www.pastureswhy, where and when

of Pasture Management

Willie LantzExtension Educator

Ag and Natural Resources Garrett County, Maryland

What is a pasture?

• A collection of plants

• Area used for feeding livestock

• Area used to house livestock

• Your definition of a pasture may depend on many factors such as land area available, stocking density, and management.

Managing Pastures• Goals

– Provide forage to meet the animals needs during the grazing season.

– What is your animals needs?• Horses require about 1.5% of Body Weight as a

forage.• 1000 lbs horse = 15 lbs of forage Dry Matter/day• 240 days grazing X 15lbs/day = 3600lbs DM/year• A two ton yield should be an achievable yield

since most hay systems expect 2-4 ton yields from grasses.

• How much dry matter will a pasture produce?– This will depend on several

factors:• Species• Fertility of the Soil• Soil Type• Utilization • Other Environmental factors

such as rainfall.

• The table at right indicates the amount of expected dry mater from various species at three levels of productivity

2007 Penn State Agronomy Guide

Does what the animals eat matter?• Forage quality changes with changes in

grass & legumes as they mature

Chemical composition% (DM basis)

 

Briefdescription

CP ADF NDFRelative

feed value

CP = crude protein, ADF = acid detergent fiber, NDF = neutral detergent fiber

Legume, prebloom >19 <31 <40 >151

Legume, early bloom<20% grass, vegetative

17-19 31-35 40-46 125-151

Legume, mid bloom<30% grass, early head

14-16 36-40 47-53 103-124

Legume, full bloom<40% grass, head

11-13 41-42 54-60 87-102

Legume, full bloom<50% grass, head

8-10 43-45 61-65 75-86

Mostly grass, head <8 >45 >61 <75

Table 1.8-1. Chemical composition of legumes and legume-grass mixtures at advancing stages of maturity.

2007 Penn State Agronomy Guide

Let look at two different Horses

A mature horse weighing 1,100 pounds requires 1.4 pounds of Protein/Day

A two year old growing horse requires 2.5 lbs of Protein per day

Lets Look at the what would be provided from two different pastures.

A mid bloom legume/grass pasture will have about 15% crude protein therefore a horse consuming 1.5% of the body weight will get 2.25 lbs of Protein/Day

A mature grass pasture in full head will have about 8% crude protein. A horse consuming 1.5% of its body weight will get 1.2 lbs of protein per day.

Goals of Growing Pasture

• Keep the pasture species growing and in the vegetative stage

• Keep Soil Fertility in the Optimum Range

• Control Weeds

Growing & Harvesting Grass

• No matter which method of harvesting grass (mowing or pasturing), when you harvest is critical for grass to be productive.

• Grass must produce 4-5 leaves before it is not dependent on stored carbohydrates for growth.

• Allow most cool season grasses such as Orchard Grass to get 6” – 8” before grazing

Rotate Pastures• Rotate Pastures to force animals to eat less

desirable plants resulting in an increase in the utilization of the pasture.– If allowed to graze large areas, animals will

select their preferred species of grasses/legume.

– This allows other species to get over mature and become less desirable.

– Animals will return to desirable species and overgraze.

• This will reduce these species ability to recover and eventually weaken the stand.

Grass Growth• Grasses grow from a crown (short stem at or

below the soil surface)• After harvest or pasturing, the grass must

pull needed sugars for respiration from storage areas in the crown to supplement the sugars being made in the few remaining leaves.

• If continuously overgrazed, the plants reserves will be depleted and the plant will recover slowly leading to poor production

• Slowly recovering pastures are more prone to weed infestations.

Seasonal Growth of Grass Species

Pasture Rotation

• Set up a pasture rotation that allows the grass to recover.

• Start grazing with grass pasture reach 6-8 inches of height and stop at 3-4 inches.

• More paddocks will be needed in the summer – Consider grazing hay fields– Supplement with hay or grain

Table 1.8-9. Suggested paddock sizes (A/animal unit) based on grazing period and available pasture in intensive rotational grazing system.To calculate paddock size, multiply the suggested acres per unit by the animal units (see Table 1.8-7) in your grazing group. 1.One animal unit = feed requirements of a 1,000 -lb dry cow (25 lb dry matter/day). 2.These are estimates of the percentage of pasture actually consumed. Utilization is usually improved as grazing pressure is increased.

Grazing period, days % Pasture utilization2

Available pasture (lb dry matter/A)

750 1000 1500

    --- A/animal unit 1 ---

1 80 0.042 0.031 0.021

2 75 0.089 0.067 0.044

3 75 0.133 0.100 0.067

4 70 0.190 0.143 0.095

5 65 0.256 0.192 0.128

6 60 0.333 0.250 0.167

7 60 0.389 0.292 0.194

Fertilize Pastures

Fertilize pastures yearly• Why

– For maximum plant growth plants will require more nutrients than they get from the soil.

– Most grasses require 150 pounds of Nitrogen for optimum growth. 20-40 pounds is converted from organic mater and other sources on a yearly basis.

– Legumes (clovers/alfalfa/trefoil) does not require Nitrogen but will require additional Potassium.

Fertilization cont.

• Fertilize according to your nutrient management plan.– Soil test every three years (P, K, pH)– Split applications of Nitrogen

• Apply 1/3 in early spring (March)• Apply 1/3 early summer (Mid June)• Apply 1/3 in early fall (late August)• Apply just before a rain

– Apply P & K in the fall

pH Management - Liming

Lime pastures with two ton of lime every third year

• Why– maintain a pH of 6.0-6.5

• Desirable range for soil microbes • Low pH ranges tie up plant nutrients

• Soil Test before liming – follow recommendation on soil tests or nutrient management plan

Mowing PasturesMow pastures after rotating to a new

pasture• Why – needed if grasses have went to

head. – The seed head produces an auxin which is

a plant hormone that prohibits additional stem and leaf development.

– If headed grasses are left stand it will reduce yield and recovery times.

– If animals are not rotated they will not eat mature grasses which causes animals to over graze other areas of the pasture.

Mowing Pastures cont.

• When to mow:– If the grass gets ahead of the animals and

starts to come into head.– If rotating pasture, mow the paddock only

if more than 20% of the pasture area has grass that is in head.

– If not rotating, mow about ¼ of the pasture per week if more than 25% of the pasture has mature plants

– Do not mow any shorter than 6”

Controlling Weeds

• Why Control Weeds?– Reduce crop yield by removing water

and nutrients– May Shade out desirable plants– Take up space of productive plants– Some plants are poisonous

How to Control Weeds• Do everything discusses earlier first

– Rotate Pastures– Adjust pH and Fertility– Mow Pastures

• After those factors have been corrected, eliminate problem weeds– Know the weed and the weed’s life cycle

you are trying to control• Control most weeds when they are in a

growing part of their life before they go to seed

Renovate PasturesMust answer this question first:

Why do you need to renovate the pasture?

Over Grazed

Poor Fertility

Low pH

Weeds

No Rotation

Correct these factors before evaluating if you need to renovate the pasture!

Pasture Management Resources

• University of Maryland, Maryland Forages Program (Horse Pasture Publications)– http://www.mdforages.umd.edu/publ.cfm

• University of Maryland, Maryland Cooperative Extension Publications– http://extension.umd.edu/publications/Category.cfm?ID=C

• 2007-2008 Penn State Agronomy Guide– http://agguide.agronomy.psu.edu/

• ATTRA – National Sustainable Agriculture Information Service– http://attra.ncat.org/livestock.html#Grass