why, where and when of Pasture Management Willie Lantz Extension 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 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) Brief description CPADFNDF Relative 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 Legume, mid bloom <30% grass, early head Legume, full bloom <40% grass, head Legume, full bloom <50% grass, head Mostly grass, head<8>45>61<75 Table Chemical composition of legumes and legume-grass mixtures at advancing stages of maturity 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 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.Table 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 utilization 2 Available pasture (lb dry matter/A) A/animal unit

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 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 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 Pastures Mow 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 Pastures Must 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) – University of Maryland, Maryland Cooperative Extension Publications – Penn State Agronomy Guide – ATTRA – National Sustainable Agriculture Information Service –