BIOPHYSICAL BENEFITS AND IMPACTS

Land Reclamation And Technological Innovations

Phase one of the project was implemented over the period 1987-90. This involved construction of an intake weir 9km away from the project site, land clearing and reclamation, laying the irrigation pipe network and establishment of the pilot farm of 50ha. Water is carried by a 1000mm diameter pipe from the intake point to the project farm on the valley floor. The system operates by gravity and supplies irrigation water 24 hours a day and 365 days a year with a head of 3.5 bar at the plot hydrant. Before the project, the valley floor was marginally productive because of water scarcity. As a result of the new technology introduced, gravity-fed overhead irrigation has been developed and this has dramatically improved crop productivity and yields by farmers. 

A total of 300ha out of a target of 700ha of badly degraded land have been reclaimed (see Table 1). 

225 plots on the on the valley floor have been allocated to farmers. Each plot has a hydrant fed from an underground pipe network and is equipped with galvanized steel irrigation laterals, raisers and sprinklers. The plots were leveled at a slight slope to allow adequate drainage into the natural drainage channels on the valley floor.

Erosion Control Measures

The sprinkling of irrigation water can be adversely affected by winds and to safeguard against this problem the project introduced an external vegetation windbreak between every four plots. In addition, at the perimeters of the plots natural vegetation was maintained. Tree species used as windbreak include Leucaena, Eucalyptus and Neem (Azadirachta indica). The project distributed Vetiver grass for planting across most water channels as a means to reduce the speed of water and its erosive capacity (photo 1). Planting of Vetiver grass to control erosion has been widely adopted in the project area. The grass is planted on the edges of plots, along watercourses, gullies and traditional irrigation furrows.

Rejuvenation of Vegetation

The project has been successful in the establishment of orchards and woodlots around the pilot farm of 50ha. The tree care and management expertise of KVDA, Logadri and communities were beneficial to the project's agroforestry initiatives. Communities have planted fruit trees at their homesteads and the planted trees provide fruits as well as rehabilitate the abandoned watercourses that once dissected the homesteads. There is evidence of some abandoned traditional furrows that have been reclaimed by planting fruit trees like mangoes, paw-paws, lemons, avocados, oranges, etc. Neem tree, which is well known in the area, is found at almost every homestead. This tree is particularly important because of its valuable uses as an insecticide. Neem's active extracts are used against pests like caterpillars, grasshoppers, leafhoppers and beetles. 

Soil Improvement 

In all the activities carried out in the project area to date there is no evidence of any significant effort that has been made to promote the use of natural fertilisers for soil improvement. The only activity that can be considered to be remotely related to natural soil improvement is the distribution of some Leucaena trees by the nursery. This tree is used for soil fertility improvement in agroforestry systems. The project also encourages farmers to practice crop rotation by planting legumes after cereals. Leguminous crops mainly grown are green gram, cowpeas and okra. These crops help in nitrogen fixation especially if plant residues are also used for mulching. However, residues of legume crops are not available for mulching because of the livestock that also benefit from browsing in harvested plots. The benefits of crop rotation are therefore not being fully realised. 

Provision of Training and Supporting Research 

The project has been effective in providing training to farmers on subjects such as Vetiver grass planting and management for erosion control; nursery establishment and management and tree planting and care. In addition the project has provided (and continues to provide) training to farmers on tillage practices that enhance soil conservation; crop rotation and agroforestry practices and farm management. Table 2 presents a comparison of farming practices before and after the introduction of project innovations.

Sustainability of Project Innovations

Currently irrigation water is available 24 hours a day and allows farmers to grow and harvest crops twice a year. Project benefits to the agricultural Pokot are also being shared with the pastoral Pokot who have access to crop residues and water for their livestock. Pastoralists are also guaranteed of adequate food to buy in years of poor harvest. The rejuvenation of agriculture on the valley floors has withdrawn pressure to cultivate on the hill slopes. These once degraded slopes are slowly regenerating vegetation cover. Some project beneficiaries interviewed during fieldwork alluded to positive climatic changes in the area due to bio-diversity regeneration. There is an unmistakable total sense of ownership of natural resources amongst the farmers, which is critical for sustainability. 

Gravity-fed irrigation introduced by the project does not require energy to operate it. In fact if desired, the water could be used to generate electricity as an additional benefit. The simple technology thus needs no external inputs, which would reduce benefits. Maintenance costs for the irrigation system are minimal and there is no wastage due to seepage and evaporation as was the case with the traditional furrows. All these aspects strengthen the sustainability of the innovations. 

The uninterrupted availability of water on the valley floor has brought a lot of confidence amongst farmers who have now moved away from the old practice of shifting agriculture to adopt a sedentary type of agriculture.