It was quite similar to the ordinary medicinal herb he had saved before, its top leaves had withered and blackened, while only the leaves and stems near the root still appeared to hold a trace of vitality.
The soil in which it was planted was black.
Qin Niu pinched some of the soil to smell it, then brought it close to his eyes for a careful examination.
This type of soil belonged to the clay variety, containing acidic humus.
Based on the scent, it wasn't just the decay of plant leaves and dead branches that could produce such fertilizer. It's likely that animal carcasses had been buried in the soil and, as they decomposed naturally, they enhanced its fertility.
Moreover, this process must be quite slow, otherwise the soil's fertility wouldn't be so even.
The deeper the fertility seeped into the soil, the milder its nature became.
Otherwise, if the composting was done too hastily, it would damage the roots.