Plowed tiles spreads like other biomes.

[Chiprel2]

Plowed tiles still spread on dirt.

[Ukhata]

Plowed tiles still spread on dirt.

can confirm.
also happens on my plot of land.

[jorb]

Reported here. Will fix. Thanks. Locking.

[Cajoes]

Setting up a more scientific post here listing my own observations, - will try to travel the hearthlands.

Outline of observation: Will plow a single tile of Field into test Biome, will observe said biome for the next few days and note any changes. If no spread occurrs in the next, lets say three days, the biome is not subject to Field-spread. (Or plow-cancer as I call it) and will be marked on the list as such: Biomes that can't be plowed are listed as Non-Applicable. For the sake of padding out the post.

Biomes that Biome Type: Field (aka plowed tile), spreads into:
• Dirt - Confirmed spread
• Pavement (all types) - N/A
• Cloudrange - No spread
• Sombrebramble - Observing
• Hardsteppe - No spread
• Lushfield - No spread
• ShadyCopse - Observing
• Water - N/A
• Deep - N/A
• Mountain - N/A
• Acre Clay (also listed as Dirt according to my viewer) - N/A
• FlowerMeadow - Observing
• Grass - Confirmed spread
• Greensward - Observing
• Sandcliff - N/A

I feel this will give a better overview than random 'still spreading' posts without context or observed datums and assist in tracking down the issue. My pet theory as of writing is that Dirt is somehow lower on the 'priority' of biome-spreading-into-other-biome than Field is... Maybe I should try planting trees near a patch of Dirt with Field tiles in it? Trees also affect biomes.

Edit: ... Also doing this because I am incredibly bored. I am assuming the issue has not been tracked down yet? On account of the thread not actually being locked.

If you want to add a point of data to the list, - please include the type of biome it is spreading into and maybe a screenshot, everything is better with screenshots. And diagrams.

[Granger]

Spreading happens on decay hit, as that is only happening all long as the area is loaded you'll have to have a character active in the area to get meaningful results.

[Cajoes]

Fair enough, I am fortunate enough to have several biome types within draw distance of my humble lab.

Looking at the data though, I conjecture that only Dirt and Grass (generic grass that forms after grassing a area) are susceptible to Field biome conversion.
With Grass converting Dirt into itself and Field converting both Grass and Dirt into itself. (And the exception being outside sources like players or animals, converting grass into dirt)

Hypothesis: Priority layers of Grass, Dirt and Field interaction and conversion are wonky. Instead of the neat progression of plowed Fields going fallow:

Field < Dirt < Grass

It is:
Dirt < Field > Grass

Having no knowledge of how the code in question is set up however, this is pure cold hard unfounded speculations. But it is the best I got.

[Sevenless]

Found some plowed tiles spreading in my village. I don't think they can spread into forest tiles, but they were spreading into natural grass biome (not the artificial grass biome though oddly)

[Cajoes]

By artificial I assume you mean manually planted grass from seeds? That is peculiar and does not align with the model so far established. Is planted grass distinct from naturally forming grass from deforestation?

Also notable: All other biome types (leaf-forest, pine-forest and so on) will spread into dirt tiles over time.

I don't have any heath to test on, sadly.

[Sevenless]

By artificial I assume you mean manually planted grass from seeds? That is peculiar and does not align with the model so far established. Is planted grass distinct from naturally forming grass from deforestation?

Also notable: All other biome types (leaf-forest, pine-forest and so on) will spread into dirt tiles over time.

I don't have any heath to test on, sadly.

Artificial meaning the stuff that starts spawning either when you plant seeds to make grass or deforest an area.

[Cajoes]

Huh, that is entirely counter to my observations to date. Wherein Field refuses to spread into naturally occurring biomes. (And Natural biomes will spread into Dirt, but won't touch Field)