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Africa Rice Center (AfricaRice)
Africa Rice Center (AfricaRice)

Manual labor is the cornerstone of most African agriculture but often falls disproportionately on women and children. A partnership between AfricaRice, NARS and private sector organizations in Senegal is lessening the load of drudgery and improving the usable yield and marketability of rice.

Haphazard harvesting and rudimentary post-harvest handling were identified in the mid-1990s as major problems in the Senegal River Valley by field surveys which attributed post-harvest crop losses of up to 35% to the inefficiency of manual threshing. Poor harvesting means not all grain or potentially useful straw is harvested. Such losses are compounded if threshing is inefficient at separating the grain or it produces damaged and split grains susceptible to storage damage and of lower marketable value.

Manual threshing is labor-intensive and backbreaking and mainly carried out by women rice farmers. Expensive and unreliable combined harvesters failed to provide an answer and the only available small-scale thresher in Senegal was not very efficient as it could not properly separate grains from straw after threshing.

Partnership, first between AfricaRice and international scientists at IRRI in the Philippines, identified a prototype Asian rice thresher-cleaner, and then embraced national researchers in ISRA and SAED, local master craftsmen and end-users, to develop an African technical solution that is affordable, locally-constructed and acceptable to everyone in the rice-growing community, including women.

Where manual threshing yields one tonne of paddy per day, the ASI—taking its name from ADRAO (French acronym of AfricaRice)-SAED-ISRA—produces 6 tonnes of paddy. With a grain-straw separation rate of 99%, no additional labor is required for sifting and winnowing.

A high internal rate of return (IRR) and benefit cost ratio made the ASI extremely attractive for use in the Senegal River valley, with an average purchase price of 2.8 million FCFA—around US$ 5000. Even at this price, which is several times the cost of similar non-adapted Asian machines, and taking a pessimistic view on seasonal performance, the ASI had an IRR of just under 50% in the original financial analysis.

When the ASI works 90 days, the benefit cost ratio reaches 2.3, well above standard guidelines. The economic life of an ASI is assumed to be five years, with financing over three years, and a salvage value of 30% of the purchase price. In practice, the ASI’s real-life performance ensures the initial cost and debt charges can be readily paid off earlier.

ASI has become a big hit in the Senegal River valley since its commercial release in 1997 (see Table 1) and its contribution was recognized in 2003 when the President of Senegal presented the ASI team with his special prize for science research. More than 50% of the total paddy produced in Senegal is now threshed with the ASI thresher-cleaner, and the proportion of grain threshed by ASI is increasing in other countries where similar partnerships have developed machines to suit local needs and capacities.

Overall labor demand is lower with the ASI, eliminating one of the most back-breaking tasks for women and children, and freeing family labor for other activities. For the investor, the potential returns to the ASI are greater than with the alternatives under similar conditions. Faster working lessens post-harvest delays that can affect grain quality. Higher quality grain is a prerequisite for competitiveness against imports that cost African countries much valuable foreign exchange.

ASI can even process wet straw, and is equally effective whether the rice has been manually cut or machine harvested. Local artisans (AGRITECH, Momar Dieng) and a medium-scale agricultural machinery factory (SISMAR) built the ASI prototypes for field testing with local farmers’ organizations to ensure acceptability when the new machines were finally rolled out.

Africa Rice Center, ISRA and SAED are now using this ASI partnership model in an alliance for a further development of rice harvesting technology. This time the partnership is focused on adapting a small-scale harvester from IRRI. Successful field trials of the harvester took place in Senegal in 2005 and the first production versions are expected to roll out in time for next year’s rice harvest. It is possible to transfer the 12 hp ASI engine to the ISA harvester to save costs, and the engine could also be used for powering a milling machine.

Table 1. Spillover from the ASI thresher cleaner


Local name


Machines in use

Use rate (%)



 AfricaRice, ISRA, SAED, SISMAR, AGRITECH, Local artisans, Producer groups

> 250





> 50




IER, Office du Niger, local artisans

> 100


Burkina Faso


INERA, CGF, PAFR, producer groups, local artisans





  MADR, World Bank, KAPONG Project



Côte d’Ivoire


ANADER, Local artisans



Harvesting can be a major bottleneck for irrigated rice growers because yields are relatively high and they rely on external manual labor. The successful use of improved varieties means that yields have increased to around 6 t/ha and compounded an existing problem. ISRA, SAED and AfricaRice again co-operated in the initial development. Farmers were also involved so they could provide input if necessary.

The role of the wider partners brought in was clearly defined. For instance, that of the artisan involved, and a polytechnic institute brought in to conduct training in conjunction with SAED as facilitator for the other artisans and mechanics who will eventually put the machines into production. All the partners have representatives on a monitoring team for the project.

Harvesting trials in 2005 were carried out in a field where plots had been planted with different expected harvest dates. ISA will go through an extensive on-farm assessment.

One of the key features being built into the ISA is an ability to harvest rice grain efficiently but also without damaging the straw, which is useful for livestock feed. Most of the straw is not actually sold locally but sent to Dakar and other urban areas, which do not have ready access to livestock feed. When the value of the straw is included, the profit level increase anywhere from 15-25%.

ISA is designed to be complementary to the ASI. Since the ISA can harvest grain that is not completely dry, the opportunity has been created to double-crop using the labor freed up by the use of machinery.

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Africa Rice Center (AfricaRice)



AfricaRice is a CGIAR Research Center –
part of a global research partnership
for a food-secure future.
It is also an intergovernmental association of
African member countries.


AfricaRice Headquarters
01 BP 4029, Abidjan 01, Côte d'Ivoire
T: +225 22 48 09 10; F: +225 22 44 26 29

M’bé Research Station
01 B.P. 2551, Bouaké 01, Côte d'Ivoire
T: +225 22 48 09 20; F: +225 31 63 25 78

E: AfricaRice@cgiar.org


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