El2-Foraging Around, Lancaster Farming, Saturday, September 13, 2003
Rising Plate Meter Helps Farmers Manage Pasture
Dan Deniable and Gary Pick
Department of Crop and
Soil Sciences
Cornell University
Fanners have been turning
to pasture in order to attain
high forage quality at low
cost. However, many have
found that using pasture isn’t
as easy as just opening the
gate and letting the animals
graze. In order to get the max
imum benefit from pasture,
farmers need to be able to
judge when pasture is ready to
be grazed and make plans to
ensure that an adequate sup
ply of high quality pasture is
available for the entire grazing
season. A tool developed in
New Zealand and recently
calibrated for the Northeast
helps farmers with these
sometimes difficult pasture
management decisions.
The device is called a rising
plate meter and it relates a
pasture’s height and thickness
to yield through a carefully
calibrated equation. The rising
plate meter consists of a thin
aluminum plate mounted on a
shaft by a gear connected to a
mechanical counter. As the
rod is lowered into the pas
ture, the plate is supported at
a height determined by the
sward’s thickness, height, and
the plants that compose it.
The rising plate meter is
used by taking 25-30 measure-
Alfalfa As A Fuel
And A Plastic?
Don Comis
USDA-ARS
USDA bioenergy funds are being used to
convert alfalfa into the first dual-use biofuel
plant. The leaf serves as a factory for raw,
biodegradable plastic beads, other industrial
products or better livestock feed, while the
stem goes to ethanol production.
Jo Ann Lamb, a plant breeder who serves
on a team of five scientists at the Agricultur
al Research Service’s Plant Science Re
search Unit in St. Paul, Minn., has created
the “parents” for new alfalfa varieties by
crossing European varieties with unusually
thick stems with modem alfalfa varieties de
veloped for dairy feed. The thick stems pro
vide more raw material for ethanol produc
tion.
Team member Deborah Samac, an ARS
plant pathologist, has transformed alfalfa so
it can manufacture plastic. The process isn’t
practical yet, but it could be, if a cell wall
barrier could be prevented from trapping
beads of plastic.
Besides plastics and fuel, alfalfa may be a
renewable resource for replacing other pe
troleum-based products and nonrenewable
resources, such as nitrogen and phosphorus
fertilizers. Carroll Vance, team member and
unit research leader, has isolated many
genes for creating new varieties, including
one that helps alfalfa fix more nitrogen from
the air and take in more phosphorus.
Lancaster
Farming's
Classified Ads
Get Results!
Device Measures Dry Matter Yield
ments in a single paddock.
The initial height on the coun
ter is recorded before the mea
surements and then the final
height is recorded after the
last measurement has been
taken. Generally, it takes ap
proximately 5-10 minutes to
take 25-30 measurements in a
paddock. The difference be
tween the final and initial
reading is the total accumulat
ed height, which, when divid
ed by the number of readings
taken, gives the average
height. This average height is
then placed in an equation
that gives the yield for the
paddock.
A commercially available
version of the rising plate
meter was calibrated on sever
al New York dairy farms dur
ing 1997, 2000, and 2001. Pre
vious research on rising plate
meters indicated that they
needed to be calibrated to ac
count for different plant spe
cies and for different times of
the growing season. Since the
meter was developed in New
Zealand where there are dif
ferent pasture types and grow
ing conditions, separate equa
tions were needed from those
developed by the manufactur
er.
The calibration done on
New York pastures found dif
ferent equations for pastures
of different species and for
ALL YOUR HAY & FORAGE
EQUIPMENT AT DEER CREEK!
WORKS • 3PT BALE SPEAR • STK#S24B • SI 00 • W
MISC • LITTLE GIANT GROUND ELEVATOR • STK#2I24S • SI 00 • 0
MISC • SHOCO HAY ELEVATOR 28' • STK#2I246 • $5OO • 0
JD • 5' HAY PICKUP 5 1/2' • STK#I373O • $5OO • W
NH • 472 MOWER CONDITIONER • 5TK#23465 • $6OO • W
MEYER • 518 BOX W/1200 TANDEM AXLE • STK#23IO3 • $BOO • W
JD • 660 RAKE • STK#2I36O • $950 • 0
KUHN • GMD66 DISC MOWER • STK#I7344 • $995 • W
JD • 714 WAGON • STK#I739S • $995 • W
JD • 716 WAGON • STK#I7644 • $1,300 • W
JD • 672 HAYRAKE • STK#I7S79 • $l,BOO • 0
JD • 100 BLOWER • STK#I93O6 • $2,200 • W
NH • 155-36 36’ ELEVATOR • STK#I66II • $2,500 • C
NH • 254 TEDDER • 5TK#22293 • $2,500 • C
Nl • 5407 HYD FOLD DISC MOWER • 5TK#23422 • $2,500 • W
JD • T HAY PICKUP HEAD • STK#IO7OO • $2,500 • W
Nl • 4264TEDDER/RAKE • STK#I9OB2 • $3,500 • W
MISC • RH2OO VERMEER TANDEM RAKE • STK#22O2B • $3,800 • C
different times of the growing
season. There are separate
equations for pastures con
taining either mainly fine
grasses such as Kentucky
bluegrass and perrenial rye
grass or mainly coarse grasses
such as orchardgrass, timothy,
smooth bromegrass, quack
grass, and reed canarygrass.
There are also separate equa
tions for late April through
early May, mid-May through
June, July through mid-Au
gust, and late August through
September.
The different species and
times of year require different
equations because they affect
the relationship between the
plate height and the pasture
yield. Coarse grasses such as
orchardgrass support the plate
more readily so they have less
yield per rising plate meter
height than fine grasses such
as Kentucky bluegrass. The
different times of year may
correspond to different stages
of grass growth during the
year such as early spring vege
tative growth, stem elongation
and heading, vegetative
growth after heading, and
growth into the fall in prepar
ation for the winter. These dif
ferent grass growth stages
likely affect the rising plate
meter height to yield relation
ship as well.
The equations are accurate
StrengthYouCanCountOn
enough to be useful to farmers
making management deci
sions about pasture. The exact
accuracy of these equations is
still being evaluated, but we
think they will estimate yield
within 10-15 percent. This
level is more accurate than
visual assessment or the graz
ing stick and is accurate
enough to make it worthwhile
for farmers to spend the time
taking measurements with the
device.
The primary use for the ris
ing plate meter is to determine
whether pastures are ready to
be grazed and to make pas
ture budgeting plans. The
equations report the pasture
yield in pounds of dry matter
per acre, which is an impor
tant characteristic for pasture
management. Animals are not
able to maximize their dry
matter intake of pasture if
there is less than 1,000 pounds
of dry matter per acre avail
able, and 1500-2000 pounds is
ideal. Generally, 2,000 pounds
of dry matter per acre is
equivalent to 6- to 8-inch tall
pasture.
By taking regular measure
ments of all of the paddocks
on the farm, it is also possible
to assess the average amount
of dry matter per acre for the
farm and determine whether
pasture growth is increasing
or decreasing. Increasing pas
MISC • BALE BUSTER PROCESSOR • STK#2O924 • $6,000 • W
KUHN • GA7301 ROTARY RAKE • STK#2IO33 • $6,950 • 0
JD • 630 A HAY PICK UP F/SPH • STK#2O64S • $7,500 • W
JD • 4 ROW HARVESTER CORN HEAD • STK#CLII64B • $9,500 • C
NIEM • 745 24' CENTER DEL RAKE • STK#23I6S • $10,200 • W H|
JD • 935 MOWER CONDITIONER • STK#I6SO9 • $15,500 • C
MISC • 644 LULL TELEHANDLER • 5TK#23624 • $16,500 • W “
JD • 666 CORNHEAD • STK#II963 • $19,500 • W
JD • 686 CORN HEAD F/SPH • STK#2O644 • $35,000 • W
NH • 892 FORAGE HARVESTER W/2R CRN HD • STK#IS9BI • $2,500 • C
VICON • 6 STAR ROTARY TEDDER • STK#I7S92 • $1,200 • W
CASE • 8370 HAYBINE • STK#I622O • $1,250 • C
JD • 336 BALER W/THROWER • STK#S9IO • $2,000 • W
NH • 320 BALER • STK#2I23S • $3,500 • 0
NH • 411 DISC BINE • STK#I62S3 • $5,999 • C
JD • 100 LARGE SQUARE BALER • STK#I66BI • $52,950 • W
www. dcequip. com
720 WHEELER SCHOOL RD. • WHITEFORD, MD 21160
1-800-551-6567
460 LIMESTONE RD. • OXFORD, PA 19363
1-800-255-6567
315 MAIN ST. • CLAYTON, DE 19938
1-800-367-2726
ture growth may indicate that
some paddocks will need to be
set aside for hay harvest while
decreasing growth may indi
cate that additional acres need
to be brought into the grazing
system or supplemental feed
ing needs to be increased.
Our research along with
that of others indicates that
there are some conditions that
are not appropriate for using
the rising plate meter. The
meter gives the best results
when it is used on pasture that
will be grazed in the next sev
eral days. It is not accurate
when used on recently grazed
pastures or those with lots of
weed pressure (especially
newly seeded pastures with
areas of bare ground and an
nual weeds). Care should also
be taken when using the rising
plate meter on pastures differ
ent than those on which the
meter was calibrated.
Lastly, the calibration indi
cated that there are year-to
year differences in the cali
bration equations. Our investi
gation detected some differ
ences between the equations
found in 1997,2000, and 2001.
At present, the cause of these
year-to-year differences is not
known. Future research may
show that separate equations
may be required for growing
seasons of different types (ie.,
wet years vs. dry years).
John Deere