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Assessment of field machinery performance in variable weather conditions using discrete event simulation

De Toro A., Alfredo (2004). Assessment of field machinery performance in variable weather conditions using discrete event simulation. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae. Agraria, 1401-6249 ; 462
ISBN 91-576-6485-4
[Doctoral thesis]

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Abstract

Daily field operations were simulated for 15-20 years with a model built using a discrete event simulation technique in order to analyse machinery performance on cereal farms as influenced by daily weather. Daily soil workability was inferred by means of moisture threshold values and simulated soil moisture contents from another model (the SOIL-model) using weather data from Malmö and Uppsala, Sweden. The simulation model for field machinery operations had the capacity to determine operation dates for sowing and harvesting for individual fields and years. The dates were utilized to estimate annual timeliness costs, their mean and variance for each of the machinery sets assessed. Using this procedure to determine timeliness costs, total machinery costs (specific machinery + labour + timeliness costs) were also estimated for varying machinery set sizes, farm sizes, number of drivers and locations. Some of the findings were: (a) within certain limits of machinery size and for a given farm, there was not only one set identified as ‘the least-cost set’ but several; (b) sets with high daily effective field capacity showed low variation in annual timeliness cost; and (c) the machinery set to be selected should be the largest one among those with similar ‘least-cost’ on account of its lower annual variation, which in turn should lead to lower risks. The simulation model for field operation was also applied to a case study where a machinery co-operative was evaluated. Machinery pooling enabled farms to reduce total costs by about 15% and investment requirements by about 50%. Average timeliness cost estimates were of some consideration and their annual range was large (10-120 EUR ha-1), even for the machinery systems with sufficient capacity. A seedbed field experiment on the effects of spring preparation date and associated soil water contents in a clayey soil found that preparation date had only a minor effect on soil compaction but the fraction of fine aggregates in the seedbed increased with time.

Authors/Creators:De Toro A., Alfredo
Title:Assessment of field machinery performance in variable weather conditions using discrete event simulation
Year of publishing :May 2004
Volume:462
Number of Pages:69
Papers/manuscripts:
NumberReferences
ALLI. de Toro, A. & Hansson, P.-A. 2004. Analysis of field machinery performance based on daily soil workability status using discrete event simulation or on average workday probability. Agricultural systems 79, 109-129. II. de Toro, A. & Arvidsson, J. 2003. Influence of spring preparation date and soil water content on seedbed physical conditions of a clayey soil in Sweden. Soil & tillage research 70, 141-151. III. de Toro, A. 2004. Influence of various factors o timeliness costs and their variability on arable farms (Manuscript) IV. de Toro, A.; Hansson. 2004. Machinery Co-operatives - A Case Study in Sweden. Biosystems engineering, 87(1), 13-25.
Place of Publication:Uppsala
ISBN for printed version:91-576-6485-4
ISSN:1401-6249
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:N Machinery and buildings > N20 Agricultural machinery and equipment
Subjects:Not in use, please see Agris categories
Agrovoc terms:equipment, equipment performance, costs, simulation models, seedbeds, soil water content, sweden
Keywords:Discrete event simulation, field operations, machinery management, model, seedbed, seedbed properties, soil workability, Sweden, timeliness costs
URN:NBN:urn:nbn:se:slu:epsilon-260
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-260
ID Code:553
Department:?? 4072 ??
Deposited By: Alfredo de Toro A.
Deposited On:05 May 2004 00:00
Metadata Last Modified:02 Dec 2014 10:05

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