This time, I will write about three different applications of high-tech greenhouses in wealthy nations to show what potential this rather old and familiar technology can reach, and also to discuss some potential problems related to mass implementation.
Spanish greens
I had already written about how some desert areas of Spain have helped it become one of the largest producers of certain crops in Europe, despite the difficulties. According to this article, 100,000 acres of greenhouse covered land grow more than US$1 billion worth of produce annually.
Surprisingly, its not high-end and fancy crops, and much of the produce is destined for budget german supermarkets like Lidl and Aldi. To me, this shows that costs of technology can be reasonably controlled and useful in farming lower margin crops, and is not only viable at high market prices for premium products.
Spanish greenhouses: an aerial view. (link to source)
This Spanish spectacle is not without controversy however. Despite the improved efficiency of greenhouses in retaining water, such farms have depended on groundwater abstraction because of the sheer scale of commercialised production in the region. Locals have enjoyed the jobs and the revival of the region's economic prospects, but the Spanish government has had to deal with a future water problem, as well as build costly desalination plants to deal with current problems of seawater intrusion into groundwater supplies.
I do worry that cheap vegetables are being grown and sold below the true costs of production if companies are exploiting groundwater resources for free or little cost. Such large scale usage definitely calls into question long term sustainability, and the answer is not not likely to be optimistic.
Tomatoes in Texas
Greenhouse temperature regulation is a challenge in deserts, because the internal temperatures of the greenhouse may rise to damaging levels, and much water is used to cool off the plants. However, Village Farms, an enterprise in Texas doesn't release that water vapour into the atmosphere. Instead it recycles all water inputs up to 5 times to achieve 87% water savings compared to field grown tomatoes.
Growing in controlled environments also enables the firm to control every aspect of the environment. Insects are kept out, except bees which aid pollination. Even the soil used for growing tomatoes is not conventional soil, but "coco peat", which is apparently selected for superior properties.
While I believe that it would be simpler and potentially more efficient to grow tomatoes in more suitable climates, questions of jobs and self-sufficiency (food security on national scales) may drive people to do agriculture in such inhospitable climates and may incentive governments to provide subsidies and aid to farmers in such regions. Certainly in rural Sub-Saharan Africa, families and youths have little mobility and security in their lives, and subsistence agriculture may be a large portion of their food and income.
Veggies AND Water in Doha
Probably one of the more innovative ideas is the seawater greenhouse project called the Sahara Forest Project. Sound impossible? Qatar has done it by utilising the power of the sun in deserts to evaporate and desalinate seawater, while also cooling greenhouses for growing crops. The testbed facility was only 1 hectare in size, but managed to produce cucumbers, arugala and barley. Although developed in Europe, the project has global ambitions.
The seawater greenhouse concept (link to source)
While this is unlikely to be relevant to farmers across most of Africa, particularly the driest landlocked areas, implementing such projects may increase water availability for coastal nations, My speculation is that there might even be opportunities for water export to inland nations, for use in large scale commercial farms or municipal use.
Summary of Greenhouses in agriculture
Not all greenhouses are created equal of course, and the lists of benefits and cautionary points would vary from project to project. However, in general it seems that most greenhouse projects exhibit the following characteristics.
Pros:
Protection of crops from pests, enabling higher yields and better appearances
Potential to costs save on resource inputs like fertiliser, and pesticides
Potential to recycle water inputs
Cons:
Many concepts are designed assuming access to electricity and other high-tech equipment
Need a method of heat and air regulation, as greenhouses trap gases and heat
Requires high capital investment
Requires expertise in regulating the greenhouse and growing crops under new conditions
Hope you enjoyed this stuff and as always, stay starchy
Mr. Cassava
This is a nicely illustrated blog and features a couple of nice exchanges - try to encourage these further. There is an interesting path here on greenhouses. I suggest that you keep in mind the broad subject area - water - and geographical focus - Africa. As with some of the posts to date, it is certainly fine to consult on material outside of Africa but do keep posts focused on the challenge of your thematic area. I would also be sure to refer (more than you have so far) to the peer-reviewed literature in the areas you wish to comment and engage. Cassava (and other crops choices) and their associated water demands or resilience to climate variability are, for instance, an excellent area to mine further. Perhaps with blog title and start, this was what I expecting to read.
ReplyDeleteAlthough you said that there is potential cost saving from various sources, do you think the cost of building and maintaining greenhouse overweigh its benefits as it seems to be an expensive way to grow crops which might not even sell for very high price? Not only could it be economically inefficient, it could be very environmental unsustainable depending on how it is operated (e.g. amount of power needed, pollution to atmosphere). Also, if capital was really invested in such projects in Africa, it could well be that foreigners have invested and the earnings will not stay in Africa to help locals?
ReplyDeleteHi Mona, to my knowledge the economic feasibility of greenhouse production for small farmers is still unproven in SSA. I did say that in the Texas example, the cost savings were not specified and I assume that it might be possible to produce tomatoes more cheaply in other environments and using other methods. However, I think the Spanish case hints that greenhouse produced food can be price competitive.
DeleteI think its hard for any development project in Africa to avoid funding issues. But it does not mean that expensive projects can't be paid for with aid dollars; for instance, multi-million dollar dam projects are essentially sponsored by foreign countries. On the other end of the spectrum, if technologies prove to be an affordable and sensible investment, they will be taken up naturally. In Kenya, farmers are actively building (non-climate controlled) greenhouses with their own money (see a previous post).