HIERARCHICAL INTEGRATION OF SIMULATION AND LINEAR PROGRAMMING TO ASSESS RISK-EFFICIENT CROPPING SYSTEMS
Abstract
Crop production systems are dynamic, stochastic and complex. System modifications interact to jointly affect overall performance and dynamics. For example, innovations in tillage or harvest operations could affect the timing of other field operations. Similarly, the introduction of new crops, such as energy crops, could alter the timed demand for resources and could drastically change farm income and income variation. The approach taken in this study is to combine elements of linear programming, risk analysis and simulation to provide a unified, hierarchical procedure for evaluating various cropping system alternatives. A generalized, multi-stage linear program is presented which schedules field operations and determines the crop mix which maximizes profit subject to resource availability and uncertainty. The linear program identifies sets of risk-efficient farm plans which can be further studied with a detailed farm simulator written in FORTRAN 77 and SLAM (Simulation Language for Alternative Modeling). The simulator is used to evaluate daily production dynamics, between-year linkages and the statistical distributions of farm profit and other performance measures. Finally, optimal farm plans can be identified based on stochastic dominance criteria and timeliness considerations. This type of analysis should help agricultural researchers make early evaluations of alternate cropping system scenarios. A detailed study is included to illustrate the hierarchical analysis procedure. The cropping system chosen for study was a typical, 300 hectare grain farm in west-central Indiana. Conventional crops currently being grown in Indiana are corn, soybeans and winter wheat. The analysis procedure was used to evaluate the production potential of a new crop, sweet sorghum, in competition with the conventional crops. Sweet sorghum (Sorghum biocolor (L.) Moench) is a leading contender in biomass energy systems because of its high yields of fermentable sugars and its adaptability to a wide range of climates. Results of the case study include evaluations of the time varying competition between crops for land, labor and machinery. Also, the commodity price relationships which were necessary for sweet sorghum to become a profitable alternative were determined.
Degree
Ph.D.
Subject Area
Agricultural engineering
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