Irrigation is the controlled flow of water to the farmland in order to optimize farm production. It is used to assist in the growing of agricultural crops. Irrigation has also been used for suppressing weed growing in grain fields and helping in preventing soil degradation.
Modern irrigation was introduced in Tanganyika in 1930 through the establishment of the Tanganyika Planting Company Ltd (TPC) and other commercial farms and estates. Since Independence a large potential for irrigation has been identified, partly as commercial irrigation schemes, partly for smallholders organised in water users associations (WUA). Only part of that potential has sofar been realised.
2. Present Situation of Agricultural Irrigation in Tanzania.
At present Tanzania has large number of small, medium and large scale irrigation schemes. The total area under irrigation is at present 270,000 ha of a 29,400,000 ha total area suitable for irrigation. 2,300,000 ha is considered high potential and 4,800,000 ha is considered medium potential for irrigation.
The actual land under irrigation 3.8 % of total potential and this is only 0.92% of the total area suitable for irrigation.
Irrigation and drainage are interlinked. Irrigation is the controlled supply of irrigation water. This can never be achieved without proper control of excess water (‘drainage’).
This is also vital to avoid salinization of soils and hence making farming land less productive. Irrigation is another way to increase productivity of farm land and create conditions for a more stable harvest and hence increase income.
Irrigation and drainage services are often combined into one Government Irrigation and Drainage Department in Tanzania this is called the Zonal Irrigation Office. Some irrigation schemes are built with private funds or funds and labour input from farmers’ associations, producer cooperatives; irrigations associations.
3. Potential for Investment in Agricultural Irrigation.
29,400,000 ha is considered the total area suitable for irrigation. Another source mentioned that 2,300,000 ha is considered high potential and 4,800,000 ha is considered medium potential for irrigation, which still need to be developed.
Large areas available for irrigation and mechanisation (flat; deep soil) with sufficient access to (irrigation) water in their respective ‘catchment areas’.
Irrigation combined with mechanization can improve land and labour productivity, hence increase the low farm income as farmers in the past were dependant on rainfall farming with risks of floods, drought etc.
Effective irrigation also needs to be combined with increased use of farm inputs (high quality seeds, fertilizers, agrochemicals etc) to reach maximum yield increase. Also mechanisation can improve productivity and reduce dependence on hoe / ox plough for land cultivation.
Irrigation and drainage structures can also be built with private funds or funds and labour input from farmers’ associations, producer cooperatives; irrigations associations. However, cost of design and building physical irrigation and drainage structures is high: up to USD 1,000 – 1,500 = TZS 1.6 – 2.4 million per ha for technical irrigation and USD 500 – 700 = TZS 0.8 – 1.1 million per ha for semi-technical irrigation.
Traditional irrigation – which is less productive due to inadequate water control is cheaper per hectare. On individual farms, especially on intensive horticulture farms (vegetables, fruits & flowers), sometimes individual pump irrigation may be technical and economically feasible.
4. Operation & Maintenance of Irrigation Schemes and set up of Water Users Associations /Irrigation Members Associations.
In order to improve operation and maintenance of irrigation schemes it is recommended to:
5. High potential areas for Introduction and/or expansion of Agricultural Irrigation.
6. Financing needs for / in Agricultural Irrigation Schemes.
Due to the high cost of building medium size and large scale (semi-) technical irrigation schemes, most irrigation and drainage works are implemented with government funds (sometimes also with grants/loans from international financial institutions). Usually the design is made by private engineering companies, who will later also be responsible for supervision of the selected building contractor.
Sources of Funds for large scale irrigation schemes: World Bank; IMF; AfDB; EU; JICA etc, due to high capital investment cost and long repayment period.
For the realisation of small and medium size scale irrigation schemes, sometimes members of SACCOS and Farmers Associations use own funds and own labour efforts to develop their own irrigation potential. Other funding agencies are: Government of Tanzania (GOT); SAGCOT; Donor Agencies, etc.
Individual agri-business entrepreneurs / farmer groups may seek financial assistance for agricultural production in irrigation areas for:
7. How PASS can help farmers with small scale Irrigation or individual Enterprise pump Irrigation