The Norfolk weekly news-journal. (Norfolk, Neb.) 1900-19??, 1911-10-27
SOIL MOISTURE
AND MANAGEMENT
GROWING CROPS USE A GREAT
DEAL OF WATERSUPPLY NOT
ALL AVAILABLE.
BY p. r. Parker, Department of
Agronomy, University OF Nebraska.

are common III the corn belt region
contain II or II inches of water in
the upper four feet of soil when crops
are growing most rapidly. One cubic
foot of silt or clay loan soil contain
ing the proper amount OF moisture for
good growing and tilling conditions
contains about two and one-half gal
| Ions of water.
The water contained in soil is
not all available for crop growth, in
other words crops will wilt when
there is considerable water yet in the
| soil. In the month Of August, 1909,
when the corn was wilted badly and
| beginning to dry prematurely, the
upper four feet of soil contained Is
Or 10 per cent of water, which is
equivalent to Z or inches of rain.
tall. The unavailable water in
cubic foot of loan soil is equal to
about one gallon.
The amount of available water con
tanned in a soil, therefore, is the diff.
| ference between the total water con.
tent and the unavailable water which
would amount to about or 6 inches
in the case OF the loan and silt loan
soils mentioned above This is equi-
| ValCnt to about one and one-half gal
| Ions per cubic foot.
Crop Requirements for Soil Moisture.
Growing crops use a great deal of
water According to good authority
from 200 tG 500 pounds of water are
required for every pound of dry mat
ter produced. For instance, If the
wheat crop produced TWO tons of dry
wheat and straw per acre it tranSpircs
or evaporates GOO tons Of water per
acre during the growing season on the
basis of 800 pounds OF water for every
! pound of dry matter produced. This
amount OF water is equivalent to or
inches OF rainfall.
The available moisture content of
| loan and silt loan soil IN the upper
four feet under good growing condi.
| tons and the wheat crop require
ments for water are therefore very
similar in amounts. This does not
| mean, however, that the wheat crop
can reach maturity and produce
maximum yields without more water
than that contained in the soil when
the crop was sown, even If it con-
tanned enough water for best growing
conditions at that time.
AS stated before, tho crop grows
best when the soil contains the Cd.
timum content of moisture and the
growth is gradually less as the water
content is reduced below this point.
In order that the crop may make it's
best growth at all stages Of it's grow.
ing period, X is necessary that the
soil in which it's roots are growing be
supplied with the optimum moisture
content at all times.
There are several factors which
tend to maintain this state of equi-
llbrium between the growing plants
and the available moisture in the root
zone. Some authorities put great
stress upon the replenshing supply
of moisture which moves up capillari-
ly from below the root zone, thus en-
abling the plant roots TO have a
constant supply of water continually
az their disposal, Cor as the soil
moisture is reduced N the vicinity OF
the growing roots the water from be-
low or otherwise surrounding the
| roots moves toward the dryer soil.
Prom this viewpoint the depth to
bottom water is quite an important
consideration
Moisture Content Of Soils.
The continual movement of grow.
ing plant roots no doubt is signi-
11cant factor in considering the water
supply for crop purposes, for as the
roots and root hairs grow, their alb.
| sorbing portions are continually
reaching out into new regious where
been greatly reduced and by the time
the wheat crop reaches full maturity
the upper four feet of soil are pretty
| well occupied with wheat roots. When
the wheat crop is nearing it's full
growth, but yet growing most active,
ly, its large area of roots permeating
the upper four feet of silt loan soils
in the root zone. The crop require.
| ments are comparatively large at this
stage. The moisture content in the
| upper four feet of soil about the
middle of June is ordinarily very near
| the limit of the available supply. The
| farmers Of Nebraska and surrounding
states are fortunate in that more rain
| falls as a usual thing during the
| months of June and Suly than any
| UCher two months of the year. The
| crop Yields have been greatly reduced
| many times by few days of dry
weather, although the growing condi
| tons may have been almost ideal dur
ing the rest of the growing period
| This critical period may occur at al
most any stage.
The farmer plays very important
| part in maintaining the proper bal.
| ance between the crop requirements
for water and the available moisture
by proper management OF the land
This requires close attention and
proper and timely application of the
| principles OF soil management.
Above Water
1.-THE times are hard, my dear" said
! a man to his better half, land / find 1t
| 90,