scholarly journals Crop physiology calibration in CLM

2014 ◽  
Vol 7 (5) ◽  
pp. 6733-6771 ◽  
Author(s):  
I. Bilionis ◽  
B. A. Drewniak ◽  
E. M. Constantinescu
Keyword(s):  
Sequential Monte Carlo ◽  
Net Ecosystem Exchange ◽  
Crop Productivity ◽  
Biofuel Production ◽  
Community Land Model ◽  
Terrestrial Carbon Cycle ◽  
Crop Development ◽  
Choose Parameter ◽  
Parameter Values ◽  
The Impact

Abstract. Farming is using more terrestrial ground, as population increases and agriculture is increasingly used for non-nutritional purposes such as biofuel production. This agricultural expansion exerts an increasing impact on the terrestrial carbon cycle. In order to understand the impact of such processes, the Community Land Model (CLM) has been augmented with a CLM-Crop extension that simulates the development of three crop types: maize, soybean, and spring wheat. The CLM-Crop model is a complex system that relies on a suite of parametric inputs that govern plant growth under a given atmospheric forcing and available resources. CLM-Crop development used measurements of gross primary productivity and net ecosystem exchange from AmeriFlux sites to choose parameter values that optimize crop productivity in the model. In this paper we calibrate these parameters for one crop type, soybean, in order to provide a faithful projection in terms of both plant development and net carbon exchange. Calibration is performed in a Bayesian framework by developing a scalable and adaptive scheme based on sequential Monte Carlo (SMC).

scholarly journals Calibration of the Crop model in the Community Land Model

2013 ◽  
Vol 6 (1) ◽  
pp. 379-398 ◽  
Author(s):  
X. Zeng ◽  
B. A. Drewniak ◽  
E. M. Constantinescu
Keyword(s):  
Net Ecosystem Exchange ◽  
Crop Productivity ◽  
Crop Model ◽  
Biofuel Production ◽  
Community Land Model ◽  
Terrestrial Carbon Cycle ◽  
Crop Development ◽  
Choose Parameter ◽  
Parameter Values ◽  
The Impact

Abstract. Farming is using more terrestrial ground with increases in population and the expanding use of agriculture for non-nutritional purposes such as biofuel production. This agricultural expansion exerts an increasing impact on the terrestrial carbon cycle. In order to understand the impact of such processes, the Community Land Model (CLM) has been augmented with a CLM-Crop extension that simulates the development of three crop types: maize, soybean, and spring wheat. The CLM-Crop model is a complex system that relies on a suite of parametric inputs that govern plant growth under a given atmospheric forcing and available resources. CLM-Crop development used measurements of gross primary productivity and net ecosystem exchange from AmeriFlux sites to choose parameter values that optimize crop productivity in the model. In this paper we calibrate these values in order to provide a faithful projection in terms of both plant development and net carbon exchange, using a Markov chain Monte Carlo technique.

scholarly journals Crop physiology calibration in the CLM

2015 ◽  
Vol 8 (4) ◽  
pp. 1071-1083 ◽  
Author(s):  
I. Bilionis ◽  
B. A. Drewniak ◽  
E. M. Constantinescu
Keyword(s):  
Land Surface ◽  
Sequential Monte Carlo ◽  
Net Ecosystem Exchange ◽  
Crop Productivity ◽  
Biofuel Production ◽  
Community Land Model ◽  
Crop Development ◽  
Choose Parameter ◽  
Parameter Values ◽  
The Impact

Abstract. Farming is using more of the land surface, as population increases and agriculture is increasingly applied for non-nutritional purposes such as biofuel production. This agricultural expansion exerts an increasing impact on the terrestrial carbon cycle. In order to understand the impact of such processes, the Community Land Model (CLM) has been augmented with a CLM-Crop extension that simulates the development of three crop types: maize, soybean, and spring wheat. The CLM-Crop model is a complex system that relies on a suite of parametric inputs that govern plant growth under a given atmospheric forcing and available resources. CLM-Crop development used measurements of gross primary productivity (GPP) and net ecosystem exchange (NEE) from AmeriFlux sites to choose parameter values that optimize crop productivity in the model. In this paper, we calibrate these parameters for one crop type, soybean, in order to provide a faithful projection in terms of both plant development and net carbon exchange. Calibration is performed in a Bayesian framework by developing a scalable and adaptive scheme based on sequential Monte Carlo (SMC). The model showed significant improvement of crop productivity with the new calibrated parameters. We demonstrate that the calibrated parameters are applicable across alternative years and different sites.

Influence of long-term fertilization on soil microbial biomass and dehydrogenase activity in relation to crop productivity in an acid Inceptisols

2019 ◽  
Vol 56 (3) ◽  
pp. 305-311
Author(s):  
Debasis Purohit ◽  
Mitali Mandal ◽  
Avisek Dash ◽  
Kumbha Karna Rout ◽  
Narayan Panda ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Dehydrogenase Activity ◽  
Nutrient Content ◽  
Crop Productivity ◽  
Maturity Stage ◽  
Microbial Biomass Nitrogen ◽  
Biological Potential ◽  
Initiation Stage ◽  
The Impact

An effective approach for improving nutrient use efficiency and crop productivity simultaneously through exploitation of biological potential for efficient acquisition and utilization of nutrients by crops is very much needed in this current era. Thus, an attempt is made here to investigate the impact of long term fertilization in the soil ecology in rice-rice cropping system in post kharif - 2015 in flooded tropical rice (Oryza sativa L.) in an acidic sandy soil. The experiment was laid out in a randomized block design with quadruplicated treatments. Soil samples at different growth stages of rice were collected from long term fertilizer experiment.The studied long-term manured treatments included 100 % N, 100% NP, 100 % NPK, 150 % NPK and 100 % NPK+FYM (5 t ha-1) and an unmanured control. Soil fertility status like SOC content and other available nutrient content has decreased continuously towards the crop growth period. Comparing the results of different treatments, it was found that the application of 100% NPK + FYM exhibited highest nutrient content in soils. With regards to microbial properties it was also observed that the amount of microbial biomass carbon (MBC) and microbial biomass nitrogen ( MBN) showed highest accumulation in 100 % NPK + FYM at maximum tillering stage of the rice. The results further reveal that dehydrogenase activity was maximum at panicle initiation stage and thereafter it decreases. Soil organic carbon content, MBC, MBN and dehydrogenase activity were significantly correlated with each other. Significant correlations were observed between rice yield and MBC at maturity stage( R2 = 0.94**) and panicle initiation stage( R2 = 0.92**) and available nitrogen content at maturity stage( R2 = 0.91**).

AN ECONOMIC STUDY FOR THE IMPACT OF BIOFUEL PRODUCTION EXPANSION

2018 ◽  
Vol 3 (2) ◽  
pp. 259-260
Author(s):  
I. S. Ali ◽  
A. M. Taryal ◽  
S. A. Abou-El Naga ◽  
M. M. Abd-El Menem
Keyword(s):  
Biofuel Production ◽  
Economic Study ◽  
The Impact

Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

2006 ◽  
Vol 41 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Zhe Zhang ◽  
Eric R. Hall
Keyword(s):  
Parameter Estimation ◽  
Phosphorus Removal ◽  
Growth Yield ◽  
Pilot Scale ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Parameter Values ◽  
The Impact ◽  
Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

scholarly journals Impacts of Microcystins on Morphological and Physiological Parameters of Agricultural Plants: A Review

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 639
Author(s):  
Alexandre Campos ◽  
El Mahdi Redouane ◽  
Marisa Freitas ◽  
Samuel Amaral ◽  
Tomé Azevedo ◽  
...  
Keyword(s):  
Drinking Water ◽  
Human Health ◽  
Economic Loss ◽  
Crop Productivity ◽  
Physiological Parameters ◽  
World Health ◽  
Potential Threat ◽  
Regulatory Limits ◽  
Agricultural Plants ◽  
The Impact

Cyanobacteria are a group of photosynthetic prokaryotes that pose a great concern in the aquatic environments related to contamination and poisoning of wild life and humans. Some species of cyanobacteria produce potent toxins such as microcystins (MCs), which are extremely aggressive to several organisms, including animals and humans. In order to protect human health and prevent human exposure to this type of organisms and toxins, regulatory limits for MCs in drinking water have been established in most countries. In this regard, the World Health Organization (WHO) proposed 1 µg MCs /L as the highest acceptable concentration in drinking water. However, regulatory limits were not defined in waters used in other applications/activities, constituting a potential threat to the environment and to human health. Indeed, water contaminated with MCs or other cyanotoxins is recurrently used in agriculture and for crop and food production. Several deleterious effects of MCs including a decrease in growth, tissue necrosis, inhibition of photosynthesis and metabolic changes have been reported in plants leading to the impairment of crop productivity and economic loss. Studies have also revealed significant accumulation of MCs in edible tissues and plant organs, which raise concerns related to food safety. This work aims to systematize and analyze the information generated by previous scientific studies, namely on the phytotoxicity and the impact of MCs especially on growth, photosynthesis and productivity of agricultural plants. Morphological and physiological parameters of agronomic interest are overviewed in detail in this work, with the aim to evaluate the putative impact of MCs under field conditions. Finally, concentration-dependent effects are highlighted, as these can assist in future guidelines for irrigation waters and establish regulatory limits for MCs.

scholarly journals The Pitfalls of Relating Weeds, Herbicide Use, and Crop Yield: Don't Fall Into the Trap! A Critical Review

2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  
Keyword(s):  
Crop Yield ◽  
Weed Management ◽  
Crop Production ◽  
Yield Loss ◽  
Crop Yields ◽  
Cropping Systems ◽  
Crop Productivity ◽  
Arable Farming ◽  
Herbicide Use ◽  
The Impact

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.

The effect of long-term fertilization on forage crop productivity and quality in the North

2020 ◽  
Author(s):  
Н.Т. Чеботарёв ◽  
Н.Н. Шергина
Keyword(s):  
Crop Rotation ◽  
Starch Content ◽  
Crop Productivity ◽  
Komi Republic ◽  
Perennial Grasses ◽  
Organic Fertilizers ◽  
Nitrate Content ◽  
Mineral Fertilizers ◽  
Forage Crop ◽  
The Impact

В условиях Республики Коми в полевом стационарном опыте на дерново-подзолистой легкосуглинистой почве изучена эффективность различных доз органических и минеральных удобрений, а также совместного их применения. Исследования проводили в 1978–2019 годах на опытных полях Института агробиотехнологий ФИЦ Коми НЦ УрО РАН. Целью проводимых исследований было изучение влияния комплексного применения удобрений на продуктивность и качество кормовых культур в шестипольном севообороте. Кормовой севооборот имел следующее чередование культур: картофель, викоовсяная смесь с подсевом многолетних трав, многолетние травы 1 г.п., многолетние травы 2 г.п., викоовсяная смесь, картофель. В результате научных исследований (более 40 лет) установлено, что наиболее эффективной была органоминеральная система удобрений, особенно при внесении 80 т/га торфонавозного компоста (ТНК) и минеральных удобрений. Многолетние исследования показали, что наиболее значительные урожаи кормовых культур (в среднем за три ротации) получены при использовании 80 т/га ТНК и NPK: однолетних трав — 4,4 т/га; многолетних трав — 6,2 и картофеля — 7,1 т/га сухого вещества высокого качества. Содержание сухого вещества в клубнях картофеля в вариантах с NPK составило 18,0–18,8%, на органическом фоне — 18,4–18,9 и при комплексном применении удобрений — 17,1–17,7; в контроле — 19,6%. Количество крахмала в картофеле незначительно различалось по вариантам опыта и равнялось 12,6–13,1%. Содержание нитратов не превышало ПДК (250 мг/кг сырой массы). Количество сухого вещества в однолетних и многолетних травах изменялось незначительно и составляло 19,0–19,8 и 25,0–26,8% соответственно. Установлено, что удобрения способствовали повышению содержания сырого протеина в однолетних и многолетних травах до 13,1–15,0% (в контроле — 11,2%) и 8,8–10,6 % (в контроле — 8,1%) соответственно. The impact of various rates of organic and mineral fertilizers was analyzed in the Komi Republic on sod-podzolic soil with low loam content. The research took place at the Institute of Agricultural Biotechnology in 1978–2019. The goal was to test forage crop productivity and quality under fertilization and six-field crop rotation. Crop rotation happened as follows: potatoes, vetch-oat mixture overseeded by perennial grasses, first-year perennial grasses, second-year perennial grasses, vetch-oat mixture, potatoes. For 40 years the combination of mineral and organic fertilizers was the most effective. The highest yields for three rotations were observed under the application of 80 t ha-1 of peat-manure compost and NPK: annual grasses produced 4.4 t ha-1; perennial grasses — 6.2, and potatoes — 7.1 t ha-1 of high-quality dry matter (DM). Potato tubers accumulated 18.0–18.8% of DM under NPK application, 18.4–18.9 — under organic nutrition, 17.1–17.7 — when using complex fertilization, and 19.6% — in the control. Starch content varied within 12.6–13.1% in potatoes. Nitrate content did not exceed the maximum acceptable concentration (250 mg/kg of raw mass). DM concentrations amounted to 19.0–19.8 and 25.0–26.8% in annual and perennial grasses, respectively. Fertilization increased crude protein amount in annual and perennial grasses up to 13.1–15.0% (versus 11.2% in the control) and 8.8–10.6 % (versus 8.1%), respectively.

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