Potash and high fertility soil

[Reade Pringle]

When I use potash on high-fertility soil, it turns into terra preta and boosts the maximum potassium content in the soil. I'm wondering if the other values, which were at 65% for Nitrogen and phosphorus, will slowly increase to 80% because that's the value terra preta has when it's first tilled. Otherwise, is there a difference between high-fertility soil that's turned into terra preta versus terra preta crafted with compost and the like?

Thanks.

[Zane Mordien]

I've meant to test this myself, but I don't care about anything but K crops.

[LadyWYT]

22 hours ago, Reade Pringle said:

Otherwise, is there a difference between high-fertility soil that's turned into terra preta versus terra preta crafted with compost and the like?

Terra preta is terra preta--there's no functional difference there. The advantage to using high fertility soil to craft it though, if I'm not mistaken, is that you get two pieces of terra preta for each set of ingredients you input, instead of just one, making it a more efficient crafting choice if you have it available.

[Cladow]

I think that answer misses the point of the question, the application of potash is unrelated to the crafting grid recipes.

According to the wiki - https://wiki.vintagestory.at/Potash#Usage, applying potash to soil increases only the K nutrient by 15%, the change in soil remains visual, and therefore, does not make it true Terra Preta.

Crafted Terra Preta does have all nutrients equally high, and adding a block of High fertility soil to the recipe does double the number of crafted blocks from 1 to 2.

[Echo Weaver]

@Cladow A related question -- does applying potash to terra preta permanently increase the K nutrient, or is terra preta's max K as high as you can get?

Edited July 14, 2025 by Echo Weaver

[Maelstrom]

3 hours ago, Echo Weaver said:

@Cladow A related question -- does applying potash to terra preta permanently increase the K nutrient, or is terra preta's max K as high as you can get?

yes, it does.

To get the best farmland, craft terra preta, place it in world, till it into farmland and, as the final step, apply potash.  Bonemeal and saltpetre can also be applied for temporary ferilization benefits.