GRASS ROOTS
3 to 6 feet Deep
By O. J. NOER
Dr. R o b e r t H a g e n at Davis, Calif., is
intensely interested in grasses f o r special
purpose turf. Some of his turf plots are
designed to study w a t e r relationships because w a t e r is becoming scarce in Calif o r n i a and other western states, due to
demands of increased population.
Some v e r y interesting observations have
been made b y Bob on several of the plots
of U-3 strain of Bermudagrass and of
Merion bluegrass. The soil is a loam of
g o o d structure and has a g o o d w a t e r holding capacity. The turf has remained
g r e e n all summer. R a i n stopped in April.
P l o t s w e r e w a t e r e d only once, and by
mistake, when Dr. H a g e n w a s a w a y .
T h e 6 ft. sampling tube used b y Dr.
H a g e n to measure root depth consists of a
m e t a l pipe of one in. inside diameter with
a barrel shaped cap on the bottom which
has a sharp cutting edge. T h e driving
mechanism is square in shape and is made
of cast steel w i t h rods extending f r o m
opposite sides. The rods fit inside the
sampler tube and serve as guides f o r
d r i v i n g the sampler into the soil. The soil
cores are taken a t 6 to 12 in. intervals
and can be examined f o r structure, f o r
moisture, and the presence of grass roots.
T h e ability of U - 3 Bermuda to continue
g r o w t h and stay green is due to the deep
root system. T h e r e w e r e roots at the 6 ft,
depth. T h e soil a t that depth still had
some moisture. Merion bluegrass had roots
a t a 3 f t . depth, and the soil there showed
evidence of moisture.
These plots w e r e most impressive when
visited b y the w r i t e r on October 9, 1952.
T h e grass on both the U-3 and the Merion
bluegrass plots was dense and the color
w a s pleasing. I t makes one think about
w a t e r i n g practices and wonder about the
interval between w a t e r applications esTop:
Gob
Hagen
shows
U-3
Bermuda
plot
at
Davis, C a l i f , to W m . Daniels of Purdue and C . G .
Wilson of U S G A G r e e n Section.
M i d d l e : This U-3 Bermuda at Davis, Calif,, was
watered only once during the season, after rains
stopped in April.
Bottom; Across the sign is root of U-3 Bermuda
taken from 5 f t , depth at Davis, Calif., plot
pecially on loam soils of g o o d structure
and water-holding capacity.
These tests bear out the contention t h a t
w a t e r should be used to keep the grass
alive, and used to m a k e turf lush and
green. Grasses of the permanent perennial t y p e like Bermuda, bluegrass, fescue
and bent can and do withstand some wilting without loss of turf, provided the root
system is deep enough to tap moisture in
the deeper soil. W h e n loss occurs the
roots are near the top. Then grass dies
f r o m t o o much o r t o o little w a t e r , and is
v e r y sensitive to — and sometimes severely and permanently damaged by — herbicides such as 2,4-D, 2,4,5-T, etc., and m a y
be badly injured b y sodium arsenite which
is otherwise s a f e when used a t moderate
rates.
P o a annua is hard to hold because of
its shallow root system. R o o t s a r e a l w a y s
near the top so it is necessary to keep
the surface soil moist a t all times. In bad
w e a t h e r several hours of neglect m a y be
the d i f f e r e n c e between keeping and losing
it. T h a t is w h y l i g h t s y r i n g i n g w i t h w a t e r
is i m p e r a t i v e in the heat of the day during bad spells of w e a t h e r .
I n places w h e r e poa annua is the sole
grass in the ground cover, bare soil is left
when it dies. B u t w h e r e the ground cover
is a m i x t u r e of poa annua and a permanent grass, there is some c o v e r when the
poa annua is lost.
Instead of abruptly stopping the use of
all w a t e r on f a i r w a y s to curb poa annua
the more logical procedure would be to do
It gradually and t a k e steps to introduce
a more desirable c o v e r of permanent
grasses. Both schemes w o r k but the first
puts the course in bad shape f o r p l a y f o r
several seasons.
T h e investigations b e i n g conducted b y
Dr. H a g e n a t D a v i s and b y other w o r k e r s
a t S t a t e College, P a . ; a t R u t g e r s , N . J.;
a t Beltsville and elsewhere a r e sure to
provide valuable information. T h e y emphasize the w e l l k n o w n f a c t t h a t w a t e r
usage is one of the m o s t important f a c tors in golf turf maintenance. N o set
rule f o r w a t e r i n g applies e v e r y w h e r e . The
secret of success is to adapt the basic
principles to local conditions of climate,
soil and kind of grass.
Top:
This soil sampling tube will telle samples to
6 ft, depth.
M i d d l e : The soil sampler reaches 6 f t . in giving
H a g e n data on his research.
Bottom: Dr. Bob H a g e n and student assistant in
charge of the plots at Davis examine a plot of
Merion bluegrass that has roots 3 f t . d e e p . This
plot has been watered but once.