There’s something to be said for sticking with native vegetation—assuming you’re in a climate that has a good variety of native plants. Abu Dhabi recently weighed the pros and cons of a plant it has long imported and farmed, one that is sometimes used for erosion control, and decided to prevent its future planting there.
Rhodes grass, native to sub-Saharan Africa, is a perennial that, besides its usefulness for erosion control, is great for pastureland. Although it’s considered an invasive plant—some rainforest areas, as well as some parts of Australia, have had trouble with it spreading where it’s not wanted and driving out native species—that isn’t really the problem in Abu Dhabi. Rhodes grass is tolerant of high temperatures and salinity—though not of frost—and grows well in sandy soils; it seems in many ways ideal for the emirate’s desert climate.
In many ways, that is, except for a critically important one. As the director of Abu Dhabi’s farming sector in the country’s Food Control Authority pointed out in explaining the decision to stop planting it, watering the Rhodes grass consumed about 60% of available irrigation water last year. Sixty percent, in a region that relies on desalination plants for about 70% of its water.
Similar debates have taken place in the US; the production of alfalfa in California, for example, requires a huge amount of water. Although many parts of the state face water shortages, it’s not—yet, at least—as costly a resource as it would be if produced by desalination. Ironically, per capita water consumption in Abu Dhabi and the other United Arab Emirates is among the world’s highest, averaging about 100 liters per person per day (still not as high as US consumption, however).
Other plants—the noninvasive vetiver, for instance—have been widely imported in many countries for erosion control, but growing plants for grazing animals is another story. Is there a less-water-hungry pastureland crop that might work in Abu Dhabi’s climate without introducing environmental problems of its own?