One is the soil's fertility, its nutrient value. And the third is the soil's ability to drain, to shed water after a rain. All right, let's go down through your list. We've got humus content, drainage, and fertility. Well first, humus content.
Humus content is the amount of organic matter, or humus, in the soil.
And it's pretty easy to judge on a sort of a simple homeowner level. If you pick up the soil that's fairly dry and you crush it and it stays together like that, there is a decent amount of humus. Yes, nice and brown, too. Soils can be all different colors and be equally fertile and good. But this just happens to be dark-looking soil to begin with.