grazing days
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GRAZING DAYS. Pasture Management July 23, 2009. Why a Soil Test. We can’t mange what we can’t measure. With an accurate soil test, a strategy can be made to solve even the most difficult of problems Encourages plant growth by providing the best lime / fertilizer recommendations - PowerPoint PPT PresentationTRANSCRIPT
GRAZING DAYS
Pasture ManagementJuly 23, 2009
Why a Soil Test
We can’t mange what we can’t measure. With an accurate soil test, a strategy can be made to solve even the most difficult of problems
• Encourages plant growth by providing the best lime / fertilizer recommendations
• Promotes environmental quality• Saves money
What is a Soil Test
A soil test is a process by which elements (phosphorus, potassium, calcium, magnesium, sodium, sulfur, manganese, copper and zinc) are chemically removed from the soil and measured for their "plant available" content within the sample. The quantity of available nutrients in the sample determines the amount of fertilizer that is recommended. A soil test also measures soil pH. These analyses indicate whether lime is needed and, if so, how much to apply.
A routine soil test consists of:
• pH and lime requirement• Calcium• Magnesium• Phosphorus• Potassium
Can add organic matter if desired.
The soil testing puzzle is made up of three parts.
Taking the sample
UF-ESTL Available TestsTest A ($3.00)• pH• Lime requirement
Test B ($7.00)• Test A +• P, K, Mg
Photo Credit: Amy Shober, UF-IFAS
Lab procedures
Dry Screen Scoop Extract Measure
Soil Test Interpretation
V. Low Low Med. High V. High
Fertilizer responseexpected
No responseexpected
Sufficiencysoil test value
V. Low Low Med. High V. High
Fertilizer responseexpected
No responseexpected
Sufficiencysoil test value
Soil Test Results
Soil Test Phosphorus (Lbs/Acre)
Rela
tive Y
ield
(%
)
0 20 40 60 80 100 120 140
0
20
40
60
80
100
L M Optimum High
$
Amy Shober, UF-IFAS
18 essential plant nutrients:
From air/water
Carbon = C
Hydrogen = H
Oxygen = O
From soil and fertilizer
Macro-Nutrients
Nitrogen = N
Phosphorus = P
Potassium =K
Calcium =Ca
Magnesium = Mg
Sulfur = S
Micro-Nutrients
Manganese =Mn
Zinc = Zn
Copper = Cu
Iron = Fe
Boron = B
Molybdenum = Mo
Chlorine = Cl
Nickel = Ni
Cobalt = Co
Nitrogen
Relative quantitiesof soil-suppliednutrients in dryplant tissue.
Potassium
Phosphorus
Calcium
Magnesium
Sulfur
All micronutrients combined
Quickness of nutrient availability
• Soil minerals• Organic matter• Fertilizer
Very slow
Very fast
Availabilityto plants
Soil nutrient deficiency:Add fertilizer, get a response
FERTILIZER UPDATE
The future of N fertilizers
• N fertilizer comes from air, hydrogen (from natural gas), heat, and pressure.
• It is more economical to produce N off-shore where natural gas is cheap.
• The USA is now a net importer of N.• Our future N supply may be dominated by
urea produced overseas.
The future of P fertilizers
• Single superphosphate and triple superphosphate are no longer produced in Tampa.
• Production is now limited to mono-ammonium phosphate (MAP) and di-ammonium phosphate (DAP).
• Florida still has mineable P ore, but the mines are moving to the south.
The future of K fertilizers
• Saskatchewan province in Canada has several hundred years worth of mineable K salts.
• Price will be driven by worldwide demand, particularly from China and India.
Economics of Hay ProductionElena Toro, Suwannee Co. and Dan Fenneman, Madison Co. Extension Agents
Fertilizers Cost per Ton Cost per Unit/Ton
Cost to apply 80 lbs N/ Acre
Amm Nitrate 34-0-0 $350 $0.51 $41.18
375 .55 44.12
Amm Sulfate 21-0-0 250 .60 47.62
240 .57 45.71
Coated Urea 46-0-0 750 .82 65.22
Liquid 24-0-3 180 .38 30.00
28-0-0 243 .43 34.70
32-0-0 280 .44 34.99
Potash 0-0-60 675 .56 45.00
710 .59 47.33
Economics of Hay ProductionElena Toro, Suwannee Co. and Dan Fenneman, Madison Co. Extension Agents
Commercial Blends
Cost per Ton Unit per Ton 80 lbs N & K / Acre
20-0-20 $463.47 $1.16 $92.69
19-5-19 462.27 1.22 97.32
18-4-18 436 1.21 96.89
16-4-16 393 1.23 98.25
20-4-10 N 365 .91 73.00
K 365 1.83
WEED CONTROL UPDATE
Control of Annual Weeds
0
2 0
4 0
6 0
8 0
1 0 0
1 2 0
Emerg. Seed. Veg. Flower Mat.
Wee
d C
on
tro
l
Control of Biennial Weeds
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
Emerg Veg Rosette Bolting Flow ering
Wee
d C
on
tro
l
Fall
Late Summer
Winter Spring
Control of Perennial Weeds
0
1 0
2 0
3 0
4 0
5 0
6 0
7 0
8 0
9 0
1 0 0
Dorm. Veg. Bud Flower Fruiting Fall
Wee
d C
on
tro
l
Weed Control
What are the options?– Spray– Fertilize– Spray and fertilize– Mow– Do nothing
30
Bermudagrass, Ragweed and NitrogenL
bs/
be
rmu
da
/ac
N = 34 lbs/ac John Boyd, U of Arkansas
31
34 lb N will cost $20 - $40/AHerbicide will cost $8 - $25/A
Lb
s/b
erm
ud
a/a
c
N = 34 lbs/ac John Boyd, U of Arkansas
32
Herbicides, Mowingand Bermudagrass Yield
Lbs
/ac
Heavily infested with wooly croton and ragweed Baumann Texas A&M
PASTURE WEEDS
Blackberry (bush-type)
Blackberry Control
• Remedy - 1 qt/A• Pasturegard - 2 qt/A• Cimarron - 0.5 oz/A ( injury to Bahia)• Telar - 1.0 oz/A
• Do not mow within 1 yr of treatment• Blackberry is most sensitive when blooming
Dogfennel Control
• Weedmaster – application rate is highly dependant on DF size.– up to 12 inches – 2 pt– 12 to 24 inches – 3 pt– >24 inches – not recommend WM
• Often inconsistent control.
Dogfennel control
• Pasturegard – 2 pt will relatively good control on DF up to 24-30”.
• 3 pt never misses, even on big stuff. • Price keeps PG from being used more often
Cleanwave
• Active ingredient: fluroxypyr• Volatility: moderate• Use rate: 14 oz/A (for now)• Price: ~ $0.50 per ounce.
Control of 3’ tall dogfennel
Herbicide % control
6 WAT
$/A
Cleanwave (14oz) + 2,4-D (3pt)
90 12
Weedmaster (2 pt) 50 8
Weedmaster (3 pt) 80 12
Weedmaster (4 pt) 90 16
Cleanwave + 3pt 2,4-D
Weedmaster 2 pt
Weedmaster 3pt
August dogfennel treatment – Useless, right???
Brent Sellers, Univ. of Florida
5 months later – this field will explodedwith grass in spring
Brent Sellers, Univ. of Florida
5 months later – this field will explodedwith grass in spring
Treatment with Pasturegard 3 pt/A ($23/A) more than doubled grass production. Is it worth it to you?
Brent Sellers, Univ. of Florida
Prickly Pear
Prickly Pear Control
• Do not mow! These reproduce veg. and the mowed pads can root and colonize.
• Herbicides- Remedy + basal/diesel fuel – spray one at a
time.- Pasturegard is same as Remedy- 2,4-D is not effective- What about Cleanwave?
Before
After
Recommendation
• Cleanwave at 50 oz/A.• We applied in the fall (October).
• Spring applications????
Florida Pusley
Control of 6” pusley
Herbicide Rate Pusley Control (%)
2 weeks 8 weeks
Cleanwave 14 oz/A 14 18
Weedmaster 3 pt/A 56 70
Pasturegard 3 pt/A 48 84
Forefront 2 pt/A 55 90
Forefront + CW 2 pt + 14 oz 73 99
Forefront + PG 2 pt + 1 pt 90 100
Sedges
• Outrider – sulfosulfuron• Use rate: 1.33 oz/A• Cost - $20/A• 0 day grazing, 14 day haying restriction
• Safe on established Bermuda and Bahia
TSA Control
% Control
Herbicide Rate 3 MAT 6 MAT 12 MAT
Remedy 1 qt 90 70 50
Pasture gard
1.5 qt 80 60 40
750 7 oz 95 90 85
Horsenettle
• Remedy - 2 pt at bloom– Acceptable control but somewhat weak
• Milestone is excellent– Use at least 3 oz/A, 5 oz is better.
Wild Radish
Control of Wild Radish
0
10
20
30
40
50
60
70
80
90
100
2,4-D
seedling
rosette
bolting
flower
2,4-D 1 pt University of Georgia
Thistle Control
>90% Thistle Control
Growth Stage Herbicide $/A
Rosette 2,4-D $6
Bolting Weedmaster $12
Flowering Milestone $20
What about BIG weeds
Milestone is the best option
• References
Dr. Obreza, Soil and Water Science
Dr. Ferrell, Weed Science
Dr. Sellers, Weed Science