SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

Majewski, Edward; Was, Adam.

In the paper the regional, optimization model of agriculture and its use for predicting probable reactions of farmers and assessing the impact of the adaptation processes in the farming sector to agricultural policy changes and macroeconomic developments are presented. Two-phases modeling approach has been applied, with the use of linear programming, static optimization models a farm model, used to optimize the production structure of the farms typical for the region, and an agricultural sector model, used to determine the optimal farm and production structures within a region. An attempt have been made to incorporate in the model both micro and macroeconomic parameters. The result show, that different scenarios adjustments in farming sector in the...

Tipo: Conference Paper or Presentation

Palavras-chave: Regional model of agriculture; Optimization; Farm strucure; Agribusiness; C61.

Ano: 2005

URL: http://purl.umn.edu/24571

A Watershed-Based Economic Model of Alternative Management Practices in Southern Agricultural Systems

Paudel, Krishna P.; Hite, Diane; Intarapapong, Walaiporn; Susanto, Dwi.

We investigated the environmental impacts of alternative cultural practices within a watershed under different water quality standards. We used experimental data on nutrient runoff to determine the optimal amount of broiler litter application in hay production in Louisiana. To compensate for the lack of experimental data, we used biophysical simulation models to find the optimal combination of agricultural best-management practices in a watershed in Mississippi. The results indicated that stricter environmental standards lower total profit potential and litter utilization.

Tipo: Journal Article

Palavras-chave: Broiler litter; Cropping systems; Optimization; Watershed level modeling; Water quality; C6; Q1; Q25; D21.

Ano: 2003

URL: http://purl.umn.edu/43213

Climate change impacts on crop risks and agricultural production in Finland

Lehtonen, Heikki; Kujala, Sanna.

Climate Change is expected to improve crop production conditions significantly in northern Europe. In some studies a significant increase in agricultural production is expected in northern Europe while drought is becoming gradually more severe in Southern Europe and France due to climate change. Our analysis provides one of the first steps in evaluating the possible scale of changes in agricultural production and use of farm land in Finland, so far one of the least favoured agricultural areas in Europe. Drought in early summer and low temperature sum during growing period are currently the main growth limiting factors in Finland. Even though the early part of the growing period is likely to be dry also in the future, both mean and variance of crop yields...

Tipo: Conference Paper or Presentation

Palavras-chave: Climate change; Agriculture; Risk aversion; Mean-variance analysis; Sector models; Optimization; Crop production; Finland; Crop Production/Industries; Environmental Economics and Policy; Risk and Uncertainty.

Ano: 2007

URL: http://purl.umn.edu/9259

Managing multiple-use resources: optimizing reservoir water use for irrigation and fisheries

Tran, Lap Doc; Schilizzi, Steven; Chalak, Morteza; Kingwell, Ross S..

Policy makers in Vietnam face difficult choices when deciding reservoir water management strategies between irrigation and fisheries. In this paper, an economic optimization model for water management is developed to facilitate policy makers' decision making. The model includes the response of rice and fish yields to key factors including reservoir water levels, the timing and quantity of water release, and climatic conditions. The model accounts for variation in rainfall patterns, irrigation requirements, and the demand for low water levels during the fish harvest season. The model is applied to the Daton reservoir in the south of Vietnam to maximize profits in each of three production scenarios where the reservoir's water is used for: (1) only producing...

Tipo: Conference Paper or Presentation

Palavras-chave: Multiple-use resources; Reservoir water management; Optimization; Irrigation; Fisheries; And stochastic; Production Economics.

Ano: 2011

URL: http://purl.umn.edu/100721

OPTIMIZING COMPLEX BIOECONOMIC SIMULATIONS USING AN EFFICIENT SEARCH HEURISTIC

Kazmierczak, Richard F., Jr..

For simulation to be truly useful for investigating many problems in agricultural economics, non-simplifying optimization techniques need to be employed. General methods for simulation optimization that do not inhibit system characterization or analysis are available, and they would appear to provide much of the mathematical and optimizing rigor demanded by economists. This paper describes the theory and algorithm of a robust and efficient simulation optimization approach, the Complex Method. An example of implementing the algorithm is illustrated using a pest management problem.

Tipo: Working or Discussion Paper

Palavras-chave: Simulation; Optimization; Complex Method; Hill-climbing; Research Methods/ Statistical Methods.

Ano: 1996

URL: http://purl.umn.edu/31661

Optimierung unter Unsicherheit mit Hilfe stochastischer Simulation und Genetischer Algorithmen – dargestellt anhand der Optimierung des Produktionsprogramms eines Brandenburger Marktfruchtbetriebes

Musshoff, Oliver; Hirschauer, Norbert.

Optimization has been recognized as a powerful tool in teaching and research for a long time. In spite of its well known problem solving capacity, some methodological obstacles have persisted over the years. The main problem is that stochastic variables and their correlations cannot be adequately accounted for within traditional optimization procedures. In this paper, we develop a methodological mix of stochastic simulation and a heuristic optimization procedure which has become known as genetic algorithms. The simulation part of the mix allows for the consideration of complex information such as stochastic processes; the genetic algorithms-part ensures that the method remains manageable in terms of required time and resources. We demonstrate the decision...

Tipo: Journal Article

Palavras-chave: Optimization; Optimal production program; Stochastic simulation; Genetic algorithms; Uncertainty; Stochastic processes; Farm Management; Risk and Uncertainty.

Ano: 2004

URL: http://purl.umn.edu/97454

Management System for Harvest Scheduling: The Case of Horticultural Production in Southeast Spain

Perez-Mesa, Juan Carlos; Galdeano-Gomez, Emilio; Aznar-Sanchez, Jose A..

www.ifama.org

Tipo: Journal Article

Palavras-chave: Horticultural farmer; Optimization; Planning; Mathematical programming; Marketing; Cooperative; Agribusiness; Crop Production/Industries; Demand and Price Analysis; Farm Management; Land Economics/Use.

Ano: 2011

URL: http://purl.umn.edu/117598

Physiological quality of soybean seeds under different yield environments and plant density

Baron,Felipe A.; Corassa Junior,Geomar M.; Fioresi,Dejales; Santi,Antônio L.; Martini,Renan T.; Kulczynski,Stela M..

ABSTRACT Yield potential of agricultural fields associated with plant spatial arrangement could determine the physiological quality of soybean (Glycine max L.) seeds. Thus, this study aimed to evaluate the physiological quality of soybean seeds from different yield environments and plant densities. Experiments were carried out in Boa Vista das Missões-RS, Brazil, during the 2014/2015 growing season. Yield environments were delineated by overlapping yield maps from the 2008, 2009/2010 and 2011/2012 growing seasons. The experimental design was a randomized complete block in a 2 x 5 factorial arrangement with two yield environments (low and high) and five plant densities, with four replicates. Two varieties were tested: Brasmax Ativa RR (10, 15, 20, 25 and 30...

Adjustment of mathematical models and quality of soybean grains in the drying with high temperatures

Palavras-chave: Glycine max (L.); Seed vigor; Yield maps; Optimization.

Ano: 2018

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000400237

Coradi,Paulo C.; Fernandes,Carlos H. P.; Helmich,Jean C..

ABSTRACT The aim of this study was to evaluate the influence of the initial moisture content of soybeans and the drying air temperatures on drying kinetics and grain quality, and find the best mathematical model that fit the experimental data of drying, effective diffusivity and isosteric heat of desorption. The experimental design was completely randomized (CRD), with a factorial scheme (4 x 2), four drying temperatures (75, 90, 105 and 120 ºC) and two initial moisture contents (25 and 19% d.b.), with three replicates. The initial moisture content of the product interferes with the drying time. The model of Wang and Singh proved to be more suitable to describe the drying of soybeans to temperature ranges of the drying air of 75, 90, 105 and 120 °C and...

Valorization of sunflower meal through the production of ethanol from the hemicellulosic fraction

Palavras-chave: Dimensioning; Optimization; Post-harvest..

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000400385

Tavares,Bruna; Sene,Luciane; Christ,Divair.

ABSTRACT Sunflower is among the major oil seeds crop grown in the world and the by-products generated during the seeds processing represent an attractive source of lignocellulosic biomass for bioprocesses. The conversion of lignocellulosic fibers into fermentable sugars has been considered as a promising alternative to increase the demand for ethanol. The present study aimed to establish the fermentation conditions for ethanol production by Scheffersomyces stipitis ATCC 58376 in sunflower meal hemicellulosic hydrolysate, through a 23 CCRD (Central Composite Rotational Design) factorial design. Under the selected conditions (pH 5.25, 29 ºC and 198 rpm) the final ethanol concentration was 13.92 g L-1 and the ethanol yield was 0.49 g g-1.

Nitrogen efficiency in oats on grain yield with stability

Palavras-chave: By-product; Biomass; Xylose; Biofuel; Optimization.

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001101036

Silva,José A. G. da; Goi Neto,Constantino J.; Fernandes,Sandra B. V.; Mantai,Rubia D.; Scremin,Osmar B.; Pretto,Rafael.

ABSTRACT Nitrogen (N) is the nutrient most absorbed by the oat crop. Unfavorable climate conditions decrease its efficiency, generating instability and reduction in yield. The objective of this study was to improve N use efficiency in oat grain yield by the economic value of the product and of the input and by models that scale the stability, considering systems of succession of high and reduced residual-N release in favorable and unfavorable years for cultivation. The study was conducted in the years 2013, 2014 and 2015 in two systems of succession (soybean/oat, maize/oat) in randomized blocks with eight replicates, using the N-fertilizer doses of 0, 30, 60 and 120 kg ha-1. The N-fertilizer dose for maximum economic efficiency in oats should be considered...

Estimate of the optimal level of concentrates for dairy cows on tropical pastures by using the concept of marginal analysis

Palavras-chave: Avena Sativa; C/N; Predictability; Biometric models; Optimization.

Ano: 2016

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001201095

R. Bras. Zootec.

Oliveira,André Soares de; Campos,José Maurício de Souza; Lana,Rogério de Paula; Detmann,Edenio; Valadares Filho,Sebastião de Campos.

It was adopted in this work a methodology to estimate the optimal level of concentrate food for dairy cows on tropical pastures based on the theory of marginal analysis. An empiric model was developed and validated for application of the methodology using a database composed of 62 means of treatments from 32 studies in which milk production was evaluated regarded to the levels of concentrate feeding. Milk production (MP) showed quadratic behavior in response to concentrate intake (CI): MP (kg/cow/day) = 10.554 + 1.5855CI - 0.0552CI². Evaluation of the MP values observed over the predicted ones pointed the non-rejection of the null hypothesis, indicating that the model can be applied on the prediction of milk production, and consequently, on the optimal...

Optimum contribution selection using differential evolution

Palavras-chave: Marginal production response; Milk production; Modeling; Optimization.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000900024

R. Bras. Zootec.

Carvalheiro,Roberto; Queiroz,Sandra Aidar de; Kinghorn,Brian.

A program to determine optimum contribution selection using differential evolution was developed. The objective function to be optimized was composed by the expected merit of the future progeny and the coancestry among selected parents. Simulated and real datasets of populations with overlapping generations were used to validate and test the performance of the program. The program was computationally efficient and feasible for practical applications. The expected consequences of using the program, in contrast to empirical procedures to control inbreeding and/or to selection based exclusively on expected genetic merit, would be the improvement of the selection response and a more effective control of inbreeding.

A simplified Excel® algorithm for estimating the least limiting water range of soils

Palavras-chave: Evolutionary algorithms; Genetic response; Inbreeding; Optimization; Selection.

Ano: 2010

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010000700005

Scientia Agricola

Leão,Tairone Paiva; Silva,Alvaro Pires da.

The least limiting water range (LLWR) of soils has been employed as a methodological approach for evaluation of soil physical quality in different agricultural systems, including forestry, grasslands and major crops. However, the absence of a simplified methodology for the quantification of LLWR has hampered the popularization of its use among researchers and soil managers. Taking this into account this work has the objective of proposing and describing a simplified algorithm developed in Excel® software for quantification of the LLWR, including the calculation of the critical bulk density, at which the LLWR becomes zero. Despite the simplicity of the procedures and numerical techniques of optimization used, the nonlinear regression produced reliable...

Mathematical tool to size rural digesters

Palavras-chave: Nonlinear regression; Spreadsheet software; Optimization; Soil physics; Soil quality.

Ano: 2004

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000600013

Scientia Agricola

Florentino,Helenice de Oliveira.

Anaerobic digesters have been highlighted due to the current energy crisis and its consequent search for alternative energy sources, allied to the intense process of livestock farming and agriculture modernization, which besides demanding a lot of energy, produces a great amount of crop and animal residues, most of the times generating sanitary problems. The aim of this work is to provide a mathematical tool to establish parameters for projects of construction of rural digesters, considering the response to energy demand, the suitability of the dimensions of the systems, yield factors and the guarantee of functionality. Non-linear optimization models, of easy resolution, for the three main types of rural digesters were formulated in this way. With the...

On the controlling of temperature: A proposal for a real-time controller in broiler houses

Palavras-chave: Mathematical model; Optimization; Parameters for designing.

Ano: 2003

URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000100028

Scientia Agricola

Detsch,Denise Trevisoli; Conti,Dante; Diniz-Ehrhardt,Maria Aparecida; Martínez,José Mario.

ABSTRACT: Environmental conditions in broiler houses, specifically temperature, are key factors that should be controlled to ensure appropriate environment for broiler rearing. In countries with tropical/subtropical climate, like Brazil, high temperatures produce heat stress to animals, affecting the production process. This research proposes a real-time model to control temperature inside broiler houses. The controller is a self-correcting model that makes real-time decisions on the ventilation system operation (exhaust fans) together with temperature prediction at the facility. The model involves partial differential equations (PDE) whose parameters are updated according to data registered in real-time. Some experiments were carried out at a pilot farm...