The combination of green and "gray" spaces in cities, along with the variability of growing modes, means some city crops — like cucumbers, potatoes and lettuces — yield at least twice as much as their rural counterparts:
As urban populations boom, urban agriculture is increasingly looked to as a local food source and a way to help combat inequitable food access. But little is known about how productive urban agriculture is compared to conventional, rural farming. A new study digs in, finding urban gardeners and hydroponics can meet and sometimes exceed the yields of rural farms.
"Despite its growing popularity, there's still quite a lot we don't know about urban agriculture, like whether the yields are similar to conventional agriculture, or even what crops are commonly grown," says Florian Payen, an environmental scientist at Lancaster University and lead author of the study, published today in AGU's journal Earth's Future.
The new study compiles studies on urban agriculture from 53 countries to find out which crops grow well in cities, what growing methods are most effective, and what spaces can be utilized for growing. [...]
"Surprisingly, there were few differences between overall yields in indoor spaces and outdoor green spaces, but there were clear differences in the suitability of crop types to different gray spaces," Payen says. Certain crops like lettuces, kale and broccoli are more naturally suited to be grown vertically in indoor spaces than others. "You can't exactly stack up apple trees in a five- or ten-layer high growth chamber," he says, "though we did find one study that managed to grow wheat stacked up like that."
Other crops, like watery vegetables (e.g., tomatoes) and leafy greens, performed well in hydroponic environments. And crops grown in fully controlled environments can be grown throughout the year, allowing harvests to happen more times per year than in open-air environments, which leads to higher annual yields. But scientists will need to keep studying these systems to plan cost-effective agriculture solutions.
[...] It remains to be seen whether growing food in cities has a smaller or larger overall carbon footprint than conventional agriculture; the answer likely varies. Researchers are also studying how foods grown in cities might be impacted by pollution. And some crops included in the study's literature review lacked the numbers to be included in statistical analyses, pointing to a need for more research on urban crops like fruits and cereals.
Journal Reference:
Florian Thomas Payen, Daniel L. Evans, Natalia Falagán, et al., How Much Food Can We Grow in Urban Areas? Food Production and Crop Yields of Urban Agriculture: A Meta-Analysis [open], Earth's Future, 2022. DOI: 10.1029/2022EF002748
(Score: 4, Interesting) by JoeMerchant on Friday September 02 2022, @11:13PM (7 children)
My wife started medium scale hydroponics about a year ago (25 plants inside, another 25 outside) and it has become very apparent that the plants do much better when you pay attention to them every day. ph levels, water levels, insects, pruning and harvesting, some indoor plants need manual pollination, the only thing that is truly 100% automated are the lights.
If you invest that 200 hours per year in plant care, you get more lettuce than a family of four will ever eat, some scallions, and a few peppers. Strawberries have proven to be tricky, as has broccoli and friends. Of course 200 hours of labor buys an awful lot of food from the grocery store, too.
I think the more efficient way to do urban farming, by far, is to go at it full time with thousands of plants, and sell the surplus.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 4, Interesting) by istartedi on Saturday September 03 2022, @12:22AM (6 children)
Strawberries have proven to be tricky
I grow everything outdoors, and I gave up on them early. I got berries, but something nibbled them fast and it was smaller than the chicken wire I tried as protection, so I figure it to be an insect pest. I found out that strawberries are some of the most treated crops. Organic must be taxing that to the limit--perhaps they do something like spread lots of diatomaceous earth which still passes organic muster; but I decided to take the L and move on.
Tomatoes are the literal and metaphorical low-hanging fruit of home gardening. I put 8 plants out most years, and get so many to freeze and give away. They require no special treatment of any kind.
I've also had a fairly easy time with corn and pumpkins, but haven't tried the 3 sisters yet--I augment with chicken manure.
The hardest plant that I've had success with is hot peppers--Serrano and Habanero. I gave up on the latter because they're too hot and I don't even care for their flavor note that much. The Serrano have to be protected from deer of all things. I don't think they'll eat the peppers, but they'll absolutely destroy your leaves if you don't protect the plants. Also, ants and aphids so I have used the aforementioned diatomaceous earth, and a few squirts of neem oil along with selective pruning to get a good crop of peppers.
This is isn't urban though--it's in soil out in far flung NorCal; but when you said "strawberries", it brought back memories. Hat's off to anybody who can grow them anywhere without dumping chemicals on them.
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(Score: 0) by Anonymous Coward on Saturday September 03 2022, @02:33AM
When I have a few plants in the ground, my dog ends up eating any strawberries I get. :)
I have too many tall trees around me that I can't get any more than an hour or two of direct sun in any given spot, so I can't seem to grow anything interesting, even tomatoes (I'll get maybe one on a plant, or three or four of the grape-sized ones). I have a grape vine in the backyard, and again because of the sun it produces maybe a dozen grapes in total, but I never see them ripe. I thought it was the birds, but one day I saw my dog with his head in the vines. Friends suggested I try lettuce. I've thought about messing around with getting some LEDs and grow boxes for indoors, more as a science experiment at first than expectations of producing much of anything.
Any produce I've tried to grow anywhere around my home turns up a total seasonal crop that you could comfortably eat in one setting if it all came ripe at the same time. I've got friends and co-workers who complain about the amount of cukes or tomatoes or whatever they get, but that's not been me. The best spot I get sun is down by the curb, but anything I've put in pots there (hot peppers and peppers) get ravaged by the deer.
(Score: 2) by JoeMerchant on Saturday September 03 2022, @03:49PM (4 children)
So, our yard is 85% tree shaded, and even the spots that get sun it's mostly reduced hours.
I started strawberries in 12 8" terracotta pots hung on a 2x4 that is mounted on 2x4 posts about 28" off the ground with a drip irrigation system on a timer, 1 minute twice a day 7 days. I bought 24 plants called "Sweet Charlie" from some rando on Amazon, they arrived as roots only in good condition and all 24 lived, but I suspect they had been highly pumped with every chemical known to agriculture... this was April and by mid-May I was getting my first berries, in the medium-small range. I just gave them the water and some fish meal for nutrients, but I suspect my potting soil had some fertilizer in it as well. They're supposed to be "June bearing" but we're zone 9 and by June the berries were done and we were into runners. Since I already had 2 plants per pot, I tried clipping off the runners but the runners were relentless. I took a couple of pots over to a shadier ground garden we have setup with regular sprinkler irrigation and the runners took in the ground quickly, but even with lots of fish meal they never have grown much there, I'm going to guess it's the reduced sun and if we ever get the weeds under control on the sunny side of that garden I'll try to root some over there.
So, year 2 comes around and I'm expecting May berries, but they're really sparse and smalle this year. Then July comes around and I'm expecting runners: last year I literally had hundreds, this year I think I've had 4 or 5. The plants are bigger and stronger, some are down to one per pot, one drip nozzle clogged and that pot died. The ground garden had some small berries but some kind of pest would eat them just before they got ripe.
I like the "pots in the air" arrangement, it makes it possible to weed while standing up and it definitely seems to cut down (but not eliminate) pests.
I tried some of the Sweet Charlie runners in our outdoor hydroponic setup last year, they fizzled there - even with good sun. Probably a pH thing, the hydroponics are my wife's area: I know I don't have the attention span for them, and apparently she doesn't either for more than a month or two at a shot. My wife got some "special for hydroponic strawberry plants" and tried them indoors and outdoors - indoors has LED lights and lettuce grows like crazy on it - but strawberries... not so much. The hydroponic will grow some peppers, if you're growing a couple of Habaneros a year that's a good number, our Habanero plant didn't do well but other peppers have. I like the Habanero flavor, the key is to not get too much, possibly wear gloves - at least handle with care, and balance the flavor with things like coconut cream, or maybe curry if that's your thing, or both. What I don't like are the (easier to grow here) jalapenos and similar "green" flavored peppers - I don't know how to get rid of that objectionable-to-me green flavor in them, it does cook out with enough heat and time, but the "good" pepper flavor cooks out even more quickly.
All in all, it seems to me like outdoor gardening varies by location, and that can be from one house to the next due to sun, soil, pests, etc. certainly what works in Miami Florida doesn't work in Jacksonville Florida, and more drastic changes in climate only make things even more different. I had hope for the indoor hydroponics, maybe if we get an automated pH and nutrient balancer worked out that could be productive and reproducible in more locations.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by istartedi on Sunday September 04 2022, @02:05AM (3 children)
Interesting. I guess indoors or out, tightly controlled or not, the strawberry struggle is real.
I forgot to mention that while I grow outdoors, I *start* seedlings indoors except for corn and pumpkins. Have you ever walked through the garden center and seen them selling corn seedlings? I've seen that the past few years. It seems like something that would only sell to ignorant hipsters who are just starting out; but I should probably withhold judgement. Maybe there's a reason; but corn starting is generally just waiting for warm soil, putting the kernel in a hole, and covering it, LOL.
Anyway, what made the peppers challenging was not only growing them but starting seedlings. I didn't realize how much light I needed for good pepper starts at first. I eventually purchased a 4' LED light (nothing fancy, just white) and got fantastic pepper starts--maybe a bit leggy and one day I might experiment with pruning but I didn't even grow them this year because of the drought.
So anyway, we have a lot of shade too. Only one part of the yard is "full Sun" but I don't grow anything there now. I *tried* to grow a lemon tree there. It's doable here but this is inland coast range Mediterranean, not the gentle Bay Area climate. We get a lot of 100F scorch, and occasional wet snow. My neighbor's mature citrus probably gave me too much confidence to think that I could grow a Lisbon lemon there. The cold didn't kill it. It was a combination of heat, ant/aphid action, and scale. Oh boy. Scale. If you don't know what they are, count your blessings. I babied it with a shade cloth, hit it with neem oil, mechanically removed the scale, watered and it was no-go.
The nearly 100% sunny side yard is now grass in winter, bare dirt in Summer for fire safety, and that's it. My neighbor grows a cactus in that kind of situation. That's one option. I plant the peppers in the shadier part of the back yard. The pumpkin vines are sheltered by the corn, but they trail towards the shade, not the Sun. The plants know what's up, I suppose. They'll get burned up here. I think the tomatoes might actually be in more like 85% Sun, and even less than that at times because I use shade cloth on them for the first month or so.
So yes, huge variety by location and even around the block. My neighbor catches afternoon Sun and has little scorpions that live under rocks. I've never seen one in my yard.
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(Score: 2) by JoeMerchant on Sunday September 04 2022, @12:25PM (2 children)
Corn... I have never gotten more than a 2" ear of corn to grow, usually more like 1" - or nothing, I do get a lot of nothing. The plants always sprout, but seem to fizzle around 24" tall. Tried "three sisters" several times, all the plants sprout, but no squash ever, maybe a couple of beans... really sad.
They hydroponics are selling to those hipsters, and they come with (or should I say: also sell) "prestarted seedlings in growth media" which is how my wife did the peppers. We also tried the seed bed with its own light on a timer and a thermostatically controlled heater mat, etc. and... lettuce. Not much besides lettuce started in there, at least not strongly enough to transfer to the "tower".
Florida = citrus, right? Yeah, so much so that we also get all the nasty monoculture (because they all are on the same root stock) diseases. I believe I'm dealing with greening disease now, hard to tell, there's an adjacent bamboo stand competing for water and nutrients in the ground, and light for the tree that looks the worst, and that nutrient competition is basically what greening disease does, so the symptoms look pretty identical. I have 3 orange trees near the bamboo, and the thing that makes me most believe I don't have "the greening disease" is that their symptoms seem to vary based on how much bamboo rhizome activity I see near their trunks. Those are close to the kitchen door and I setup a timed sprinkler on them, so we shouldn't have water stress anymore. Then I have a Persian lime out in the yard, impractically far for irrigation and it has just struggled for the past 3 years, not putting on much growth at all, but mainly exhibiting intermittent water stress - unlike the bamboo adjacent oranges. Lots of effort for what amounts to a $5 bag of citrus harvest every year so far.
Every year I throw our pumpkin seeds on the giant brush pile and in the irrigated garden hoping for something to happen, I get a few vines but they don't last. I've also tried potatoes and carrots in the gardens, and they are a major timing challenge around here - if you don't get the temperature profile right all you have are little micro-tubers, and if you leave them in the ground hoping for better luck next year they are consumed by nematodes or something similar - incidentally infesting that area making future tuber gardening impractical for several years. I got giant sunflowers to grow once, just once out of about a dozen tries over the last 30 years, seems like removal of weed competition, and a lucky water / temperature weather profile, were the keys. They definitely aren't easy, but are mightily impressive when they work, and if you plant enough of them you do get quite a bit of surplus seed from the flowers.
Florida = bugs, TRUE! We stay occasionally at this little house on a pond in Georgia and they have a couple of gliders around the fire pit, so my wife wanted one for the garden, so we bought it at Lowes and put it out there and: it's like a blood-drive mobile in our yard. If the mosquitoes aren't working, there's some kind of invisibly tiny bug that lives in the weave of the seat fabric and chews on any exposed flesh. Haven't had the chiggers here (high on a sand-hill) like we did in the swamp at our previous house, but I bet if we left the Spanish moss on the ground too long they would find us here, too. The neighbors have a horse pasture (sadly, horse died last year) that they mow, and fertilize, and I'm sure treat for bugs too - I'd rather not think about what bleeds over from that field into our yard, but... they can sit out in the field at dusk where we would be eaten alive.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by istartedi on Sunday September 04 2022, @05:35PM (1 child)
Oh wow, you're in Florida. I think it would be harder to grow most everything there. Sure, year round good climate; but as you say--BUGS! No good freeze, perhaps not even a normal frost to kill them.
I have no idea why your corn would be stunted. I googled around a bit but I figure no quick googling is going to fix a problem you've known about so long. The only time I've seen that here is on a "permaculture" lot. Apparently, crop rotation isn't a part of that philosophy, and the dude didn't want to use fertilizer, I guess because that wasn't "permaculture" either so.... what did he expect?
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(Score: 2) by JoeMerchant on Sunday September 04 2022, @05:59PM
Yeah, I'm sure I'm missing the corn trick, probably soil amendment for pH plus nutrients. There are corn "research fields" south of Miami that grow 8' tall stalks of all kinds of varieties.
Main problem in Florida is: everything grows. Bugs, weeds, etc. It's a constant soup of life that makes competition for whatever you are trying to do. And: my strawberries in pots seem to have been browsed by one of our rare city deer recently, about 60 percent of the leaves gone, I was thinking grasshoppers (we get the big ones), but no bugs were to be found, and the munch pattern was more deer on inspection / reflection.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 3, Insightful) by MIRV888 on Saturday September 03 2022, @12:08AM (4 children)
The soil around here was downwind from the incinerator for neighborhood trash. That incinerator ran for 70 years. I would never eat food grown around here. I suspect I'm not the only on with contaminated soil.
(Score: 4, Insightful) by Immerman on Saturday September 03 2022, @05:17AM (3 children)
Don't let that stop you, there's no need to get your local soil involved.
Aeroponics is quite popular and lends itself to vertical gardens in windows, etc.
Or even just a container garden using dirt purchased from somewhere clean.
(Score: 2) by JoeMerchant on Saturday September 03 2022, @03:53PM (2 children)
Indeed, there's lots of studies in Australia about lead in urban soils and how that affects the garden food, and the short of it is: change the dirt - you probably don't want that lead in the dust that blows up during dry season anyway.
It's not just trash incinerators: coal fired power plants have been major sources of nasty stuff for a long time now too. Spoke with our local ex-mayor about our coal plant once and she was just so smugly sanguine about it: "oh, we paid millions of dollars years back for all the best scrubbers, that's not a problem at all" - yeah, honey, how about the reason why we spent those millions and the decades that the plant ran before they were installed, not to mention that just because they cost millions doesn't mean they're perfect...
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by Immerman on Saturday September 03 2022, @06:44PM (1 child)
Not to mention decades of burning leaded gasoline - that contamination will never go away on its own.
But Japan has greenhouses in the Fukushima fallout zone - just don't build grow your veggies in contaminated dirt and they're fine.
(Score: 2) by JoeMerchant on Saturday September 03 2022, @06:52PM
Radiation is a funny thing, a little bit is actually good for you in a lot of cases (like endogenous production of Vitamin D, for starters), but that good/bad line is all over the place for different people in different circumstances, and then somebody gets cancer and everybody stares (usually wrongly) at the nuke plant across the street. I mean, when that plant is Three Mile Island in mid 1979, then they're probably not wrong, but _most_ of the others are safer than sunbathing (possible exceptions for Savanah River and the other military oriented sites...)
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 3, Insightful) by ElizabethGreene on Saturday September 03 2022, @01:16AM (1 child)
It doesn't seem like a huge revelation that high input dense agriculture produces more crops per acre than conventional agriculture. What would be surprising was if high-input agriculture was less expensive per Kg produced vs (relatively) low-input agriculture. To my knowledge that is not the case, and tfa doesn't seem to touch on it.
(Score: 3, Interesting) by JoeMerchant on Saturday September 03 2022, @04:03PM
>To my knowledge that is not the case
The real answer is: it varies. There's all kinds of factors and one of the biggest is: how efficient is your market? Can you get the food to table before it spoils?
In an ideal urban farming situation, the losses during transport are near zero and the transport itself is just "last mile" without the trans-continental journeys that most food takes these days, at least in U.S. markets. So, even if the big-ag super-efficient grown food is only 20% of the cost per kg, when they lose 50% due to transport and inability to meet market demand spoilage - now you're up to 40% of the cost, and factoring in the cost of packaging for thousands of miles journeys through all kinds of heat and cold and the cost of transport itself and you can see how a efficiently marketed local farm produce can beat efficient distant farms, even if the cost of production at the growing point is 5x.
Now, do the urban farmers have teams of marketing mavens locking up shelf space in all the groceries and restaurant supply chains? Hell no, and that's a huge dis-advantage in getting their produce to table before it spoils. They also don't have the same experience in growing produce to meet market demands, etc. If you could get all that business muscle and intelligence into urban farming, I think it would kick distant farming's ass right outta the park, but... urban farming is by nature a large collection of small farmers instead of a small coalition of humongous grower enterprises, so they're going to have a very hard time competing, and the existing grower enterprises (like fossil fuels, etc.) are making plenty of money in their present business model, thank you very much, so why would they risk cash cow on trying something new?
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by MIRV888 on Sunday September 04 2022, @03:50AM
I just use hydro, indoors of course.
;-)