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Promotion of low-cost and water saving technologies for small-scale irrigation, M. De Lange

Mama de Lange
MBB Consulting Engineers, South Africa

Defining transfer of technology
Small-scale irrigation
Improved, low-cost and water saving technology
Factors hampering transfer of appropriate small-scale irrigation technology
Promoting improved small-scale irrigation

Defining transfer of technology

Is "technology transfer" a misnomer? If it implies trying to find situations to which existing technology can be fit, then "technology transfer" would appear to be contrary to the development principle of incrementally improving what people already know. The approach should be to participatively assess farmers' requirements and then seek technology which, with minor adaptation, could suit those requirements.

In South Africa, knowledge about appropriate applications of technology for small-scale irrigation should be transferred, firstly to designers and manufacturers and then to donors and consultants. The realization that small-scale irrigation has its own unique requirements and is not merely a scaling down of well-known commercial technology, usually comes with sympathetic exposure to the actual field situation. A general problem with simple low-cost technology is that since it essentially aims to limit expenditure, it is not worthwhile for consultants' to promote it.

It must be recognized that there is a difference between transferring technology to farmers who are familiar with irrigation or even arable farming, and those who have never had experience. South Africa is an arid country with limited water resources and relatively little traditional irrigation. In addition the emphasis there has been on the creation of large and medium-scale irrigation schemes. Furthermore, there has been inadequate support to informal irrigation. There is a dire need for direct interaction between knowledgeable technical people and small-scale irrigation farmers, to create opportunities for improvement of established practices. In this regard. South Africa is eager to learn form other Southern and Eastern African countries with stronger irrigation traditions. The role of government, donor organizations and NGOs needs to be debated and decided.

Successful transfer of technology is dependent on at least three factors: the availability of the physical technology or equipment; the skills to use the equipment; and the organizational ability and know-how to manage the operation and maintenance (Still Well, 1994).

Small-scale irrigation

In South Africa, the most successful small-scale irrigation farms are those which developed from farmers' initiatives. This is in contrast to government initiated, large-scale smallholder schemes, which have been rife with problems. The spirit of "small-scale" irrigation is in the fact that it is managed and controlled by farmers who are the users. Small-scale irrigation is easiest where a farmer has independent access to a water source. It becomes increasingly difficult as the flexibility and independence of farmers' decision-making decreases. This flexibility and independence, in turn, can be related to the number of participants on a scheme, the management requirements of the water supply infrastructure (in-scheme) and the nature of the irrigation technology (in-field).

Another important distinction is the level of risk with which the farmer prefers to operate. Intensive, highly commercial farming is high risk. In contrast, small-scale farmers often seek to reduce risk. Consequently, optimal production is often (but not always) at lower input and yield levels than those recommended for high risk farming (De Lange et al., 1995). The important implications this scenario has for the choice of technology and system capacity will be discussed later in this paper.

Approximately 40 000 small-scale farmers, 15 000 medium-to-large-scale farmers, 120 000 permanent workers and an unknown number of seasonal workers are involved in irrigation farming, which consumes approximately 51% of South Africa's water on some 1.3 million ha. It contributes 25 to 30% of South Africa's agricultural output. There appears to be 202 small-scale farmer irrigation schemes involving some 47 500 ha. Only 37% of participants are commercially oriented. The remaining 63% are foodplot holders who may sometimes sell some produce (Backeberg et al., 1996). This percentage does not, however, include independent small-scale farmers who are not accommodated on formal schemes.

TABLE 1 Small-scale farmer irrigation schemes in South Africa, 1996 (from Backeberg et al., 1996)


No. of schemes

Area irrigated

No. of farmers

No. of food plots

No. of commercial

Main commodities

Eastern Cape


9 460

7 365

3 752

2 613

Maize, vegetables, citrus, lucerne

Western/Northern Cape



1 004



Vegetables, deciduous fruits, lucerne



3 874




Wheat, cotton, vegetables, maize, lucerne, fruit



19 895

7 425


7 115

maize, vegetables, groundnuts, wheat, cotton, citrus, fruit



8 341

18 745**

17 190

1 555

Sugarcane, maize, vegetables



5 429

1 689



Sugarcane, vegetables, fruit



47 486

37 108

23 239

12 869

* Includes 22 schemes (5 257 hectares) not yet settled
** Details of farmers on 14 schemes not available

Improved, low-cost and water saving technology

Technology is taken to mean the physical water supply infrastructure, which is a component of the scheme infrastructure and the in-field irrigation equipment, its design, construction, operation and maintenance.

When assessing the cost and water saving characteristics of technology, a distinction must be made between water supply and irrigation technology. This distinction is necessary since the funding and management of scheme infrastructure is usually a government/donors concern, while the in-field equipment is more likely to be funded and managed by farmers themselves. In addition to the cost and the water saving characteristics of both water supply and irrigation technologies, the importance of their manageability has already been highlighted.

In South Africa, the cost of irrigation equipment is significantly limiting small farmer development. The cost of a single hosepipe is often unaffordable for beginner farmers. Therefore, a modular approach to the development of both the water supply and irrigation systems is recommended. To assess the technological requirements, we need to ask ourselves: whose priority is it to save water? With the current review of water law and water supply priorities, South Africa has a renewed national drive towards water conservation. In practice, however, farmers will use water sparingly mainly when it becomes scarce, or if time and labour consuming irrigation practices constrain water application, or if water availability limits the expansion of a highly lucrative business.

The manageability of technology can contribute to an "enabling environment" for farmer adoption. It is often argued that if water is available and easy to apply, then farmers will use more than is necessary. Therefore, to promote farmer adoption, technology should be effective, easy to apply, in the desired amount, easy to operate and maintain with local resources and affordable.

A brief discussion is presented below of irrigation technology currently being used for small-scale irrigation in South Africa (De Lange et al., 1995).

Sprinkler systems

A major advantage of sprinkler systems is that a farmer can start small and expand as he learns how to use and can afford the system. If the farmer plans to expand, provision should be made at the planning stage. However, sprinkler irrigation is not always the best method for all small farmer situations. Ready access to equipment dealers and technical support are vital to achieve sustained efficiency.

Design requirements may differ from the conventional if irrigation management is to fit into the life pattern of a part-time farmer and may result in a more expensive system. For instance, shorter or varied sprinkler stand times may have to be used.

Centre pivots

Although "small-scale" is difficult to define and certainly not related to farm size only, farmers in this category generally irrigate 10 ha or less. Centre pivots are designed to irrigate relatively large areas, with circles generally ranging in size from 30 up to 100 ha in area. The equipment cost per hectare becomes very high for smaller pivots, therefore, small farmers using centre pivots have to share the equipment, which invariably leads to management and operational problems. In addition, centre pivots are mechanically complex and require skilled maintenance and are therefore not recommended for small farmer schemes.

Micro and drip (trickle irrigation)

With micro and drip (trickle) irrigation, it is more difficult to detect problems than with sprinkler irrigation. This is because the emitters are so small and so many and each applies water to such a small area. If the system is not carefully monitored, application rate may double or halve without the farmer noticing. This need for monitoring places a high demand on the farmer's time. If the farmer thoroughly understands his system and the principles of irrigation and can afford the time, then monitoring becomes an additional chore which is manageable.

An interesting aspect of micro and drip irrigation in the field, is the unexpected willingness of small farmers to actually move dripper lines between irrigations, as though they were conventional sprinkler laterals. Another example is of micro sprayers on long spaghetti tubing, initially installed to irrigate fruit trees, but which are now also being moved around like a miniature replica of a dragline system for intercropping vegetables between the fruit trees.

The possibility of such laborious irrigation practices has hitherto been discounted on larger farms, where they are impractical. However, this is a good example of how, under special circumstances, practices which seem unacceptable or ineffective can, in fact, make a significant contribution to both management and production.

Micro irrigation, which has only been used to a limited extent by small farmers therefore warrants further investigation. Unless the vulnerability of the system can be reduced, its applicability remains limited for farmers with inadequate access to technical support, training services and equipment dealers. This will be the subject of a WRC study commencing in 1996.

Flood irrigation

Flood irrigation is not suitable for all soil conditions, but has a major advantage over other types of irrigation for small farmer irrigation (or any situation where access to support services is limited). The advantage of the system is that it usually can be designed to operate at very low running costs with gravity feed, without pumping or any mechanical equipment. While the maintenance of infrastructure like weirs, canals and diversion structures is important, this can be handled in a regular, programmed and largely preventative manner. Emergency breakdowns requiring urgent access to support services are rare in gravity systems.

Flood irrigation is regarded as more labour-intensive than mechanized systems. However, it is often more suitable where small farmers live a considerable distance from their fields and can travel to the fields only once, complete the irrigation in three to four hours, and then return home. In comparison, a farmer-housewife may find it impractical to travel to the fields a number of times per day to shift sprinkler lines.

Short-furrow or furrow-basin flood irrigation

This system has the additional advantage that weeding and insect control are done simultaneously with the irrigation. Another advantage of furrow-basin irrigation is that there is very uniform distribution of water across the whole field, even in cases where the gradient varies or where the flow rate is inconsistent. Variations in gradient or flow rate would make other methods of flood irrigation difficult or even impossible.

Small-scale technology needs in South Africa include the following:

· affordable, reliable, robust, low volume pumps with sufficient pressure to run one or two sprinklers at a time;

· general improvement of the ability to design and develop appropriate short-furrow flood irrigation systems; and

· general sensitization of designers toward small-scale requirements.

Factors hampering transfer of appropriate small-scale irrigation technology

The use of appropriate technology on small-scale irrigation developments could be improved significantly. Some of the problems most frequently encountered are discussed below.

Lack of interaction between farmers and technical advisers

Farmers are still not sufficiently part of the process of choosing the technology suited to their circumstances, especially when schemes are being developed or rehabilitated. The interaction between technical advisors and farmers seems to be particularly difficult when:

· technical advisers lack the skills, commitment and/or back-up to interact meaningfully with the farmers; and

· farmers have no irrigation experience or have had inadequate exposure to technologies to debate the options.

Water saving

Saving water is often not a farmer priority.

Cost of development

The cost of irrigation development is prohibitive, especially for schemes.

Consultants' costs

Consultants' costs possibly could be reduced if the scope of pre-feasibility reports include only relevant information to back up recommendations and more reference to examples and precedents. Such a report could be generated through communities' own participative analysis and planning. These studies, as well as standardized design functions, could be handled by well-trained, local "technical irrigation assistants" instead of consultants.

System capacities

The estimation of scheme and in-field system capacities is often unrealistic. In most cases the conventional approach is recommended and is then applied without modification. CROPWAT is regarded as being the desired procedure for estimating crop water requirements. The crop factors utilized assume, by definition, "a disease free crop grown in large fields under optimum soil water and fertility conditions and achieving full production potential under the given growing environment". This is a situation rarely applicable in the case of cash-strapped risk-avoiding small farmers. This is recognized by low yield estimates and cash returns but not by appropriately adjusted irrigation requirement determinations.

It is common practice to design system capacity to keep up with atmospheric demand in the peak month. Few planners utilize the valuable scheduling module in CROPWAT which quantifies the buffer effect of water stored in the profile and periods of under-irrigation and stress at peak. Usually it is found that when the realities of production conditions are taken into consideration system capacity can be reduced to half or less without irrigation becoming the limiting factor in production. There is, however, another side to the coin. Irrigation hours are often grossly over-estimated, assuming night irrigation and the continuous availability of labour, and this can lead to inadequate system capacity.

It can be argued that there should be sufficient capacity to cater for indifferent weed control and shallow soils, but this is a fallacy. There is no way in which effective irrigation technologies can be found, developed or applied in circumstances where the natural resources and the basic crop production know-how are lacking.

Reduced capacity may limit expansion possibilities, but some innovation could possibly help avoid this by using a modular approach to water supply and irrigation design.

Type of technology

The type of technology often does not lend itself to modularity and may also limit the possibilities for local manufacturing and/or trading.

Design experience

There is inadequate design experience for development of irrigation schemes for management by the users. In some cases the in-field irrigation system limits farmers' flexibility and decision-making. Operation and maintenance often receives inadequate attention and is often the responsibility of government agencies.

Availability of suitable technology

The available technology is not always suited to small-scale irrigation requirements. For example, small pumps with sufficient flow rate and pressure from which one or two sprinklers can be run, are not available in South Africa. Currently, fire fighter pumps are being used, but they have not been designed for the long operating hours typically needed for irrigation purposes.

Demand and supply of equipment

Manufacturing of equipment specifically suited to small-scale circumstances is probably hampered by the (lack of) demand. A thorough market analysis on the quantities needed on a regional (SADC) basis could provide opportunities for an integrated approach.

Promoting improved small-scale irrigation

Start with the people

In South Africa, we have not had sufficient success with small-scale irrigation to be able to standardize or generalize. In that respect, we are very much in a developing phase and have to treat each project as being unique and specific in its requirements. One successful development (albeit non-irrigation) provides us with some pointers for a possible approach, namely the Phokoane maize project. Much of the success of this people-based development is attributed to Johann Adendorff's needs analysis approach. It provided him with the basis for the interventions and farmer training that brought about a tenfold improvement in average production on an 8 000 ha area consisting of individual plots of between 1-2 ha each.

Once a needs analysis has been done and the technical aspects of production and the appropriate training established, the design or selection of appropriate equipment can be undertaken.

It appears to be important to start where success is most likely. There has been much debate about what this means in practice, but based on observation, the farmers' will to succeed appears to be paramount. Further, success is generally easier where tradition and experience is available to build on. Marketing outlets for produce are essential for sustainable production, while success is possible despite less than ideal natural resources.

Sharing experience

"Regular personal interaction between those who can and those who want to" (Crosby, 1996) has proved to be a powerful tool for improvement at all levels. Field visits and workshops could possibly be enhanced by mobile demonstrations which may have wider impact and which could focus discussions amongst and between farmers, technical people and possibly even donors.

Improve accessibility

It would sound commonplace to say that adequate access to equipment, design and installation capacity, spares/maintenance support, training, finance and enabling government policies would help promote improved small-scale irrigation. Assuming that the criteria of adequacy, appropriateness and affordability apply throughout, the following ideas are presented for consideration.

Access to equipment

The idea of travelling or round robin salesmen to improve accessibility to equipment and spares, has been mooted. The idea looks particularly promising where sales visits could coincide with weekly village market days and providing that prices could be kept reasonable. Adequate technical training of salesmen would enhance their contribution significantly.

Access to design and installation

The role that well-trained, motivated local technical irrigation assistants could play, has been discussed tentatively.

Access to spares/maintenance support

Local businesses providing technical irrigation support should be encouraged. While local (village level) manufacture may not always be viable in South Africa, local trading and spares supplies could probably be incorporated into spaza (informal) type trading.

Access to training

All disciplines involved in small-scale irrigation development could benefit from appropriate training or briefing. Farmers have expressed a need for hands-on familiarization with technology and generally seem to lack a basic understanding of irrigation principles. All the other disciplines (e.g. designers, support personnel, donors) in turn, need at least briefing on the nature and idiosyncrasies of small-scale irrigation.

Access to finance

Funders' ability to support small-scale, low-cost, community/farmer initiated projects have been inadequate in South Africa. Funding criteria should be very clear and well-known to applicants and should possibly place more emphasis on the importance of communities' own analyses, planning and responsibilities and less on external control measures. Pre-feasibility requirements should be on a need-to-know basis to avoid the costs involved in elaborate studies and should be structured to facilitate quick decision-making and feedback to applicants.

Supporting government policies

The overall understanding of the requirements of sustainable small-scale irrigation development and active support to small-scale farmers could be improved significantly by increasing contact between farmers and knowledgeable technical support staff in the field.

Unfair competition through bulk supply by outside agents should be avoided, especially if spares are likely to be problematic. Instead, local manufacture or trading should be promoted where possible, through local service providers rather than government or agency monopolies.

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