PLANNING THE COLLECTION AND TRANSPORTATION OF RICE STRAW IN ,

Y.-C. Chiu, S.-J. Guo, S. Chen, C.-Y. Tsai, J.-M. Tsai

ABSTRACT. The purpose of this study was to design a rice straw collection and transportation method. Four bale forms were designed for processing 75,474 tons of rice straw produced in Nantou County: large large-round bale, small large- round bale, large small-round bale, and small small-round bale. Nine trucks, individually weighing 2, 3, 3.49, 6.2, 7.5, 11, 15.5, 17, and 24 tons, were used for transportation analysis. This study proposed six hypothetical scenarios for rice straw collection and transportation. For each scenario, centralized and noncentralized transportation were implemented, in which centralized transport involves a route from various townships to neighboring farmers’ associations to the final rice- straw treatment site, and noncentralized transport is direct delivery from various townships to the final treatment site. A geographic information system was consulted to construct a map for the locations of various townships and to assess the optimal routes for rice straw collection and transport. Considering the trucks of varying weights, the transportation costs of various rice straw delivery methods were calculated to determine the optimal collection and transportation locations. The results revealed that the optimal plant locations for rice straw processing and distribution are the rice straw production areas in , Nantou, Township, and Jhushan Township. A centralized transportation of small large-round bale was the optimal method and form. The cost of rice straw collection and transportation is US$31.66 and US$20.7 per ton, respectively. A 3.49-ton truck was used for first-stage transportation, traveling an average distance of 15.9 km; a 15.5-ton truck was used for second-stage transportation, traveling an average distance of 24.9 km. Additionally, US$1.5776 million is required annually for collecting and delivering rice straws in Nantou County. In this study, a rice straw collection and transportation method was devised for Nantou County and plant establishment at the final sites for rice straw treatment was assessed. In the future, a decision-supporting system for rice straw collection and transportation can be further developed. Keywords. Bioethanol, Collection and transportation, Geographic information system, Rice straw, Waste utilization.

ice, mainly grown in Asian regions, is one of the per hectare of rice field can be produced (Chen, 2008), world’s central food crops, the cultivation of yielding a total of 1,564,572 tons of rice straw. Consequent- which accounts for over 11% of the world’s ly, a lack of control over rice farmers burning rice straws arable land (Maclean et al., 2002). Substantial would further intensify environmental pollution. The rice Ramounts of waste are produced during rice cultivation, straw is of low value and thus the constraining of harvesting, and postharvesting. During postharvest handling, transportation costs is key issue. Therefore, developing a rice rice straw is typically cut into 30- to 60-mm pieces by using straw collection and transportation system is crucial for a combine harvester. After several days of sun exposure, rice alternative utilization methods to be viable. straw is buried in soil to decompose into fertilizer or is Nantou County is located at the geographic center of burned to ash and integrated into soil. Smog caused by Taiwan and is the only noncoastal county in Taiwan. frequently burning rice straw in open fields is commonly Nantou County is mountainous with abundant tourism seen in Taiwan during rice harvest season. Such emissions resources. Therefore, tourism is a key source of income for typically cause air pollution and endanger traffic safety (Su Nantou. However, burning rice straw has caused air et al., 2008). According to Agricultural Statistics Yearbook pollution, reduced visibility, and affected the environmental (Council of Agriculture, 2012), 260,762 ha are used for rice quality in Nantou. Due to higher population density in cultivation in Taiwan, and approximately 6 tons of rice straw Taiwan, most of the farmlands are close to highways and resident houses. In order to avoid the pollution problems caused by burning rice straws, Taiwan’s government has Submitted for review in April 2014 as manuscript number ITSC been considering encouraging farmers to collect rice straws 10718; approved for publication by the Information, Technology, Sensors, by supplementary allowance. The collected rice straws will & Control Systems Community of ASABE in June 2016. The authors are Yi-Chich Chiu, ASABE Member, Professor, Syun- be sent to incinerators as waste combustion material or Jhih Guo, Graduate Student, Department of Biomechatronic Engineering, reused for other applications. Therefore, developing a rice National Ilan University, Taiwan; Suming Chen, Professor, Chao-Yin straw collection, transportation, and recycling system for Tsai, Post Doc. Researcher, and Jin-Ming Tsai, Research Assistant, controlling farmers in burning rice straw in order to reduce Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taiwan. Corresponding author: Yi-Chich Chiu, 1, Sec. 1, air pollution warrants immediate attention. Shen-Lung Rd, Yilan 26041, Taiwan; phone: +886-3-9317804; e-mail: [email protected].

Applied Engineering in Agriculture Vol. 32(5): © 2016 American Society of Agricultural and Biological Engineers ISSN 0883-8542 DOI 10.13031/aea.32.10718 1 Rice straw collection and transportation is time- Table 1. The distribution of rice production consuming and labor-intensive. Therefore, developing a in Nantou County in 2012. Paddy Field The Ratio of time- and cost-effective rice straw collection and Area Rice Straw Paddy Field Area to transportation system is required. Fang et al. (2013) (ha) (ton) Township Area (%) investigated the rice straw collection and transportation and Caotun Township 3,090 18,540 29.7 analyzed the cost for collection and transportation of rice Jhushan Township 552 3,312 2.23 Mingjian Township 551 3,306 6.63 straw in Taiwan. Velázquez-Martí and Annevelink (2009) Nantou 520 3,120 7.26 used ArcGIS, a geographic information system, to establish Renai Township 84 504 0.07 a network for planning biomass collection and site Puli Township 75 450 0.46 selection; they defined the collection and transportation Lugu Township 77 462 0.54 Jiji Township 46 276 0.93 range as a radius of 4 km and the regional production to be Shueili Township 20 120 0.19 over 1,000 tons per year, to develop an optimal collection Guoshing Township 6 36 0.03 and transportation system. Total 5,021 30,126 1.22 Devlin et al. (2008) devised a route for Irish truck transportation through a geographic information system and Caotun Township (3,090 ha) is the largest, followed by route weighting. Using this method, heavy items were those in Jhushan Township, Mingjian Township, and selected for determining the lowest transportation cost. In Nantou. In 2012, these regions produced 18540, 3313, addition, they indicated that the shortest routes are not 3313, and 3120 tons of rice straw, respectively. Approxi- necessarily the most economical routes, because the mately 30,000 tons of rice straw waste is annually produced maintenance cost for the shortest route was substantially in these areas because the main crop is rice. Other Nantou higher than that for routes that considered route weighting. County townships do not specialize in producing rice and, Zhang et al. (2011) indicated that the selection of a therefore, generate comparatively less rice straw waste. production plant location is crucial for cost-effective biofuel production. The location of a biofuel plant RICE STRAW COLLECTION AND TRANSPORTATION substantially affects transportation costs. A geographic PROCESSES information system was used to determine the lowest Figure 1 shows the process flow for rice straw treat- transportation cost based on the optimal location for a ments. After a combine harvester is used for harvesting biofuel plant, road and rail transportation systems, and rice, the remaining rice straw in the field must be sundried biological material distribution. for 2 to 3 weeks to reduce the moisture content to prevent Rice straw can be used as animal feed and as footwear the rice straw from decaying (fig. 1), which impedes the or coating material; it can also be used for building baling process. Rice straw is baled into large round or small thatched cottages, making rope and straw mats, producing round bales. A tractor attached to a hay collector is used to organic fertilizer, bioderived fuels, or bioethanol, and can collect the rice straw, after which it is processed in a hay be buried or burned in open fields or in incinerators. baler to produce large round bales. By contrast, a rice straw Currently, rice straw is rarely used as animal feed, as baler is used on the field to produce small round bales, footwear or coating material, or for building thatched which are tiny and light. Therefore, workers stack these cottages; in addition, these applications only require small small bales in the field before transferring them to a truck amounts of rice straw; therefore, these treatment processes for subsequent transportation. Large round bales are were not considered in this study. directly moved to a cargo truck by using a farm truck. The purpose of this study was to design an adequate method for rice straw collection and transportation in Nantou County, Taiwan. This study estimated the rice straw production and distribution of various local rice cultivation areas in Nantou, and assessed plant construction for rice collection and transportation to formulate a plan for reducing logistics costs and enhancing transportation efficiency. This study also adopted ArcGIS to identify the most suitable routes, analyze relevant costs, and develop an optimal rice straw collection and transportation system.

MATERIALS AND METHODS RICE STRAW PRODUCTION IN NANTOU COUNTY Table 1 shows the distribution of the rice production in Nantou County in 2012. The rice cultivation area in Nantou County is 5,012 ha, producing approximately 30,126 tons of rice straw. Openly burning rice straw or dumping it into rivers or open fields severely pollutes the environment. Among various townships, the area of paddy fields in Figure 1. Process flow of rice straw treatment.

2 APPLIED ENGINEERING IN AGRICULTURE

Subsequently, the rice straw bales on cargo trucks are Calculating the Allowable Load of Round Bales for a transported to various destinations to undergo their final Truck treatments (e.g., produced into ropes, straw mats, Truck capacity and the maximum load-carrying capacity bioethanol, or burned). Because the rice straw required for of a truck were used to derive the maximum load of round producing rope and mats must be arranged in a specific bales that the trucks can carry. First, truck capacity was directional order, it must be baled into small round bales, divided by the bale volume to obtain the theoretical value of which are typically packed directionally. By contrast, the the maximum bale load in terms of capacity. Second, the rice straw required for producing bioethanol or for burning maximum load-carrying capacity of a truck was divided by can be baled into large or small round bales without the bale weight to attain the theoretical value of the considering directionality. maximum bale load in terms of weight. Finally, from the intersection of the two aforementioned conditions, the ideal Baling Rice Straw number of round bales that a truck can carry can be obtained. Currently, hay balers and rice straw balers are the The allowable cargo height was used to calculate the agricultural machinery used for baling rice straw. After rice maximum number of bale levels per bale stack. Considering is harvested, a combine harvester is used for threshing, and placing round bales in the two-dimensional areas of truck the resulting rice straw is spread across the field. When the beds, three types of stacks are possible: a flat stack, moisture content of the rice straw is reduced to a certain horizontal stack, or vertical stack. The actual number of level, a tractor is used to drag a baler to bale the rice straw, round bales that a truck can carry can be obtained by which is then transported by a truck to the required identifying the maximum value for the three stack types. The destination. A hay baler can bale rice straw into large large- ideal number and the actual number of round bales that the round bales or small large-round bales. A rice straw baler trucks can carry were used to derive the optimal number of can produce large small-round bales and small large-round round bales that the trucks can transport. Autodesk 3ds Max bales. Table 2 shows the specifications for the various was used to draw a schematic diagram to simulate the nine round bales. trucks of various weights carrying the four types of round Rice Straw Transportation rice straw bales uni-directionally arranged and optimally This study investigated existing truck types for the stacked within load limits. Figure 2 shows an example of a transportation of round rice straw bales. Because the cargo 15.5-ton truck carrying large small-round bales. This truck load and the number of trips vary with the type of truck can carry 160 round bales (i.e., 4.8 tons), and the stack in this used, the capacities of various trucks were calculated. example is within the 10.63-ton load limit. Table 3 shows the maximum cargo capacity of various Final Treatment and Use of Rice Straw trucks, which was calculated by multiplying the truck bed This study investigated four types of rice straw treat- length by the truck bed width and the allowable cargo ment: burning in an incinerator, making straw rope, making height. The allowable cargo height was calculated by straw mats, and producing bioethanol. subtracting the truck bed height from a statutory height limit on vehicles. According to the Road Traffic Act, the height limit for small trucks below 3.5 tons is 2.85 m from the ground and that for large trucks above 3.5 tons is 3.5 m from the ground.

Table 2. Specifications of the rice straw bales. Radius (m) Height (m) Weight (kgf) Large large-round bale 0.7 1.4 250 Small large-round bale 0.6 1.2 220 Large small-round bale 0.25 1.1 30 Figure 2. Using 3ds Max to simulate the scenario of stacking large Small small-round bale 0.2 0.8 20 small-round bales on a 15.5-ton truck.

Table 3. Specifications of nine transportation trucks. Length of Truck Bed Width of Truck Bed Height of Truck Bed Allowable Cargo Height Allowable Load Volume Truck Type (mm) (mm) (mm) (mm) (ton) (m3) 2-ton Veryca 2,306 1,481 744 2,106 0.8 7.2 3-ton Mitsubishi Delica 2,850 1,635 801 2,048 1.2 9.5 3.49-ton Isuzu 4,215 1,475 848 2,001 1.4 12.4 6.2-ton Isuzu 4,215 1,475 755 3,045 4.1 18.9 7.5-ton Isuzu 4,952 1,680 800 3,000 4.7 24.9 11-ton Hino 7,050 2,175 900 2,900 7.7 44.4 15.5-ton Hino 8,190 2,445 900 2,900 10.6 58.1 17-ton Hino 8,250 2,460 900 2,900 12.2 58.8 24-ton Hino 8,805 2,490 1,085 2,715 16.1 59.5

32(5): 3 a) Burning rice straw in a refuse incinerator. 81% to 85% of rice straw is combustible. Burning rice straw can reduce its volume and produce thermal energy. In addition, the combustion conditions in an incinerator and pollutant emissions can be controlled to prevent air pollution, which typically results when burning rice straw in open fields. b) Making straw rope. Straw rope and mats made from rice straw are evenly soft and can be used in various industries (e.g., agriculture, fishing, horticulture, forestry, sanitary, ceramics, marble, mining, ply- wood, cane sugar, and foundry). Rope maker’s winch is currently used for fabricating straw rope, which does not require strenuous effort. However, preparing the materials for rope production is, by contrast, an Figure 3. Centroids of various townships in Nantou County. exhausting task. c) Making straw mats. Straw mats were previously used centroid locations of these townships facilitated in agriculture. Straw mats can be used to cover rice determining site selection and transportation routes. The straw during seedling cultivation for preventing weed farmers’ associations in the townships were used as the growth and sun exposure and maintaining soil mois- transshipment points and the collection and transportation ture. In addition, straw mats are used to protect crops sites for six scenarios were analyzed. (e.g., peanuts grown in coastal regions) from strong winds. Route Planning d) Producing bioethanol. Ethanol fuel produced from In this study, the seven models of rice straw collection grain and cane sugar is called first-generation bioeth- and transportation points were as follows: (a) the centroids anol, whereas those from agricultural waste such as for the 13 townships in Nantou County, (b) the centroids rice straw, bagasse, corn stalks, or wood fiber is for the rice straw production area in the 13 townships, called second-generation bioethanol. The technology (c) the centroids for the 11 townships in Nantou County for converting rice straw fiber into ethanol has been excluding Renai and Sinyi Township, (d) the centroids for developed for commercial production, which should the rice straw production area in the 11 townships except be realized in the near future. for Renai and Sinyi Township, (e) the centroids for Caotun Township, Nantou, Mingjian Township, and Jhushan ROUTE PLANNING FOR RICE STRAW COLLECTION AND Township, (f) the centroids for the rice straw production TRANSPORTATION area in the Caotun, Nantou, Mingjian, and Jhushan, and the In this study, route planning involved creating centroids (g) the Wurih incineration plant. In this study, the centroid for the collection and transportation sites and analyzing the locations of the geographic area and rice production area transportation routes. These centroids were devised for were considered. Renai and Sinyi Townships were 13 townships in Nantou County and the farmers’ excluded because these townships are located in mountain associations in the 13 townships, and the six scenarios are areas, thus the rice straw production areas and the paddy as follows: (a) the centroids of 13 townships in Nantou fields are small and transportation costs are high, as County, (b) the centroids of the rice straw production area indicated in a survey on the yearly production of rice straw in the 13 townships, (c) the centroids of 11 townships in in Nantou County. Two methods for rice straw collection which Renai and Sinyi Townships were excluded, (d) the and transportation were applied, namely, centralized (i.e., centroids of the rice straw production area in the transport route from the townships to nearby farmers’ 11 townships (Renai and Sinyi Townships were excluded), associations to the final treatment site) and noncentralized (e) the centroids of the Caotun, Nantou, Mingjian, and (from the townships directly to the final treatment site) Jhushan Townships, and (f) the centroids of the rice straw production area in Caotun, Nantou, Mingjian, and Jhushan Table 4. The coordinates for the centroids of Townships. ArcGIS 10.1 was used to determine the optimal various townships in Nantou County. routes and calculate the transportation and truck costs. Township Longitude Coordinates Latitude Coordinates Caotun 120°46'34.07" 23°58'37.18" Planning Collection and Transportation Sites Nantou 120°42'26.55" 23°55'05.11" In analyzing the centroids for the 13 townships in Mingjian 120°42'02.02" 23°51'16.97" Jhushan 120°42'41.55" 23°41'37.19" Nantou County, assume that rice crops are evenly Jhongliao 120°51'59.37" 23°53'00.45" distributed over a local area and the centroid of the local Jiji 120°49'17.42" 23°48'23.04" area is an irregular-shaped geometric center. Then, Lugu 120°47'14.74" 23°42'17.86" Guoshing 120°55'26.53" 24°00'42.21" AutoCAD was used to create the centroids of various Shueili 120°54'35.82" 23°45'48.05" townships in Nantou County (fig. 3). Google Earth was Puli 121°03'41.30" 23°57'52.88" employed to convert the coordinates of various townships Yuchih 121°01'44.44" 23°49'37.84" into latitude and longitude (table 4). Identifying the Renai 121°10'08.57" 24°02'49.16" Sinyi 120°57'42.51" 23°41'26.91"

4 APPLIED ENGINEERING IN AGRICULTURE transportation. The software ArcGIS was used to determine C. Tax costs for agricultural machinery: Assume that tax optimal routes based on the shortest path and the cheapest is 2% of farm machinery costs. The calculation for- transportation cost, which were analyzed in this study. mula for tax costs is presented below. Tax costs: COST CALCULATION FOR RICE STRAW COLLECTION AND TRANSPORTATION P0021× .  mu Rice straw is used to produce bioethanol or burned in an ×  (3) HSTon incinerator; for these purposes, rice straw is baled into large round bales, and the directionality of the rice straw is not Fixed costs of agricultural machinery are the sum of considered. Small round bales are directional; therefore, depreciation costs, interest costs, and tax costs, as follows: they can be used for making rope and mats, producing bioethanol, or burning in an incineration plant. Fixed costs: Mechanized rice straw baling can be categorized into P1×−()α 1 P1 ×+()α β 1 two approaches according to bale shape and size. One ×+ × × NH× S 2 HS method involves using a rice straw baler developed in (4) Taiwan; the other method involves using a hay baler to P0021× .  mu +× compress rice straw into round bales. These baling methods HSTon require different agricultural machinery and equipment for rice straw processing and delivery. Variable costs for agricultural machinery: Baling rice straw into large round bales requires a tractor A. Maintenance costs: Maintenance costs vary according onto which a hay collector is hooked for gathering rice to usage methods, status of machinery, workload, and straw. Subsequently, another tractor onto which a hay baler operating environments. According to an investiga- is hooked is used to produce large round bales, which are tion, the maintenance costs of agricultural machinery then arranged in a field and transported on a farm truck to a are approximately 0.031% of the purchase price of cargo truck. Therefore, the agricultural machinery required new agricultural machinery (ASAE Standards, 1963). for large round bale production includes a hay collector, a Equation 5 is the calculation formula for maintenance hay baler, a tractor, and a farm truck. Baling rice straw into costs: small round bales requires a tractor onto which a rice straw Maintenance costs: baler can be hooked. Workers stack the small round bales in a field, which are then transported using a farm truck to a P00311× .  mu ×  (5) cargo truck. Therefore, the agricultural machinery required 100 S Ton for small round bale production includes a rice straw baler, a tractor, workers for stacking bales, and a farm truck. B. Tractor usage costs: A tractor can be used for various The costs for using agricultural machinery for baling, operations. Assume that tractor usage costs per hour collecting, transporting, and using rice straw include fixed are B; thus, the cost is calculated as: costs (i.e., machine depreciation, interest, and tax costs) Tractor usage costs: and variable costs (i.e., maintenance, tractor usage, fuel, miscellaneous supplies, and labor costs). The calculation B1mu×  methods are as follows.  (6) HSTon Fixed costs for agricultural machinery: A. Depreciation costs: Using the straight-line deprecia- C. Fuel costs: Fuel consumption for diesel engines is tion method, assume that farm machinery costs are P approximately 12.4 hp/h. Assume that horsepower monetary unit (mu), the residual value ratio after N output is 80%, diesel price is D dollars/L, and tractor years is α, the number of yearly usage hours is H, and horsepower is T ps, then the fuel cost is calculated the operation ability of agricultural machinery is S using equation 7. tons/h. The formula is expressed as: Fuel costs: Depreciation costs: ××××11mu ×−() T 80% D  (7) P1α 1mu 12. 4 S Ton ×  (1) NH× STon D. Costs of miscellaneous supplies: Assume that the B. Interest costs for agricultural machinery: Assume that cost of miscellaneous supplies is 15% of fuel costs. the rate of interest per annum is β. Equation 2 is the Equation 8 is the calculation formula for the costs of calculation formula for interest costs. miscellaneous supplies. Interest costs: Costs of miscellaneous supplies: ×+() mu p1α β 1mu Miscellaneous costs× 15% (8) ×× (2)  2HSTon Ton

32(5): 5 E. Labor costs: Labor costs include machine operators required for the work. Equations 1 to 10 are used to and on-site workers. Assume that the hourly wage is calculate related costs (tables 5 and 6). Q, the number of daily working hours is 8, and the Baling operations for producing small round bales number of people employed is M. The labor cost is necessitate a rice straw baler and at least four workers, calculated using equation 9: including a baler operator, two workers (to move and stack the bales), and one farm truck driver. Currently, the baling Labor costs: process occurring in a farm entails a baler operator to produce bales, farm field workers to move and stack the ××1mu QM  (9) bales, which are transported to a cargo truck using a farm STon truck. At this point, the rice straw baler can be moved to F. The variable costs of agricultural machinery are the another area for baling operations, while the cargo truck sum of maintenance, tractor usage, fuel, miscellane- driver delivers them to the required destination. Considering ous supplies, and labor costs. Equation 10 is the large round bale production, a hay baler is used and at least calculation formula for variable costs. three workers (including a hay collector operator, a baler operator, and a farm truck driver) are required. Specifically, Variable costs: the hay collector operator collects the rice straw in the field P00311× . B 1 1 1 and then delivers them to another area. A hay baler operator ×+×+××××T80% D produces large round bales, which are then transported by a 100 S H S 12. 4 S (10) farm truck driver to a cargo truck. 1mu +×+××fuel cost 15% Q M  As shown in table 5, the fixed cost for a ton of large round STon bales is 41.33 US cents higher than the fixed cost for a ton of small round bales. Large round bales are slightly more G. Transportation costs: Assume that truck rental is C expensive than small round bales because rice straw mu/day (eight hours for a day), average fuel con- collection is required during a baling operation. As shown in sumption is G (km/L), transportation distance per day table 6, the variable cost for a ton of small round bales is is K (km), and the operation ability for transportation 23.61 US cents higher than that for a ton of large round per day is L kg. Equation 11 is the calculation formu- bales. This price difference is attributed to the additional bale la for transportation costs. stacking process required during baling operation. The baling Transportation costs: cost per ton of small round bale is US$54.89 and that of large round bales is US$31.69, which differs by US$23.2, GKDCmu××+ indicating a minimal difference in the fixed cost of both  (11) LKg bales. This difference is caused by variable costs, which substantially affect the total costs of the baling operation. RESULTS AND DISCUSSION Table 5. Fixed costs for small and large round bale collection. OST NALYSIS OF TRAW OLLECTION C A S C Unit Cost of Unit Cost of Considering small round bales, a newly purchased rice Small Round Bales Large Round Bales straw baler, a Sun L-500 (San-Shen Agricultural Machinery Items for Cost-Effective Analysis (US cents/ton) (US cents/ton) Science and Technology Co., Ltd., Yilan, Taiwan) is used Hay collector depreciation costs - 8.33 as an example. The price of the rice straw baler is Hay collector interest costs - 0.71 Hay collector tax costs - 1.85 US$13,300. This machine can bale 2 tons of rice straw/h Baler depreciation costs 125.00 148.44 and produce 100 bales/h, with each bale weighing 20 kg. Baler interest costs 10.69 12.70 Regarding large round bales, collecting rice straw is first Baler tax costs 27.78 32.98 required and then a hay baler is used for baling. Using a Farm truck depreciaiton costs 46.87 46.87 Farm truck interest costs 4.01 4.01 newly purchased hay collector as an example, its price is Farm truck tax costs 10.42 10.42 US$6,700. This piece of equipment can collect 15 tons of Total fixed costs 224.77 266.31 rice straw per hour. The price of a newly purchased hay baler is between US$23,300 and US$40,000; hence, the Table 6. Variable costs for small and large round bale collection. average price is US$31,700. Hay balers can process 4 tons Unit Cost of Small Unit Cost of Large of rice straw/h and produce 16 bales/h, with each bale Round Bales Round Bales weighing 250 kg. Collecting and baling rice straw requires Items for Cost-Effective Analysis (US cents/ton) (US cents/ton) Maintenance costs 206.67 259.19 a tractor with a functional power take-off (PTO) shaft. Tractor usage costs 3,333.33 2,111.10 Therefore, a tractor driver is required and the operation Fuel costs 278.33 176.27 efficiency is assumed to be 80%. Costs of miscellaneous supplies 41.75 26.44 Small round bales are short and light; therefore, farm Labor costs 333.33 211.10 Farm field worker costs 952.38 - field workers are needed to move and stack them in a field. Farm truck maintenance costs 77.50 77.50 Stacking 35 round bales/h requires two farm field workers. Farm truck fuel and usage costs 7.14 7.14 Farm trucks, with the ability to move 20 tons of round Farm truck miscellaneous 1.07 1.07 bales/h, are priced at approximately US$50,000 and price supplies costs Farm truck driver costs 33.33 33.33 varies according to brand and weight. One truck driver is Total variable costs 5,264.84 2,903.14

6 APPLIED ENGINEERING IN AGRICULTURE

PLANNING THE ROUTE THAT YIELDS THE LOWEST transportation is higher than that of centralized transportation. TRANSPORTATION COST Rice straw is typically transported along farmlands that TOTAL COSTS FOR RICE STRAW COLLECTION AND are accessible through agricultural roads, which large TRANSPORTATION trucks often cannot use. Thus, the weight of a truck for Various rice straw bales differ in weight and volume, first-stage transportation is limited to below 3.5 tons (i.e., which influence the number of bales that a truck can carry 2-, 3-, and 3.5-ton trucks). These three trucks are combined and the number of trips required. Equations 1 to 10 are used with six other types of trucks (i.e., 6.2-, 7.5-, 11-, 15.5-, 17-, to calculate the collection costs of various types of bales. and 24-ton trucks) for transshipment. With the As shown in tables 8 and 9, small large-round bales are the 18 combinations coupled with the route distance optimal form for transporting to the Wurih incineration determined by ArcGIS, the lowest transportation cost can plant. During centralized transportation, 3.49-ton truck is be obtained using equation 11. In addition, the 12 scenarios used in the first stage to transport the bales from the farm to described in Section 2.3 are also included for analysis. neighboring farmers’ associations (average distance of Transportation costs are calculated based on truck rental, 13.706 km), and 15.5-ton truck is used in the second stage driver wages, and truck fuel costs. Truck rentals and fuel to transport the bales from the farmer associations to the costs vary according to truck weight. When a 3.49-ton incineration plant (average distance of 37.774 km). By truck is used to transport small large-round bales, the using equation 11, the transportation cost per ton is assumptions for calculating unit cost are as follows: Fuel US$21.76 and the collection cost per ton is US$31.66. The consumption is 0.1 L/km; the load capacity is 660 kg, the total collection and transportation cost for 30,126 tons of transportation speed is 60 km/h, diesel price is US$1.08 per rice straw in Nantou County is US$1.60973 million. L, and the driver wages are US$53.33 per day. Although a According to the analysis of 12 scenarios, the first-stage round trip is required for rice straw transportation, a truck centralized transportation involves transporting to the rice carries rice straw only during outbound trips. Therefore, the straw production area in Caotun Township, Nantou, load capacity per truck is 330 kg; the fuel cost for a truck Mingjian Township, and Jhushan Township, in which the carrying 330 kg of rice straw and traveling 480 km per day shortest route is from the centroid of Mingjian Township to (i.e., 8 hours) is US$51.52 (i.e., 0.1 × 1.08 × 480); driver the Mingjian farmers’ association (distance of 2.473 km), wage is US$53.33 per day; and truck rental is US$83.33. followed by that from the centroid of Nantou to the Nantou Therefore, the unit transportation cost is US$1.19/ton·kg farmers’ association (distance of 2.536 km). The shortest (i.e., [53.33+83.33 +51.52]/[330×480]). Using the transportation route for second-stage transportation is from aforementioned assumptions, the unit transportation costs the Nantou farmers’ association to the rice straw production for various trucks carrying various types of rice straw bales area in Caotun, Nantou, Mingjian, and Jhushan Township can be obtained. (distance of 3.231 km), followed by that from the Mingjian As shown in table 7, the scenario for the lowest centralized farmers’ association to the rice straw production area in transportation cost is to transport rice straw from farm fields to Caotun Township, Nantou, Mingjian Township, and nearby farmers’ associations to the rice straw production area Jhushan Township (distance of 7.096 km). Overall, the in Caotun Township, Nantou, Mingjian Township, and shortest total centralized transportation distance is Jhushan Township. A 3.49-ton truck is used for first-stage 5.767 km from Nantou to the production area because the transportation traveling an average distance of 15.911 km. A treatment sites at Caotun, Mingjian, and Jhushan 15.5-ton truck is used for second-stage transportation traveling Townships are located near Nantou. an average distance of 24.92 km. The transportation cost for The optimal method is to transport rice straw from farm small large-round bales is US$20.7 per ton, and that for small fields to the rice straw production area in Caotun, Nantou, small-round bales is US$17.5 per ton. According to table 8, Mingjian, and Jhushan Townships. The first-stage and the scenario for the lowest noncentralized transportation cost is second-stage transportation distances are 15.911 km and to transport rice straw on a 3.49-ton truck from farm fields to 24.92 km, respectively. The transportation cost per ton is the rice straw production area in Caotun Township, Nantou, US$20.7, the optimal bale pattern is small large-round bale, Mingjian Township, and Jhushan Township (an average and the collection cost per ton is US$31.66. The total cost transportation distance of 37.071 km). The transportation cost for rice straw collection and transportation is US$1.57760 for large large-round bales is US$29.66 per ton, and that for million, the lowest cost among the 12 scenarios. small small-round bales is US$26 per ton. For both centralized and noncentralized transportation, transporting rice straw to CONCLUSION the rice straw production area in Caotun Township, Nantou, This study planned and analyzed the optimal modes for Mingjian Township, and Jhushan Township is the least rice straw collection and transportation in Nantou County. expensive. The average distance for centralized transportation According to the results, a centralized transportation from is 3.75 km longer than that for noncentralized transportation. the 13 townships in Nantou County to the centroid location Because agricultural roads are typically used, only trucks of the rice production areas in Caotun Township, Nantou, weighing below 3.49 tons can be used for first-stage Mingjian Township, and Jhushan Township yielded the transportation. Therefore, the cost of noncentralized least cost at US$1.5776 million per year.

32(5): 7 Table 7. Optimal rice straw collection and transportation method in various hypothetical scenarios and related costs (centralized transportation). The Optimal Model for Various Scenarios Bale Truck Weight Collection Cost Transportation Cost Total Cost in Centralized Transportation Form (1st 2nd)[a] (US dollars/ton) (US dollars/ton) (1000 US dollars) The centroid of the 13 townships in Nantou County SLR[b] 3.49  15.5 31.66 22.53 1,632.83 SSR[b] 3.49  15.5 54.86 19.3 2,234.33 The centroid of the rice straw production area in the SLR 3.49  15.5 31.66 21.33 1,596.67 13 townships SSR 3.49  15.5 54.86 18.06 2,197.20 The centroid of the 11 townships excluding Renai and SLR 3.49  15.5 31.66 20.89 1,583.42 Sinyi SSR 3.49  15.5 54.86 18.26 2,203.20 The centroid of the rice straw production area in the SLR 3.49  15.5 3166 21.26 1,594.67 11 townships excluding Renai and Sinyi SSR 3.49  15.5 54.86 17.86 2,191.17 The centroid of Caotun Township, Nantou, Mingjian SLR 3.49  15.5 31.66 21.13 1,590.67 Township, and Jhushan Township SSR 3.49  15.5 54.86 18.06 2,197.20 The centroid of the rice straw production area in Caotun, SLR 3.49  15.5 31.66 20.7 1,577.60 Nantou, Mingjian, and Jhushan SSR 3.49  15.5 54.86 17.5 2,180.13 To Wurih incineration plant SLR 3.49  15.5 31.66 21.76 1,609.73 SSR 3.49  15.5 54.86 18.76 2,218.27 [a] 1st 2nd: 1st denotes the truck weight for the first-stage transportation; 2nd denotes the truck weight for the second-stage transportation [b] SLR represents small large-round bales and SSR denotes small small-round bales

Table 8. Optimal rice straw collection and transportation methods in various hypothetical scenarios and related costs (noncentralized transportation). The Optimal Model for Various Scenarios Bale Truck Collection Cost Transportation Cost Total Cost in Noncentralized Transportation Form Weight (US dollars/ton) (US dollars/ton) (1000 US dollars) The centroid of the 13 townships in Nantou County LLR[a] 3.49 31.66 39.6 2,146.97 SSR[a] 3.49 54.86 34.6 2,695.27 The centroid of the rice straw production area in the LLR 3.49 31.66 33.46 1,962.20 13 townships SSR 3.49 54.86 29.16 2,531.60 The centroid of the 11 townships excluding Renai and LLR 3.49 31.66 33.96 1,977.27 Sinyi SSR 3.49 54.86 29.8 2,550.67 The centroid of the rice straw production area in the LLR 3.49 31.66 34.03 1,979.27 11 townships excluding Renai and Sinyi SSR 3.49 54.86 29.63 2,545.63 The centroid of Caotun, Nantou, Mingjian, and Jhushan LLR 3.49 31.66 37.73 2,090.73 SSR 3.49 54.86 32.56 2,634.00 The centroid of the rice straw production area in the LLR 3.49 31.66 29.66 1,847.73 Caotun, Nantou, Mingjian, and Jhushan SSR 3.49 54.86 26 2,436.20 To Wurih incineration plant LLR 3.49 31.66 38.06 2,100.80 SSR 3.49 54.86 33.2 2,653.10 [a] LLR represents large large-round bales and SSR denotes small small-round bales

The costs of the two-stage centralized transportation Chen, S. (2008). Study of resource utilization of agricultural waste method are lower than the costs of the one-stage non- which causes air pollution. Final report of research project. centralized transportation method. This study also assessed Nantou County Gov., Taiwan: EPA. the optimal methods for transporting rice straw to the Council of Agriculture. (2012). 2012 Agricultural Statistics Yearbook. : Council of Agriculture. Retrieved from Wurih incineration plant in and the related costs. http://www.coa.gov.tw The results showed that the cost of the centralized Devlin, G. J., McDonnell, K., & Ward, S. (2008). Timber haulage transportation method, (i.e., first sending the rice straw routing in Ireland: An analysis using GIS and GPS. J. Transport from various townships to farmers’ associations and then to Geography, 16(1), 63-72. the Wurih incineration plant) is lower than the that of the http://dx.doi.org/10.1016/j.jtrangeo.2007.01.008 noncentralized transportation method, yielding a difference Fang, S. S., Chen, S., Tsai, J. M., Tsai, C. Y., & Chen, Y. L. (2013). of US$491,070. A 3.49- and 15.5-ton truck is optimal for Study on the model of collection and transportation for rice the first-stage and second-stage transportation, respectively. straw in Taiwan. J. Agric. Machinery, 22, 35-56. Finally, the optimal bale form is small large-round bale. Maclean, J. L., Dawe, D. C., Hardy, B., & Hettel, G. P. (2002). Source book for the most important economic activity on earth (3rd ed.). Wallingford, U. K.: Cabi. ACKNOWLEDGEMENTS Su, M. H., Jun, I. G., Wang, J. B., & Huang, S. (2008). The We gratefully acknowledge the financial assistance of development potential of rice straw fiber alcohol. In Energy the Environmental Protection Bureau, Nantou County report (pp. 11-13). Taipei, Taiwan: Bureau of Energy, Ministry Government, Taiwan. of Economic Affairs. Velazquez-Marti, B., & Annevelink, E. (2009). GIS application to define biomass collection points as sources for linear programming of delivery networks. Trans. ASABE, 52(4), 1069- REFERENCES 1078. http://dx.doi.org/10.13031/2013.27776 ASAE Standards. (1963). Cost and use, farm machinery. St. Joseph, Zhang, F., Johnson, D. M., & Sutherland, J. W. (2011). A GIS- MI: ASAE. based method for identifying the optimal location for a facility to convert forest biomass to biofuel. Biomass Bioenergy, 35(9), 3951-3961. http://dx.doi.org/10.1016/j.biombioe.2011.06.006

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