We’re not just protecting and enriching the soil for the fun of it, of course. Its fertility—its ability to support and nourish plant life—is critical if we want to support and nourish our own lives with a bountiful harvest come fall.
There are many ways to encourage fertility in the soil, some natural, some artificial. What I’ve described with regards to mulch and composting is, as Michael Pollan explains, an approach that imitates nature.
Each of the biological processes at work in a forest or prairie could have its analog on a farm: Animals could feed on plant wastes as they do in the wild; in turn their wastes could feed the soil; mulches could protect bare soil in the same way leaf litter in a forest does; the compost pile, acting like the lively layer of decomposition beneath the leaf litter, could create humus. (The Omnivore’s Dilemma p 149)
But, needless to say, caring for the soil in this way requires that we invest time and labor. Setting up a vermiculture bin and an outdoor compost heap, maintaining their moisture levels, turning their content to aerate the innermost material, continuously separating compostable greens and browns from the rest of the household trash, feeding minced apple cores and coffee grounds to the worms every few days...
It would be far easier, and in that sense seemingly more efficient, to forget all this. We could toss all our kitchen wastes together and toss them out; we could neglect the dirt in the backyard as mere dead ground or even dumping ground, like previous tenants did. Then one day if we decided we’d like to grow something, we could purchase synthetic fertilizer and apply a layer. Why not take that route instead?