On this point, I will tentatively disagree (but it's not a contest), if only because it takes only one season for the mud-to-hit-the-fan, so to speak. And for the weeds to grow.
On this point I want to offer particular kudos as to this pit bottom. First: That you, RE#1, have both mud and soil at all. Bravo! I have this thing--a pet peeve you might call it--about "grain size,*" and particularly so modeling in N-scale myself. Ballast, for instance...if the ballast grains stand up so much so that you can see airspace underneath them, it's a dead giveaway that it's a model. But just adding a layer of soil in between those grains can really take the modeling to a whole new level, regardless of scale. The soil drops down in between the chunks of ballast (as it would if real), and it becomes much more difficult to tell, regardless of scale.
[* They usually do too, because N-scale in particular is so small and the grains of crushed rock are, therefore, so light in weight. Call me not a rivet counter but more of a dirt counter, I guess. Have pity, please. I'm trying to find a hobby that might correct this...problem]
Second: Your soil itself and the dried up cracks. Just brilliant stuff.