Mathematical modeling dynamics and economic for different systems / Dinâmica de modelagem matemática e econômica para sistemas diferentes (original) (raw)
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Use of SIDE Model for the Financial and Economical Analysis of an Agricultural Exploitation
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca: Horticulture, 2010
The current research offers information and useful tools for the management and economic administration of agricultural exploitations, reflected by the development of a complex informatic system. The informatics system for the economical diagnosis- SIDE facilitates the financial and economical analysis of an agricultural exploitation. The program allows the introduction and generates data for both the vegetal and animal production.The aim of this program is to offer the possibility for the potential users to valorise with results as good as possible the resources on which the farm dispose and includes a technical and economical indicators system regarding the performance and efficiency diagnosis analyze. System of indicators classified into specific indicators and outcome indicators. Among find these indicators: profit, balances interim administration, rates of profitability, gross margin, the threshold of profitability, the degree of indebtedness. These indicators are used to proje...
A whole-farm model for economic analysis in a goat production system in Mexico
In north-central Mexico, the production of goat meat is associated to summer cultivation crops for family consumption. The objective of this study was to construct a simulation model for the economic analysis in this goat±agricultural system. Linear programming was used to optimize system net income. Several scenarios were generated varying the price scenario (1992 and 1995) and the use of technology (traditional and recommended). The approach visualized the system general response and the impact of a subsidizing program. The model was limited to a maximum cultivation area of 64 ha and a maximum herd of 200 does. The model proved that recommended technology in 1992 increased the net income of the system, but it did not in 1995. In both cases, it was necessary to buy maize stubble to supply the requirements of dry matter animal intake. Traditional technology was more versatile to goat meat and maize stubble's price changes. The model selected a cultivated area of 64 ha for the 1992 price scenario as well as for 1995 when subsidies were included. However, as subsidies were removed in 1995 the model output was only 8 ha. When the surface of rainfed crops was 16 ha or more, the use of technology helped to increase the net income. Thus, subsidy policy induced an expansion of the agricultural cultivated area in the system. On the other hand, the largest incomes for all the modeled scenarios were noted when the herd size was maintained at 100 does. The scenarios presented express the rationality in the process of decision making by farm owners. For instance, they prefer grain crops instead of forages cultivation due to the subsidy policy; they do not use recommended technology since it is not rewarded economically; and they embrace the traditional system because it is more ¯exible to price changes. #
Revista Brasileira de Zootecnia, 2016
A linear programming mathematical model was applied to a representative dairy farm located in Brazil. The results showed that optimization models are relevant tools to assist in the planning and management of agricultural production, as well as to assist in estimating potential gains from the use of integrated systems. Diversification was a necessary condition for economic viability. A total cost reduction potential of about 30% was revealed when a scenario of lower levels of diversification was contrasted to one of higher levels. Technical complementarities proved to be important sources of economies. The possibility of reusing nitrogen, phosphorus, and potassium present in animal waste could be increased to 167%, while water reuse could be increased up to 150%. In addition to economic gains, integrated systems bring benefits to the environment, especially with reference to the reuse of resources. The cost dilution of fixed production factors can help economies of scope to be achieved. However, this does not seem to have been the main source of these benefits. Still, the percentage of land use could increase up to 30.7% when the lowest and the highest diversification scenarios were compared. The labor coefficient could have a 4.3 percent increase. Diversification also leads to drastic transaction cost reductions.
Financial Analysis of Crop-Livestock-Forestry Systems in Goias, Brazil
Journal of Agricultural Science and Technology B, 2019
Integration system is used to denote practices that combine systematic use of the land and technologies, in which forest species are used in conjunction with herbaceous plants and/or animals respecting a spatial or temporal arrangement. Knowing that this type of production seeks to balance ecological and economic factors, it is important to understand the financial benefits and risks involved in this production. Financial analysis, therefore, acts as an important analysis tool to foster this type of activity. The paper aimed to conduct analysis of investment risk of a crop-livestock-forestry system deployed in Brazil, comparing two different production scenarios, scenario I with 17 ha and scenario II with 25 ha. The risk analysis was performed using the Monte Carlo method and sensitivity analysis (by varying the factors: the discount rate, productivity and price). A cash flow was elaborated based on annual cost and revenues data of the agricultural crops (corn and soybeans), livestock and eucalyptus, using an interest rate of 6% per year. The results indicated that the optimal age for cutting the eucalyptus was at seven years on both scenarios; scenario I had better return on investment using deterministic and probabilistic methods; scenario I presents higher investments risks; there is a negative relation between discount rate and annualized net present value (ANPV); increased productivity of crops provides greater profitability to the system; there has been an increase in the economic viability of the system, as value has been added to the products. Monte Carlo method and the sensitivity analysis showed to be an appropriate tool to analyze the risk of crop-livestock-forestry systems, making it possible to foresee how the project will respond to possible scenarios.
EVALUATION OF FACTORS INFLUENCING FARM PROFIT IN EXTENSIVE RUMINANT SYSTEMS USING STRUCTURAL EQUATIONS (Atena Editora), 2023
A pecuária extensiva em geral é mais sustentável do que os métodos intensivos. No entanto, a sua rentabilidade é geralmente baixa, o que pode afectar a motivação dos jovens para iniciarem a criação de gado e muitas vezes leva-os a procurar emprego noutro local. O objetivo deste artigo é estudar os fatores que afetam o lucro agrícola das fazendas extensivas de ruminantes em áreas marginais do sul do Chile. Para isso, utilizamos a Modelagem de Equações Estruturais (SEM), que fornece uma visão aprofundada das relações de diferentes variáveis (itens) com o lucro da Fazenda (variável alvo). O construto exógeno obtido (variável estrutural), composto pelos itens Área de pastoreio, Mão de obra contratada e Unidades pecuárias totais (CN), exerce influência explicativa direta e significativa sobre o construto endógeno (variável econômica), que inclui os itens Custo do feno , Vendas Totais e Registros Econômicos, mostrando inclinação significativa e positiva na variável alvo (Lucro da Fazenda). Estas variáveis estruturais condicionam em grande medida todo o processo económico. No entanto, as decisões empresariais ligadas à gestão agrícola influenciam factores estruturais e afectam o valor das receitas, das despesas e do lucro agrícola. O estudo dos fatores que influenciam o lucro da Fazenda esclarece as principais fragilidades do sistema em termos de operação financeira, bem como possíveis melhorias, abrangendo as dimensões social, técnica e ambiental.
Mathematical modelling and economic evaluation
Mathematical Modelling, 1987
In small developing cotmtries many significant agroindustrial projects are not marginal. Therefore a model is proposed that includes all the main components of the sector. This model can be used to evaluate new projects, policies, to test the prevailing degree of market imperfection in the sector and in general to provide a better understanding of the sector so that the economic agents in it can increase their efficiency. This approach is based on Samuelson's proof that a spatial partial equilibrium system can be converted into a maximization problem. The approach is exemplified by a model of the chilean wheat sector in 1978.
Journal of Dynamics and Games, 2019
Extensive livestock farmers have to manage climate risk. Therefore , there is a need to generate quantitative tools to evaluate the biophysical and economic impacts on extensive farming based on native grasslands. We present an ecological model based on the predator-prey approach, used to simulate the effect of forage deficiency on the farm's economic performance. Different scenarios of animal stocking rate and carrying capacity of grassland are considered to assess the impact of forage deficiency in spring. Results suggest a cubic response of Gross product per hectare as function of Gross margin, according Mott's theoretical model for meat production on grassland systems in response to stocking rate. The maximum value of this cubic response function strongly depends on the initial grass height and climate scenarios. The initial grass height is critical to maximize secondary productivity and farm economic results. Scenarios including grass reserves can buffer the deficiency on grass growth rates and pasture offer, as occurs in drought periods at the time when farmers try to make animals gain liveweight. Our analysis reinforces the usefulness of forage assignment adjustment by modulating stocking rate to improve liveweight gain and economic results under climate change conditions.
Agricultural Systems, 2019
, steep slopes, high elevations, fragmented fields) along with the regular risks inherent to agriculture, such as economic fluctuations. We thus hypothesized that simultaneously producing dairy and beef herds (i.e., "mixed cattle systems") on mountain farms is a good compromise between a farm's expected profits and the variation in these profits. To explore the profit stability of mixed cattle systems in the face of price variations, we used the bioeconomic optimization model Orfee to simulate one farm strategy: adjusting the number of cattle. The model simulated three mixed cattle systems (dairy and beef herds) and two specialized cattle systems (dairy or beef herd) on two farms in southern Auvergne (France) that differed in agronomic potential, field configurations and animal productivity. A local sensitivity analysis of beef, milk and feed price was combined with a global sensitivity analysis based on metamodels. Results indicated that the number of cattle was adjusted as a function of resource availability, farm structure, and product prices on the market. Compared to specialized systems, mixed cattle systems usually seemed an effective strategy to manage economic risk, with good compromise between expected profits and variation in profits.
2020
Adopting wheat that has additional aptitudes to the only function of grain production in crop-livestock integration systems may be an economical alternative for better using the vast expanse of farmland during the autumn-winter period in southern Brazil. The objective of this study was to evaluate economically the crop-livestock integration (CLI) system, in comparison to systems of grain production only. The treatments consisted of six CLI systems, containing either annual winter pasture, soil cover or dualpurpose cereals: system I (wheat/soybean and vetch/maize); system II (wheat/soybean and black oat/maize pasture); system III (wheat/soybean and black oat/soybean pasture); system IV (wheat/soybean and pea/maize); system V (wheat/soybean, dualpurpose triticale/soybean and vetch/soybean); and system VI (wheat/soybean, dual-purpose white oat/soy and dual-purpose wheat/ soybean). The treatments were repeated four times in the randomized block design. Calculation of the operational cos...
Agricultural Systems, 1994
We developed a deterministic, multi-period linear programming (LP) model of the dual-purpose (milk-beef) cattle production system in the Sur del Lago region of Venezuela. The LP model selected animal, forage, and purchased feed activities subject to nutritional, land, and herd composition constraints to maximize discounted herd net margin. A cattle nutrition model prOVided original coefficients for feeds and animal nutrient require ments. Revised coefficients resulted from an iterative procedure to avoid errors from the interaction between diet and requirements. Model applications demonstrated that alternatives to traditional feeding practices are profitable and nutritionally feasible. However, the benefits of alterna tive nutritional management depend on labor availability. Our simulation of price policy changes in the late 1980s indicated that dual-purpose pro ducers may e~perience increased relative incentives for milk production under the new input and output prices. The model is adaptable to dual purpose production systems elsewhere in Latin America.