Licking Valley courier. [volume] (West Liberty, Ky.) 19??-current, 1913-06-26

poor qualty or Darnyard manure
which has had much of the plant food
leached out of 1t has considerable
value because Of the humus 1t makes.
Another cheap and valuable source
Of humus, but one which must be used
understandingly, is crops grown to
turn under as manure. The legumes
are especially valuable for this pur-,
pose because of the nitrogen they con-
tain, but other crops, such as rye and
even corn sown thick, may sometimes
be made to supply large quantities of
humus Of fair quality. Crops thus
used are called green manures.
A proper circulation Of air in the soil
is just as important as any other fac
tor of plant growth. Nearly half of the
volume Of ordinary soils is occupied
by air spaces. Plant roots must be
+ supplied with air, and the soil must be
| porous enough to permit of free circu-
lation. A good supply Of humus and
proper tillage will accomplish this re-
suit in clay soils. Sandy soils are usu-
ally too porous, needing humus to help
them retain water.
Another reason why air must circu-
late freely in the soil is that large
quantities Of oxygen are required to in
sure proper decay Of organic matter to
supply plant food. Also carbonic acid
gas Is produced by the decay Of or
ganic matter, and this must escape cas-
lily to make room for the atmospheric
oxygen needed in the soil. One Of the
most important objects of plowing is
to loosen up the soil for aeratlon.
Considerable evidence has been ac-
cumulated during recent years to show
that during the growth of the plant
certain unknown organic substances
are given Off which, when they accu-
mulate in the soil to any extent, are
harmful to the further growth Of plants
of the kind that produced them. 1t is
possible that some of the benefits
known to arise from systematic crop
rotation may be explained on this ba-
sis. These harmful substances seem
to be disposed Of rapidly by certain
soils, usually those in which organic
matter is readily converted into humus.
In connection with the study of these
poisonous organic products it has been
found that they may be destroyed or
at least rendered harmless in variety
of ways. Barnyard manure or decay
ing organic matter, such as green
crop Of rye or cowpeas, turned under
has very marked effect In freeing the
soil from them Almost all Of the com.
mon commercial fertilizing materials
act more or less in the same way.
Thorough and complete airing Of the
soil by plowing aud thorough surface
tillage will often destroy or overcome
these poisonous substances. When the
same crop is not grown oftener thar
every three or four years on the same
land the injurious substances croI
throws off seem to have time to dlsap
pear before the same crop is grown
again; hence the benefit from crop no
tatlon. When the soil is well supple
with humus there is seldom any trou
BILE from this source, and the same croT
may be grown year. after year will
good yields, though continuous cult
vation of the same crop may invite in
jury from certain insects and fungous
diseases which live over in the soil OIL
In the remains Of the crop.
Improper methods Of tillage add very
greatly to the evil effects that result
from lack of humus. In many parts
Of the country the land is plowed only
three or four inches deep. In mos
cases work done in subsoiling is prac
tically wasted, and 1t Is doubtful il 4
ever pays. A much better method 1!
to plow little deeper each year unit
depth Of eight or ten inches is reach
ed. This gives a deep layer of goot
soil, particularly II the supply Of humu'
is kept up.
When new soil or that which ha
lain undisturbed for several years i
broken up 1t is always best to plov
deep from the beginning, for the deep
er layers will be about as fertile a
any, except the top inch or two. 1t 4
wise, too, never to plow the SAM
depth twice in succession. In general
fall plowlng should be from seven t
nine or ten Inches and spring plowinl
from Ave to seven inches deep. Their
are special cases In which these rule
do not apply.
We plow the soil In order to loose
up Its texture and get air into 1t; ais
to turn under stubble, manure, etc,
make humus. Killing weeds is anothe
; object accomplished by plowing. Afte
: a soil has been thoroughly pulverlze
to great depths, so that there is no dar
= ger of turning up packed clay, tn
= deeper the plowing the better the crop.
But the cost also increases with deptl
: so that ordinarily 1t does not pay I
J plow more than about ten Inches deer
Some crops prefer rather loose see
b bed. Other crops, such as wheat an
, alfalfa, prefer fairly compact see
} bed; hence frequent narrowing an
rolling after plowing Is good practlc
; before seeding to these crops. Nevel
t theless It pays to plow the land fC
t them, even IL we have to compact
. again before seeding.
Sandy soils are usually not injure
by handling when wet, but the case
different with clay soils. The effet
D produced by working clay soils wet
known us pudding. The proper tin
: to plow land is when II IL Just moi
r enough to break up mellow, neltht
: wet enough TO leave slick surfa(
5 where rubbed by the moldboard NJ
e dry enough to break up IN large clod
5 IL continued rain follows wet plowlr
little harm follows, but hot, dry wint
would soon leave only mass OF nj
D manageable clods. In spring and mi
summer plowlng particularly II is
! the utmost Importance to run the I'm
+ row Immediately after the plow. TIL
q prevents the formation of clods.
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