Greenhouses for the desert?

Newsweek recently wrote an article about the future of farming. I came across some thought provoking claims that I will summarise.

1. The world has focused on rice, wheat and corn in calorie production, but a few other crops produce more calories (and nutrients) per unit of land, such as potatoes and sweet potatoes.
2. The Tabernas desert in Spain grows more than half of Europe's fresh vegetables and fruit with the help of greenhouse controlled environment. 
3. Plants grown in controlled environments using artificial light (so-called pinkhouses) grow 20% quicker than outdoor grown plants, and require fewer resource inputs.
4. Crop rotation practices not only help lands recover nitrogen naturally, but also serve to diversify rural diets and thus provide more complete mixes of nutrients (something I tried to echo in a previous post).

Now I know why the cherry tomatoes I eat come from Spain!

Greenhouses have been around for a long time now, and it should come as no surprise that high-tech controlled environment farming has been seriously considered and implemented in land-starved cities. 

Unfortunately hurdles to be faced are large. Newsweek reported that controlled-greenhouses are far less suitable for growing staple crops like rice, corn and wheat, given that their prices are so cheap, that additional costs from investment may be impossible to recover. According to farmers they've interviewed, even farmers in developed countries worry about making ends meet despite all the increased yields and efficiency brought about by technology. If crop yields across the world increase, food prices may tumble. This may be a good thing for some of the world's poor, but many farmers may themselves may be priced out of the business, and the global poor who rely on cash crops and employment on farms may also suffer greatly. In Africa as well, it may be impossible to transplant the exact same technologies used in the west due to costs, lack of transport networks, or lack of electricity and water.


Perhaps one possible solution may be to gradually encourage Africans to produce more higher value cash crops using technology grants and collective practices to increase their market power and ensure that their crops are sold quickly whilst they are fresh.

What is really interesting about these greenhouses to me is not the faster rate of growth per se, but the input savings that may be had! According to Newsweek, pinkhouse plants "need 91 percent less water, negligible fertilizer and no treatment with herbicides or pesticides".

It may just be me, but I expect resource savings to be compounded when applied to desert or semi-arid climates in Sahelian or Sub-Saharan Africa. Less growth time obviously means that  plants stay planted for shorter lengths of time and lose less water to evapo-transpiration. A greenhouse environment can mean that high yielding, expensive varieties can be grown without associated costs in protecting them or wastage of fertilisers.

Controlled environments could mean that plants can be grown throughout the year. We may not need large, industrial scale warehouses, perhaps plastic, aquarium sized containers with rollers can be pushed into the open during the day and kept watered with low yielding wells. Perhaps the evaporated water within the greenhouse may be somehow gathered and used as filtered water?  

While high-tech farming has generally been thought to be the domain of rich countries only, I suspect that high-tech doesn't necessarily need to remain high-cost. I will be sure to follow up with a more in depth post about technologies that may potentially play a role in the future of African farming.



Stay starchy,
Mr Cassava