EM 8649 Reprinted May 1997$1.75

ement

Many Oregonians own small

acreages and raise a few livestock,for example, cattle, horses, pigs,sheep, goats, llamas, or chickens.These owners can enhance theirfarms productivity by managingmanure as a soil amendment.Manure is a source of nitrogen,

Derek Godwin, Extension agent, CurryCounty; and J.A. Moore, Extensionbioresource engineer; Oregon StateUniversity.

Figure 1.Utilizing Best Management Practices allows small farms to protect surface andgroundwater.ivestock Operationsand groundwaterManure Managin Small Farm LProtecting surface D. Godwin and J.A. Moore

Clean, safe water for consump-tion, recreation, irrigation, manu-facturing, and fish and wildlifehabitat is important to Oregonians.Nonpoint source pollution is themajor cause of water qualitydegradation in Oregon.

Nonpoint source pollution is anaccumulation of small pollutionsources and single pollution eventsthat, as a whole, cause significantdegradation to water quality. Forexample, runoff water may carrysmall amounts of soil particles,pesticides, nutrients, or bacteriafrom several land areas (Figure 1).

When combined in a watersource, these small amounts ofpollution add up to a large prob-lem. Proper management of thesepotential pollution sources isneeded to maintain clean andusable water resources.

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phosphorus, potassium, and many significantly to pollution. Excess surface and groundwater, and what

decomposition ammonium (NH4+)

t

sFigure 2.Organic nitrogen and phosphorus in sup by growing plants. Nutrients also can be lost t

soluble nitrogen andphosphorus leachate

t2oil are converted through microbial decompositionhrough volatilization, surface runoff, and leaching

groundwater andsubsurface flowt t to plant-available forms, which are taken to groundwater.

to streamsmicronutrients that can increasesoil fertility. It also is a source oforganic matter, which can improvesoil water-holding capacity andtilth.

If not managed properly,however, manure can contribute

nutrients, disease-causing organ-isms, and organic matter frommanure can contaminate surfaceand groundwater.

The following sections discussmanure as a pollution source, howits constituents can contaminate

practices can help prevent pollu-tion. Best management practices(BMPs) that can help you protectwater quality and maintain yourfarms productivity are outlined.Additional sources of informationand assistance also are listed.

precipitation

water runoff

water infiltration

soluble nutrients

plant uptake

microbial

organic matter, nitrogen, phosphorus

microbial decomposition

phosphoruscompounds

animalmanures

nitrogenvolatilization

water runoff withnutrients, organic

matter, andmicroorganismscrop

residues

to streams

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Manure as asource of . . .. . . Plant nutrients

The nitrogen in fresh manure isin the form of ammonia andorganic nitrogen. The organicnitrogen is in particles such as hayand grain (organic matter).

In the soil, microorganismsconvert the ammonia and organicnitrogen to nitrate (NO ), which is

growth of algae. Excess algaegrowth can deplete dissolvedoxygen, change the taste of thewater, and cause discoloration.

. . . MicroorganismsMicroorganisms abound in

animal intestinal tracts, and manyare excreted in manure. A few ofthese organisms can cause diseasein humans and livestock.

These disease-causing organ-isms (pathogens) can live in and

Water pathwaysThe main concern is to keep

manure out of water pathways soits constituents arent carried tosurface and groundwater. Live-3readily available to plants(Figure 2). The conversion ofammonia to nitrate usually occursquickly, providing an immediatenutrient source for plants. Theconversion of organic nitrogen tonitrate occurs more slowly, provid-ing a nutrient source over time.

Nitrate is water soluble andmoves easily with water in the soil.It can move below the root zone tocontaminate a water supply.

Most of the phosphorus inmanure is in the form of largeorganic molecules. When youapply manure to soil, the organicphosphorus binds to soil particlesand is immobilized. Once immobi-lized, it slowly becomes availableto plants as phosphate (PO4).

Phosphorus also can travel witheroded soil particles in runoff tosurface waters, or can dissolve andleach to groundwater. In surfacewater, phosphorus stimulates theManure contains organic matter,which serves as a food source formicroorganisms. As microorgan-isms break down organic matter,they consume oxygen. When largeamounts of organic matter arebroken down in streams or ponds,the microorganisms use all thedissolved oxygen, and fish andother aquatic animals that needoxygen die.move with water. In surfacewaters, many settle into a streamssediments, live there for extendedperiods of time, and are resus-pended when the water is dis-turbed.

However, when pathogens arecarried with water into the soil,they usually are filtered out anddie. This natural filtering processprotects groundwater.

. . . Organic matterstock owners should pay attentionto how water moves across theirpasture and around buildings.

Water flows downhill over thesurface toward the areas of lowestelevation, or it enters the soil andtravels down toward the ground-water. Any low, wet areas ordrainage-ways can be sources ofboth surface and groundwater.

Runoff occurs when rainfall orirrigation intensity exceeds the rateat which water can enter the soil(infiltration rate). Sandy soils havelarge soil particles and pore spacesand can accept water at a fasterrate than clay soils (smallerparticles and pore spaces).

Some areas around buildings,such as soils compacted by animalor machine traffic, have very lowinfiltration rates. These areasproduce runoff under most stormconditions. Roofs and paved areasprovide no infiltration. These areasproduce runoff under all stormconditions, in turn increasing theamount and rate of water that runsoff of nearby areas.

In the summer, when soils aredrier, it may take several heavyrainfalls to cause surface runoff;however, in winter, when soilsalready are wet, a single small raincan cause runoff. The amount ofrainfall necessary to cause runoffalso depends on the surface slope.There is more runoff from steeperslopes.3

rPotential pollution proble

Manure deposited instreams or onstream banks

reamFigure 4.Gravity flow or pumped water provides a drinking area away from the stbank.4pump

water troughFigure 3.Limit stream access to small areas for watering.

2" x 4" or other stop device toprevent cattle hooves from

slipping into stream

ramp

10 ftAllow animal access to only small sections of streams.You can use fences to limit access. Water gaps are fenced openings that

allow animals to drink in a stream (Figure 3). However, in areas thatexperience high rainfall rates and flooding, such as the Oregon Coast, highmaintenance demands limit the use of water gaps.

Provide alternate watering areas away from streams.A water tank at an easily accessible location can greatly reduce the

amount of time animals spend in a creek (Figure 4). Place the tank in orclose to the animals normal path toward the creek. Water can be pumped ogravity-fed to the tank.

ms and their Best Management Practices

Maintain healthy riparian vegetation and/or vegetated filterstrips along streams.

The plants that grow in wet areas next to streams are called riparianvegetation (Figure 5). They provide shade, habitat, and food for fish andwildlife. Vegetated filter strips are protected areas planted to grass that arelocated next to creeks, winter turnout areas, impervious areas, and manurestorage piles.

Overgrazing or hightraffic areas next towater sourcesFigure 5.Use vegetated filter strips to slow runoff, increase infiltration, and filterpollutants from runoff water.

riparian buffer

vegetatedfilter stripsRiparian vegetation and vegetated strips slow runoff; increase infiltration;and filter microorganisms, nitrogen, phosphorus, organic matter, andsediment from small-volume surface runoff. When runoff volume is high,with flow depths of 2 to 3 inches, the ability to filter pollutants is greatlyreduced.

Subdivide non-vegetated and impermeable areas greater than 1 acre withfilter strips. The width needed for an effective filter strip varies with the sizeand slope of the area draining toward the strip. Recommended widths are: 2550 feet for 03 percent slopes 50100 feet for 38 percent slopes More than 100 feet for steeper slopes

The use of a vegetated earthen berm or diversion ditch greatly enhancesthe filtering ability of the strip. These should drain onto other vegetatedareas for further filtering.

Protect all filter strips from excessive animal use, especially during wetseasons. You can mow filter strips, but dont mow them real short.5

fUncontained manureand mud in wetweatherFigure 6.Careful management of grazing, manure storage, and clean watprotect surface and groundwater from contamination during wet weather.

to ditch

s6Reduce the amount of contaminated water to be handled by providinggutters and down spouts that move clean roof runoff away from buildingsand storage areas. Create diversion ditches or earthen berms that move cleanwater away from livestock facilities.

Control grazing and keep livestock off pastures in the winter.Overgrazed pastures are potential sources of surface runoff and ground-

water contamination due to compacted soils and lack of filtering vegetation.Cross-fencing the pasture into smaller paddocks and controlling livestockgrazing and movement can help maintain healthy, vigorous forage plants.

Because soils are wet and pasture growth is minimal during the winter,pastures will be overgrazed and physically torn up if livestock are left out.Keep livestock in small winter holding areas and collect their manure. Inhigh rainfall areas, it is necessary to place material such as chips above thesoil to keep animals out of the mud. You can use gravel, but it is difficult to

keep rocks out of the pasturewhen you clean out themanure and haul it to yourfields in the spring.

er runoff can

graveled drive

covered manurestorage

minimal winteringarea

clean water

grass filter strips

gutter collectsclean water and

directs awayfrom lot areas

sKeep manure piles protected from rain and surface runoff.Place the storage on high, well-drained ground away from surface water

sources. Cover all manure and soiled bedding, and protect them from runof(Figure 6). There are several ways to cover manure pilesfrom a simplepinned-down tarp, to a storage area with a roof and concrete floor.

Make sure your storage either contains the liquids or provides a drain tomove runoff to soils and vegetation that can adequately filter leachate.

Calculate the amount of manure produced and bedding used during thestorage period in order to design an adequate-size storage area. For help,refer to EC 1094, Calculating the Fertilizer Value of Manure. In WesternOregon, a storage length of 120 days usually is adequate to allow spreadingthe manure on unsaturated soil when the pasture is growing.

Keep clean runoff from flowing through livestock facilities andmanure storage piles.

Excessive nutrientson a pasture

Dairy 150 0.19 0.06 0.011 Layers 4 0.0035 0.0034 0.0012 Broilers 2 0.0024 0.0024 0.0006Horse 1,000 0.75 0.31 0.072250 0.32 0.11 0.023500 0.66 0.22 0.047

1,000 1.32 0.45 0.0941,400 1.85 0.59 0.131

Beef Cattle 500 0.50 0.17 0.051

750 0.75 0.26 0.0791,000 1.0 0.34 0.1091,250 1.2 0.43 0.12

Cow 1.05 0.36 0.11Swine Nursery pig 35 0.038 0.018 0.0052 Growing pig 65 0.070 0.034 0.0099 Finishing pig 150 0.16 0.078 0.023

200 0.22 0.104 0.036 Gestate sow 275 0.15 0.069 0.023 Sow and litter 375 0.21 0.1 0.031 Boar 350 0.19 0.081 0.023Sheep 100 0.062 0.045 0.0066PoultryCollect and store manure in winter, then spread it on pastures whenplants are growing.

Spread the manure on pastures in the spring or early summer when thereis little chance of runoff and growing plants can readily use nutrients.

Stored manure, with or without bedding, provides food and a place forbacteria to grow, thus making it a readily compostible material. Compostingkills most disease-causing organisms, reduces the manure pile size, andprovides a more stable nitrogen source that greatly reduces the possibility ofleaching. Consult your county office of the OSU Extension Service formore information about composting.

Apply manure and fertilizer based on crop needs.Spreading manure from one 1,000-lb cow, three 150-lb pigs, or twelve

100-lb sheep on 1 acre of pasture may provide the yearly phosphorusrequirement for the plants (Table 1). If you apply manure based on pasturegrass nitrogen needs only, you may apply excess phosphorus, which will beavailable for runoff and leaching. In this case, apply manure at the rateneeded to supply P and purchase supplemental N fertilizer to meet cropnitrogen needs. Worksheets for calculating the fertilizer value of manureand land area required for application are available from the OSU ExtensionService and other agencies.

Table 1.Daily manure production and nutrient content of manure from variousfarm animals.

Animal Manuresize production N P

Animal (lb) (cu ft) (lb) (lb)7

techniques to reduce the impactson surface and groundwater. Thefollowing agencies can help: Oregon State University Exten-

sion Service

Publication OrdersExtension & Station CommunicationsOregon State University422 Kerr AdministrationThis publication was produced and cooperative program of Oregon StatExtension Service offers educationanational origin, age, marital status,Rights Act of 1964, Title IX of the EUniversity Extension Service is an E

Oregon Department of Agricul-ture (ODA)These agencies can help you

select BMPs for your livestockoperation. They also have informa-tion on pasture renovation andmanagement, soil testing, andwell-water testing. FSA alsoprovides a Water Quality Incen-tives Program, which can offsetpart of the cost of these tests andimprove overall farm management,as well as some cost-sharingopportunities for building livestockmanure-handling facilities.

You make a differenceProper management of livestock

waste usually can be accomplishedwith minimum investment. Yourefforts do make a difference.

1996 Oregon State University Natural Resource ConservationService (NRCS)

Farm Services Agency (FSA) Soil and Water Conservation

District (SWCD)distributed in furtherance of the Acts of Congress of Mae University, the U.S. Department of Agriculture, and Ol programs, activities, and materialswithout regard to disability, and disabled veteran or Vietnam-era veteranducation Amendments of 1972, and Section 504 of the qual Opportunity Employer.

EM 8646, by M. Gamroth andJ. Moore (Oregon State Univer-sity, Corvallis, 1996). 75

Calculating the Fertilizer Value ofManure from Livestock Opera-tions, EC 1094, by J. Mooreand M. Gamroth (Oregon StateUniversity, Corvallis, reprinted1993). $1.00

Dairy Manure as a FertilizerSource, EM 8586, by J. Hart,M. Gangwer, M. Graham, andE. Marx (Oregon State Univer-sity, Corvallis, reprinted 1996).75

Livestock Manure ManagementWorksheet, EM 8596, byR. Miner (Oregon State Univer-sity, Corvallis, 1995). $1.00

Livestock Manure ManagementFact Sheet, EM 8597, byR. Miner (Oregon State Univer-sity, Corvallis, 1995). $1.25

Manure Application Rates forForage Production, EM 8585,by J. Hart, E. Marx, andM. Gangwer (Oregon StateUniversity, Corvallis, 1996).$1.00

Manure Management Practices toReduce Water Pollution,FS 281, by J. Moore andT. Willrich (Oregon StateUniversity, Corvallis, reprinted1993). No charge.y 8 and June 30, 1914. Extension work is aregon counties. Oregon State University

race, color, religion, sex, sexual orientation, statusas required by Title VI of the CivilRehabilitation Act of 1973. Oregon State

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You can access our EducationalMaterials catalog and some of ourpublications through our WorldWide Web page athttp://wwwagcomm.ads.orst.edu/

Other publicationsThe Midwest Plan Service has a

number of publications on live-stock facilities, manure storage andtreatment, etc. These publicationscan be purchased at OSU Exten-sion county offices or from OSUsBioresource Engineering Depart-ment in Corvallis.The next stepProper manure management

starts with identifying existing andpotential pollution problem areas.The next step is to plan anddevelop manure management

For more information

OSU ExtensionpublicationsAssessing your Manure Manage-

ment for Water Quality Risk,

To order copies of the abovepublications, or additional copiesof this publication, send thecomplete title and series number,along with a check or money orderfor the amount listed, to:

Figure 1Manure as a source of. . .Plant nutrientsFigure 2

MicroorganismsOrganic matter

Water pathwaysPotential pollution problemsManure deposited in streams. . .Figure 3Figure 4

Overgrazing or high traffic. . .Figure 5

Uncontained manure and mud in wet weatherFigure 6

Excessive nutrients on a pastureTable 1

The next stepYou make a differenceFor more information