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Old 07-07-2003, 03:47 AM
Andrew Stephenson
 
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Default Plausible population support productivity figures / sq.Km?

I am writing a work of fiction and need to get a "reality test"
feel for how many people a square kilometer (etc) of land could
plausibly be expected to support.

If this is not the right NG, could someone suggest one, please?

Otherwise, here's an outline of the (NB) fictional situation:-

The land is former estuarial mud, like that produced by the UK's
River Thames. For story reasons too complex to detail here, the
land suddenly came under cultivation about thirty years ago using
essentially horse-aided manual techniques, by people with a sound
knowledge of modern agriculture but limited access to machinery
and artificial fertilisers. Mixed crops are raised, rotated and
all that. They have the kind of tools a good manual workshop or
smithy could make.

The climate is basically hot desert -- think of the US Mojave or
northern Sahara deserts: dry air, lots of strong sunshine, little
rain. Frost might occur but low temperatures are more likely to
be due to night-time cooling, as the altitude is about 100 ft.

Happily, good water is absolutely not a problem. Pests are few.

I imagine that by now the land is becoming used up, despite their
efforts to feed it with whatever, ahem, fertiliser comes to hand.

Would anyone care to guess at the productivity of 8.3 square Km?

TIA.
--
Andrew Stephenson

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Old 07-07-2003, 03:13 PM
Oz
 
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Default Plausible population support productivity figures / sq.Km?

Andrew Stephenson writes
The land is former estuarial mud, like that produced by the UK's
River Thames. For story reasons too complex to detail here, the
land suddenly came under cultivation about thirty years ago using
essentially horse-aided manual techniques, by people with a sound
knowledge of modern agriculture but limited access to machinery
and artificial fertilisers. Mixed crops are raised, rotated and
all that. They have the kind of tools a good manual workshop or
smithy could make.

The climate is basically hot desert -- think of the US Mojave or
northern Sahara deserts: dry air, lots of strong sunshine, little
rain. Frost might occur but low temperatures are more likely to
be due to night-time cooling, as the altitude is about 100 ft.

Happily, good water is absolutely not a problem. Pests are few.

I imagine that by now the land is becoming used up, despite their
efforts to feed it with whatever, ahem, fertiliser comes to hand.



Let's look for a maximum. With no pests or diseases, and adequately
fertilised, I imagine some 12T DM/Ha of harvestable high energy feed
would be available. Maybe more, but less if legumes were grown (as would
be likely).

For the sake of argument (ie I can't be bothered to look it up) let's
allocate 1k DM food per family of four per day so about 3 families/Ha.
They would be vegetarians, of course. At this density farm animals would
not be required, there being adequate labour to do it all by hand.

That would be about 1200/sq km or on 8.3 sq km some 10,000 people.

Now let's start deducting.

If we are to go to a more-or-less organic-type situation, with diseases,
but few pests (aphids, maybe) then you might like to halve this.

If you want some animals, which are inefficient converters, then perhaps
halve it again. So maybe 2500 people or say 800 families.

Of course if something becomes limiting, phosphorus for example, or
disease then you can cut some more. The choice is yours as to how
quickly you cut it.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.

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Old 07-07-2003, 05:11 PM
Andrew Stephenson
 
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Default Plausible population support productivity figures / sq.Km?

Thank you, everybody, for your prompt and helpful responses. It
looks like my initial (NB wild) guesstimate of 30,000 people must
be cut back to 10,000 tops -- good thing I thought to check. As
round numbers always sound fake (weird, really), let's say 9,403.

The point about favouring legumes and rice is worth knowing; but
I've got to allow my characters to have livestock, as a source of
leather at least. I had already considered having them clearing
more brownfield land for crops, so that's definitely on (maybe an
extra 100 hectares so far). Odd corners (totalling around 50 Ha)
have trees growing fruit and useful stuff. Scrap wood, metal and
such are plentiful. It all (well, most of it) makes sense, given
the situation.

Otherwise, it's a lean time all round, with the added plot point
that land is steadily becoming impoverished and production will
continue to fall -- likely, yes? (And I just realised salination
is a likely menace. Zot... Well, it _is_ fiction; I can mention
it as another impending problem.)

Any further thoughts are very welcome.
--
Andrew Stephenson



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Old 07-07-2003, 05:13 PM
Andrew Stephenson
 
Posts: n/a
Default Plausible population support productivity figures / sq.Km?

Thank you, everybody, for your prompt and helpful responses. It
looks like my initial (NB wild) guesstimate of 30,000 people must
be cut back to 10,000 tops -- good thing I thought to check. As
round numbers always sound fake (weird, really), let's say 9,403.

The point about favouring legumes and rice is worth knowing; but
I've got to allow my characters to have livestock, as a source of
leather at least. I had already considered having them clearing
more brownfield land for crops, so that's definitely on (maybe an
extra 100 hectares so far). Odd corners (totalling around 50 Ha)
have trees growing fruit and useful stuff. Scrap wood, metal and
such are plentiful. It all (well, most of it) makes sense, given
the situation.

Otherwise, it's a lean time all round, with the added plot point
that land is steadily becoming impoverished and production will
continue to fall -- likely, yes? (And I just realised salination
is a likely menace. Zot... Well, it _is_ fiction; I can mention
it as another impending problem.)

Any further thoughts are very welcome.
--
Andrew Stephenson

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Old 07-07-2003, 09:04 PM
Gordon Couger
 
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Default Plausible population support productivity figures / sq.Km?


"Andrew Stephenson" wrote in message
...
Thank you, everybody, for your prompt and helpful responses. It
looks like my initial (NB wild) guesstimate of 30,000 people must
be cut back to 10,000 tops -- good thing I thought to check. As
round numbers always sound fake (weird, really), let's say 9,403.

The point about favouring legumes and rice is worth knowing; but
I've got to allow my characters to have livestock, as a source of
leather at least. I had already considered having them clearing
more brownfield land for crops, so that's definitely on (maybe an
extra 100 hectares so far). Odd corners (totalling around 50 Ha)
have trees growing fruit and useful stuff. Scrap wood, metal and
such are plentiful. It all (well, most of it) makes sense, given
the situation.

Otherwise, it's a lean time all round, with the added plot point
that land is steadily becoming impoverished and production will
continue to fall -- likely, yes? (And I just realised salination
is a likely menace. Zot... Well, it _is_ fiction; I can mention
it as another impending problem.)

In farming a hail storm at just before harvest in population such as yours
that is living hand to mouth is catastrophe of immense proportion as it any
thing that effects the crops look up 'year without a summer' on google. Your
village need food storage.

Goats and sheep are probably your best livestock because they can be grown
on food that human can't use. Goats eat leafy plants and sheep eat grass for
the most part. They are also a handy size for killing. Chickens will fit in
will eat a lot of insects and convert rice to high quality protein as
efficiently as you can grow soy beans on rice land. If you collect the
manure every day they probably make as much fertilizer as well.

Gordon


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Old 07-07-2003, 11:56 PM
Jim Webster
 
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Default Plausible population support productivity figures / sq.Km?


"Gordon Couger" wrote in message
news:3f08739a_3@newsfeed...

Goats and sheep are probably your best livestock because they can be grown
on food that human can't use. Goats eat leafy plants and sheep eat grass

for
the most part. They are also a handy size for killing. Chickens will fit

in
will eat a lot of insects and convert rice to high quality protein as
efficiently as you can grow soy beans on rice land. If you collect the
manure every day they probably make as much fertilizer as well.


Also consider Doves as in Dove Cotes, an excellent source of meat, and also
saltpeter for gunpowder

Jim Webster
Gordon




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Old 08-07-2003, 04:20 AM
Andrew Stephenson
 
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Default Plausible population support productivity figures / sq.Km?

Thanks again, people. To cut bandwidth, a compendium response:-

*** Gordon:

[Hail storms; food storage] Good point. No serious risk of hail
but dust and wind are hazards in deserts. Will crank that into
the setup.

[Goats, sheep, chickens] Useful. Ta. That certainly simplifies
the energy budget considerably, if goats/sheep will eat junk veg.

*** Larry:

[horse stats] Useful figures. Already had horses down as luxury
items; your reasoning provides hard justification. Hence, people
would only endure the cost of owning a horse if it did a job in a
special way. Eg, as a mobile source of power and/or force. Main
use I see is for haulage. I shall downplay the horses: maybe a
couple of dozen in all.

*** Jim:

Also consider Doves as in Dove Cotes, an excellent source of
meat, and also saltpeter for gunpowder


More good points. I already have pigeons as a semi-pest species,
largely controlled by raptors, like kestrels. One food source I
considered was hamsters, which ISTR Andean households routinely
rear in semi-captivity. As rodents (?), they should be able to
thrive on nutritionally dubious scraps.
--
Andrew Stephenson

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Old 08-07-2003, 08:08 AM
Jim Webster
 
Posts: n/a
Default Plausible population support productivity figures / sq.Km?


"Andrew Stephenson" wrote in message
...
Thanks again, people. To cut bandwidth, a compendium response:-
More good points. I already have pigeons as a semi-pest species,
largely controlled by raptors, like kestrels. One food source I
considered was hamsters, which ISTR Andean households routinely
rear in semi-captivity. As rodents (?), they should be able to
thrive on nutritionally dubious scraps.


isn't it Guinea Pigs they eat in Peru?

Jim Webster
--
Andrew Stephenson



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Old 08-07-2003, 09:08 AM
Gordon Couger
 
Posts: n/a
Default Plausible population support productivity figures / sq.Km?


"Andrew Stephenson" wrote in message
...
Thanks again, people. To cut bandwidth, a compendium response:-

*** Gordon:

[Hail storms; food storage] Good point. No serious risk of hail
but dust and wind are hazards in deserts. Will crank that into
the setup.


We lost all the cotton in west Texas to rain and sand blowing this year.
Desertficatin is a real bitch.

[Goats, sheep, chickens] Useful. Ta. That certainly simplifies
the energy budget considerably, if goats/sheep will eat junk veg.

*** Larry:

[horse stats] Useful figures. Already had horses down as luxury
items; your reasoning provides hard justification. Hence, people
would only endure the cost of owning a horse if it did a job in a
special way. Eg, as a mobile source of power and/or force. Main
use I see is for haulage. I shall downplay the horses: maybe a
couple of dozen in all.

==========
You can eat them as well.

*** Jim:

Also consider Doves as in Dove Cotes, an excellent source of
meat, and also saltpeter for gunpowder


More good points. I already have pigeons as a semi-pest species,
largely controlled by raptors, like kestrels. One food source I
considered was hamsters, which ISTR Andean households routinely
rear in semi-captivity. As rodents (?), they should be able to
thrive on nutritionally dubious scraps.


Rodents are starting to need food more like people. Stay with ruminants they
can use food that humans can't.

If you live by the sea it is a great source of food and convenient way to
get rid of characters that become untidy without and fuss or muss.

Gordon


 
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