Calculations of Arable Land

Assumptions:

1) A well fed populous consumes 4 hectoliters (400 liters) of grain per person per year.
2) 5:1 should be our base harvest (five grains) per grain sown in good areas, 4:1 in poorer areas. The worst areas only achieve 2:1.
In France from 1300-1499, the ave is 4.3
In England from 1250-1499, the ave is 4.7
In England from 1500 as far as 1700, the ave is 7.0
In France from 1500 all the way to 1820, the ave is 6.3
In Germany and Scandinavia from 1500-1699, the ave is 4.2
In Eastern Europe from 1550-1820, the ave is 4.1
3) 1.5 hectoliters are sown on 1.0 hetares (1 tenth of a sq kilometer, or 2.5 acres)

Sow 1 hectoliters on .67 hectares, produce five hectoliters of grain. Save one for the following season, and consume four. So, assume generously that 5 people require 3 hectares (3 sq hectometers, or .3 sq kilometers, don't you love the metric system!) Now take into acount the fallow system used. Northern Europe used a three-field system, Southern Europe used a two field system (weaker soils, more emphasis on wheat). In the far North, Scotland for example, wheat gets harder to grow, so oats and rye rotate through a poorer system.

Wherever the BR information states a good agricultural area, assume the numbers above: 5:1, perhaps even 6:1, and a three field system.

When the BR sources look less favorable there are two things to consider:
1) northern lattitude- reduce to 4:1 grains harvested per sown, it drops productivity by 25% (3 to eat rather than 4, because 1 hectoliter is always required for the following season) 2) southern lattitude- reduce to a two field system drops by 17%.

When the BR sources suggest a poor agricultural area, drop yields to 50% (either 2.5:1 in a three field, or 3:1 in a two field system).

Also keep in mind that the technology information given on p. 19 of the BR rulebook recommends (implicitly) reducing yields of Rjurik, Vos, and humanoids. Anyone specifically interested in these economies should contact me for the more complicated information on their diverse agro-economies. The Vos, in poor areas will have some 2:1 yield agriculture, but you can surely see that other investments in hunting, raiding, or brutal population limitation will be applied.

Animals;

Livestock will tend to improve your crop fertility, but require a huge investment in land. Overall animals are the best investment in terms of return on labor and soil fertility, but they are the worst return in terms of land use.

So, the system I use goes like this:

Using a six mile hex (the distance a dwarf can walk in normal day), we get an area of almost 20 sq miles per hex, or about 500 hectares. This will support some 800 people, if all the land is agricultural. When I do a general map of an area, I assume three hexes per level for province levels one through three. This gives me lattitude to work with later. I can explain 2,400 people in a level one province, 4,800 in a level two, and 7,200 in a level three. I also have hexes of mixed forest and farm land, I require six hexes per level (produce for 400 people). Simple forests are 9 or 10 to the level (producing a *maximum* of 100 persons worth of subsistance). That's still 5 persons/sq mile, high for forest land, but a plausible maximum. Hills and plains can support 400 people (most of whom are not living in these hexes) by herding animals. The hills are supporting a very low population directly, but the export of animals and animal products (in exchange for grains, tools &c) supports higher farm populations and urban populations. Remember, grain must be transported to market, cattle can walk itself to slaughter.

These figures assume the 5:1, three field data. Remember to increase the hexes required as mentioned above.

When it comes to importing food, try to avoid it when possible. The cost of grain transported over Roman roads increased the cost of the grain by 1% per mile. 100 miles, doubles the cost of grain. By sea is more reasonable, but still costly. Realms importing food must have exports.

My 6 mile per hex maps use 14 terrain types, which I use to calculate the carrying capacity of a province as well as movement for day to day campaigning, and theoreticly military movement if a PC ever wishes to direct his war machine at that level.

By Kenneth Gauck

This page hosted by Geocities. Get your own free page!