CONNECT Training Forage Soil Fertility

Gene Pirelli, Polk County

Mylen Bohle, Crook County

OSU Extension Service

Pasture and Grazing Management

• What Do You Want From a Pasture?

– Feed Quality

– Feed Quantity

– Palatability

– Quality of Turf, Durability and Longevity

– Grazing Tolerance

– Seasonal Production (Spring, Summer, Fall, Winter)

– Animal Health

– Animal Performance

Key Points About Pasture Fertility

• Soils are a basic resource that must be considered in

management decisions. Degradation of the soil resource

can take a lifetime to recover.

• Nutrients in a soil-plant-animal system are dynamic and

cyclic.

• Intensive management and high stock density are required

to minimize the tendency to be concentrated near water,

shade, and other attractions.

• Soil testing (and in some cases plant tissue testing) is

essential to prescribing nutrient additions to pasture

Grazing: What is Happening in the Pasture

• Affects plant growth by defoliation

• Animal Traffic patterns & compaction

• Herbage fouling

• Partitioning of nutrients to body, urine, and feces

• Dispersion / Redistribution of nutrients in urine and feces

Soil Fertility Management

• Sufficiency – Economic Response

• Maintain – What you remove, you put back

• Build the soil – Add back more than removed

Soil Sample

• How to Take A Soil Sample

• Pasture: Sample 0-6 inches for Everything

• Hay Field: Sample 0-12 inches for Everything

Sample 0-6 inches for pH in case SMP Buffer Test is Needed.

• Test is Good for 2-3 Years

• “Monitor”

General Soil Test Critical Numbers

• Nutrient Grass Alfalfa pH 5.3-8.5 5.8-8.5 (7.0) P 10 15 K 150 (?) 150 (?) S >9 >9 Ca 1,000 1,000 B N.A. 0.5 Zn 1.0 (?) 1.0 (?) Mg 60 60 Cu 0.6 0.6 Mn 1.5 1.5 Cl ? ? Mo ? ? Sol Salts <1.0% <1.0% Se N.A. N.A. Na <10% <10%

General Nitrogen Recommendations for Irrigated and High Rainfall Grass and Grass-

Legume Pastures Plant Composition

Yield Potential of the Pasture

1 - 2 (tons/acre)

2 – 4 (tons/acre)

4-6 (tons/acre)

6-8 (tons/acre)

Nitrogen Fertilizer (lb./ acre)

100% Grass

50 75 100-150 150-200

75% Grass / 25% Legumes

25 50 75-100 100-150

50% Grass / 50% Legumes

0 25 50 75

25% Grass / 75% Legumes

0 0 25 50

General Phosphorus Recommendations for Grass and Grass-Legume Pastures in the

Interior Columbia Basin P Recommendation

(lb./P2O5 / acre)

Soil Test P (ppm) Irrigated Rain-fed

0-3 100-125 60-100

4-7 75-100 40-60

8-10 50-75 20-40

11-15 0-50 10-20

>15 0 0

Pasture and Grazing Management in the NW, 2010

General Potassium Recommendations for Grass and Grass-Legume Pastures

Soil Test K (ppm)

K2O Recommendation (lb/K2O / acre)

0 - 40 180 – 220

40 – 70 140 – 180

70 – 100 80 – 120

100 – 150 40 – 60

> 150 0

Pasture and Grazing Management in the NW, 2010

Sulfur Recommendations

• Sample 0-12 inch depth

• If > 10 ppm: No need to apply

• If < 10 ppm: Apply 30 lb./acre Sulfur

• High Rainfall / Irrigated: Apply Annually

General Micronutrient Soil Test Values (ppm) and Interpretation

Nutrient Low Marginal Adequate

Zinc < 0.8 0.8 – 1.0 > 1.0

Iron < 3.0 3.0 – 5.0 > 5.0

Copper < 0.2 -- > 0.2

Manganese < 1.0 -- > 1.0

Boron < 0.25 0.25 – 0.50 > 0.5

Pasture and Grazing Management in the NW, 2010

Nutrient Distribution Cycling in a Grazed Pasture

• Pastures require less fertilization than field crops.

• Grazing livestock return as much as 85 to 95 % of the Nitrogen, Phosphorus, Potassium, and other nutrients consumed to the pasture through urine and dung.

• Nutrients are not distributed uniformly, however. They are concentrated next to the water source, shade, bedding areas, and trails.

Pasture and Grazing Management in the NW, 2010

Nutrient Distribution Cycling in a Grazed Pasture (cont.)

• After 4-5 grazing seasons, and P and K concentrations within 30 feet of water sources can be 5 times greater than other areas of the pasture.

• When grazing patterns remain unchanged for more than 20 years, increased P and K concentrations can be found up to 100 feet from the water source

Pasture and Grazing Management in the NW, 2010

Concern about Manure in Pasture

• To Reduce Parasites, you can pick up the manure from the pasture

• Animals do not eat where they defecate

• Compost properly before applying back out on pasture

• Harrow your pastures to break up manure piles

• If Grazing “Properly”, manure breaks down more rapidly

Plant Tissue Testing

• If you want to tissue test your pasture, clip vegetative plants between 3-4 inches and 6-9 inches or so.

• Collect about 25 plants or samples.

• Deliver the samples to the lab the same day or air dry plants before shipping

Plant Tissue Testing (cont.)

• Example: pasture clipped just before heading would contain about:

• 2.0 % N

• 0.25% P

• 1.5% K

• 0.2% S

Pasture samples test results will generally be higher than these numbers

Fertilizer Application Based on Soil Test

• Nitrogen – 3 applications annually of 50-60 lb/acre??

• Phosphorus ? • Potassium ? • Sulfur

– 20-30 lb./acre annually

• N - P - K - S • 16 - 16 - 16 - 16 • (Nitrogen, Phosphorus, Potassium, Sulfur)

1992 Grass Yield (ton/acre) Response to Nitrogen Fertilizer in Central Oregon

N Rate (lb/acre)

Bluegrass/Clover

Old Orchard

Timothy Old Mixed Grass/Leg

New Orchard

Orchard/ Legume

1st Harvest 1992

0 0.45* 1.30 0.68 0.72 1.51 1.11

50 0.89* 2.15 2.18 1.88 2.66 1.95

2nd Harvest 1992

0 0.30 -- 0.13 -- 0.99 1.58

50 1.27 -- 1.03 -- 1.96 1.89

3rd Harvest 1992

0 0.32 0.63 -- 0.27 0.75 Drought

50 1.24 1.42 -- 0.63 1.72 Drought

* Cattle grazed before harvest, -- plots compromised by additional fertilizer

Mylen Bohle, OSU Extension Service

1993 Grass Yield (ton/acre) Response to Nitrogen Fertilizer in Central Oregon

N Rate (lb/acre)

Bluegrass/Clover

Old Orchard

Timothy Old Mixed Grass/Leg

New Orchard

Orchard/ Legume

1st Harvest 1993

0 0.83 1.31 -- -- 1.44 2.24

50 2.15 2.02 -- -- 2.72 2.74

2nd Harvest 1993

0 0.97 0.66 0.22 0.98 0.85 1.73

50 1.21 1.93 1.87 1.29 1.65 2.40

3rd Harvest 1993

0 0.35 0.03 0.10 -- 0.17 0.10

50 0.61 0.23 0.37 -- 0.94 0.36

-- plots compromised by additional fertilizer

Mylen Bohle, OSU Extension Service

T-Sum N Timing

• Add GDD’s from January 1st until reach 360 gdd’s F

• Add high and low temp / 2 = average – 32 degrees F base temp

• Examples

– 50 – 32 = 18 (add) 18

– 30 – 32 = -2 (discard) 18

– 36 – 32 = 4 (add) 22

March 3, 2010 T-Sum N Timing Update

• Christmas Valley: 206 gdds

• Bend: 360 gdds

• Powell Butte: 365 gdds

• Madras: 396 gdds

• Time to fertilize pastures, or should have fertilized pastures, if you want to shift pasture forage production up earlier in the spring

• (For Hay T-Sum N Timing is 720 gdds)

T-Sum N Timing Effect on Grass Pasture Powell Butte 1999

0

500

1000

1500

2000

2500

Check 353 554 754

T-Sum Timing (gdd's)

Yie

ld (

lb/a

c)

1st Graze 2nd Graze

T-Sum N Timing Effect on Grass Pasture Powell Butte 2000

0

500

1000

1500

2000

2500

Check 324 533 726

T-Sum Timing (gdd's)

Yie

ld (

lb/a

c)

1st Graze 2nd Graze

T-Sum N Timing Effect on Grass Pasture Madras 1999

0

500

1000

1500

2000

2500

Check 331 595 775

T-Sum Timing (ggd's)

Yie

ld (

lb/a

c)

1st Graze 2nd Graze

T-Sum N Timing Effect on Grass Pasture Madras 2000

0

500

1000

1500

2000

2500

Check 352 500 740

T-Sum Timing (gdd's)

Yie

ld (

lb/a

c)

1st Graze 2nd Graze

OSU’S FG 63

• Includes recommendations for major nutrients in Western Oregon

• Helps to interpret soil test results

• Provides guidelines for pounds of nutrients to apply

Apply to Match Feed Needs

and to Supplement the

System

Nitrogen is a Component of Crude Protein

Forage labs measure crude protein by analyzing nitrogen and multiplying by 6.25

Ruminants use nitrogen as a protein source

Grazing Animals Can Remove a Significant Amount of Nitrogen

Nutrient Requirements for Feeder Lambs

WEIGHT

Daily

Gain

Crude

Protein

(Lbs)

Crude

Protein

(%)

TDN

(%)

65 Lbs .75 Lbs .41 14.5 63

110 Lbs 1.0 Lbs .35 10.0 77

Nutrient Requirements Are High for Growing and

Lactating Animals

Ewe weight

130 lb (1)

155 lb (1)

175 lb (1)

200 lb (1)

TDN

Protein

TDN

Protein

TDN

Protein

TDN

Protein

Stage of Production

lb

Maintenance

1.30

0.23

1.50

0.25

1.60

0.27

1.70

0.29

Early pregnancy

1.60

0.27

1.70

0.29

1.80

0.31

1.90

0.33

Late pregnancy (2)

2.60

0.45

2.80

0.47

2.90

0.49

3.00

0.51

Early lactation, single

3.30

0.70

3.60

0.73

3.70

0.76

3.80

0.78

Early lactation, twins

3.70

0.89

4.00

0.92

4.30

0.96

4.60

0.99

Early lactation, triplets (3)

3.90

0.99

4.20

1.02

4.60

1.06

5.00

1.10

Grazing Animals Return

Nitrogen and Other Nutrients

Back to the Soil

Fertilizer, in many cases, supplies only part of the total N consumed as plant protein

T-Sum 200

A method of calculating the appropriate time for the first N

application

Forage

Growth

in

Western

Oregon

pastures

Forage

Growth

in

Western

Oregon

pastures

Feed Increase Needed Here

Benton County Site

Harvested

4/26 Check Mid-

Season

T-Sum plus

mid-season

Pounds of

Dry Matter 2553 2156 5267

Percent

Nitrogen 2.07 1.96 2.34

Nitrogen

Uptake (Lbs/A) 53 42 123

N Application

Date 4/5 2/4 & 4/5

Phosphorus • Apply in Fall

• Stable, Does Not Move once Incorporated into soil.

• Soil Test to Determine if Soil Levels are Rising

General Phosphorus Recommendations for Grass and Grass-Legume Pastures on the West-

Side of the Cascades Soil Test P

(ppm) P Recommendation

(lb/P2O5 / acre)

0 – 20 60 – 100

20 – 40 0 – 60

> 40 0

Pasture and Grazing Management in the NW, 2010

Potassium

• Depletes Rapidly with Haying and/or Intensive Grazing

• Apply in Fall

• Low Levels Reduce Grass and Clover Vigor

General Potassium Recommendations for Grass and Grass-Legume Pastures

Soil Test K (ppm)

K2O Recommendation (lb/K2O / acre)

0 - 40 180 – 220

40 – 70 140 – 180

70 – 100 80 – 120

100 – 150 40 – 60

> 150 0

Pasture and Grazing Management in the NW, 2010

Sulfur

• Low Levels cause grasses and clovers to exhibit slow growth

• Small, yellow leaves on clovers is a sign of deficiency

Other Nutrients to Consider

• Lime

• Boron

• Molybdenum

Recommended Lime Application Rates (tons/acre) for Grass Legume Pastures on Acidic Soils

SMP Buffer pH Recommended Lime Application (tons/acre)

<5.5 4 to 5

5.5 – 5.8 3 to 4

5.8 – 6.1 2 to 3

6.1 – 6.5 1 to 2

> 6.5 0 to 1

Pasture and Grazing Management in the NW, 2010 From Hart, Pirelli, Cannon, and Fransen, 2000

Questions?

Discussion

Soil Fertility Critical Numbers

Nutrient Grass Alfalfa pH 5.3-8.5 5.8-8.4 (7.0) P 10 15 K 150 (?) 150 (?) S >9 >9 Ca 1,000 1,000 B N.A. 0.5 Zn 1.0 1.0 Mg 60 60 Cu 0.6 0.6 Mn 1.5 1.5 Cl ? ? Mo >1? >1? Sol Salts <1.0% <1.0% Se N.A. N.A. Na <10% <10%

Nutrient Distribution Cycling in a Grazed Pasture

• Pastures require less fertilization than field crops.

• Grazing livestock return as much as 85 to 95 % of the Nitrogen, Phosphorus, Potassium, and other nutrients consumed to the pasture through urine and dung.

• Nutrients are not distributed uniformly, however. They are concentrated next to the water source, shade, bedding areas, and trails.

Pasture and Grazing Management in the NW, 2010

Nutrient Distribution Cycling in a Grazed Pasture (cont.)

• After 4-5 grazing seasons, and P and K concentrations within 30 feet of water sources can be 5 times greater than other areas of the pasture.

• When grazing patterns remain unchanged for more than 20 years, increased P and K concentrations can be found up to 100 feet from the water source

Pasture and Grazing Management in the NW,

2010

Soil Fertility Management

• Sufficiency – Economic Response

• Maintain – What you remove, you put back

• Build the soil – Add back more than removed