhi Sun, Mei Yang, Zhengyun Lou, Zongmao Chen
9,10-Anthraquinone (AQ) was a new contaminant, with unknown sources, occurred globally in tea. European Union (EU) fixed the maximum residue limit (MRL) of 0.02mg/kg. The pollution source of AQ in tea was traced from the view of AQ deposit on tea crop by simulation. The possible contamination pathway and main factors to decrease AQ were explored in tea cultivation- tea manufacture- tea infusion, on the basis of AQ analytical methods by using solvent extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS) quantification...
April 1, 2018: Food Chemistry
https://www.readbyqxmd.com/read/29112843/modeling-future-water-footprint-of-barley-production-in-alberta-canada-implications-for-water-use-and-yields-to-2064
#8
Mohammad Badrul Masud, Tim McAllister, Marcos R C Cordeiro, Monireh Faramarzi
Despite the perception of being one of the most agriculturally productive regions globally, crop production in Alberta, a western province of Canada, is strongly dependent on highly variable climate and water resources. We developed agro-hydrological models to assess the water footprint (WF) of barley by simulating future crop yield (Y) and consumptive water use (CWU) within the agricultural region of Alberta. The Soil and Water Assessment Tool (SWAT) was used to develop rainfed and irrigated barley Y simulation models adapted to sixty-seven and eleven counties, respectively through extensive calibration, validation, sensitivity, and uncertainty analysis...
November 4, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29110424/increasing-drought-and-diminishing-benefits-of-elevated-carbon-dioxide-for-soybean-yields-across-the-us-midwest
#9
Zhenong Jin, Elizabeth A Ainsworth, Andrew D B Leakey, David B Lobell
Elevated atmospheric CO2 concentrations ([CO2 ]) are expected to increase C3 crop yield through the CO2 fertilization effect (CFE) by stimulating photosynthesis and by reducing stomatal conductance and transpiration. The latter effect is widely believed to lead to greater benefits in dry rather than wet conditions, although some recent experimental evidence challenges this view. Here we used a process-based crop model, the Agricultural Production Systems sIMulator (APSIM), to quantify the contemporary and future CFE on soybean in one of its primary production area of the US Midwest...
November 7, 2017: Global Change Biology
https://www.readbyqxmd.com/read/29107774/analysis-of-the-efficacy-and-cost-effectiveness-of-best-management-practices-for-controlling-sediment-yield-a-case-study-of-the-joumine-watershed-tunisia
#10
Slim Mtibaa, Norifumi Hotta, Mitsuteru Irie
Soil erosion can be reduced through the strategic selection and placement of best management practices (BMPs) in critical source areas (CSAs). In the present study, the Soil Water Assessment Tool (SWAT) model was used to identify CSAs and investigate the effectiveness of different BMPs in reducing sediment yield in the Joumine watershed, an agricultural river catchment located in northern Tunisia. A cost-benefit analysis (CBA) was used to evaluate the cost-effectiveness of different BMP scenarios. The objective of the present study was to determine the most cost-effective management scenario for controlling sediment yield...
November 3, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29107362/minimising-farm-crop-protection-pressure-supported-by-the-multiple-functionalities-of-the-discuss-indicator-set
#11
Hilde Wustenberghs, Davina Fevery, Ludwig Lauwers, Fleur Marchand, Pieter Spanoghe
Sustainable crop protection (SCP) has many facets. Farmers may therefore perceive transition to SCP as very complex. The Dual Indicator Set for Crop Protection Sustainability (DISCUSS) can handle this complexity. To provide targeted support throughout the transition to SCP, complexity capture must be synchronised with the time course of on-farm decision-making. Tool use must be tuned to farmer awareness and appropriate level of data in consecutive stages. This paper thus explores the potential functionalities of DISCUSS in relation to both complexity and time...
October 26, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29103648/adapting-crop-rotations-to-climate-change-in-regional-impact-modelling-assessments
#12
Edmar I Teixeira, John de Ruiter, Anne-Gaelle Ausseil, Adam Daigneault, Paul Johnstone, Allister Holmes, Andrew Tait, Frank Ewert
The environmental and economic sustainability of future cropping systems depends on adaptation to climate change. Adaptation studies commonly rely on agricultural systems models to integrate multiple components of production systems such as crops, weather, soil and farmers' management decisions. Previous adaptation studies have mostly focused on isolated monocultures. However, in many agricultural regions worldwide, multi-crop rotations better represent local production systems. It is unclear how adaptation interventions influence crops grown in sequences...
November 2, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29099842/assessing-the-combined-effects-of-climatic-factors-on-spring-wheat-phenophase-and-grain-yield-in-inner-mongolia-china
#13
Junfang Zhao, Feiyu Pu, Yunpeng Li, Jingwen Xu, Ning Li, Yi Zhang, Jianping Guo, Zhihua Pan
Understanding the regional relationships between climate change and crop production will benefit strategic decisions for future agricultural adaptation in China. In this study, the combined effects of climatic factors on spring wheat phenophase and grain yield over the past three decades in Inner Mongolia, China, were explored based on the daily climate variables from 1981-2014 and detailed observed data of spring wheat from 1981-2014. Inner Mongolia was divided into three different climate type regions, the eastern, central and western regions...
2017: PloS One
https://www.readbyqxmd.com/read/29093514/causes-of-variation-among-rice-models-in-yield-response-to-co2-examined-with-free-air-co2-enrichment-and-growth-chamber-experiments
#14
Toshihiro Hasegawa, Tao Li, Xinyou Yin, Yan Zhu, Kenneth Boote, Jeffrey Baker, Simone Bregaglio, Samuel Buis, Roberto Confalonieri, Job Fugice, Tamon Fumoto, Donald Gaydon, Soora Naresh Kumar, Tanguy Lafarge, Manuel Marcaida Iii, Yuji Masutomi, Hiroshi Nakagawa, Philippe Oriol, Françoise Ruget, Upendra Singh, Liang Tang, Fulu Tao, Hitomi Wakatsuki, Daniel Wallach, Yulong Wang, Lloyd Ted Wilson, Lianxin Yang, Yubin Yang, Hiroe Yoshida, Zhao Zhang, Jianguo Zhu
The CO2 fertilization effect is a major source of uncertainty in crop models for future yield forecasts, but coordinated efforts to determine the mechanisms of this uncertainty have been lacking. Here, we studied causes of uncertainty among 16 crop models in predicting rice yield in response to elevated [CO2] (E-[CO2]) by comparison to free-air CO2 enrichment (FACE) and chamber experiments. The model ensemble reproduced the experimental results well. However, yield prediction in response to E-[CO2] varied significantly among the rice models...
November 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29080301/assessing-uncertainties-in-crop-and-pasture-ensemble-model-simulations-of-productivity-and-n2-o-emissions
#15
Fiona Ehrhardt, Jean-François Soussana, Gianni Bellocchi, Peter Grace, Russel McAuliffe, Sylvie Recous, Renáta Sándor, Pete Smith, Val Snow, Massimiliano D A Migliorati, Bruno Basso, Arti Bhatia, Lorenzo Brilli, Jordi Doltra, Christopher D Dorich, Luca Doro, Nuala Fitton, Sandro J Giacomini, Brian Grant, Matthew T Harrison, Stephanie K Jones, Miko U F Kirschbaum, Katja Klumpp, Patricia Laville, Joël Léonard, Mark Liebig, Mark Lieffering, Raphaël Martin, Raia Silvia Massad, Elizabeth Meier, Lutz Merbold, Andrew D Moore, Vasileios Myrgiotis, Paul Newton, Elizabeth Pattey, Susanne Rolinski, Joanna Sharp, Ward N Smith, Lianhai Wu, Qing Zhang
Simulation models are extensively used to predict agricultural productivity and greenhouse gas (GHG) emissions. However, the uncertainties of (reduced) model ensemble simulations have not been assessed systematically for variables affecting food security and climate change mitigation, within multispecies agricultural contexts. We report an international model comparison and benchmarking exercise, showing the potential of multimodel ensembles to predict productivity and nitrous oxide (N2 O) emissions for wheat, maize, rice and temperate grasslands...
October 28, 2017: Global Change Biology
https://www.readbyqxmd.com/read/29079090/n-loss-to-drain-flow-and-n2o-emissions-from-a-corn-soybean-rotation-with-winter-rye
#16
K Gillette, R W Malone, T C Kaspar, L Ma, T B Parkin, D B Jaynes, Q X Fang, J L Hatfield, G W Feyereisen, K C Kersebaum
Anthropogenic perturbation of the global nitrogen cycle and its effects on the environment such as hypoxia in coastal regions and increased N2O emissions is of increasing, multi-disciplinary, worldwide concern, and agricultural production is a major contributor. Only limited studies, however, have simultaneously investigated NO3(-) losses to subsurface drain flow and N2O emissions under corn-soybean production. We used the Root Zone Water Quality Model (RZWQM) to evaluate NO3(-) losses to drain flow and N2O emissions in a corn-soybean system with a winter rye cover crop (CC) in central Iowa over a nine year period...
October 24, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29076459/an-optimized-content-aware-image-retargeting-method-toward-expanding-the-perceived-visual-field-of-the-high-density-retinal-prosthesis-recipients
#17
Heng Li, Yajie Zeng, Zhuofan Lu, Xiaofei Cao, Xiaofan Su, Xiaohong Sui, Jing Wang, Xinyu Chai
Retinal prosthesis devices have shown great value in restoring some sight for individuals with profoundly impaired vision, but the visual acuity and visual field provided by prostheses greatly limit recipients' visual experience. In this paper, we employ computer vision approaches to seek to expand the perceptible visual field in patients implanted potentially with a high-density retinal prosthesis while maintaining visual acuity as much as possible. Approach. We propose an optimized content-aware image retargeting method, by introducing salient object detection based on color and intensity-difference contrast, aiming to remap important information of a scene into a small visual field and preserve their original scale as much as possible...
October 27, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/29070449/assessing-cover-crop-management-under-actual-and-climate-change-conditions
#18
María Alonso-Ayuso, Miguel Quemada, Marnik Vanclooster, Margarita Ruiz-Ramos, Alfredo Rodriguez, José Luis Gabriel
The termination date is recognized as a key management factor to enhance cover crops for multiple benefits and to avoid competition with the following cash crop. However, the optimum date depends on annual meteorological conditions, and climate variability induces uncertainty in a decision that needs to be taken every year. One of the most important cover crop benefits is reducing nitrate leaching, a major concern for irrigated agricultural systems and highly affected by the termination date. This study aimed to determine the effects of cover crops and their termination date on the water and N balances of an irrigated Mediterranean agroecosystem under present and future climate conditions...
October 22, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/29070084/productive-economic-and-risk-assessment-of-grazing-dairy-systems-with-supplemented-cows-milked-once-a-day
#19
B Lazzarini, N Lopez-Villalobos, N Lyons, L Hendrikse, J Baudracco
Milking cows once a day (OAD) is a herd management practice that may help to reduce working effort and labour demand in dairy farms. However, a decrease in milk yield per cow occurs in OAD systems compared with twice a day (TAD) systems and this may affect profitability of dairy systems. The objective of this study was to assess productive and economic impact and risk of reducing milking frequency from TAD to OAD for grazing dairy systems, using a whole-farm model. Five scenarios were evaluated by deterministic and stochastic simulations: one scenario under TAD milking (TADAR) and four scenarios under OAD milking...
October 26, 2017: Animal: An International Journal of Animal Bioscience
https://www.readbyqxmd.com/read/29069361/climate-change-impacts-on-the-potential-distribution-and-abundance-of-the-brown-marmorated-stink-bug-hemiptera-pentatomidae-with-special-reference-to-north-america-and-europe
#20
Erica Jean Kistner
The invasive brown marmorated stink bug, Halyomorpha halys (Stål; Hemiptera: Pentatomidae), has recently emerged as a harmful pest of horticultural crops in North America and Europe. Native to East Asia, this highly polyphagous insect is spreading rapidly worldwide. Climate change will add further complications to managing this species in terms of both geographic distribution and population growth. This study used CLIMEX to compare potential H. halys distribution under recent and future climate models using one emission scenario (A2) with two different global circulation models, CSIRO Mk3...
October 23, 2017: Environmental Entomology
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