Halophyte Agriculture in Namibia

The water just off the coast of Namibia is quite cold. The Benguela Current flows along the west coast of Africa, which keeps the temperature and humidity down on the Namibian coast, and is the cause of both the Kalahari desert and the Namib desert. This cold current fundamentally causes Namibia to be mostly desert.

Halophyte agriculture could be a major business in Namibia. For example, Salicornia and other gourmet greens could be an export. Salicornia greens are high in protein, and could be converted to animal feed as well. Quinoa and amaranth can also be grown in saline soils, as staple human food sources. Other plants yield high levels of protein while grown in saline soils, although they do require post-production processing to make the protein available.

There are several research institutions devoted to halophyte agriculture in the Middle East and Australia, in particular, ICBA in Dubai, or ACPFG in Australia. Halophyte agriculture has also been studied specifically in respect to Namibia.

Halophyte agriculture along the coast of Namibia would greatly increase water evaporation. This in turn would lead to night fogs and ultimately to increased rainfall in the Namib desert.

A halophyte plant of interest is Atripex spp, which produces a high protein yield, but is not appropriate for direct human consumption, and is not efficiently digestible by ruminants. I visualize the extraction of protein from this plant for use in vegan meat substitutes or in feed for pigs, fish, or chickens.

Applying the principles of chemical engineering to extraction of protein opens up the range of plants that can be considered for halophyte agriculture dramatically.

Part of the proposed halophyte system for Namibia would involve creation of relatively shallow lagoons offshore. The water in these lagoons could be controlled at a higher temperature than the ocean water flowing offshore.

The lagoons could support desirable types of fish, crustaceans, seaweed, and coral reefs. It would be possible to create lagoons with different temperature conditions. It would even be practical to create whole ecosystems for the purpose of preserving endangered sea life, such as the corals currently going extinct on the great barrier reef of Australia.

These aquatic nature preserves would also create a tourist industry for diving, and a captive fishery for the Namibians themselves. This is enabled by the relatively shallow slope of the continental shelf just offshore of Namibia.

The offshore farming of seaweed would also be a logical companion market for Namibia. This could occur in offshore lagoons with accurate temperature control based on tidal mixing of cold seawater with the lagoon water to maintain accurate temperature control.

Mangrove swamps are excellent habitat and breeding grounds for numerous fish species. Mangroves can be used to make paper and building products. There are also many other perennial woody plants such as coconut and seagrape that would be a logical part of a mangrove-based halophyte forest ecology.

Water distribution for a coastal halophyte agricultural system would logically involve waterways with halophyte trees along the shore, enabling a local fishery. Seagrape and many other halophytes produce nutritious fruits and grains suitable for direct human consumption, and can also feed a marine ecosystem that yields fish protein.

The cold water (~14o C) offshore of Namibia prevents the formation of coral reefs or mangrove forests but by controlling the flow it should be possible to enable mangrove forests and coral reefs; these extremely rich environments could succeed by creating a zone with much warmer water temperature near the shore.

The continental shelf off the coast of Namibia is relatively wide, averaging about 100–150 km before the drop-off to the deep sea. In addition, there is a coastal plain next to the ocean on much of the shore of Namibia. This sort of geography makes it possible to create a shallow water isolated environment near to the shore where coral reefs could live, and salt marshes and lagoons at the coast, as is desirable for halophyte agriculture.

What is needed is a national government to take an interest and to make it a national priority to develop this industry. Namibia appears to be ideally suited to take the lead on this important technology.

There’s no country on earth that is better situated by geography and weather conditions to do this than Namibia.

The government of Dubai has been supporting halophyte research and development perhaps more than any other government on Earth. It appears to me that some sort of cooperation at the governmental level between Namibia and Dubai would be very helpful.

It is highly desirable to do halophyte agriculture on a desert coast facing an ocean where there is a cold current just offshore, as is the case in Namibia. The offshore current running beside Nàmibia also happens to be very nutrient rich. The proximity of highly reliable sunlight with a cold offshore current makes it possible to create lagoons with a wide range of controlled temperatures in Namibia.

By building sea-level canals that are shaped in the form of loops with both ends entering the ocean or a lagoon fed by seawater every tidal cycle, the tidal flow can be used to push seawater into the canals as the tide comes in, and then gates are closed to retain that water until just before the next tide starts to come in, at which time the gate on the opposite end of the canal from where the seawater had entered the canal can be opened to return the somewhat saltier and now nutrient deficient water to the ocean or to a warm water lagoon.

This method can basically pump the seawater around the canal loop using the tidal flow to create the needed head pressure. This works best if there is a coastal plain. The water entering and exiting the canals could either be from the lagoons, or I think more desirably the water flowing into the canal would bypass the lagoon system via pipes.

This project would require excavation; that would largely be done by barges designed to traverse the canal system as the canals are being dug. The material dug out to build the canals can be used to create an offshore sandbar which would then be reinforced to create stable lagoons with warmer water than the seawater just offshore.

The tidal pumping mechanism described above can also be supplemented by the use of electric pumps. By using pumps it will be possible to create consistent flows for each tidal cycle.

Along the coast of Namibia, the soils will be sandy and therefore quite permeable. One desirable way to carry out seawater irrigation is to have saltwater pumped up onto sandy soil between the canals and then to flow back into the canals to be exhausted to the sea at the next opportunity. By also using a coffer dam that’s located at the furthest extent of the canal loop from the ocean, one can arrange for the seawater to flow from one leg of the canal towards the other leg of the canal through the sandy soil at low tide.

Halophyte agriculture in Namibia could supply food, building supplies, and fuel for a rapidly developing economy. It would also provide employment for many people. Some of the agricultural waste could be converted to biochar to help enhance soils elsewhere in Namibia while also obtaining carbon sequestration credits from Western donors.

What is needed to move this forward is a political sponsor for this idea in Namibia. That might be the first Lady of Namibia, Monica Geingos, who is obviously very concerned with creating an economic way forward for Namibia. She is also in charge of economic development.

Frankly, I am looking for a way to move this idea forward. If you read this far please please share your thoughts on how to move this idea forward.

If you happen to know thought leaders in Namibia or Dubai please pass this along.