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Urban farms could be incredibly efficient—but aren't yet
In some ways, hyper-local food is a counterculture movement, focused on growing herbs and vegetables in the same dense urban environments where they will be eaten. It trades the huge efficiencies of modern agriculture for large savings in transportation and storage costs. But is urban farming environmentally friendly?
According to researchers at Australia's University of New England, the answer is pretty complex. Within their somewhat limited group of gardeners, urban agriculture is far more productive for the amount of land used but isn't especially efficient with labor and materials use. But the materials issue could be solved, and the labor inefficiency may be a product of the fact that most urban farmers are hobbyists and are doing it for fun.
The researchers—Robert McDougalla, Paul Kristiansena, and Romina Rader—defined urban agriculture as taking place within a kilometer of a densely built environment. Working in the Sydney area, they were able to find 13 urban farmers who were willing to keep detailed logs of their activity for an entire year. Labor and materials costs were tracked, as was the value of the produce it helped create. The energetic costs of the materials and labor were also calculated in order to assess the sustainability of urban farming.
The plots cultivated by these farmers were quite small, with the median only a bit over 10 square meters. Yet they were extremely productive, with a mean of just under six kilograms of produce for each of those square meters. That's about twice as productive as a typical Australian vegetable farm, although the output range of the urban farms was huge—everything from slightly below large farm productivity to five times as productive.
For the vast majority of crops, however, the urban farms weren't especially effective. They required far more labor than traditional farms, and, as a result, the total value of the inputs into the crop exceeded the income from selling it. In other words, the urban farmers were losing money, at least by traditional accounting measures.
PNAS, 2018. DOI: 10.1073/pnas.1809707115 (About DOIs).
(Score: 2) by takyon on Saturday December 29 2018, @04:36PM (5 children)
Humanity has had subsistence farmers for thousands of years. Today, we have ways of massively increasing yields, while reducing and automating the work. Maybe a hobbyist can sustain themselves with a shipping container sized garden. Of course, that might cost them $100k and they need some land to stick it on. But it could be a better investment than buying a boat.
Fast forward 20 years and the hobbyists could be even better off. Imagine a container that had a plexiglass roof with an automatically retractable cover, and sensors to let in a fixed amount of sunlight. The outside of the container could be covered in flexible solar panels to power internal LED grow lights. You could have little robots inside capable of harvesting the produce at exactly the right moment. Sensors could determine the health of each plant and when a tomato, cabbage, whatever will not benefit from remaining unpicked. Aquaculture (fish) could be integrated into the system to provide nutrients. Etc. I can't guarantee this arrangement would provide the dietary variety you need, but excess produce could be sold, traded, or preserved/canned.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 1, Informative) by Anonymous Coward on Saturday December 29 2018, @04:47PM (2 children)
Bad news: the problem with cost is very real in the scenario you describe. You can get jaw-dropping levels of production if you use layered aeroponics, with solar panels feeding carefully placed, tuned LED grow lights, with doped water sprays and calibrated environmental controls, CO2 injection and drone-based maintenance.
Of course, by then you'd damn well better be harvesting gold nuggets, or it's just not worth it.
This is the problem with farming: it's a terribly capital-intensive industry, producing commodities, with wildly varying price structures based on unforeseeable events. Your cyberpunk farmtronic proposal will turn a profit possibly once a decade, and the rest of the time bleed money like a drunkard in Vegas.
(Score: 2) by takyon on Saturday December 29 2018, @05:00PM
No problem, just hand out some tax breaks and call them victory gardens!
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by c0lo on Saturday December 29 2018, @09:52PM
Depends on the crops and weather conditions
In Australia growing lettuce, kale, herbs in shipping containers [abc.net.au] is a reality. The investment is jaw-dropping ($200-300K for a 40ft module), but one has some advantages:
- no weeding or using pesticides, sterile crops (or go bust) at harvest with no need for washing
- the "farms" can be placed very close to highly urbanized area - there are the eateries and restaurants with a predictable volume so you can plan for capacity
- no (chilled) storage space necessary, practically no transport cost
- very fresh produce makes a premium produce - the affluence of people working in the business district means you can put a modicum premium on the price.
In the linked:
The retail price for a lettuce head in supermarket is around $2 - 2.5. At this price, my guts feel a ROI in 7-10 years (if ever; power prices is a killer in Australia) - quite far from being a highly attractive business proposition.
However, in highly urbanized areas, like Hong Kong or Japan, it may make business sense.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Saturday December 29 2018, @05:44PM
What would you want a fixed amount of sunlight for? AFAIK there aren't many crops that are so dependent on daylight-length that this is necessary, and it would be cheaper just to go full-growlight for those. For temperature regulation, a purely mechanical system using pneumatic pistons to open/close a vent depending on the temperature is cheap and efficient (completely passively, dependent only on temp changing internal pressure).
(Score: 2) by c0lo on Saturday December 29 2018, @10:17PM
You mean something more like Modular Farms [modularfarms.com.au]?
'Cause, no, if you don't stack the crop vertically, all you have is a(n automated) glass-house - you already are in the "diminishing returns" zone relatively to normal glass-houses. And if you go with vertical farming, a retractable roof won't get you enough light. Plus, the roof/wall surface won't get you enough PV surface to power all the LEDs you need to use.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford