Technical, Economic and Environmental Evaluation on Mechanical Rice Straw Gathering Method

Abstract

Rice straw is a rice by-product, which is currently mostly wasted in Vietnam, in particular in the Mekong delta. At present, the cost of straw gathering is increasing because of the increased use of combine harvesters. High labor cost and lack of labor makes manual collection unfeasible. Farmers therefore often just burn it, which causes pollution, increased greenhouse gas emissions and loss of opportunities to value add. An economic and environmental evaluation and technical field testing of a straw baler with 4 ha/day capacity was therefore conducted in Long An province. During the field testing data on the gathering capacity, fuel consumption, labor requirement and other cost items were collected. The test results showed that the baling cost is US$19.0 per ton of rice straw, the pay-back period of 2.1 years and the internal rate of return of 38%. In addition to the baling cost, the transportation cost varies from US$24 for a distance of 100 km to US$32 for 150 km. The benefits of the machine are not only economical but also include the reduction of field burning.

An Assessment on the Technical and Economic Feasibility of Mechanized Rice Straw Collection in the Philippines

“…The amount of rice collected per unit area was based on the amount collected by the baler. To facilitate comparison across seasons and locations, the fresh rice straw yields were converted into their dry equivalent of 11% moisture content based on the study of [27]. The moisture content of rice straw (RS) at harvest was obtained using the standard air oven method.…”

“…Mechanized rice straw collection, like any other mechanical process, requires capital investment. A small round baler made in Japan that uses an electromechanical twine threading system to collect dried straw costs about US$8500 [27]. In Brazil, a large round and square baler for processing sugarcane straw (bale weight of 381 kg round and 294 kg square) would require an investment of US$80,585 and US$146,341, respectively [25].…”

“…Additional costs for operating the baler would include the twine, fuel, lubricants, and oil. An economic analysis conducted in Vietnam indicated that this small round baler could be operated at a cost of US$19.0 per ton of straw, and the investment cost could be recovered in 2.1 years at an internal rate of return (IRR) of 38%, assuming an annual operation of 40 days [27].…”