Arizona republican., 1914-12-22
Edited bv
WEEKLY PRESS
LETTER
Agricultural Extension Ser
vice, University of Arizo-
ma College of Agriculture,
Experimental Station.
SLICK SPOTS


When travelling with the Agricul.
turaI demonstration Train and ad-
dressing the farmers of Arizona re-
Gently on the Improvement of our
Soils, DR.. A E. Vinson, biochemist
OF the University of Arizona Agri
cultural Experiment Station. pointed
out several of the causes of slick
spots or spots that do not take wa
Ter readily He said in part: The
soil is mixture of various sized
particles ranging in size from a grain
of mustard seed to fragments so
small that they are visible only with
a microscope, material larger than
mustard seeds he did not consider a
part of the soil. but rather foreign
matter that would eventually become
soil. If the soil were composed
largely of the coarser particles, it
could be easily worked, and the
farmer would speak of it as being
light; although in reality, as it lies
in the field, it is much heavier. vol
ume for volume, than the finer cIayey
soils that the farmer calls heavy.
These fine-textured, so-called heavy.
clay soils are, in general, more
abundantly supplied with both avail
able and reserve plant food than
the coarse, easily worked sands and
sandy loans; but ofen they do not
take water well, due to their perman-
emily puddled condition. 1t is not
within our power to change the size
of the particles that form our soils: |
but by proper cultural methods we
may often bring about a rearrange- |
ment and cementing of the particles |
into groups, forming fine pellets and |
producing a crumbly structure When |
a soil is in this condition it takes
water well and it is in the best |
possible state of filth. Under IA
vorable conditions nature. by various
means tends to improve the filth of
her soils. Alternate wetting and
drying freezing the action of plant
roots and of worms and insects. all
end to form the fine material of the
soil into crumbs. There exist. how
ever, in the soil certain substances,
'ome of which promote this granu-
alton and others that prevent it.
Thus. when clay is suspended in wa
er and little lime is added, the ;
inc clay particles quickly collect in
little flakes and we say the clay has
'een fiocculated by the lime So in
he SOIL lime, carbonate, which we [
nov better in the forme of lime
tone, marble and calichc, causes a
imilar Ejaculation. The soil that | l
as an abundance of lime is always l
Otter and takes water more readily 6
han it would without it. {
The limeiess Slick Spot I
Recently DR.. Vinson secured from I
farmer in the Salt River Valley c
wo samples of soil from a slick l
pot in one of his fields; one sam c
lie representing the first foot. the y
Their the second foot Examination t
y carefully wetting the soils showed c
ne first foot to take water poorly $
nd when finally wet to have dense n
lex appearance as though it had q
cen stirred and puddled On the y
'ntrary. the second foot sample t
rank in the water instantly. re- b
aimed dull and glossless. and show O
decided crumb structure to the !
re: when tested with few drops VI
muriatic acid, the first foot show II
no effect, but the second boiled 1t
, vigorously. This difference in re-
'ton was due to lack of lime in the al
rst foot and abundance in the Sec M
Id. The first foot was in poor me- Ell
lanical condition and allowed the IN
alter to slide over because 1t lacked m
ne. Further tests. that can be pl
ade only in the chemists labora- ia
ry' proved this soil to be free from m
kali ly
The Remedy ca
Here then was type of slick III
ot clearly due to a deficiency of sh
ne. The remedy is not hard to sl'
I'd. Since the second foot had an su
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