Making a world as Agriculturally productive as possible

Question

Basically, God decided to create the perfect world for man to work the land. Even then, he voluntarily decided to follow the laws of physics.

I've investigated about some factors that supposedly improve agricultural output, like Floodplains, Volcanic Ash soils, Certain kinds of soil, and even the concept of Superhabitable planets. I don't know if all (or some) of these features be integrated into one biome, but they are not Necessary, i just need the world to be as fertile as possible. I already asked a question about floodplains, but the answers there made it obvious that i wouldn't be able to rely only on river floodplains, and i don't know how would tidal floods affect soil quality.

Bonus points if the biome is also biologically productive (animal and plant biomass).

Thanks for your time and attention!

Answer 1

The most agriculturally productive places on earth are large river systems, (US, India, Heilongjiang) which in turn are caused by have wide expanses of flat land inside the Ferrel cells, with well weathered mountains on the downwind side (west) and and oceans supplying wet air on the other.

Start with an earthlike planet, the less earthlike it is the fewer earth crops you can grow on it.

So your planet should be made of large-ish continents (roughly a little smaller than North America sized, maybe 18-20,000,000 km²) with most of the continent's landmass centered between 30 and 60 degrees in latitude. About 2-3 such continents per hemisphere is ideal. We are maximizing the amount of temperate and wet subtropic landmass. Their should be large volcanically active mountain ranges on the west coast of each, with the east coast open to the sea. The mountains maximize rainfall, rivers, and soils production. Prevailing high altitude winds slowly spread volcanic ash across the continent while low altitude winds bring moisture, which also brings erosion. Water erosion spreads minerals and soil from the weathering mountains. Leaving the lower latitudes mostly ocean does mean hurricanes will be common, but that can actually work in your favor hurricanes generate extra rainfall and increase marine production.

Put a few small continents near the equator and scatter a lot of island chains between the equator and 30 degrees. That will minimize the bad effects of hurricanes by robbing them of power, while maximizing the positive ones. As a bonus it gives you lots of fishing communities, resorts, and plenty of land for tropical crops.

Leave the poles open ocean except for a small continent centered on each pole, that will maximize ocean circulation (helps fishing and agriculture) and minimize temprature fluctuation. Antarctica helps stabilize our temprature by isolating the polar climate.

With this the vast majority of your planets surface is naturally maximized for agriculture and aquaculture. the land that is not useable for agriculture is either on the pole or mountains, both of which are needed. Your only arid land should be thin strips of land on west coast of each of the large continents which can be used for cities, greenhouse agriculture, or livestock. It also means the extensive ocean you need anyway is maximized for fish production. Of course any land producing grain can also be used to feed livestock so meat or grain is your choice. You can have extensive forest or not as you choose, humans will do what they have always done clear the land they want. I recommend having mostly forest on the norther end of the continents and near the mountains, since tree farming is also agriculture. this also provides an abundant building material, again helps stabilize the climate, and humans can replace warmer forest with tree fruit orchards and farmland.

Answer 2

I feel I'm cheating here, but:

• About Earth sized planet. Little bit smaller ideally
  • Gravity is about half.
  • Slight increase in rotation speed too.
• 50% of the planet surface is smooth, flat, granite. Perfect foundations.
  • Chunks of near-pure metal meteors litter the smooth surface, they can be forged into simple equipment essentially immediately, allowing humanity to start building regardless of where they land.
  • A local small fluffy animal builds nests that look like termite mounds. These mounds can be ground up into every nutrient a plant could ever need.
    • And the animal itself is delicious. Breeds like rabbits, tastes like bacon.
• 25% of the planet is densely packed mineral deposits of amazing purity and incredibly easy to access.
  • This is concentrated near the high latitudes, which is on the cold side of ideal crop growing but not freezing. Like 5 degrees C.
  • I could mine 1000kg of pure Iron in a day using hand tools.
• 25% of the planet is pure water.
  • This is concentrated near the equator.
  • Which is a little bit on the hotter side. Like 30 degrees C.
  • Perfect beach weather.
• The planet is slightly closer to the sun than Earth - giving about 2kw/sqm of solar output.
  • But the planet isn't hotter. It's actually slightly cooler, due to a lower upper atmosphere CO2.

Humans land their spacecraft there, discover that this is a wonderous gift from god, and start building farms. Not horizontal farms, but vertical farms. Using the abundant metals and open building area they're able to quickly fabricate massive hydroponics facilities.

The easily pumped water and plentiful solar allow for incredible productivity. We're looking at about 1,940 tons of wheat per hectare, which gives the 50% of the surface which has farms on it a yearly yield of $4.9 * 10^{13}$ tonnes of wheat, enough to maintain a population of $2.47 * 10^{14}$ (247 trillion) people.

The people are able to use the lower gravity and the faster rotation speed to build a space elevator using 2020 technology, allowing their crops to be exported to the rest of humanity.

Answer 3

The problem with volcanic ash soils is pretty obvious- you only ever find them in close proximity to volcanoes. Sooner or later, it's bound to go off again, and any settlement built close enough to take advantage of that fertile soil goes the way of Pompeii and Herculaneum. Volcanoes can go centuries or millenia between major eruptions, so what the first settlers in an area assume is long-dead can go off again, and you've got a couple of hours at best to evacuate. And when a major agricultural area gets destroyed by ash and toxic gases, there's a knock-on effect as it creates food shortages elsewhere.

If the goal is simply to produce the maximum amount of calories from a biosphere, here's a possibility. We start with a warm, wet planet- large areas of shallow seas and no polar ice caps, like Earth during the Cretaceous. Some "Precursor" civilization already came through and seeded this planet with life in the form of photosynthetic microbes. After thousands of years of being abandoned, the planet is now covered in microbial mats which produce massive quantities of simple sugars. Sort of a biological version of a "grey goo" scenario.