アフリカ・ミオンボ林帯とその周辺地域の在来農法 (特集 作物からみたアジア・アフリカ)

Abstract

Various indigenous farming systems have been practiced in miombo woodlands in southern Tanzania and northern Zambia. One of the main characteristics of these systems seems to be the fallowing areas that allow soil fertility to accumulate during periods of vegetation recovery. This paper attempts to categorize these farming systems by vegetation types and the methods used to decompose organic nutrients, and goes on to discuss the relationships among farming systems, vegetation, and rural societies. The agricultural technologies observed in indigenous farming systems have ensured the survival of the vegetation in daily food production. Maintenance of the vegetation has been essential to the continuation of the farming systems, which have heavily depended on the biomass on the fallow land. While the vegetation suitable for this practice often differs, the vegetation within a particular society and culture has been retained. Thus, the agricultural technologies of rural societies have been mutually related to the sustainability of the indigenous farming systems. Recently, however, population pressure, political changes and so on have changed rural societies, and indigenous farming systems have come to be regarded as simply an agricultural technology for food production. This isolation from social norms has caused a temporal imbalance between vegetation recovery and land use, and the vegetation has consequently degraded irreversibly. In current societies, with their greater focus on economy, it may be difficult to revive the relationship previously seen between the indigenous farming system and the society. It is, therefore, required to find an alternative way that the modern farming systems already introduced into rural areas may contribute to sustainable use of the forest.