Application of a Model for Planning Transportation and Spread of Digested Slurry to Farmlands

In this paper, application of a model for planning transportation and spread of digested slurry to farmlands is presented, which was developed by the authors. The model estimated a plan without intermediate storage tanks for transportation and spread of annual volumes of 10,000 m super(3) digested slurry, based on existing statistical data. Three cases were given for the estimation. Case 1-S modeled relatively short-distance transportation of digested slurry, and the farm area consisted of 220 ha of paddy fields and 30 ha of upland fields. By contrast, Case 2-S and 2-M modeled relatively long-distance transportation, and the farm area consisted of 100 ha of paddy fields and 150 ha of upland fields. Numbers of vacuum trucks in all units were equal in the application term for Case 1-S and 2-S whereas specific numbers of vacuum trucks were set for each field to reduce labor for Case 2-M. Case 1-S showed the lowest annual labor and the shortest annual travel distance for vacuum trucks of the three cases. However, Case 1-S demanded the most spreaders and trucks because most transportation and spreading were concentrated in the term before rice planting in Case 1-S. According to the comparison of Case 2-S and 2-M, variable settings for vacuum truck numbers reduced the initial expenditures for machinery and operations.