The Fargo forum and daily republican., 1910-01-18
The Effect Of Crop Rotation on
Soil Fertility and Crop Production
ILLUSTRATED BOSS OF MINNESOTA
A. c., IS FEATURE ADDRESS AFTERNOONS
SESSION AT THE TR-sTATE CONVENTION

The Effect Of Crop Rotation on Sol
Fertility and Crop Production, was the
subject of a most interesting address
delivered this afternoon by Prof. An.
drew Boss Of the Minnesota school oi
agriculture Professor Boss illustrated
his talk by charts showing the methods
of rotation which have been found tc
be best and the results of the expert
ments which ave been made at tile
Minnesota school. In part his address
was as follows:
To correctly understand the effect OF
crop rotation on soil fertility and crop
production 1t is necessary, first, to con-
slider the character of the soil. Gener-
ally speaking, soil is a mixture of rock
fragments, decaying plant matter and
animal matter. These ingredients are
found in varying mixtures and Of very
different value so far as crop produc-
ton is concerned. We should bear in
mind that the earths surface TO begin
with was a solid mass of rock, that
though disintegrated by the action of
the air, water and other elements, COM
bined with the action of plant roots
this mass of rock has been broken up
into fragments of varying sizes. These
fragments have been transported either
by glacial action or by flowing waters
and deposited in various places and In
widely varying texture and compost
tion. At one time IL is conceded the
larger part of our agricultural region
WAS covered with water. Upon it's re-
cession vegetation started and scatter
ing plants grew annually only TO ripen
and decay at the end of the season.
This process Of vegetation during the
growing season and decay of plant life
during the remainder of the year re-
suited ultimately in the surface soil
becoming mixed with plant roots and
laws, thus forming a coat of humus
or vegetable matter on the surface.
This general statement holds true
in regard to any soil that has been
brought under cultivation. When the
virgin prairies, therefore, are broken
at depth of three to five inches the
soil particles which are rock or finer
fragments become mixed with portions
of plants which are vegetable matter
and a comparatively rich soil is formed
IL Is termed rich because Of the large
amount of plant food contained there
in regardless of chemical analysis. II
is a well known fact that good crops
can be grown for time on such a
soil but that continued cropping to
grain, corn, or any other crop results
sooner or later in soil exhaustion. This !
OCCURS whether the ele- |
ments of fertility are plentiful or not |
and apears co be due to a purely me- |
chanical or physical condition of the [
soil rather than to the utter depletion |
Of the mineral elements. The essential |
elements of plant growth may be pres
ent but are not available for crop
growth and this combined with the |
tendency of land cropped to a single
crop to become infected with plant dis
ease results in lower production.
Should Consider Requirement of Crops.
The essential elements of fertility of
my soil are nitrogen, phosphoric acid,
potash and lime. These are likely to
be lacking i'm any soil other elements,
Iilicia, chlorine and iron are also nec-
sssary but are usually present in suffic-
ent quantity for the use of plants.
n our farming operations, therefore,
We should consider the requirements of
7arious crops for these elements of fer
ility and so arrange our cropping sys-
EN- as to provide or render available
hese elements which are absolutely
to successful crop growth. 1t
ihould be borne in mind that crops
eed in approximately the surface foot
II soil. While the roots go deeper than
his with many classes of crops IL is
'nly necessary for the purpose of COM
,arison to consider the surface foot.
That there Is a sufficient quantity of
he essential elements in most of our
oils is evidenced by the following fig
lres which are taken from Snyder's
Soils and Fertilizers:
Nitrogen, per acre, 5000 TO 10000 !,
,ounds; Is to 10 pounds required an
lually by crops per acre.
Phosphoric acid, per acre, 1000 to
200 pounds; 25 pounds required an
ltraily by crops per acre.
Potash, per acre, 1900 to $4,000
sounds; 35 to so pounds required an
IualIy by crops per acre.
Calcium, per acre, from / to 20 per
ent; 10 to rs pounds required annu-
lily by crops per acre.
It will be noticed, therefore, that
here Is usually a sufficient supply of
hese elements from crop growth. Even
nough no more nitrogen were added
o the soil 1t would require from so to !
90 years to exhaust the nitrogen in thel !
oil with the other elements in like :
roportion. Our chief effort then
hould be to render available the eIe- !.
lents OF fertility present and to keep
he soil in good physical condition in :