NPK harvest penalty

[DioHei]

I’m not sure whether this is a bug or intended behavior, but the reduction of the NPK deficiency penalty to 0% happens not after exceeding the blue lines with the optimal values for a given crop, but only after all NPK values in Menu -> Field Detail reach 70%.

It seems to me that this is because in SoilFertilitySystem.lua, line 216, the thresh uses OPTIMAL_THRESHOLD from Constants.lua, which is set to 70, instead of the OPT values from SoilConstants.CROP_NUTRIENT_TARGETS.

And a follow-up question:
For example, let’s say I start harvesting oats on a field with a yield penalty of -16%. During harvesting, the penalty shown on the display increases to -20% because the NPK levels decrease.

Does this increasing penalty affect the amount of grain going into the tank during harvesting, or is the entire field is harvested with the original -16% penalty?

In my opinion, it should remain at -16% for the whole field, because if the crop is already ready for harvest, it has already absorbed the nutrients from the soil, and the decreasing nutrient levels should no longer affect it.