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> The limiting factor for arability in the north here is not temperature, but soil (or, rather, the absence of it.) According to Wikipedia, "Approximately half

> The limiting factor for arability in the north here is not temperature, but soil (or, rather, the absence of it.) According to Wikipedia, "Approximately half of Canada is covered by forest."[1] If the soil is deep enough to grow trees, why can't it grow crops? https://en.wikipedia.org/wiki/Forests_of_Canada https://en.wikipedia.org/wiki/Forests_of_Canada

EdwardDiego 5y ago
Because trees and human crops use the soil very differently. (And trees just doing their own thing use soils far differently to trees being grown for a silvicultural enterprise, for obvious reasons, we want more timber faster) Here's a very obvious example, the Amazon, there's reasons that slash and burn farmers there have to keep cutting down more forest, it's called "soil exhaustion". [0] Another example from an areas I can speak more soundly on, look at the forest in this photo[1], lots of trees, right? Some of them are 100m high. But they're growing on a podzol[2]. Good luck growing crops in that without massive amounts of uneconomic inputs. You'd need huge amounts of lime to reduce the acidity, huge amounts of organic material to increase fertility, never mind the question of managing water retention - too much is bad, too little is bad. Oh, and of course you might need to add additional minerals like selenium or cobalt. [3] Soil science is a separate discipline for a reason. It's complicated as hell. [0]: https://www.dw.com/en/the-amazon-nutrient-rich-rainforests-on-useless-soils/a-50139632 https://www.dw.com/en/the-amazon-nutrient-rich-rainforests-o... [1]: https://hikingscenery.com/wp-content/uploads/2020/06/P1050707-1024x362.jpg https://hikingscenery.com/wp-content/uploads/2020/06/P105070... [2]: https://en.wikipedia.org/wiki/Podzol#Characteristics https://en.wikipedia.org/wiki/Podzol#Characteristics [3]: https://teara.govt.nz/en/document/14187/bush-sickness https://teara.govt.nz/en/document/14187/bush-sickness So sure, once you've cut down all the trees, and then spent millions remedying water retention/drainage issues of soil structure, millions adding organic material, millions changing pH, and millions remedying any mineral deficiencies, sure, you can grow food there. Although, have you thought about erosion? And why removing trees can render soils far more prone to erosion?
maerF0x0 5y ago
Many reasons including PH, Soil retention under weathering (tree roots hold soil, and reduce wind erosion from leaves too), preferred fertilizer mix (nitrogen for example). This all said, there are plenty of farming techniques that can make the land productive, it's just not as simple as clear cut + plant.
cmrdporcupine 5y ago
I invite you to drive three or four hours north of Toronto and see for yourself. Or just Google image search "Canadian shield", I think it will become clear to you. It's beautiful country, BTW. But not farm country. (I personally would welcome the challenge, but my wife and kids would probably not appreciate it) It's a thin layer of top soil overtop of granite, often exposed. a) it's variable terrain and mostly not level and full of exposed rocks, so not suitable for mechanized agri. Just getting a house built there with a well or basement often involves dynamite b) Trees roots can penetrate nooks and crannies most agri crops can't. c) the soil pH is wrong, it's quite acidic in spots. It goes on like that for probably more than 1/2 of the Canadian land mass BTW.
- hervature 5y ago
  As somebody who grew up 5 hours north of Toronto where the primary industry is agriculture, I find this incredibly insulting. Do you think a picture in a textbook exemplifies the entire region? Go look at satellite photos of the triangle Ville-Marie, Rouyn-Noranda, and Val-d'Or and tell me what you see? It will be nothing but farmland and this is in the dead center of the Canadian shield.
  - EdwardDiego 5y ago
    I'm not surprised that there are areas in the Canadian Shield where soils are deeper - the Shield is very old, and erosion is a thing, and soils collect in lower lying areas. I'm guessing that the area you're describing has a lot of lakes, or swamps, or both. Might be a bunch of drainage schemes put in place to make waterlogged soils useful for agriculture? One swallow doth not a summer make. And one hollow doth not a viable agricultural soil over an entire geological structure make. (Obviously there's more than one place in the Shield where deeper soils are present).
  - cmrdporcupine 5y ago
    Whatever, I never said anything about it being 100% monolithically seas of exposed granite. I've been around Northern Ontario and seen plenty of farmland, but it's the exception to the rule and that can be clearly seen in satellite maps. BTW that area looks neat. I'd like to visit. But it does look like the farmland there is a product of a low lying lake basin, maybe sedimentary deposits left over after glaciation? And sticks out like a sore thumb from the surrounding area. (EDIT: just read up on the "Timiskaming Graben"... cool!) I do think, on the whole, northern Ontario stands to do better out of climate change than many other places in the world.

EdwardDiego 5y ago

Because trees and human crops use the soil very differently. (And trees just doing their own thing use soils far differently to trees being grown for a silvicultural enterprise, for obvious reasons, we want more timber faster) Here's a very obvious example, the Amazon, there's reasons that slash and burn farmers there have to keep cutting down more forest, it's called "soil exhaustion". [0] Another example from an areas I can speak more soundly on, look at the forest in this photo[1], lots of trees, right? Some of them are 100m high. But they're growing on a podzol[2]. Good luck growing crops in that without massive amounts of uneconomic inputs. You'd need huge amounts of lime to reduce the acidity, huge amounts of organic material to increase fertility, never mind the question of managing water retention - too much is bad, too little is bad. Oh, and of course you might need to add additional minerals like selenium or cobalt. [3] Soil science is a separate discipline for a reason. It's complicated as hell. [0]: https://www.dw.com/en/the-amazon-nutrient-rich-rainforests-on-useless-soils/a-50139632 https://www.dw.com/en/the-amazon-nutrient-rich-rainforests-o... [1]: https://hikingscenery.com/wp-content/uploads/2020/06/P1050707-1024x362.jpg https://hikingscenery.com/wp-content/uploads/2020/06/P105070... [2]: https://en.wikipedia.org/wiki/Podzol#Characteristics https://en.wikipedia.org/wiki/Podzol#Characteristics [3]: https://teara.govt.nz/en/document/14187/bush-sickness https://teara.govt.nz/en/document/14187/bush-sickness So sure, once you've cut down all the trees, and then spent millions remedying water retention/drainage issues of soil structure, millions adding organic material, millions changing pH, and millions remedying any mineral deficiencies, sure, you can grow food there. Although, have you thought about erosion? And why removing trees can render soils far more prone to erosion?

maerF0x0 5y ago

Many reasons including PH, Soil retention under weathering (tree roots hold soil, and reduce wind erosion from leaves too), preferred fertilizer mix (nitrogen for example). This all said, there are plenty of farming techniques that can make the land productive, it's just not as simple as clear cut + plant.

cmrdporcupine 5y ago

I invite you to drive three or four hours north of Toronto and see for yourself. Or just Google image search "Canadian shield", I think it will become clear to you. It's beautiful country, BTW. But not farm country. (I personally would welcome the challenge, but my wife and kids would probably not appreciate it) It's a thin layer of top soil overtop of granite, often exposed. a) it's variable terrain and mostly not level and full of exposed rocks, so not suitable for mechanized agri. Just getting a house built there with a well or basement often involves dynamite b) Trees roots can penetrate nooks and crannies most agri crops can't. c) the soil pH is wrong, it's quite acidic in spots. It goes on like that for probably more than 1/2 of the Canadian land mass BTW.

hervature 5y ago
As somebody who grew up 5 hours north of Toronto where the primary industry is agriculture, I find this incredibly insulting. Do you think a picture in a textbook exemplifies the entire region? Go look at satellite photos of the triangle Ville-Marie, Rouyn-Noranda, and Val-d'Or and tell me what you see? It will be nothing but farmland and this is in the dead center of the Canadian shield.
- EdwardDiego 5y ago
  I'm not surprised that there are areas in the Canadian Shield where soils are deeper - the Shield is very old, and erosion is a thing, and soils collect in lower lying areas. I'm guessing that the area you're describing has a lot of lakes, or swamps, or both. Might be a bunch of drainage schemes put in place to make waterlogged soils useful for agriculture? One swallow doth not a summer make. And one hollow doth not a viable agricultural soil over an entire geological structure make. (Obviously there's more than one place in the Shield where deeper soils are present).
- cmrdporcupine 5y ago
  Whatever, I never said anything about it being 100% monolithically seas of exposed granite. I've been around Northern Ontario and seen plenty of farmland, but it's the exception to the rule and that can be clearly seen in satellite maps. BTW that area looks neat. I'd like to visit. But it does look like the farmland there is a product of a low lying lake basin, maybe sedimentary deposits left over after glaciation? And sticks out like a sore thumb from the surrounding area. (EDIT: just read up on the "Timiskaming Graben"... cool!) I do think, on the whole, northern Ontario stands to do better out of climate change than many other places in the world.