Strength and weaknesses of the indigenous farming system of the Matengo people of Tanzania

Deogratias F. Rutatora

Thanks to their indigenous farming system, the Matengo people of Tanzania have for over a century been able to produce enough food to meet the requirements posed by an extraordinary population pressure and an extremely uncooperative soil type. But will the system be able to cope with the changes now taking place in and around Matengoland? A report based on research conducted under the auspices of the Miombo Woodland Agro-ecological Research Project based at Sokoine University of Agriculture, Morogoro (Tanzania).

The Matengo people are one of the three large ethnic groups living in Mbinga district of Ruvuma region in Tanzania, the other two being the Ngoni and the Nyasa. The Matengo occupy the highlands, a mountainous area in the extreme southwestern region to the east of Lake Nyasa (see map), having migrated into the area about 150 years ago.
These highlands are characterized by strongly dissected mountains and narrow valleys where the elevation ranges from 1400 to over 2000m. The original vegetation must have been montane forest, but this has been almost completely destroyed.
The area is densely populated: 120 people per square kilometre (Araki 1995). This far exceeds the average population for Mbinga district as a whole (24 in 1988, ICRA Report 1991). A number of villages in the Matengo highlands even report a population density ranging from 150 to 300 (Schmied 1989). The growth rate in the area was 3.4% in 1988, as opposed to the general population growth rate of 2.8% for the entire country.
The main economic activity is farming, which is practiced on a small scale. Coffee is the main cash crop.

Matengo agricultural activity
The Matengo highland zone is an area of high agricultural productivity, due in part to the utilization of a unique indigenous farming system known in Kiswahili as 'ngoro', or Matengo pit system. This grass-fallow-tied ridge system linked to strict crop rotation is keyed to the specific nature of the area--hilly with limited arable land--and the pressure of a highly concentrated population. The Matengo pit system is practiced mainly on the steeper slopes, for the cultivation of such crops as maize, beans, wheat and sweet potatoes, and in some areas tobacco, all on a rotational basis.
On less steep slopes the Matengo occasionally construct bench terraces for their coffee farms, while ridge cultivation is also used on less steep slopes and on flat land.
The agricultural system of the Matengo people has been extensively analysed and ngoro is found to be a system that makes it possible to raise sufficient food crops in the mountaineous area, while at the same time protecting the land from soil erosion (Pike 1938; Stenhouse 1944; Schmied 1989; and Rutatora et al. 1995).

Crop rotation
The Matengo pit scheme encompasses an elaborate system of crop rotation. The pits are usually prepared between late February and early March at high altitudes, and in April at low altitudes. At this time beans and/or wheat are planted. After harvesting the beans or wheat, the farmer lightly rakes the soil to remove weeds and crop residues, in order to prepare the ground for maize or an intercrop of maize and beans. The maize is planted in November/December where beans were harvested, while maize/bean intercropping is used where wheat was planted. This completes the two-year rotation of cereal and leguminous crops.
When the last crop is harvested, the earth banks or ridges are split and the soil is turned over to make new banks or ridges into which all the collected grass and crop residues are incorporated. The new banks or ridges are built over the old pits and the new pits are constructed where the old banks or ridges intersected. This process can go on for a period of eight to ten years, after which the field is allowed to revert to natural grass fallow.
The length of the fallow period will, of course, depend on population pressures throughout the area, as well as on land availability and utilization. While farmers in the Matengo highlands--especially those with average-sized farms--leave their farms under fallow for an average of one year, farmers in the less populated lowlands can allow their farms to lie fallow for as long as three to five years.

Strengths of the Matengo pit system
The major strength of the ngoro system is the effective check it provides on the erosion of the hillside, since any soil that may be swept down is caught by the ridge or trapped in a pit. Even during the fallow period old pits and ridges continue to maintain this function. Preliminary findings from the Miombo Woodland Agro-Ecological Research Project show that the Matengo pit system controls soil erosion better than conventional conservation practices, even on sites with differing degrees of slope

Table 1 Effect of conservation practices and slope on seasonal soil loss

Source: Miombo Woodland Agro-ecological Research Project Report No.1 (1995:35)

Moreover, since organic matter is regularly returned to the soil in the form of weeds and crop residues buried in the pits, the system is an example of low external inputs combined with the use of locally available resources. In the third place, moisture or water is conserved in the pits for later use by the plants. And finally, yields have been found to be higher than those produced by means of other farming systems, such as flat and ridge cultivation (Rutatora et al. 1995; Schmied 1989).

Weaknesses
The most important weakness of ngoro is that it is much more labour-intensive than other popular agricultural systems. In addition, most of the work is performed by women. Up to now, all attempts to mechanize ngoro have failed, so that the women will have to continue to use the heavy hand-hoe. And finally, the system is not suitable for crops such as cassava (root crop) and coffee because they suffer from excessive soil moisture.

Continuation under threat
Although the Matengo pit system of cultivation has sustained land productivity for over 100 years, providing such benefits as soil erosion control, soil moisture conservation, and improved soil fertility, the continuation of the system now appears to be under threat. The main danger is the increase in population, which has not only led to a reduction in the size of farms at family level, but has also contributed to the intensification of agricultural activities. This includes continuous cultivation which, among other things, has led to a decline in soil fertility.
Secondly, the ngoro system suffers from the competition represented by the production of a lucrative cash crop, namely coffee. Past reports by Schmied (1989) and ICRA (1991) indicate that Matengo families are largely dependent on coffee and that this cash crop has helped to raise their standards of living. Over the years, the introduction of coffee has resulted in a reduction in the size of farms run by individual farmers: either they have been forced to continuously crop the same areas, or they have had to leave the Matengoland to look for other suitable areas for growing food crops. As Araki points out (1995:13) "Farmers' interest in coffee is generally high and coffee farms are expanding at the expense of existing food crop fields, which push them still farther away."
Thirdly, when people migrate--temporarily--to lowland areas, they adopt other systems of farming.
Fourthly, where higher standards of living and/or temporary migration lead to the use of hired labour without close supervision, the Matengo pits tend to be poorly constructed, resulting in lower productivity.
Fifth, the system of 'ngokela', or reciprocal labour, is being phased out, and sixth, there is a lack of government support for the ngoro system.

A stable system
Although the above mentioned factors seem to indicate otherwise, most of the farmers in Mbinga district believe that the Matengo pit system will always be practiced in the Matengo highlands, despite the constraints upon it. Our investigations reveal that this conviction is based on their own experience that the other popular systems of farming, such as ridging, have proved ineffective in dealing with soil erosion and have failed to improve soil fertility. To some extent, this conviction is rooted in Matengo history. After they migrated here 150 years ago, they invented and practised the ngoro farming system, which enabled them to stay where they were over long periods of time. Moreover, the introduction of coffee--a permanent crop--has forced the Matengo to improve their permanent settlements.
Today, when people consider migrating, they must first decide who should remain behind and who should inherit the coffee plot. At present, the Matengo have adopted a dual-residence strategy, in order to keep the system stable and to meet the household food requirements. The farmers continue to farm their small ngoro plots near their homes in the old villages, but have taken up temporary residence in a new village (Sugimura and Rutatora 1997). Analyses of the ngoro system on the original sites shows that it is no longer capable of providing the people with a livelihood. At present, however, the Matengo social system still supports ngoro and the adaptations described in this article.

Further research
Our research thus far indicates that the Matengo are able to adapt their agricultural pit system to the constraints imposed by population pressures and the need for cash crops. The remarkably strong conviction prevalent among the Matengo, that the revitalization of the ngoro system will make it possible to support future generations as well, calls for follow-up observation and further research into the strengths and weaknesses of the system. At the same time, the strong points of the system in terms of the conservation of soil and moisture make it worthwhile to explore how the Matengo pit system can be used to advantage elsewhere under similar ecological and socioeconomic conditions.

Dr Deogratias F. Rutatora
Sokoine University of Agriculture
P.O. Box 3002
Morogoro
Tanzania
E-mail: DRutatora@sua.ac.tz

References
Araki, S. (1995) Miombo woodland agro-ecological research project: progress report. Morogoro: Faculty of Agriculture, Sokoine University of Agriculture.

International Centre for Development-Oriented Research in Agriculture (ICRA) (1991)
Analysis of the coffee based farming systems in the Matengo Highlands, Mbinga District, Tanzania. Working Document Series 15. Wageningen: Agricultural University Press.

Pike, A.H. (1938) 'Soil conservation amongst the Matengo tribe', Tanganyika Notes and Records 6:79-81.

Rutatora, D.F., J. Rugambisa, D. Mwaseba and A.Z. Mattee (1995) Socio-economic issues revolving around indigenous knowledge systems and sustainable development in the Miombo woodlands of Mbinga district, Tanzania: a preliminary report. Morogoro: Faculty of Agriculture, Sokoine University of Agriculture.

Schmied, D. (1989) Subsistence cultivation, market production and agricultural development in Ruvuma region, southern Tanzania. Bayreuth: University Press.

Stenhouse, A.S. (1944) 'Agriculture in the Matengo Highlands', The East African Agriculture Journal 10:22-24.

Sugimura, K. and D.F. Rutatora (1997) The socio-cultural and economic dynamics of the Matengo community in Mbinga district, Tanzania. A preliminary report of the Miombo Woodland Agro-Ecological Research Project. Faculty of Agriculture, Sokoine University of Agriculture, Morogoro, Tanzania.

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