On 18/08/19 22:10, Paul Allen wrote:
On Sun, 18 Aug 2019 at 07:40, Joseph Eisenberg
<joseph.eisenb...@gmail.com <mailto:joseph.eisenb...@gmail.com>> wrote:
But I see that there is some desire for a tag for generic cropland, or
farmland used to grow unspecified crops. For this I would suggest the
key "farmland=cropland" or "crop=field_cropland", rather than crop=yes
(less specific) or produce=crop (unclear).
Before we get to the details of how we're going to tag it, we need to
be clear on what
"it" is.
Modern agricultural techniques (mainly the use of fertilizers, whether
natural or
artificial) permit monoculture, where a single type of crop is grown
in the same
field, year after year. This we can map with crop=* (or crop=yes or
whatever
replaces it when we know a monoculture crop is grown but we don't know
what it is, although that seems unlikely).
However, it is still fairly common to use crop rotation where
different crops are grown
in different years, or even two different crops in the same year.
See https://en.wikipedia.org/wiki/Crop_rotation One crop in the
rotation may be
grass, harvested for silage to later be fed to animals. In some cases
a field
in a crop rotation may be used as pasture for a year to directly feed
animals.
Land in crop rotation may be left fallow for a year, with no crop. OTOH,
where the land is very uneven then it might be used for nothing but
pasture
(sheep or goats are the usual "crop" on land like that).
Sheep. goats, cattle, kangaroos or camels are not 'crops' but 'produce'.
Maybe we need crop=rotation rather than crop=yes. I suspect we need
both. Not
necessarily as the tag crop=yes if everyone thinks there's a better
tag, but we need to
cover "this is used to grow crops in some sort of rotation" and "this
is used to grow
crops but I can't figure out what type from this distance and I don't
know if it's
monoculture or rotation."
And where part of that rotation includes animals the tag should be
produce=rotation?
Possibly the mapper will not know if the rotation is only plants.
Or maybe we should restrict ourself to mapping it as farmland because,
in general,
we don't know what a farmer is going to do with a given field from
year to year. There
are specific cases where we're fairly sure a field is used for
monoculture and we
have specific tags for those: orchard, vineyard, etc. But, in general,
just because I
see oilseed rape in a field this year that doesn't mean it's going to
be oilseed
rape next year (it usually isn't, around here).
In some parts only cattle are run, in other parts sheep, in other parts
plants, and in some parts a combination.
Where that is this single use it is easy to tag e.g. produce=cattle,
where there is variation from time to time then it gets complicated.
I should also point out that many farms around here devote some or all
of their land
to tourism. Is that crop=tourist? Where the tourists pitch their
tents or park their
caravans is a camp site, but some of the farmland may be left for
tourists to
use recreationally (aka the farmer having given up on farming completely
because it's no longer economic).
If it has totally gone from farm use then it needs to be re-tagged. '
Occasional use I don't think should be tagged.
Regular use can be tagged using the conditional attribute.
A problem maybe seen with 'fallow'. While this seems to be 'weeds' to
the casual observer, growing weeds by a farm will be seen as destructive
to their other activities and any weeds will be discouraged. Usually
'fallow' land will be planted out with some cheap coverage that can be
usefully turned back it to the soils. So 'fallow' to me is a 'produce'
of 'fertiliser' that does not leave the paddock.
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