JORDBRUGSPROBLEMER I TANZANIA

Abstract

Møberg, J.P., 1979: Jordbrugsproblemer i Tanzania. Geogra- fisk Tidsskrift 78: 10–19. København, June 1, 1979.

Some charasteristic soil types in Tanzania are described and prevailing agricultural problems discussed.

SUMMARY

A treatment of the soil conditions, land use pattern, and soil problems in Tanzania in such a short paper can only be very brief and incomplete. The paper should therefore only be considered as a brief introduction to the subject.

Two of the most important external factors influencing the land use pattern and soil problems in Tanzania today are the soil moisture conditions (Figure 1) and the population growth—which is around 2. 7–3.0% per annum—and its distribution (Figure 2). Figure 1 indicates that large areas of Tanzania may be considered as semiarid. On the contrary, only a few isolated areas in the mountains can be classified as belonging to the humid tropics.

In order to cope with the subject, an attempt has been made to consider the soil conditions, land use pattern, and the soil problems in each of the main geomorphological regions, in which Tanzania can be divided (Saggerson 1962). In each of these regions the subjects have been considered in each landscape section.

Figure 3 to 8 contain the results of the attempt. The soils in the Craton area suffer mainly from water shortage; erosion, poor soil structure, and low content of plant nutrients in the soils on the slopes are other problems of importance.

Erosion is the most serious soil problem in the Block Mountains. The soil moisture conditions vary from section to section in the landscape, but water shortage often limits land use on the alluvial fans and in the »rainshadow« areas.

The Masai steppe and the South East plateau have serious water shortage problems. This has prevented the development of these areas. Erosion will certainly increasingly be a problem, as the population is pressed into these areas.

The land use problems vary considerably in the Coastal area, partly because of the heterogeneity of the parent material and partly due to variation in soil moisture conditions. Especially in the central and southern part of the area is water shortage a problem. Erosion and low content of plant nutrients are also problems in many parts of the area.

Although the conditions vary, the Volcanic areas are certainly the geomorphological section in Tanzania which is most intensively cultivated. Generally the soil moisture conditions are favourable, and the content of plant nutrient high. Erosion problems are common only in some parts and in some landscape sections. Only water, and in some cases lack of good soil management, hinder the full utilization of these high-potential soils.

The main land use problem in the Flood plains are water control and water and soil management. This has up to now limited the development of these highly potential soils. There is no doubt that through effective water control combined with rational land use and water management, these areas may be the main food producing areas of Tanzania in the future.

Among problems, more general in nature, related to efficient land use can be mentioned: The conservatism of human nature which delays changes and acceptance of new cultivation methods. The lack of responsibility towards the soil. The lack of understanding and trust between cultivators and extension officers.

The rapid population growth, which causes heavy pressure on land, is behind the rapidly growing soil use problem and the pressing need for changes in land use.