all of the nutrients that the crop contained and,
depending on the crops that are grown, enough humus
to replenish the soil’s supply.^1 The carbon that left the
soil in the form of carbon dioxide will be returned if
plants that store large amounts carbon in their mature
bodies (such as corn, amaranth, wheat, and rice) are
grown and added to the soil as cured compost.
Initially Adding Nutrients and Humus to the Soil
Not all soils naturally have all of the nutrients that they
need for their optimum health and crop productivity.
Deep-rooted crops such as alfalfa and comfrey can be
grown to bring up nutrients from below the range of
most roots, then composted and added to the topsoil.
Additionally, when cured compost is added to the soil,
nutrients that were previously unavailable in the soil
may be made available by the biogeologic cycle. (In this
c y c l e , humic acid—which is produced from the
decomposition process and is contained in the cured
compost—along with the carbonic acid developed
around the plant’s roots, can increase soil microbial
activity, decompose larger minerals, and possibly alter
soil pH so that previously unavailable nutrients are made
available.) However, if the needed nutrients are not in
the deeper regions of the soil, they will not be present in
the cured compost. In other words, if the nutrients are
not present, the cured compost made from plants grown
on the nutrients-de cient soil will not contain the