Soil Management on the Homestead

An ideal soil structure is one having large and stable
pores which extend from the surface to the sub-soil strata.
The size and arrangement of soil particles govern the flow
and storage of water, the movement of air, and the ability
of the soil to supply nutrients to the plants. A ready
supply of air is especially necessary so that soil organic
matter can be decomposed by aerobic bacteria. Spaces around
soil particles also act as channels for conducting water
through the soil. About one-half the volume of soil should
consist of these soil pores and fissures. Many of these
spaces are filled with micro-fauna: the gums and mucilages
formed in the microfauna breakdown of organic matter helps
to bind soil particles together.

Now observe the sample of earth that comes from the average
farm. Tillage and clean cultivation drastically reduce the
number of large pores available for the movement of air and
water through the soil. Overcropping and monoculture also
weaken soil structure. The cultivation of annual crops
creates mechanical, chemical, and biological demands on the
soil all of which cause the soil to lose its crumb
structure.

A revolution against “farm implements”–great
destroyers of soil structure–is long overdue. When
Jethro Tull invented the moldboard plow, he said “tillage
is manure”. But we now know that soil tilth is created by
decay, not by implements. The primary reason pioneer
farmers plowed was to get rid of weeds: when weeds were
plowed under the farmer had time to get his forage crop
started before wild vegetation recovered from the plowing
setback. Plowing cuts loose, then granulates, and finally
inverts slices of earth on top of surface organic matter.
As a result, bare soil is exposed to the direct eroding
action of wind and rain (soil aggregates are badly
destroyed through the beating action of rain). In this
manner, plowing (as well as other forms of tillage) breaks
down the soil structure and leaves the surface liable to
crusting, The small pore size associated with surface crust
increases the water runoff by restricting water intake,
which thereby reduces the amount of moisture stored for
future crop use.

As far as I am aware, there are no suitable
tillage implements: all destroy soil aggregates–some
more than others! For one thing, when surface moisture is
just right for tillage, the subsoil moisture content (being
higher) is in prime state for maximum compaction. Equipment
compaction takes place throughout the whole process of crop
production–from planting and cultivating to
harvesting. Excessive compaction of moist soil limits water
absorption by limiting the supply of highly essential
oxygen. Compacted soils, like soggy-wet soils, hinder
germination because much oxygen is required to digest the
stored foods in seeds. In the germination process, carbon
dioxide is given off and a maximum pore space is essential,
as the gaseous interchange around the germinating seed must
be maintained. Furthermore, the pore spaces must be
contiguous–from subsoil to atmosphere. In this way
the carbon dioxide can be dissolved with moisture in the
surface layers (by capillary attraction) forming carbonic
acid. This acid is the most efficient natural solvent of
minerals, releasing (in particular) phosphorus and potash
for the plant use.

Organic gardening magazines probably receive more revenue
from hand-operated rotary plow, like the “Rototiller”, ads
than from the balance of all other advertisements. Ads that
sell these machines to unsuspecting gardeners are just one
more example of the innocence flawing the “organic”
movement. No amount of organically-produced compost could
even begin to compensate for the total destruction of soil
structure which these machines deliver. Rototillers are the
worst type of tillage implements: soil is not merely cut
and turned over, it is sheared to dust. Powdery
soils will cake and crust upon wetting and drying.
Furthermore, the sharp tines completely destroy such
essential soil microflora as algae–which keeps
microbes supplied with greens through the production of
chlorophyll.

Mulch Planting

In my judgment, mulch planting has been proven to
be the best soil-building alternative to tillage..
Practical mulch planting techniques will be discussed in
following PLANT MANAGEMENT chapters; our only
interest at this point is how mulch planting aids in the
development of soil structure and fertility. Obviously,
fiberizing the land with organic matter prevents surface
compaction and crusting. Furthermore, this organic matter
gradually decays, and in so doing releases carbon dioxide.
As we have seen, the carbon dioxide combines with
water-forming carbonic acid, which in turn releases
essential nutrients from parent subsoil minerals. As the
decay process continues, microbial activity leaves a
residue of gelatinous and filamentous growth which acts as
a collodial complex, drawing particles together into
structural aggregations. Again, as we have seen, the
aggregation structure acts as a conduit, connecting upper
soil layers with the subsoil. Organic matter therefore acts
as a regulator of air and water in the soil: the
foundation of productive land is based on the organic
content of the soil . Force roots, not tillage tools,
through the soil.

Mulch planting does even more for soil structure: it sets
the stage for the creation of humus. Humus is as important
to soil as it is difficult for a person to understand. S.
A. Waksman’s major work on humus runs to over 500 pages!
Farmers in past centuries believed that humus was directly
utilized as basic plantfood by crops. Liebig, father of
commercial fertilizer, disproved this, showing that plant
growth was dependent upon inorganic compounds. Organic
matter is fertile only after it is broken down into
inorganic forms. However, to depart from Liebig’s
conclusion, inorganic compounds are made available by
microbes in a humus medium and not, as he
proposed, applied externally as plant-food!

Humus is organic matter in its decomposed state. It
contains the breakdown products and dead bodies of
microorganisms–which give humus its characteristic
dark color. It is these microorganisms, dying in the humus
layer, which slowly decompose organic matter, thereby
liberating and making soluble continuous streams of carbon
dioxide, nitrogen (in the form of ammonia), phosphorus, and
other elements. The gelatinous and filamentous residues
give humus the property that binds soil particles into
structural aggregations; and this structural aggregation of
soil is the most favorable medium for the development of
root systems and for the future growth of microbes.
Aeration and water-holding capacity is increased: the soil
is able to absorb more heat. Heat is also given off as a
result of air circulation through humus–especially in
light sandy soil where air moves freely as water drains
away quickly. More organic matter must therefore be
supplied to sandy soil than to clay or silt soils, to
prevent this “burning up” of humus.

Humus is a veritable storehouse of nutrients. It is also a
cementing agent, binding constituent soil aggregations
together: one pound of soil colloidal particles is said to
cover five acres of surface. Humus has functions and
qualities unknown by modern science: Waksman mentions that
when all extractions have been made by known processes
there is still 30% of the humus unaccounted for. The most
important adage that comes from a study of humus is that
growth equals decay: the growing season must
necessarily also be the decaying season.

Soil Bacteria

There’s another adage that every homesteader should
memorize: proper soil management is the care and
feeding of bacteria. Microbes are vital to the
decomposition of organic and mineral wastes into basic
plant nutrients. And, of the microbes that inhabit the
soil, 99% are bacteria. The rest consist of fungi,
protozoa, and algae. Bacteria are divided into aerobic
those which thrive under conditions of abundant oxygen
— and anaerobic bacteria, which live in conditions
where oxygen has been used up; that is, where pore spaces
are filled up with carbonic acid and water.

Activities of soil bacteria populations are fantastic: one
type produces antibiotics; one type digests proteins (most
important of which is nitrogen); other types gather
nitrogen from the air. These latter bacteria live in
nodules on the roots of certain legume plants. Nitrogen gas
is extracted from the atmosphere and made available to the
host plant in return for carbohydrates. Another, even more
amazing, type of bacteria lives in association with the
feeder roots of certain plants — for mutual benefit:
the plant is able to assimilate mineral nutrients more
readily.

Earthworms are always included, usually at top priority, in
any discussion of soil microbe population. Actually, in
comparison with the soil development accomplished by
bacteria, earthworms are pikers! At best, earthworms are
indicators of good soil fertility, not its cause.
Darwin overstated the case for the ubiquitous worm: they
have no mechanism for creating plant food, capturing solar
energy, or fixing nitrogen from the air. Earthworm
“aeration” of the soil is insignificant, and the “richness”
of earthworm casting is just one snore organic gardener
myth. In reality, the earthworm reduces soil fertility to
the extent that it burns up energy passed off as carbon
dioxide. The leafy diet of earthworms is especially low in
mineral nutrients.

Compost is another organic gardening myth worth exploring
in this chapter on soil management. A massive literature on
compost making has been compiled by ORGANIC GARDENING AND
FARMING editor J. I. Rodale (THE COMPLETE BOOK OF
COMPOSTING; 1971; 1,000 pages!), and compost making
has traditionally been the farming criterion separating the
good guys from the bad guys. In reality, mulch planting is
a complete, integral process, requiring no further
additives in the form of soil conditioners, amendments, or
fertilizers. Organic matter applied in mulch planting is
utilized in its entirety, without gaseous loss as is the
case whey making a separate compost pile. Mulch planting
seems to call for a “sheet. compost” program, where organic
matter is spread directly on the ground surface. The only
real advantage of centralized composting is where hip
excrement is utilized. More on this will appear in
subsequent chapters.

Soil Replenishment

Whether one adds compost, or any form of fertilizer, to a
soil principle of soil replenishment remains the
same, and has little to do with soil structure. Given an
adequately based organic content, however, the soil microbe
population can create its own nutrient demands in a soil
structure that is compatible to the needs of these
microbes. Experiments at the New Jersey Agricultural
Experiment Station disclosed the fact that fresh residues
applied on an equal organic matter basis produced as much
as three times the soil aggregation as did composts
prepared from the same material. Obviously an “applied”
nutrient — whether it be humus-rich compost or
commercial fertilizer — cannot have the same
influence on soil structure as a more indigenous organic
treatment.

As a matter of fact, the indiscriminate application of
fertilizers can have a harmful effect on crops: if
a little nitrogen added to the soil is good, a whole lot
added is not necessarily better! An excess of one
fertilizing element in the soil may lead to a deficiency of
another. Too much nitrogen leads to a deficiency of
potassium; too much potash leads to a deficiency of
magnesium. Excessive nitrogen added to the soil may
over-stimulate the growth of leaves and stems and interfere
with seed formation. There are good arguments against the
use of commercial fertilizers which are applied at the time
seed is planted: the fertilizer supplies soluble salts for
plant nutrition at the very time when the seed is equipped
with its own stored-up organic supply. The solubility of
commercial fertilizers is much too high in most instances
(phosphate rock is treated with sulfuric acid to make it
even more available to plants). As soon as plant roots
reach these soluble chemicals they go into a spasmodic
growth spree, which in turn upsets the delicate soil
balance.

Nitrogen is the most important of all fertilizer elements
required for plant growth: it regulates directly a plant’s
ability to make protein. Large amounts of nitrogen
are needed, especially at early stages of plant growth, and
also because so much nitrogen is lost to the atmosphere as
gas, or from the soil through leaching. Pre-agribusiness
farmers used to leave their fields in rough-stubble
throughout the winter months to facilitate rapid snow and
rain penetration into the soil, thereby minimizing nitrogen
loss from the sky. All nitrogen comes from the air: it is
returned to the atmosphere at the same constant rate that
it is removed from the air.

Other elements besides nitrogen can be recovered from the
air. Field sorrel, for instance, is an extra-heavy user of
phosphorous. It can supply itself even though a chemical
analysis where it grows reveals no phosphorous present.
Unlimited quantities of minerals are also present in the
soil and these essential nutrients are made available to
the crop in a properly structured soil aggregation.

Mineral nutrients can be “locked in” — made not
available — when the soil structure is compacted,
waterlogged, or where insufficient moisture prevails.
Raising or lowering the acidity of a soil can have a major
influence on soil nutrients. Raising the pH of an acid soil
from 5.5 to 6.4 (making it more alkaline) increases the
availability of phosphorous about ten times. And reducing
the pH of alkaline soil from 8.3 to 6.9 (making it less
alkaline) increases phosphorous availability 500%. The pH
(literally, parts-of-hydrogen) refers to the balance of
acidity alkalinity. The scale extends from 10 (high
alkalinity) to 4 (high acidity). Most plants thrive at a pH
range of 6.0 to 6.9. At this range bacteria seem to thrive,
thereby speeding the decay of organic matter and the
liberation of nitrogen. At a pH below 6.0 only those
bacteria which break organic matter into an inferior
ammonia are active; at higher pH the breakdown produces
more valuable nitrate nitrogen.

A quartz, granite, sandstone, or shale parent soil usually
produces an acid topsoil, whereas marble and limestone
produce alkaline soil. Ground limestone is traditionally
applied to reduce soil acidity. If available, use dolomite
limestone as it contains magnesium carbonate as well as
calcium carbonate. Magnesium is an important soil
amendment. If a soil is too alkaline, apply sulfur or
gypsum. It is the oxidation of sulfur that reduces
alkalinity. And organic matter encourages sulfur oxidation,
which further illustrates the importance organic matter
plays in soil management practices. A light, sandy soil
— or one highly weathered — requires less
amounts of soil amendment to lower or raise pH than heavy
clay soils or soils high in organic content. Usually
gardeners use either too much or too little lime: at
Cornell University several hundred home gardens were
analyzed: one-third had too much lime, one-third had too
little, and one-third were just right.

Soil Testing

Most states have agricultural experiment stations and
extension services which will test one’s soil for lime and
fertilizer requirements. Or one may prefer to do his own
testing, using an inexpensive soil-test kit.

Soil for testing should be taken 6 inches deep, where most
crop roots live. It is important to keep soil moist several
days before testing as drought affects pH by killing
bacteria. Also a cold soil inactivates bacteria: so, in
order to get a fair pH reading, test warm, moist soil. When
using the kit to test for mineral requirements, remember
that the availability of soil nutrients varies from day to
day and from season to season. In the early spring, for
instance, nitrogen is taken up by soil organisms, so on
this basis a false reading will be made. Also a single soil
sample would not necessarily be typical of the whole
homestead. A farm usually has from 3 to 6 types of soils
— there are tens of thousands different soil types in
the U.S.

Actually, to classify soils into “types” — like
Chernogen, Podzol, Prairie, etc. — is rather
misleading as well as being unimportant. In the early
farming days, before the destruction of topsoil and humus
by bad farm practices, soils were made up of thick, black
layers of organic matter. And in this respect the part of
the soil that was important was the same as any other soil.
It is only since denuding the soil of this black mantle
that the underlying sandwich layers became discernible and
classifiable.

The most important thing that one should know about the
soil he works with is the texture of the soil
aggregations. That is, whether it is of clay, silt, sand,
or gravel texture. As noted in the previous chapter on
water management, water percolates rapidly through light
sandy soils. Clay soils have greater water storage
capacity. Also, and more to our interests here, the finer
the texture a soil possesses the more nutrients are
available. Fine clay aggregations provide more clinging
surfaces whereas in sandy soils water and nutrients are
easily leached away. The sandier the soil, the less organic
matter it contains. On this type of soil it is imperative
to build up humus content so that the filamentous and
gelatinous residues of crop refuse will fill up spaces
around sand particles and thereby overcome excessive
drainage and leaching — and the rapid conversion of
organic matter into carbon dioxide and water.

Green Manure

Inasmuch as soil is created primarily by the growth of
plants, the best soil improvement method is to grow
crops. A soil aggregation of heavy clay or silt
particles can therefore best be lightened or made more
friable by growing weeds or green manures. A green manure
is a crop grown and returned to the soil for purposes of
improving the soil. Besides the surface mulch that is made
available, roots from green manure crops penetrate deep.
When they die and decompose a water conduit is provided
through which excess water can drain from the clay subsoil,
and down which the roots of the next crop can grow more
easily.

Extremely poor, eroded, and structureless soil can be made
productive by using green manuring principles: first apply
necessary lime; then commercial nitrate fertilizer; then
turn the land to weeds. The weeds will thrive on the
applied nutrients and penetrate the subsoil with their
highly developed root systems. Mineral nutrients will be
brought to the surface through the roots of these weeds.
Some grasses and legumes will thrive on poor soils; for
instance, buckwheat, rye, lespedeza, and sweet clover.

There are other farming practices, crop rotation for
instance, which improve soil structure. A discussion of
these principles brings us to the subject content of the
next three chapters on Plant Management, so basic concepts
only will be listed:

1) Legume crops are grown to promote the fixation of
nitrogen from the air.
2) Perennial grasses, in a grass arable pasture system, are
grown to supply a constant source of humus.
3) The alternation of deep and shallow rooted crops
prevents continual absorption of nutrients from the same
zone.
4) Deep rooted plants (like alfalfa) improve subsoil
structure when roots decay.
5) Keep a cover crop growing during winter months for
protection against wind and rain. Always remember: let the
surface of the soil wear a beard.
6) Grow green manure crops between regular growing seasons
for producing organic matter.

Admittedly, this chapter on soil management fails to even
mention some of the issues which are considered paramount
in most textbook treatments on the subject. This is not an
oversight on the part of the author: only that material
which is pertinent to the development and maintenance of
soil structure has been considered at this time.