delicate totem
I'm trying to plant Nebboilo vines in the Rocce vineyard, and I'm getting unsuitable terroir errors. According to the description, it should like that vineyard (sub-alkaline, clayey, higher elevation). No other vineyards are a better fit. Is this a bug?
astral wagon
Each terroir is procedurally generated when you start a new game. Sometimes there are no suitable terroirs for certain varietals.
sand flower
Exactly, as @astral wagon said, it could happen that there are varieties that don't have perfect terroir, as the terroir are randomized.
If you want to plant Nebbiolo in this case you can look for the best possible terroir but it cannot be perfect
delicate totem
But this is majority clay, and these grapes prefer clayey soil - yet it's highlighed as being actively negative, not even neutral.. For example, trying to plant Barbera in the same plot (which also prefers clayey soil) says the soil mixture is positive, but not when planting Nebbiolo.
I guess it's just not clear how to interpret the soil composition before purchasing the lot.