Tanzania country paper
Agriculture in the Tanzania wetlands

Introduction

Tanzania is situated on the eastern side of Southern and Central Africa between 1º and 11º5' South and 29º5' and 40º5' East. It is bordered by eight countries: Kenya and Uganda to the north, Rwanda, Burundi and the Democratic Republic of Congo to the west, Zambia, Malawi and Mozambique to the south. To the east is the Indian Ocean. The mainland has twenty regions and each region has several districts. The islands of Zanzibar and Pemba have five regions, while Mafia Island forms part of the Coast Region which is on the Mainland.

Demography and Economy

With an area of 945 200 km², Tanzania has a population of about 29 million people (1988 census) and a demographic growth rate of 2.8%. Tanzania is mainly agricultural with 90% of the rural population being solely employed in agriculture. The sector contributes 60% of the country's Gross Domestic Product (GDP) and generates 84% of the total recorded export earnings. The country suffers from sporadic food shortages during bad years and is still striving towards food self-sufficiency.

Topography and Climate

Tanzania has diverse morphology, including the highest mountain in Africa (Kilimanjaro with a height of 5 895 m above sea level), the deepest lake in Africa (Tanganyika with maximum depth of 1 470 m) and the largest lake in Africa (Lake Victoria with a surface area of 70 000 km²). It also has a network of river systems that empty into the Indian Ocean, the Mediterranean Sea and the Atlantic Ocean. The Southern Highlands, the Ruwenzori Mountains in the West and smaller mountain ranges in the East are a source of many river systems. The Eastern and Western Rift Valleys traverse the country forming important internal drainage basins.

Tanzania has a warm climate with monomial rains in the central plateau and the southern highlands, while the rest of the country receives bimodal rainfall. Annual precipitation ranges from 600 mm to 1 200 mm with the highest rainfall concentrated on the coastal plains and in the highlands (Howard, 1991).

G.M. Kalinga 
Ag. Assistant Commissioner, Irrigation Department, Ministry of Agriculture and Cooperatives 
Edith Shayo 
Regional Agricultural Extension Officer, Morogoro 

Land use

Although agriculture is the leading sector in the economy, out of 43 million ha suitable for agricultural production, only 6.3 million ha are under agricultural production of which 0.45 million ha are under wetland cultivation. Yields on farm land are often only 25% - 30% of the potential yield, largely due to unfavourable weather conditions, pests and diseases, inadequate credit facilities, poor agricultural technology, lack of inputs and poor infrastructure. Improper land use also causes soil degradation and erosion which threaten some of the country's high potential land. Other activities include fisheries, forestry, bee-keeping, tourism, wildlife including natural flora and fauna.

Wetland classification

According to the Ramsar definition "Wetland are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salty, including areas of marine water, the depth of which does not exceed six metres".

From this definition, wetland in Tanzania (Figure 1) have been classified into three categories according to their origins and land physiography (Mwanukuzi 1991):

• Coastal wetlands: These were formed by wave action and tidal influence along the shoreline. They include mud flats, marshes, mangrove swamps, estuaries and deltas .They dominate in Tanga towards the Kenyan boarder and support 16.2 km² of mangrove swamps in Mtwara and 62 km² in Lindi in the south. They are characterized by heavy saline soils.
• Rift system wetlands: They are found in the rift depressions and are characterized by salt lakes, playas, swamps and short streams with inland drainage. Soils are heavy and are affected by salinity.
• Wetland of the highlands drainage basins: Long rivers originating in the highlands meander through the plains forming lakes, swamps and flood plains before draining into the ocean or lake basins (Figure 2). They are characterized by fertile alluvial soils of varying textures.

Attempts have been made to classify wetlands under the Wetland Biodiversity Project which started in 1994. The methodology used was that of aerial photography, transect walks and other detailed studies of local land systems, aquatic systems and the establishment of a data bank to store acquired information. Community participation and socio-economic research into human settlements and development is also part of the research plan. Local communities will provide information on types of flora, fauna, uses and problems. Inventory of wetlands was taken on 1 : 50 000 topographic maps, while the surveys show impact of livestock grazing.

Using the Ramsar format to identify wetlands of international importance, the lake Manyara area was selected as a Ramsar site. Other wetlands identified are as follows:

• The riverine wetlands
• Internal drainage basins
• Large natural lakes

• Artificial impoundment
• Highland swamps in Mbeya and Ufipa plateau

Constraints

The work of characterization and classification of wetland was hindered by:

• Lack of funding and facilities: Adequate funds are needed for staffing, purchase of equipment, transport and administration.
• Lack of institutional arrangements favouring coordination: The management of wetlands is the responsibility of many institutions in Tanzania. The lack of coordination between these institutions has resulted in poor management, lack of accountability, inability to respond to changes in wetlands and overlapping responsibilities between the institutions.

Sustainable use of wetlands

In the past, wetlands were considered as wastelands although they are potentially suitable for agriculture due to the availability of water and high soil fertility (Masija, 1991). At present, some wetlands are used for agriculture and also support other activities including wildlife, tourism and forestry. So far, no proper plan exists for use in agricultural production. However, interventions are necessary to protect wetlands against environmental degradation and pollution. Thus Environmental Impact Assessment (EIA) has to precede each planned project implementation.

Agriculture and livestock development

Tanzanian wetlands are mostly utilized for crop production and grazing. The principal livestock keepers are the Sukuma and the Masai. The Sukuma are the northwest of the country, south and east of Lake Victoria. They make extensive use of wetlands in the northern part of the country, for dry season grazing. Due to population pressure they have already moved to the south to the Usangu plains through the Chunya corridor. The Masai extend from the Kenya border to the Morogoro region in central Tanzania. Their traditional grazing lands were in the north but population pressure has forced them further south into Kilombero valley and now they utilise Mkata plains and Usangu plains for dry season grazing. At present, conflicts arise between pastoralists and small holder farmers who grow crops in the wetlands. Policies governing the utilization of wetlands will help to resolve conflicts and conserve the land.

Irrigation development in the major river basins

The government of Tanzania has adopted an Economic Reform Programme (ERP) which will create an enabling environment for the private sector to be involved in agricultural production through reforms of the financial sector, pricing and marketing policies.

Two principles guide the implementation of agricultural projects in the river basins:

1. Increased agricultural production must be carried out on a sustainable basis and in conjunction with sound environmental policies.
2. Water becoming a scarce resource in both quantitative and qualitative terms, it must be used in the most judicious manner.

With the introduction of improved paddy varieties and better water management paddy cultivation is done under five ecosystems in the wetland in Tanzania. These are:

• Rainfed lowland, unbounded and flooded, covering 42% of total area
• Rainfed lowland, bounded and shallow flooded, covering 32% of total area in the west and south of the country
• Upland hydromorphic in the Coast, Mwanza and Shinyanga in the lake zone
• Fully irrigated and mechanized on all NAFCO farms and in Lower Moshi scheme
• Supplementary and traditional irrigation in Usangu- Mbeya, Morogoro, Tanga and Tabora with only 2% of the total area

After harvesting of paddy, in some irrigation schemes such as Mto wa Mbu and Lower Moshi, residual moisture in the fields is used for growing short term crops before the next season. These include cowpeas, vegetables, sweet potatoes and green maize. Table 1 shows the irrigation potential in the major river basins.

Mechanization

Tillage is usually done by hand in the wetland by farmers, usually smallholders who can not afford to purchase tractors, ox-ploughs and required inputs. However farmers in irrigated areas are striving to purchase oxen and ox-ploughs through saving groups in order to reduce workload. The

TABLE 1
Irrigation potential in the major river basins (Source: FAO Review of irrigation, 1990)

government is also creating a conducive environment for farmers to opt for power tillers. Available large tractors for hire are insufficient and usually expensive. With increased mechanization, there is better land preparation and production, but more skills are needed for maintaining soil structure and controlling soil erosion. In order to increase yields, simple and affordable agronomic packages must be developed and be extended to the farmers.

National policy and strategy for the conservation and sustainable development of wetlands

The National wetland conservation and management programme was developed in Tanzania during 1990 by the National Environmental Management Council (NEMC) in collaboration with the World Wildlife Fund (WWF) and the International Union for Conservation of Nature and Natural Resources (IUCN). Such effort gained momentum after the wetlands conservation conference of the Southern African Development Community (SADC) held in June 1991, during which each SADC member country was urged to formulate its own wetlands programme. In November a seminar on wetlands of Tanzania was organized with assistance from IUCN Regional Office for East Africa. One of the recommendations of the workshop was to formulate a national Wetland Technical Committee (NAWETCO) of which the ministry of Agriculture is a member.

The first stage in the policy development process was to review sector policies as they relate to wetland utilization and conservation. Sector policies were those of the Wildlife, Forestry, Fisheries, Water, Agriculture and Land sector.

The Ministry of Agriculture recommended the following issues to be observed during wetlands policy formation:

• Agriculture should make positive contribution towards conservation of wetlands while achieving the wise use of wetland resources.
• There should be coordination between other agencies of wetlands resources.
• Identification of major sectors with direct encroachment on the environment is needed.
• There must be representation of member institutions and legal entities in the management of the environment.
• Government has the responsibility to train staff on skills in the management of wetlands.
• Participation in regional and international efforts of conserving and utilizing wetland needs to be enhanced.
• Each wetland has to be classified, demarcated and assigned a specific use.
• Development activities in wetlands should be subjected to environmental impact assessment.

Constraints to the use of wetlands

The sustainable use of wetlands is limited by the following aspects:

• Limited knowledge by the public on the usefulness and potential of the wetlands due to customs, culture and lack of appropriate education (Masija, 1991).
• Insufficient planning for the sustainable use of wetlands.
• Inadequate interaction with neighbouring countries on the wise use of shared resources.
• Insufficient coordination among beneficiaries.
• Insufficient funding for research into conservation and wise use of wetlands.

Research needs

In order to establish appropriate research programmes, potential beneficiaries of wetlands must be involved in prioritization. Areas that require emphasis include:

• Integrated approach towards the utilization of wetland resources.
• Development of wetland production packages that are sustainable.
• Areas of collaboration with neighbouring countries in conserving shared resources, for example the eradication of water weeds in Lake Victoria, the conservation of coastal mangrove swamps, better fishing methods/techniques.
• Workable policies on wetlands.
• More efficient classification and inventory.

Conclusion

There are many diverse wetlands systems in the Tanzania. The treasure harboured by these wetlands is gradually being eroded and there is an urgent need for the restoration of already degraded wetlands and the conservation of those which are threatened. As the population increases and more demands are made on resources, wetlands may be further destroyed in the name of development. However, sustainable use of wetlands should not consider protection only, it must earmark sustainable agricultural development under environmental conservation and protection.

The need for classification of wetlands according to the agricultural potential and developing a National Wetland Plan for the sustainable use of this resource is apparent. This would be possible by having supportive policies, which will be expected to involve among other issues the establishment of research needs and appropriate collaboration among neighbouring countries and other institutions. Food security and self sufficiency can be attained in the country through the wise use of these wetlands.

Bibliography

Howard, G.W. 1991. Wetland of Tanzania. In: Proceedings of a Seminar on Wetland of Tanzania. Morogoro, Tanzania. pp 1-5.

Kanyeka, Z.L. 1995. Appropriate technologies for optimizing rice production in Tanzania. Paper presented at the FAO Workshop on Food Security, Morogoro, Tanzania.

Masija, E.H. 1991. Irrigation of wetland in Tanzania. In: Proceedings of a Seminar on Wetland of Tanzania. Morogoro, Tanzania. pp 73-75.

Ministry of Agriculture. Reports 1990 - 1996.

Mwanukuzi, P.P.K. 1991. Origin and geomorphology of wetland of Tanzania. In: Proceedings of a Seminar on Wetland of Tanzania. Morogoro Tanzania. pp 28-30.