Abstract.We present a crop plan that aims to maximize farmers’ returns and minimize production costs for the analyzed agricultural holding. This study describes a model that combines linear programming (LP) and the weighted goal programming (WGP) method with penalty functions to simultaneously satisfy a variety of goals within the tolerance interval bounds in terms of their weights. The results indicate that, from an economic perspective, WGP sub-model including LP gives a better solution than using the LP sub-model separately. We designed the model to handle five different types of field and vegetable crops during crop planning and was tested for WGP optimization [WGPSC1, WGPSC2, WGPSC3, and WGPSC4 (SC4 for testing model parameterization)) on four different scenarios. For example, the farmers’ returns in the WGP scenarios were higher or equal as in LP scenario (by approx. €100 to €110) while the costs were reduced (from €2.58 in the case of mechanical labor costs and to €1,376.66 for fertilizer costs). In addition, the combination of both serves as a more viable option for diversified and economically optimized crops to be included in crop plans. It is also important that the WGP calculated higher farmer returns, even though it was run on a cropping area that was 0.02 ha smaller than that in the LP. Further, the model was tested with a parameterization process to determine and explain the role of weights and penalty functions on the quality of the model results. Keywords: Agricultural application, Agricultural economics, Farmer’s return, Mathematical modelling.

A model for the optimization of daily feed rations for dairy cows on organic farms was developed and tested on a real case study (organic farm) from Slovenia. The methodological approach was based on a combination of linear programming (LP) and weighted goal programming (WGP) techniques. For the formulation of balanced rations, penalty function intervals were introduced. The model took into account five different nutritional and mineral requirements and it precisely calculated the daily rations for dairy cows. This model was used to calculate winter and summer rations using two different scenarios (WGP(SC1) and WGP(SC2)), where the net energy for lactation and the total cost of the rations each had a significantly different importance in the optimization process. The results show the WGP(sc2) feed rations are more expensive (summer for 1.19 center dot and winter for 1.10 center dot) and more balanced compare to WGP(sc1) and LP feed rations. WGP(sc1) feed rations have the same costs and also more balanced compare to LP feed rations. The balance of the feed rations confirms the fact that deviations from the daily nutrient requirements (never exceeded more than 1%) in the WGP are much lower in comparison to the LP rations.

The objective of this study was to develop a model to assess economical and balanced feed rations for sport horses. It was based on non-parametric modelling with a combination of linear programming and a multi-objective optimization technique: weighted goal programming. The method incorporates multiple goals into optimization. The technical data presented the feed nutritional value (dry matter, metabolizable energy, metabolizable protein, etc.) and nutritional requirements, which were represented in weighted goal programming as targets. The model was tested for optimization of winter and summer feed rations, where summer feed rations are more expensive but more balanced. Optimization results show that the method of weighted goal programming is more accurate and useful in practice compared with linear programming, where only one goal (economically optimal feed rationing) is taken into account.

ABSTRACT The need for reliable information in the organic farm planning process dictates the use of modern decision support methods. The methodology of an integrated deterministic simulation system application for decision-making support on organic farms is described in this article. The deterministic simulation system KARSIM 1.0 consists of 74 deterministic production simulation models that enable different types of costs and financial feasibility calculations for organic production and food processing. The KARSIM 1.0 was applied on a sample organic farm for the simulation of five different business alternatives. The simulation model results are further evaluated with two multi-objective analysis methods: analytical hierarchical process (Expert Choice Decision Support System software) and DEX-i expert system (computer software for multi attribute decision making). Alternative 3 (spelt grain processing) results with the highest multi-objective decision evaluation (Expert Choice = 0.275 and DEX-i evaluation = very good). The combination of deterministic cost simulation model and multi criteria decision analysis with the emphasis on financial, technological, market and risk objective presents a powerful decision support tool for organic farms, however, further improvement and development of proposed methodology would be suggested.

Multifunctionality as a feature of agriculture is subject to different interpretations, depending on the state and context. However, there is no comprehensive definition of this concept. Multifunctionality originates in the supposition that agriculture, apart from the production of food also has other broader social functions and aspects, such as maintaining production potentials, encouraging rural development (keeping the population in the country, cultivating the landscape), and protecting the environment. In the first chapter the authors present a view of the multifunctional nature of European agriculture, followed by a presentation of Slovene agriculture and its most important characteristics in different contexts – economic and social. If definitions of multifunctional agriculture published so far are taken into account, it may be stated that this process is well under way in Slovenia. A special part of this paper has been devoted to the empirical evaluation of this phenomenon, where the authors indicate an incomplete approach to testing and the difficulty in objective quantification of such a complex phenomenon. Above all, it is necessary to establish clear criteria for the follow-up of multifunctional agriculture and its influences on general social interests.

Slovene agriculture is going throughdrastic changes. Most of the land is stillowned by small farmers. The production isoriented to the market and is based on modernWestern technology. It is associated withincreasing pollution and is becoming a seriousthreat to biodiversity. Many of the wild plantsare endangered due to genetic erosion withinspecies. The traditional crops and varietiesare being replaced by imported materials andthe use of chemicals has been increasing. Manyof the traditional varieties have beenneglected and/or lost. The existing germplasmcollections are incomplete and frequently donot include traditional varieties. There areonly a few breeding organizations with limitedcapacities and collections. The legislation isnot efficient enough to protect the environmentand biotic diversity. Schools, media,religious, sport, tourist, and otherorganizations should be more active inpromoting the respect for biodiversity.

In diesem Beitrag sind die okonomisch Gesichtespunkte der verschiedenen Apfelerziehungssystemedargestellt.Die Indikatoren des okonomischen Erfolgs fur drei verschiedene Apfelanbaussysteme wurden mit einem technisch-okonomischen Simulationsmodel analysiert. Die Resultate dieses Modells wurden fur die Zusamenstellung eines linearen Programms gebraucht um optimale Structur der erweiterten Apfelplantage zu bestimmen. Simulationsmodel und die linear Optimierung sind mit dem Computerprogramm QPTPRO verbunden mit dem die Optimirung auf verschiedenen Familienbetrieben moglich ist. Die Optimirungen auf Modellbetriebe zeigte, dass die Dichtpflanzung der Apfel okonomisch berechtigt ist.