To tackle the problems of extreme salinity and “absolute scarcity” of water present at the Kafrin site, the capture and storage of water was of the utmost importance. As deserts are regions were evaporation exceeds rainfall, reducing evaporation was also of great concern.
To capture every drop of rainfall possible, the site was surveyed to provide a detailed map of the site contours. Once the contour lines were identified, swales (water-harvesting ditches placed on contour) were planned for the site to capture as much of the runoff rain to allow it to sink into the ground where it is most easily stored for the benefit of soil life and vegetation.
There were 8 swales dug into the site with a total length of 1.5 km, and ranging from 2 to 3 metres wide and made 50 cm deep. Additionally, the top swales catch water runoff from the road. The downhill sides of the swales were uncompacted to facilitate water absorption; and they were heavily mulched with organic waste from local farms help combat evaporation. Along the south end of the site, there is an erosion gully. Each swale connects to the erosion gully via pipes to collect the rainfall from them during large rain events, which occur a few times a year.
On the upper side of the swale, fast-growing, pioneering support trees were planted to improve soil conditions. Among the species planted were nitrogen-fixing wattles (also good as poultry fodder), leucaena species (saline-tolerant and good for fodder and fuel), Cercidium microphyllum, AKA palo verde, which is a nitrogen-fixer (also producing edible seeds), nitrogen-fixing casurinas (which can be coppiced for fuel), and nitrogen-fixing Sesbania sesban (which can be used for fodder or fuel and the leaves can be used to make an anti-tumor, anti-helminthic [i.e. anti-parasite] tea).
On the lower side of the swales fruit trees were planted. Among these trees were fig, olive, guava, dates palm, citrus, mulberry, pomegranate, carob, tuna cactus, and grapes. Bananas, the world’s largest herbaceous plant, were also planted on site.
When starting any project, the initial stages require extra care. In this case, the young trees required additional irrigation (apart from rainfall) to get them established on the site. A mulch-covered drip irrigation system was set up to supply each tree with water. The water for the drip system is supplied by a raised goose pond. Nutrient-rich water from the pond supplies “fertigation” for the trees. And as the pond is raised, the water can be moved to the trees without the aid of pumps. Also, the pond itself is shaded to reduce evaporation and provide better shelter for the geese.
The area between the swales is planted with vegetables and grains. The grains include barley for fodder and nitrogen-fixing alfalfa . Organic material from plant production, leaves, stems, etc, is used as mulch to improve soil conditions and help retain moisture in the soil.
As mentioned, there are geese on site, but also chickens, pigeons, turkeys, ducks and rabbits. As the site matured and was able to produce enough forage, sheep and a dairy cow were added.
On site, there is an education centre building made from local materials (sandstone and cob) with sustainability in mind. The character of the building is in keeping with the local aesthetic while having design features appropriate to the climate. The building employs a wind chimney which scoops up oncoming winds and channels them over trays of wet charcoal to create an evaporative cooling effect. From there, the air is drawn out the top of the building via a solar chimney. The stone walls of the building also have a thermal flywheel effect. They slowly draw up the heat of the day releasing it at night, warming the building at night. Then in the morning the stones are cooler than the surrounding air providing a cooler environment during the day. The overall effect is to moderate the extreme desert temperatures.
In Part 3, we will have a look at the results of the project.