The Dermott news., 1916-04-13
SOILS AND SOIL FERTILITY
No 5. Organic Matter.

BY De r Hungerford. Assistant Ag.
economist, University OF Arkansas.
The organic matter of the soil Is
that part which has been derived from
the decay Of plants When the leaves.
blades of grass. stems aud roots e.
plants die they are at once attached
by molds and bacteria The dead
veCation gradually dccomposes or dis
tntegrates until the original appear
ance and structure is lost and the
material becomes dark eolored
shapeless mass. called humus
Effect of Organic Matter on the Soil.
Organic matter is beneficial to both
sandy and clay soils but in different
ways \ clay soil without organic
matter is too sticky and compact The
organic matter loosens il. permitting
The surplus water 10 drain away and
allows air to penetrate TO the roots
OF the crop On the other hand. sandy
soils are too loose and open Water
drains away too rapidly and too much
air is permitted to enter
1'SSh " W SdfifN on
Sandy soils that are well supplied
with oxcaniC matters are more reten-
tive of moisture than II lacking in that
substance. The large spaces betW cen
the sand permit the water TO draw
away SO rapidly that 1t is soon lost.
and the soil dries out II these spaces
are filed with organic matter the
water meets moro opposition in its
downward movement. consequently il
remains for a longer time in the zone
occupied by the plant roots. Tie fac
that organic matter Is exceedingly
porous add % its water holding
power This Is shown clearly by ex-
perlments showing that 100 pounds of
straw viii AXE up 700 pounds OF va
ter whereas The same amount OF sand
Will hold only twenty-five pounds. and
700 pounds 81 peat soil, which con
sists entirely Of Aumus VIII take up
from ten to- 1000 pounds of water
clay soils do not need 10 have their
water holding capacity increased be
cause they arr naturally very rcnten-
ave 81 moisture. such soils are SO
compact how ever. that the roots have
difficulty IN penetrating deeply into
the subsol Consequently the crops
are likely 20 be shallow rooted The
surface soil dries out quickly and the
crop suffers Thus accounts for the
fact that crops often suffer from
drought on cley Lands sooner uan on
supplied RI clay soils The crop Will
root dcep,r rs result OF the more
eu.a structure and therefore Will be
able 10 utillte thc moisture stored in
tac .ul soil aHd can resist drought
O-,.c,- M,,f.- ,,a el,,. ro,4
ore4t.i. MATTER rat =anl, rpnr,,.os
,.s. ra,sfc,l Cooalr,,o of sotIs ,r8
..,5s ,..=t.,,.,. ,,,ir.l f,,, ?, ais, ,or=
...r. t..,.,,. .t,,.,,rr.t of ,ttr,....,, md
5TNer plant feeds lu AN available form
Who, mo orgari,. ,7.,fsr d.c,ys This
,.i,r, food CON d.. ,..a ,,..t... ..,.
eacofre ..r,ne
CT r., ~, O.a,.,,. 49,.
r. so,ls - ~. SD, - as
r,tr. aeer,.,, Il, or..ari,. ,,,at,ar -
csusa ,ho t,sb toun,ra,nr. - ,bo
..,,,.,,..- s,,.,,,,. ,..,,.s ,,..o,,,,,,,.,,,,.,
:, tal.o nl,ca ,,r,. ra,,dly III -,
d.ncy = cornteract.d - a ear,at, ~.
a., -,
collie hy tho fc, thot m. l,rc,
.,,o,nt ~ yaeo,,,ior nrod.cad hae
oar.od ,ar,a s,,rl,. ., orra,ic ma.
.or - no s,orad nm Cor,i,uo,s GO,
r,n,, - CO.., ard ,o,,o, boc.o,..r
soor o,hous,s ~. original su,nlv 60
,ha, avan tho rtoh ho,tor sons no
oon,a danIo,oa a,,.r ,xe,tva,o a.,
,hir,v voars Tive ,rasenca =, an
abundance =, orcanic ma,ter is
-, h,a,l, o- d.rL hr,a., ooior