optimization of machinery use on farms with emphasis on timeliness costs

this study was conducted to determine timeliness costs in using machinery and their effects on farmers’ revenues. in addition, optimum cropping pattern was compared with the existing one assuming removal of timeliness cost. for the purpose of the study, mixed integer and linear programming methods were used. the study was conduced in marvdasht region in southern iran. the data were collected through interviews with a sample of 80 farm managers. selected farmers were divided into six groups in terms of farm size and farm machinery use, and in each group a representative farm was selected. findings of the study showed that 19 percent of farmers owned and 81 percent rented tractor and, as a result, timeliness cost was considerable for the latter group. the results also showed that for the farmers whose farm size was more than 10 hectares, it was justified to buy tractor and rent a combine. the results revealed that there was a gap between the optimum and existing cropping patterns with respect to timeliness cost and gross margin increased mostly in the groups that owned tractor and more than five hectares of land. finally, in order to minimize timeliness cost, joint ownership of machinery by neighboring farms was recommended.