NEWARK, Del. - “The next
time your irrigation system is
operating, climb into a rain suit
and take a look at what the water’s
doing, once it hits the ground,”
advises University of Delaware
extension agricultural engineer
Tom Williams. “It’s the only way
to tell whether you’re irrigating
properly.”
the speed with which an
irrigation system applies water to
the soil is the application rate in
inches per hour. This must be
balanced with the soil’s infiltration
or intake rate (its ability to absorb
water). When the application rate
exceeds the intake rate, runoff
occurs unless the field is perfectly
level.
Runoff causes uneven water
distribution as well as erosion,
Williams says. With runoff, fer
tilizers and chemicals applied
through the irrigation system
aren’t uniformly distributed. And
erosion moves topsoil-along with
nutrients-to other parts of the
field, or off of it entirely, thus
reducing potential yield.
“Center pivots can have the
highest application rates of any of
the mechanically moved irrigation
systems,” the engineer says. “The
longer the lateral pipeline and the
higher the crop’s water
requirement, the higher the ap
plication rate required. This rate
also varies along the lateral, with
rates increasing from the pivot to
the end gun. On a 1,320 foot system,
the last 177 feet have to cover the
same area as the first 660. This
means the water has to be applied
faster at the end of a pivot system
than at the beginning.”
On all irrigation systems, the
application rate depends on the
BARN SPRAY**
& I
BRUSH PAINTING |
Try our new concept in I
Penetration & Adhesion z
Being Self Employed Enables Me To Take The Time *
To Properly Apply My Barn Paint & Sealer At Prices i
Below Suggested Retail Cost. Average Barn Costs I
$750. The Farmers in Lane. Co. Are Lucky Because ;
Of The Amount Of Competition In Barn Painting. |
Call Us For Free Estimates |
PHARES S. HURST I
) RDI - Box 503 Z
Narvon, PA 17555 I
BRUNING PAINT 215-445-6186
BEAT THE HEAT
With Drip-Cool or Spray-Cool Systems
• DRIPPERS For Farrowing & Gestation Stalls
• MISTERS For Finishing & Gestation Pens
• SPRINKLERS
Saving One Pig Or Sow
Pays For The System!
n &
U-? , mL , c=zlr_
S~ Y DRIPPER
SPRINKLER
Balance Water Application/Intake Rates When Irrigating
sprinkler or spray package. Once
the nozzles are selected, the peak
application rate is fixed. The only
way to change it is to change the
nozzles. Changing the travel speed
of the system only changes the
total amount of water applied, not
the application rate, Williams
says.
“The further a sprinkler throws
water, the lower the application
rate on center pivot and linear
move systems,” he adds. “It takes
a lot of pressure and pumping
energy to get those large wetted
diameters. Most farmers have
opted for low-pressure systems to
reduce pumping costs, and ap
plication' rates have increased
accordingly.” For instance, a high
pressure center pivot system
might have a peak application rate
of 0.7 inches per hour, whereas the
same system with a low-pressure
180 degree nozzle package could
have a peak rate of 8 inches per
hour-more than 11 times higher.
“Obviously, there’s a tradeoff
between reduced pressure and
potential runoff,” the engineer
says. “Dr. Robert D. vonßemuth
at the University of Tennessee has
studied this problem. He’s con
cluded that it’s probably cheaper
to use a low-pressure system and
increase pumping time to offset
the resulting runoff. In his study,
low-pressure spray booms on the
center pivots had the least pum
ping costs of the systems he
compared, because they had the
least runoff of the low-pressure
systems. However, vonßernuth did
not compare cost differences
between systems.”
Droplet size also affects soil
intake rates. Large droplets
striking bare soil expend a lot of
All Solid State Controls
MISTER
energy on impact, dislodging soil
particles and causing surface
sealing and compaction, which in
turn reduce infiltration. The larger
the droplets and the heavier the
soil, the worse the problem. High
pressure and small nozzles give
smaller droplets and higher intake
rates. That’s why it’s important to
use high pressures on big gun
sprinklers to get the proper stream
breakup, William says.
Many factors determine soil
intake rates, and this makes it
hard to establish general
guidelines for matching ap
plication and intake rates. Soil
texture is the biggest factor in
fluencing intake, he says. Coarse
textured sandy soils will absorb
water much faster than fine
textured silty soils. The higher the
sand content, the higher the intake
rate; the higher the silt content,
the lower the rate. For instance, a
sandy soil may take in 2 inches or
more of water per hour, compared
to only Vi inch or less, on a silt
loam.
Intake rate also depends on the
initial moisture content of the soil.
A dry soil will absorb water very
rapidly at first, and then level off
to a lower rate as it becomes
wetter. This means potential
runoff can be reduced by applying
less water more often. For the
same reason, Williams says to
apply as little water as possible
when chemigating.
Other factors which affect water
intake rate are soil structure,
aggregate stability, organic
matter content, the tillage method
used and soil cover. In turn, all of
these are influenced by soil and
crop management practices. A
covered soil (that is, a well
mulched soil) can have twice the
intake rate of bare soil.
“The only way you can know
whether your irrigation system is
applying water as effectively as
possible is to observe it m
operation,” Williams concludes.
Carroll County 4-H and
i—mmm.FFA Fair mmmmm
Truck and Tractor Pull
August 3 f 1986
Time 10:30 A.M.
Rain Date - Aug. 10,1986
Place: Westminster Ag Center
Westminster, MD
Admission $6.00 Senior Citizens $4.00
7-12 Years Old $4.00
6 And Under With Guardian Free
/
if />
SOLID STATE CONTROLS
STARTING AT $199.00
All Necessaiy Fittings
In Stock
“So climb into that rain suit and go farm. If runoff is a concern,
take a look. Note the application keeping the ground covered with
rate, surface ponding, soil texture no-tillage under irrigation will
and cover when deciding what usually help reduce this problem.”
adiu«trr>pntc atp hp<rf for vour
California All-Jersey
Donates Funds
COLUMBUS, Ohio. California
All-Jersey, Inc., has donated
$30,000 to the J.F. Cavanaugh
Research Fund, pushing the fund
over its original goal of $lOO,OOO.
The donation brings the total
AJCC research endowment to over
a quarter of a million dollars. At
this present level, $20,000 or more
of Jersey research could be funded
annually.
California All-Jersey has been
involved in partial funding of
research projects in the past, in
cluding casein test research and
research on a cheese yield formula
for end-product pricing at Utah
State University.
California All-Jersey, in
corporated in 1953, was also a
primary advocate for the
establishment of National All-
Jersey, incorporated four years
later. Many of the officers and
Md, Hampshire Breeders
Meet For Annual Picnic
Members of the Maryland Hampshire Breeders Association
watch as Ladd herds sheep during their annual pic
nic/meeting. The meeting was held at the historic home of
Dane and Belle Fangmeyer near Westminster, Md., on July
20.
Lancaster Farming, Saturday, July 26,1M6-Cll
directors of National All-Jersey
have come from the ranks of
California’s organization.
The research fund donation was
made possible by California All-
Jersey’s voluntary check-off
program for Jersey dairymen.
The J.F. Cavanaugh Research
Fund is managed by the American
Jersey Cattle Club. The Club’s
Research Committee selects the
projects to be funded.
Areas of study that could be
funded by the foundation include
nutritional needs of high-producing
Jerseys, accuracy of fat and
protein testing, variants in Jersey
milk and their relationship to yield
of products, factors that influence
lifetime profit from Jerseys,
genetic abnormality research,
Jersey feed efficiency, and value
of Jersey milk in manufactured
products.
TROY-BILT.
mer
SALE!
Get The Best For Less!
• 4 Sizes To Choose From
• Rear-Tine, Powered Wheels For
Ease-Of-Operation
• Busts Sod, Makes Seedbeds, Tills
Out Weeds, Builds Rich Soil