Trop. Agr. Develop. 63（1）：18 － 26，2019 Geographic Distribution of Indigenous Rice-cultivation Techniques and Their Expansion in Tanzania Futoshi KATO* College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-0880, Japan Abstract In Tanzania, indigenous rice-cultivation productivity is generally lower than that of rice cultivation using modern irrigation systems, even though it is a nationwide practice. Practical improvements in indigenous rice cultivation are required to increase the productivity, stability, and sustainability of rice cultivation. Tanzania is a major rice-producing country in Africa and the demand for rice is continuously increasing; therefore, indigenous rice cultivation has also increased for more than 20 years. This study was focused on indigenous rice cultivation and aimed at elucidating the geographic distribution of indigenous rice cultivation and characterizing the techniques used. Fieldwork was conducted in Mwanza, Shinyanga, Tabora, Mbeya, Dodoma, Rukwa, Morogoro, and Dar es Salaam, which are the major rice-producing areas in Tanzania. Two basic rice-cultivation techniques are used in that country; one utilizes runoff from rainfall and the other uses floodwater from streams, rivers, and swamps. The former is practiced in northern and western Tanzania and is characterized by transplanting, building levees, and plowing with bullocks, while the latter is practiced in south-central Tanzania and is characterized by broadcasting seed, irrigating with floodwater, and using tractors. Furthermore, rice cultivation that utilizes runoff expanded from northern to southern regions of Tanzania in parallel with the migration of the Sukuma people; this has increased the diversification of Tanzanian rice cultivation. These indigenous rice-cultivation techniques were found to be affected by geographical, meteorological, and social conditions. Key words: Africa, Efficient water utilization, Indigenous cropping system, Sowing methods in the 2000s (Isinika et al., 2003). Although rice is an Introduction important cash crop and staple food in Tanzania, most Asian rice (Oryza sativa L.) has been domesticated rice-cultivation techniques are indigenous. According in Asia and has spread throughout the African continent. to Kanyeka et al. (1994), modern irrigated paddy fields Although African rice (Oryza glaberrima L.) has been do- occupy only 5% of the area under rice cultivation in mesticated in western Africa, it is not widely cultivated Tanzania, while the remaining 95% is cultivated using in the eastern part of Africa, where Asian rice cultivation indigenous techniques. is very common. Asian rice is used in indigenous cultiva- Rice cultivation has a long history in Tanzania. Car- tion systems, and it is an important staple food in some penter (1978) reported that Asian rice was introduced areas of East African countries. to East Africa by traders from Arabia or India approxi- Rice is the second-most important crop after maize mately 2,000 years ago. Rice had been cultivated solely in Tanzania. In 2007/2008, the total area under rice in the coastal areas on the Indian Ocean until the 19th cultivation was 906,708 ha and domestic production was century, when rice cultivation started in inland areas 1,431,948 t (United Republic of Tanzania, 2012). Tanza- and various cultivation techniques were established. nia ranked fourth among the African countries in rice Therefore, there is regional diversity in the indigenous production, indicating that it is a major rice-producing techniques in Tanzania. country in Africa (FAO, 2013). The diversity of indigenous rice cultivation is However, rice had been cultivated for household related to various ecological and topographical aspects consumption before Tanzania gained independence, of Tanzania (Monyo and Kanyeka, 1978). Hilly plains and it has recently become a cash crop, traded in the spread in the northern and western regions, while vast domestic market because of increased demand (Kato, plains with many rivers, streams, and swamps are found 2007). Furthermore, this increased demand has been ac- in the southern region (Adams et al., 1996). Therefore, celerated by the progression of economic liberalization the characteristics of local topography have especially influenced agricultural practices. Communicated by R. Ikeda Furthermore, Brookfield and Stocking (1999) ar- Received Dec. 26, 2017 gued that diversity in agricultural methods was derived Accepted Aug. 17, 2018 from the adaptation of farmers to social and physical * Corresponding author [email protected] environments. There exist many social conditions within Kato: Indigenous rice-cultivation techniques in Tanzania 19 each region of Tanzania, as well as many ethnic groups of 25 regions on the mainland and five regions in that have various cultures and lifestyles. Agro-pastoral- semi-autonomous Zanzibar (Fig. 1). The country has ists, practicing bullock plowing, live in the northwestern more than 100 ethnic groups with different cultures that and western highlands, while agriculturalists do not practice various styles of subsistence farming. maintain livestock in the southern lowlands (Murdock, The major rice-producing areas are in Morogoro, 1959). Thus, various indigenous rice-cultivation tech- Shinyanga, Mwanza, Mbeya, Tabora, and Rukwa. Fig. 2 niques reflect these factors. illustrates the regional distribution of rice production in This study was based on the hypothesis that Tanzania in 2007/2008. Morogoro, Shinyanga, Mwanza, indigenous rice-cultivation techniques are affected by Mbeya, Tabora and Rukwa contributed to 21%, 18%, 13%, geographical, meteorological, and social conditions 12%, 9%, and 9% of the total rice production in Tanzania, in Tanzania, focusing on the present indigenous rice- respectively (United Republic of Tanzania, 2012). cultivation techniques, and was aimed to elucidate the On-site fieldwork was conducted for over 33 months geographic distribution and characteristics of recent between 2003 and 2016 (September 2003–August 2004, indigenous rice cultivation, based on fieldwork. Further- more, this study was aimed at classifying rice-cultivation techniques with a consideration of the environmental Others and social background of such practices. Urgent im- Rukwa 18% Morogoro 9% 21% provements in rice-cultivation technologies are needed to tackle the fragile food security in African countries, including Tanzania, and these techniques are a critical Tabora developmental priority. For these reasons, it is important 9% Shinyanga to comprehend various aspects concerning Tanzanian 18% indigenous rice-cultivation technologies, especially the Mbeya 12% Mwanza relationships between water environment and these 13% technologies. The results of this study should contribute Fig. 2. Rice production in 2007/2008. The data source is the to future research and aid in the improvement of indig- Ministry of Agriculture and Food Security, Tanzania. However, four regions (Njombe, Geita, Katavi, enous rice-cultivation technologies. and Simiyu) were created in 2012, and agricultural data from these new regions are not available. Data Materials and Methods from the Mwanza region include the amount of rice Study sites and survey production in the northern part of the Geita region, and data from the Shinyanga region contain those of The United Republic of Tanzania is a major rice- the southern part of the Geita and Simiyu regions in producing country in East Africa. Tanzania is composed this figure. FigFig.. 1. 1.R eRegionsgions of ofth ethe U nUnitedited R eRepublicpublic of ofTa Tanzania.nzania. G rGrayay re gregionsions re representpresent th thee r eresearchsearch s sitesites iinn tthishis sstudy.tudy. 5 18 20 Trop. Agr. Develop. 63（1）2019 September 2005–October 2006, July 2007–August 2007, November. December 2010–January 2011, December 2011–January The Mwanza region is located in northwestern 2012, December 2012–February 2013, December 2013– Tanzania, which neighbors Lake Victoria. The average January 2014, August 2014, December 2014–January annual rainfall is 700–1,400 mm. The rice-producing vil- 2015, August 2015, and December 2015–January 2016). lages in Mwanza are situated in broad or narrow valleys, Surveys were conducted in the major rice-producing separated by rocky granite hills (Meertens et al., 1999). regions in Tanzania, including Mwanza, Shinyanga, The Shinyanga and Tabora regions receive less Tabora, Mbeya, Dodoma, Rukwa, Morogoro, and Dar es rainfall than the Mwanza region. The average rainfall is Salaam. 600–1,200 mm. In those two regions, the rice-producing The highest rice-producing wards and villages in villages are situated on upland plains that are comprised each region were selected as research sites based on of gentle hills, interrupted by wide valley bottoms. reports on rice production volumes from regional or The Dodoma region is among the most arid area district agricultural offices. From each research site, in Tanzania, with an average annual rainfall of 500–700 approximately 10 local farmers, who grew rice as a mm; its rice-producing area is located near the Bahi main crop for subsistence, were randomly chosen as swamp and its watershed. informants. Rice-cultivation techniques (e.g., building In the northern Mbeya and Rukwa regions, the an- levees, sowing methods, land preparation methods, wa- nual rainfall is 750–800 mm. Rice-producing villages are ter sources, and cropping calendars) were recorded in scattered all over these regions, especially near lakes, these sites