If the investment costs and the inherent risks of conventional trickle and sprinkle irrigation are too high for most smallholders, are there any low-cost alternatives? Most of the innovations in this direction have been in trickle and to some extent sprinkle irrigation. India, Nepal and China stand out as countries that have sought to promote the use of low-cost systems by smallholders. These countries have established national manufacturing capacity and placed emphasis on 'simple' systems that do not rely on automatic control or other labour-saving devices.
Low-cost systems attempt to retain the benefits of conventional systems whilst removing the factors preventing their uptake by poor smallholders: purchase cost, the requirement of a pressurized supply, the associated pumping costs and complexity of operation and maintenance.
Low-cost systems are not widely reported in the literature, although this could be a consequence of the nature of the organizations and agencies involved in their development and promotion, which are mainly development NGOs, rather than a reflection of their potential value for smallholders. Some equipment has been developed and tested by NGOs and church affiliated groups but such centres are often not well resourced to engage in wide-scale production and marketing of their products.
Several low-cost trickle technologies and some sprinkle systems have been developed, which are now in use in several countries. In most cases these are aimed at improving distribution and application of water. Attempts have been made to make them as simple as possible so that they can be manufactured at lower cost and operated and maintained easily. Systems are usually sold in kit form for relatively small areas of land (e.g. 25 m2). This too helps to keep the cost down and the idea is that farmers can add to the kits as they receive cash from the increased profits on their crops. This incremental development is not easily accomplished with normal commercial systems, particularly when pumps are needed to pressurize the systems. Low-cost can mean low initial capital outlay rather than low-cost per hectare. Some recent innovations are given in the following sections.
These are manufactured by Chapin Watermatics, USA. Each kit supplies water to two 15 m laterals laid on a 1 m raised bed, cropping just 15 m2.
Chapin estimates that his company has donated 15 000 - 20 000 bucket kits to different programmes in Africa. These kits are given to the projects and sold to the users for US$7. When the cost is worked out for a hectare it comes to US$4 660/ha, which is not so low. However, it is the low incremental cost that enables farmers to begin using this system. Even US$7 per kit is a subsidised price and it is argued that this is not sustainable development. Equipment is imported and distributed at this price by mission stations and aid programmes. USAID has already funded the distribution of Chapin's kits and KARI (Kenya Agricultural Research Authority) is evaluating the equipment. Chapin has also promoted larger one-quartre acre (0.1 ha) kits which International Development Enterprises replicates with its low-cost, locally manufactured kits.
The `wagon wheel' systems are found in Western Cape, South Africa. They comprise a central water tank with laterals radiating as spokes to a length of about 5 m. Each wheel irrigates a circle of about 8 m2.
International Development Enterprises (IDE) is an international NGO that first started to develop low-cost irrigation kits in India and Nepal in 1995. Field tests are now being conducted in Sri Lanka, Bangladesh, and Viet Nam.
Various kits have been produced to meet different circumstances:
The kits were all designed to be incremental, allowing farmers to start with a small kit and then expand by investing profits derived from the crop sales. The divisibility of the systems as a means of reducing the initial and subsequent capital investment is a vital part of making such systems available to poor farmers who cannot afford significant capital expenditure. Laterals are designed to be moved, which can significantly reduce the amount of equipment needed.
In Nepal, a typical trickle user has invested about US$26 for the trickle system, US$15 for other inputs, uses family labour (idle in the off-season), and increases his/her income from cash cropping from around $10 to around $100 (per capita GNP in Nepal is around $200).
IDE typically works with two types of farmers: those who are already growing commercial crops, and subsistence farmers. In most cases, the commercial farmers are able to take immediate advantage of the system benefits. Subsistence farmers can benefit through the possibility of having their resources go further and gaining access to a cash economy. The extent to which this is a successful strategy is not known.
IDE fully recognize that coming up with an appropriate technology is a small part of the solution. Focus is on reducing costs by using locally available materials, involving local manufacturers and dealers and placing emphasis on sustained marketing and demonstration so that the manufacture and supply of the equipment is commercially attractive.
IDE has developed a highly effective strategy for mass marketing of low-cost income-generating technologies in developing countries.
The basis of this is that:
By following this strategy, a sustainable, delivery infrastructure can be put in place. Demand for the technologies has a chance of increasing together with income that can support this infrastructure.
Using this strategy IDE has already had a great deal of success with the marketing of treadle pumps in Africa. The intention now seems to be to promote the same model for low-cost irrigation systems.
Netafim, an Israeli trickle irrigation manufacturer, has developed what it calls the Family Drip System that can be adapted to variable plot sizes. This was developed in China and comprises their standard emitters, pipes and filter equipment. The kit works at low head and is pressurized from a tank rather than by pumping. It has the appearance of a large-scale system that has been scaled down for use by smallholders rather than a system that has been designed specially for this market.
The costs of the system range from US$150-240 for 1 000 m2 (US$1 500-2 400 per ha). Having introduced these systems in China, Netafim plans to replicate this experience in 50 other countries. There is as yet little evidence of how successful these systems are for smallholders.
An FAO/Japanese funded programme is investigating the potential for smallholder irrigation using a combination of surface irrigation methods and water distribution using pipes (FAO 2000). A wide range of ideas are under evaluation at a training school in Ouagadougou, Burkina Faso, which includes the use of low head tanks, simple drippers for applying water and the use of hose pipes. The intention is to find suitable systems that help to reduce water wastage in water short areas, and which at the same time are low in cost and simple to use. Local materials such as PVC piping is being used with simple connections so that components can be resourced locally rather than relying on imported materials. The tests are still at an early stage and it will be some time before they are tested and evaluated in the field.
Many other examples of various technologies being adapted for use by smallholders are listed in the report of a workshop organized in Ouagadougou by IPTRID and FAO in 1998.
Some early experiences
Technical studies were reported by Miller and Tillson (1989) in Sri Lanka and Batchelor et al. (1993) in Zimbabwe on the use of low-cost trickle systems for smallholders. In both cases the systems evaluated relied on imported, high cost, commercial trickle tapes although both systems were low head and had very simple filtration. Batchelor et al conclude that even with these simplifications the equipment was too expensive and difficult to obtain. Neither study led on to programmes of wide-scale promotion or adoption.
Low-cost systems have several characteristics in common:
Over the past decade, a small, but significant revolution has been taking place in smallholder irrigation in the developing world with the introduction of the treadle pump. This simple, human-powered device can be manufactured and maintained at low-cost in rural workshops in developing countries. Acceptance of these pumps in Bangladesh, where it was first developed in the early eighties, has been described as extraordinary. Over 1.3 million pumps are now in daily use in that country. Farmers have spent US$40 million on treadle pumps at approximately US$35 each (IWMI 2000). Their use in Africa is growing and a recent appraisal of their potential has just been published (Kay and Brabben 2000). Some 10 000 pumps are reported to have been sold across West, East and southern Africa since 1997 at a cost between US$50-120. Most are used for vegetable production and enable smallholders to enter the market economy.
The experience of introducing treadle pumps into Africa serves as a useful model for the introduction of other irrigation technologies.
Treadle pumps work on the principle of suction lift using a cylinder and piston to draw water from a resource below ground level, e.g. a river or shallow groundwater. It was originally developed for the hand pumping of domestic water and has been skilfully adapted for use in irrigation, where a much greater volume of water is needed, by changing the driving power from arms and hands to feet and legs. These are more powerful muscles and are capable of lifting much more water. Two pistons are used, each connected to a treadle on which the operator stands and presses them up and down in a rhythmic motion.
The pumps were initially imported. Now most treadle pumps are manufactured locally although they do need special tooling to produce good quality pumps. The emphasis is on selling pumps to farmers on a commercial basis rather than supplying them as gifts. For this reason the supply chain is a vital aspect of the pump's success. These have been set up in Kenya, Zambia and in countries in West Africa. The supply chain must also function as a conduit for spare parts, maintenance services and feedback to manufacturers. The poor uptake of pumps in Zimbabwe is undoubtedly linked to the lack of an effective supply chain. Treadle pumps are well known in the country, however, no agency has taken on the responsibility of wide-scale marketing, and production is not continuous.
The economic benefits of introducing treadle pumps have been significant. In Zambia incomes have risen more than six fold from US$125 achieved with bucket irrigation on 0.25 ha of land to US$850-1 700 using treadle pumps. This was attributed not only to increased crop yields but also to being able to increase the area of land irrigated. Cropping intensity rose in some cases up to 300 percent (three crops a year) with noticeable increases in the variety of crops grown. Because of the increase in water availability, farmers were more willing to take risks with new crops. Similar benefits have been reported in other countries where treadle pumps have been introduced.
Problems have also been created through the increase in crop production. Higher yields can bring about the problem of a market glut when supply exceeds demand. This is a particular problem with common household crops and it is exacerbated by the tendency of farmers to grow the same crops at the same time of year. Exploiting more distant markets increases transport costs and highlights the problem of poorly developed feeder roads in remote rural areas.
Attempts to use treadle pumps in Africa in the early 1990s were less successful than in Bangladesh, because conditions in Africa are very different. The groundwater is much deeper and the irrigated land much more hilly. Water must be pushed further from its source to the point of use. The development of pressure pumps has helped to overcome this constraint in many countries thus resulting in significant sales of pumps over the past few years.
Attempts are underway to combine the use of treadle pumps with low-cost water distribution systems such as trickle kits and hosepipes in Zimbabwe, Kenya and in countries in West Africa where treadle pumps are used. The argument is that once water has been lifted by treadling there is every incentive to use it as effectively as possible. Water is usually pumped into tanks for distribution, although there is no reason why it cannot be pumped directly into the distribution system. The output from a treadle pump tends to be intermittent yet this should not pose too much of a disadvantage. However, it is still early to say if such combinations will be useful.
Enterprise Works, an NGO working in Niger, looked into the prerequisites for uptake of treadle pumps. Many of their findings would apply equally to other low-cost technologies. In order for a technology to be commercialised and adopted it should be produced as close to the end user as possible. It must be affordable for the buyer and profitable to the producer. The technology must also function reliably and the purchaser must be satisfied. It only takes a few dissatisfied customers to ruin the market for a new product. No technology can be considered appropriate for all conditions. This is where the identification of appropriate sites becomes important. Appropriate site criteria include a:
The setting up of supply chains and ensuring that there is sufficient manufacturing capacity of a high enough quality to meet the demand is also essential. As demand is something that usually needs to be stimulated when new technologies are introduced, there is the opportunity to balance marketing activities with the development of the supply chains. In this way it may be possible to balance the level of expectation created among farmers with the means of satisfying it.
To be profitable a technology must have a low overall cost that does not expose the owner to debt. It must then make money. Fear of failure has often driven people towards high tech solutions to avoid the problems of breakdown. All machinery fails eventually and in developing countries, failure tends to occur sooner because maintenance is poor and conditions more hostile. The result is machinery graveyards that can be seen surrounding many towns and villages. For this reason the need for strong supply chains to support the supply of spare parts and maintenance must not be underestimated.
Comments about the role of low-cost irrigation systems in sub-Saharan Africa are similar to those made for modern technologies. Low-cost systems have the potential to raise productivity and enhance rural livelihoods. Even though costs for these technologies may be relatively low they are still only accessible to farmers who can afford to buy them, usually they are growing cash crops such as vegetables, fruit and flowers that provide sufficient returns to pay for the investment. They have little to offer poor farmers and so are unlikely to be taken up by them without appropriate financial and technical support.
Low-cost systems have yet to be tested and evaluated properly in the region. There are also concerns about commercial interests encouraging farmers to use modern technologies when other less expensive options may be appropriate.
One exception to this is treadle pumps, which have been undergoing various evaluations in the laboratory and in the field over the past five years. So far the results in terms of uptake and benefits have been encouraging. Their adoption by smallholders and the way in which support services have been developed is undoubtedly a model that the developers of other technologies might emulate.