So, first off, a more explanatory examine would be better, in particular to differentiate between the three compost types.

However, the current examine is not far from the truth. Compost can make growth, if not faster, then less slow, albeit indirectly. There are a couple of posts in this thread that convey why - even protected, disease can cause crops to grow more slowly (skipped growth cycles) and composts decrease disease chance.

It's a semantic argument, though. a) it's not always the case, and b) a more accurate examine would be more useful. Something along the lines of decreasing disease chance and increasing yields would be better.