Period: 15 January 2005 - 15 February 2005. Country: Tanzania
(1) Agro-Ecological Study on the Transformation of Indigenous Agriculture in the Southern Highlands of Tanzania
KONDO Fumi  (Division of African Area Studies)
Key Words: East Africa, Indigenous Agriculture, Transformation of Subsistence Activities, Valley Bottom Cultivation, Agroforestry.

Preparing logs to be cut with a diesel powered table saw
Sawing logs with a diesel powered table saw
Sawing with a pit saw
(2) The Bena are farmers who inhabit the southern highlands of Tanzania in East Africa. They employ a valley bottom cultivation system in the dry season, while using hillside fields in the rainy season. Historically, they practiced slash-and-burn agriculture using both types of fields. Over the years, they have improved their own agricultural technologies and created a new cultivation system that fits the present macro socioeconomic conditions of Tanzania. In the valley bottom fields, they have adopted the use of chemical fertilizers (Triple Superphosphate, TSP) and modified their cultivation method to enable continuous cultivation in the same field. On the other hand, they have created a unique method of agroforestry combining afforestation and slash-and-burn cultivation in hillside fields. The main objectives of this study are as follows: (1) To clarify how the new cultivation system was created, and analyze its influences on the total ecosystem and its sustainability. (2) To evaluate the socioeconomic influence of this new cultivation system on Bena society.

(3) From Jan. 15, 2005 to Feb. 15, 2005, I conducted fieldwork in Kifanya Village, Njombe District in the Iringa Region of Tanzania. In recent years, the Bena people have planted black wattle trees (Acacia mearnsii) to use as charcoal and pine trees (Pinus patula) for timber on fallow hillside fields. They fell and use these trees after 10 to 20 years, and burn the remaining branches and leaves, making cultivation possible with little or no chemical fertilizer. Through my research, (I) I elucidated the historical relations of tree planting, lumbering and slash-and-burn cultivation. And (II), I collected soil samples from various stages of the fallow and cultivation process from hillside fields, in order to analyze annual changes in soil fertility resulting from the growth of trees and burning of the fields.

(I) In my earlier research, conducted in 2000, I found that slash-and-burn cultivation fields were usually prepared on cutover areas of black wattle forest. However, these fields are currently prepared mainly on cutover areas of pine forest. This change was caused by the following factors: (1) The Bena began to actively plant pine trees after the 1980s, and many pine forests planted at that time have become mature. (2) The introduction of diesel-powered table saws as a substitute for pit saws led to an increase in sawing speed, resulting in an expansion of the cutover area of pine forests.

(II) I am currently analyzing soil samples. The two following points were clarified: (1) The soil under the pine forests is strongly acidic. (2) However, ash from the burnt vegetation can neutralize soil acidity.

Based on these findings, I will evaluate how the changes in the Bena cultivation system relate to changes in their society.

21st Century COE Program -Aiming for COE of Integrated Area Studies-  HOME