Applied Engineering in Agriculture Vol. 33(4): 479-489 © 2017 American Society of Agricultural and Biological Engineers ISSN 0883-8542 https://doi.org/10.13031/aea.11876 479 PERFORMANCE EVALUATION AND FIELD CHARACTERIZATION OF THE SIFANG MINI RICE COMBINE HARVESTER S. K. Amponsah, A. Addo, K. A. Dzisi, J. Moreira, S. A. Ndindeng ABSTRACT. Performance of a Sifang mini rice combine, originally developed in China, was evaluated under local farmer field conditions in Benin. Results from field evaluation show that the combine worked satisfactorily on less dense rice fields with minimal weeds at grain moisture contents between 19.1% and 20.1% w.b. on soils with moisture content from 23% to 33% d.b. while causing no significant changes to soil physical properties. With harvesting speed ranging from 0.8 to 4.5 km/h, the harvester had a field capacity of 0.10 to 0.39 ha/h and consumed fuel of up to 11 L/ha while having track slip of 6% to 9%. Harvesting using 2- and 1-L gear offered the best efficiency for IR841 and Nerica L20 rice varieties, respectively. As harvesting speed increased, harvesting efficiency decreased and crop throughput increased irrespective of rice variety. The combine produced low mechanical grain damage with total grain loss ranging from 1.43% to 4.43% and 1.85% to 5.6% for the IR841 and Nerica L20 rice varieties, respectively. At an investment cost of US$5000 and hiring at US$10 per h, owning the mini combine harvester becomes profitable after 342 h of machine use; equivalent to approximately 133 ha of paddy field harvested at a harvesting capacity of 0.39 ha/h. Further testing of the combine under a wide range of crop and soil conditions across different agro-ecological zones and economic comparison with manual harvesting is recommended. This would offer smallholder farmers diverse options of rice harvesting mechanization to facilitate future adoption of improved technologies. Keywords. Crop throughput, Field capacity, Field efficiency, Grain loss, Mini rice combine, Sifang. ice is the most rapidly growing food commodity in sub-Saharan Africa (SSA) and is now SSA’s second largest source of food energy (Seck et al., 2013). In sub-Saharan Africa, rice is one of the most important crops and its production represents an important significant activity to overcome food shortage and improve self-sufficiency for both local consumption and export (Saed et al., 2011). A report by USAID (2009) indicated that more rice is consumed in West Africa than in other parts of the continent. In 2000, the import surplus of rice in Africa reached 4.35 million t, making it the top rice- importing region in the world (Kubo and Purevdorj, 2004). Aside from production constraints, such as land tenure, removal of subsidy on inputs, and absence of water control systems, which are major reasons for Africa’s high dependence on imported rice (USAID, 2009), unavailability of appropriate harvest and post-harvest machinery and technologies is a great disincentive to most rice farmers, especially in the SSA. Manual harvesting of rice is a laborious, time-consuming and costly operation which requires about 100-150 persons hour labor to harvest 1 ha of paddy field (Alizadeh and Allameh, 2013). The problem of harvesting and threshing is worsened with the introduction of new rice varieties because of the greater amount of crop that has to be handled (Khan, 1971; IDRC, 1976). Takeshima et al. (2013) also indicated in a study that while a combine harvester takes a few hours to harvest 1 ha, seven people are required to harvest the same area in two days. Moreover, manual harvesting is associated with sizable grain losses, grain damage, and additional time to harvest. Unfortunately, more than 70% of the rice in Africa is harvested by hand using a sickle, knife, or machete (Rickman et al., 2013). Mechanization of rice harvesting has been identified as the most promising area for intervention and for realizing the potential of this crop (Rickman et al., 2013). Currently there is a dearth of research information on mechanization of rice production in Benin and the West African sub-region as a whole, especially in the area of harvesting. Most international and national research efforts in rice production have been focused on developing and releasing improved varieties for enhanced yields, but the same cannot be said for rice mechanization. AfricaRice (2015a) reported that when production was doubled in The Gambia between 2007 and 2010 for Nerica rice variety, farmers found it difficult to Submitted for review in May 2016 as manuscript number MS 11876; approved for publication by the Machinery Systems Community of ASABE in April 2017. The authors are Shadrack K. Amponsah, Doctoral Candidate, Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana; Ahmad Addo, ASABE Member, Associate Professor, Department of Agricultural and Biosystems Engineering, KNUST, Kumasi; Komla A. Dzisi, Associate Professor, Department of Agricultural and Biosystems Engineering, KNUST, Kumasi; Jean Moreira, Scientist, Africa Rice Centre, Cotonou, Benin; Sali A. Ndindeng, Scientist, Africa Rice Centre, Cotonou, Benin. Corresponding Author: Shadrack Kwadwo Amponsah, CSIR-Crops Research Institute, P.O. Box 3785, Kumasi, Ghana; phone: +233 243571076/ +233 206255587; email: skamponsah@hotmail.com. R