analysis of runoff from southern great plains feedlots

8/2/2019 Analysis of Runoff From Southern Great Plains Feedlots

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Analysis of Runoff from Southern Great Plains Feedlots

R. N. Clark, A. D. Schneider, B. A. StewartM E M B E R

ASAE

M E M B E R

A S A E

CON FINE D beef cattle feeding hasgreatly increased during the last

decade. The Southern Great Plainshas experienced tremen dous growth incattle feeding during this period. Thenumber of cattle fed has increasedfrom abo ut 1 million in 1965 to 5.3million in 1974. Almost all of thesecattle are fed in lots larger than1 000-head capacity. Also, during thisdecade, water quality control regulations have been established requiringthe impoundment of all runoff and

waste water from these feedlots.Two types of runoff catchment

basins are used in the Southern GreatPlains, which meet the zero dischargerequirements of water control agencies. One is a natural-occurring, wet-weather lake called a playa. Theselakes are shallow, flat bottom, saucerlike basins that collect runoff duringperiods of wet weather and have nodrainage outlet. The bottoms containa dense, low permeability clay. Runoffcan be disposed from playas byevaporation or dewatering. The other

type of catchment is a manmadeho ld ing pond genera l ly exca va teddownslope from the feedlot. Mostholding ponds require dewatering todispose of runoff.

D ES CRIP TIO N O FRES EA RCH S ITE

In 1970, a research study was begunto determine the amount and composition of feedlot runoff in the SouthernGreat Plains. For this study, a 20 000-head capacity feedlot was selected

near Bushland, Texas. The feedlotwas constructed on virgin sod adjacent

Article was submitted for publication inSeptem ber 1974; reviewed and app roved forpubl icat ion by the Structures an d EnvironmentDivision of ASAE in March 1975. Presented asASAE Paper No. 74-4017.

Contribution from the Soil, Water, and AirSciences, Southern Region, ARS, USDA, incooperat ion with the Texas Agricul tural Experiment Station, Texas A&M University.

The authors are: R. N. CLARK and A. D.SCHNEIDER, Agricul tural Engineers, andB. A. STEWART, Soil Scientist, SouthwesternGreat Plains Research Center, ARS, USDA,Bushland, Texas.

FIG. 1 Cattle feedyard an d the playa that impo unds the runoff. Contours

are meters above mean sea level.

to a playa lake (Fig. 1). The shadedportion of Fig. 1 indicates the pen areathat was instrumented for runoffmeasurements . The upper (east) endis almost flat and the lower (west) endhas a slope of 3 percent. The averageslope for the entire area is abo ut 1.5

percent. Feedbunks on the north andsouth sides and a road across theupslope east end prevent water fromflowing on or off three sides of thearea. An H-flume for measuring therate of runoff and an auto ma tic runoffsampler were installed west of the penarea. Runoff samples were collectedperiodically for chemical and suspended solids analyses. The instrumen ted pa r t o f the lo t cover sa p p r o x i m a t e l y 4 h e c t a r e s a n d is

norma lly stocked with a bout 3 000cattle.

RA IN F A LL-RU N O F FRELA TIO N S H IP S

Rainfall has been near normal fortwo of the three years that runoff has

been measured. Rainfall totaled 460,453, and 374 mm during 1971, 1972,and 1973, respectively. Runoff totaled94 , 52, and 20 mm, respectively, forthe same periods. Fig. 2 shows therunoff measured from runoff-producing storms. In general, rainstorms lessthan 10 mm did not produce runoff.

The regression analysis of these datashows a linear relationship betweenrainfall and runoff. The regressioncoefficient indicates that about one-

R U N O FF = 0 . 3 6 5 R A I N F A L L - 3 . 6 4

R = 0 8 3

8 01 0 2 0 3 0 4 0 5 0 6 0 7 0

RAINFALL — mm

FIG. 2 Rainfall-runoff relationship for a cattle feedlot at Bushland,Texas .

1975—TRANSACTIONS of the ASAE 319



5 0

4 0

3 0

2 0

i 0

, , , , T , , ,. B e l l v i l l e . T X

/ M e a d , N E/ / G r e t n a , N E

/ / I / ^ Pra t t ,KS

^ / ^^ ^ / ^ ^ ^ - B u s h l o n d . T X

' s ^ ^ ^

\

\

\

H

-

R A I N F A L L — m m

FIG. 3 Rainfall-runoff relationship for cattle feedlots at several locations.

third of the rainfall ends up as runoff,

when the rainfall exceeds 10 mm.T w o l a r ge s to r m s ha d s im i l a r

rainfall totals but had different runoffamounts. Storm A (Fig. 2) occurredafter a 4-month-long dry period, and

the lot was dry and packed. It had aduration of about 6 hr . Storm B (Fig.2) had a duration of about 24 hr andoccurred after a relatively wet period.Observations have shown that lessrunoff occurs when previous rainfallhas wet the lot surface. The wetsurface is roughed by the animals andn u m e r o u s d e p r e s s i o n s fo r s u r f a c estorage are created; whereas a dry lotis packed smooth and has little surfacestorage.

T h e m a x i m u m 2 4 - h r r a i n f a l lreceived during the study period was

63 mm, and there were five timeswhen more than 50 mm of rainfallwere observed. During the 35 yr ofrainfall records at Bushland, morethan 50 mm of rainfall have beenobserved only 30 times. Therefore,t he se da t a shou ld r e pr e se n t t heexpected rainfall over a 10- or 15-yrdesign period.

In Fig. 3, the linear regression curvef or Bu sh la nd i s c om pa r e d w i thregression curves for Pratt, Kansas(Manges et al. 1971); Mead, Nebraska(Gilter tson et al . 1972); Gretna,

Nebraska (Swanson et al. 1971); andBellville, Texas (Wise and Reddell1973). The amount of runoff fromBushland was significantly less thanfor any other location. Bushland hasthe lowest rainfall and highest evaporation rate of any location shown.Consequently, the feedpen surface isgenerally drier than for lots in otherareas and capable of absorbing morewater .

Feedlots in the Southern GreatPlains are generally stocked at ahigher density than lots in areas ofhigher rainfall and lower evaporation.

A feedlot with a high an imal densityusually has a thick er man ure p ack toabsorb water. As the lot becomes wet,the animals move around and the hoofdepressions in the manu re pack hold alarge percentage of the rainfall on the

lot long enough for it to be absorbedor evaporated.

CH E M I CA L CO M PO SI T O N O FR U N O F F

The automatic sampler collectedwater samples as the runoff wasdischarged from the H-flume. Eachsample was stirred in a blender andsubsampled for analysis. Regardlessof the chemical, the concentrationvaried erratically from one sample tothe next. This variation occurred bothwithin storms and between storms.For this reason, histograms of thewater quality data are shown in Figs.4, 5, and 6 and are listed as Bushlandrunoff. The histograms show the

r e l a t i ve f r e que nc y o f t he sa m pleconcentrations, and the mean value islisted for each chemical concentrationor parameter .

Generally, the Bushland runoff hada higher concentration of salts andsolids tha n runoff from Neb rask a,Kansas, and East Texas. Severalfactors account for this higher concentration. The layout of the pens and

f e e d b u n k s c r e a t e d l o n g , n a r r o w ,drainage areas; consequently, much oft h e r u n o f f t r a v e l e d c o n s i d e r a b l elengths over the feedlot and had timet o d i s so l v e so l u b l e c o m p o u n d s .Another factor is the high stockingrates used in the area. The lots in theSouthern Great Plains have about oneanimal for every 11 m

2. The lower

rainfall and greater evaporation concentrates more salt in the manurepack, which in turn makes for a moreconcentrated runoff.

As a comparison to the Bushland

runoff data, runoff holding facilitiesat 36 feedlots in the Southern GreatPlains were sampled in August andSeptember 1973. The chemical datafor these samples are shown in Figs. 4,5, and 5 and separated into holdingponds and playas. These data werea l so qu i t e va r i a b l e , bu t ove r a l lc o n c e n t r a t i o n s w e re o n e - t h i r d t oone-half the concentrations measuredas fresh runoff du ring a rain storm .The main difference between the twosets of data appears to be the solidscontained in the samples. The freshrunoff samples contained an averageof 15 000 p pm solids which werebroken up in a blender before thesamples were analyzed. The survey

c0 - 5 0

51 - 1 0 0

1 0 1 - 3 0 0

3 0 1 - 6 0 0

6 0 1 - 1 0 0 0

> I 0 0 0

0 - 5 0

5 1 - 1 0 0

1 0 1 - 3 0 0

3 0 1 - 6 0 0

6 0 1 - 1 0 0 0

> I 0 0 0

0 - 5 0

5 1 - 1 0 0

1 0 1 - 3 0 0

3 0 1 - 6 0 0

6 0 1 - 1 0 0 0

> I 0 0 0

B U S H L A N D R U N O F F

P e r c e n t o f s a m p l e s ,

) 2 5 5 0 7 5 1 0 0i i i 1 »

x = l 0 8 3

lI

— i — i — i — i

x = l 3 2 0

hi

r • • •i

_ jx = 2 0 5

A R E A

P e

0—

J

-

- fii

I—i

H O L D I N G P O N D S

' c e n t o f s a m p l e s

2 5 5 0 7 5 1 0 0 0- ¥ - • 1 i ' j

n i

x * M 5

1— I 1 "1

1_J

x = 4 5 5

T I I I 1

15 f = 4 3

A R E A P L A Y A S

P e r c e n t o f s a m p l e s

2 5 5 0 7 5 1 0 0

, ' ' ZZT"_l

x* = 2 0

Jx = 6 0

_

. . . r

JL x = 12.1Ji

FIG. 4 Concentrations of nitrogen, potassium, and phosphorus found in fresh feedlot runoff,

Bushland; area feedlot holding ponds; and area playas.

3 2 0TRANSACTIONS of the ASAE—1975



BUSHLAND RUNOFF

Percent o f samples

0 25 50 75 100

IE 0- 50

o- 51-1002 101-300

| 3 0 1 - 6 0 0

O 6 0 1 - 1 0 0 0

> I 0 0 0

E

°- 0 - 5 0

* 5 1 - 1 0 0| 1 0 1 - 3 0 0

-» 3 0 1 - 6 0 0

2 601-1000> i 0 0 0

E

£ 0 - 5 0

2* 5 1 - 1 0 0

| 101-300

w 3 0 1 - 6 0 03 6 0 1 - 1 0 0 0

i xooo

—— , n , -,X * 5 8 8

I

1

1 i i n

x » 4 4 91

iJ

1 1 T 1

11 9 9

AREA HOLDING PONDS

P e rcen t o f t a m p l t t

0 25 50 75 100 C

— 1 '

L

i i i i

i_ _ i« • 9 9

' 1 • ' •

1_ l

1 - 7 2

AREA PLAYAS

P t r c t n f o f t a m p l t t

) 25 50 7 5 100

1 ' 'i

*» 5 4

-

• r • •

i

| - 5 5

| \ I I ""1 l

jj

[ 1 - 3 0

FI G . 5 Co n c e n tr a t i o n s o f s o d i u m , c a l c i u m , a n d m a g n e s i u m fo u n d i n f r e sh f e e d l o t runoff,

Bushland; area feed lot hold ing ponds; and area p lay a s .

samples contained only small amountso f s o l id s , becaus e s amp les w erecollected after settling. This wouldindicate that the removal of solids andt h e a d h e r i n g c h e m i c a l p o l l u t a n t scould improve the quality of the waterby a factor of two.

Normally, when a feedlot is adjacent to a playa, the feedlot runoff isdiluted by runoff from the remainderof the playa watershed. Holding pondscollect almost no outside runoff w ater;t h u s , c o n t a i n c o n s i d e r a b ly h i g h e r

concentration of salts. For example,the mean electrical conductivity was1.0 and 4 .5 mm ho s/c m for the play asand the holding ponds, respectively.

DISPOSAL OFFEEDLOT RUNOFF

Playa Lakes

The use of playa lakes as feedlotrunoff retention basins offers severaladvantages. The play as are natura lbasins without drainage outlets andrequire no construction cost. Prob

ably, the best advantage from adisposal standpoint is the naturald i l u t i on . Nor ma lly a feedlo t wi l lcomprise less than 20 percent of thetotal drainage area of the playa, thus,providing considerably dilution of thefeedlot runoff. The water in mostplayas can be used for irrigationwithout harmful salinity effects.

Holding Ponds

When irrigating from a holdingpond where the drainage area isrestricted to the feedlot, dilution with

other water will almost always be

necessary. Data in Figs. 4, 5, and 6indicate that straight feedlot runoffhas an extreme salinity hazard whenused as irrigation water, since thee lec t r i ca l conduc t iv i ty i s gene ra l lyabove 3 mm hos /c m. Water usedfo r i r r iga t ion genera l ly s hou ldn o t e x c e e d 2 m m h o s / c m(United States Salinity LaboratoryStaff 1954). The Sodium AdsorptionRa t io s (S A R) ind ica te tha t mos tholding pond water has a low ormedium sodium hazard; therefore,

total salts are a more serious problemthan sodium.A s am ple ca lcu la t ion w i th the

leaching equation developed by theU ni ted S ta te s S a l in i ty Labora to ry

illustrates the potential hazard ofirrigating with highly saline feedyardrunoff (United States Salinity Laboratory S taf f 1954, page 43) . Thefeedyard runoff will generally be usedon feed grains or small grains wherethe electrical conductivity of the soilsaturation extract should not exceed 8mmhos /cm. At Amar i l lo , Texas , theaverage consumptive use of water for

these crops is about 700 mm pergrowing season. Assume that theconsumptive use is furnished by 200mm of rainfall, 400 mm of groundwater, and 100 mm of feedyard runoffwith electrical conductivities of 0, 0.5,and 5.0 mm hos /cm , respectively. Thiscommonly used leaching equationind ic a tes tha t 100 mm o f deeppercolation per year would be requiredto maintain the salt balance. On thefine-textured soils of the SouthernHigh Plains that are furrow irrigated,deep percolation is normally less than

100 mm (Aronovici and Schneider1972). For this reason the maximumapp l ica t io n o f und i lu te d f eedyardrunoff should not exceed 100 mm peryear or one irrigation per year.

These values can be used only asexamples because of the great variability in feedlot runoff. Before runoffis used as irrigation, water samplesshould be analyzed to determine theaverage concentration of salts. Thesalt tolerance of grasses and cropsvaries considerably; therefore, thesalinity hazard level of the water,c r o p , and soi l should each becons ide red be fo re i r r iga t ing w i thfeedlot runoff. Ground water used forirrigation in the Southern High Plains

BUSHLAND RUNOFF

Percent of samples

25 50 7 5 100

0 - 5 0

5 I - I 0 0 |

1 0 1 - 3 0 0

O 3 0 I - 6 0 0 R

X 6 0 1 - l O O O M

> I 0 0 0

AREA HOLDING PONDS

Pe r c e n t o f s a m p l e s0 2 5 5 0 7 5 1 0 0

A RE A P L A Y A S

Percent of samples

x « 1 7 2 9

s

6 2 3

D 25 50

1 '" "iI

h x* 86

7 5 10"1

26

O ©

S IZ £Oo

0 - 1

1 -22 - 4

4 - 66 - 1 0

1 - 8 . 4

-otzr PR « 4 . 5 I« 1.0

0 - 1

1 -2

2 - 4

4 - 6

6 - 1 0

> I 0

h1 - 5 . 3

1 - 4 . 6 I - I . 4

FIG. 6 Concentration of ch lor ide and values of conductance and SAR found in fresh feed lot runoff,

Bushland; area feed lot hold ing ponds; and area p layas .

1 9 7 5 — T R A N S A C T I O N S o f t h e A S A E 3 2 1



normally has a low or medium salinityhazard. A mixture of five parts wellwater and one part runoff from theBush la nd f e e d lo t w ould ha ve amedium salinity hazard. A 5 to 1dilution ratio will reduce the salinityhazard for most holding pond water inthe Southern High Plains.

Feedlot runoff will normally havelittle value as a fertilizer source.

Although fresh runoff contains significant amounts of total nitrogen (N),much of it is lost before it can benefitcrop growth. Most N in runoff is in theorganic form. In the holding pondsand playas, the organic N is mineralized to NH4, which is converted toN H 3 t o m a i n t a i n t h e N H 3 : N H ^equilibrium. After conversion, theN H 3 is volatilized. Under the anaerobic condition in the playa and holdingpon ds, NO ] is quickly denitrified, andthe N is lost as N 2 gas. I r r igationexperiments by Swanson and Ellis

(1973) showed that only about 5percent of the N leaving a feedlot canbe measured in the irrigated crop orsoil. To obtain the most efficient useof the initial N , the feedlot runoffshould be used for irrigation asquickly as possible. Feedlot runoffdoes conta in sufficient p otassium (K)to benef i t soi l s which lack thisfertilizer element; however, most soilsof the South ern High P lains alreadyhave sufficient K for high crop yields.

TABLE 5 . AVERAGE DITCH TEMPERATURE AND FLOW RATE

Winter Summer

Average temperatu re , C 2.4 17.6

Temperature range,C -1.7-12.8 4.4-27.8

Average surface

veloci ty, m/sec 0.46 0.49Range of surface

veloci ty, m/sec 0.24-0.70 0.34-0.70

m e t h o d , t h e e n e r g y i n t h e f e e d s t u f f s

c o n s u m e d b y t h e c a t t l e w a s p a r t i t i o n e d

i n t o a f e c a l a n d u r i n a r y c o m p o n e n t . I t

w a s t h e n a s s u m e d t h a t t h e e n e r g y i n t h e

f e c e s a n d u r i n e w a s r e l a t e d t o t o t a l e n

e rg y i n t a k e i n t h e s a m e m a n n e r a s f e c a l

a n d u r i n a r y d r y m a t t e r w a s r e l a t e d t o

d r y - m a t t e r i n t a k e .

T o t a l s o l i d s - r e d u c t i o n v a l u e s o f 3 2 . 6

322

Large amounts of runoff must be usedbefore enough phosphorus (P) couldbe added to be beneficial. Generally,the harmful effects of salinity andsodium (Na) will overshadow th e beneficial effects from N, K., or P.

S U M M A R Y

R u n o f f a m o u n t s a n d c h e m i c a l

quality have been measured from aSouthern Great Plains cattle feedlot atBushland, Texas. The rainfall- runoffr e l a t i o n s h i p f or r u n o f f - p r o d u c i n gstorms was linear, with about one-third of the rainfall in excess of 10 mmending up as runoff. Other researchers in the Great Plains obtained similarresults except that the amount ofrainfall ending up as runoff was lowera t B u s h l a n d . C o n c e n t r a t i o n s o fva r ious r unof f c ons t i t ue n t s w e r ehigher than those found for cattlefeedlots elsewhere. Low rainfall, high

evaporation rates, and high stockingrates cause the manure pack in thefeedlots to contain more salts, thusallowing increased concentrations inrunoff.

A dilution ratio of about five partswell water to one p art feedlot runoffwould reduce the salinity hazard forirrigation from very high to mediumf or m os t ho ld ing ponds i n t heSouthern Great Plains. Runoff caughtin playas where the area of the feedlot

Be e f Ca t t l e Wa s t e s i n O xida t ion D i t c h

(Continued from page 318)

a n d 3 2 . 0 p e r c e n t f o r t h e w i n t e r a n d

s u m m e r t e s t s w e r e o b t a i n e d , r e s p e c

t i v e l y , a s s u m i n g d r y - m a t t e r w a s t e p r o

d u c t i o n p e r h e a d t o b e 2 . 3 k g . T o t a l

s o l i d s - r e d u c t i o n v a l u e s o f 2 8 . 1 a n d 2 7 . 2

p e r c e n t w e r e o b t a i n e d f o r t h e w i n t e r

a n d s u m m e r t e s t s , r e s p e c t i v e l y , u s i n g

t h e p a r t i t i o n i n g o f e n e r g y t o e s t i m a t e

w a s t e p r o d u c t i o n .

References1 Albin, R. J., J. Wunstad, D. Zen n, D.

W e l l s , W. Grub, E . Coleman, and G.Mee naghan . 19 71 . Cat t le performance insouthwestern feedlots. J. Anim. Sci . 33:206(Abst r . ) .

2 Blaxter, K. L. 19 61 . The ut i l izat ionof energy of food by ruminants. Symposiumon Energy Metabol ism, Wageningen, TheNether l ands 2 :213.

3 Hegg, R. O., and R. E. Larson. 1972.Solids balance o n a beef cattle oxid ationdi tch. Proceedings of the 1972 Cornel l Agri cu l tura l Waste Management Conference

is one -f if th or less of th e to talwatershed area could be considered ashaving a low or medium salinityhazard. Any use of feedlot runoff forirrigation requires close watch on saltsin the water and soil.

References

1 Aronovici, V. S., and A. D. S chneider.1972. Deep percolation through Pullman soil in

the Southern High Plains. Jour, of Soil andWater Conserv. 27:70-73.2 Gilbertson , C. B. , J. A. Nienabe r, T. M.

McCalla, J. R. Ellis, and W. R. Woods. 1972.Beef cattle feedlot runoff, sol ids t ransport , andset t l ing characterist ics. TRANSACTIONS ofthe ASAE 15:1132-1134.

3 Man ges, H. L., L. A. Schmid, and L. S.Mu rphy. 1971. Land disposa l of cattle feedlotwater. In Livestock Waste Management andPol lut ion Abatem ent , Proc . Internat l . Symp. onLivestock Waste, ASAE, St. Joseph, Mich.49085.

4 Swanson, N. P., L. N. Mielke, J. C.Lorimor, T. M. McCalla, and J. R. Ellis. 1971.Transport of pollutants from sloping cattlefeedlo t s as a f fec t ed by ra infa l l i n t ens i ty ,duration, and recurrence. In Livestock WasteManagement and Pol lut ion Abatement , Proc.Internat l . Symp. on Livestock Waste, ASAE,St. Joseph, Mich. 49085.

5 Swanson, N. P. , and J. R. Ellis. 1973.Irrigation of perennial forage crops with feedlotrunoff. ASAE Paper No. 73-241, ASAE, St .Joseph, Mich. 49085.

6 United States Salinity Laborator y Staff.

1954. Diagnosis and improvement of saline andalkali soils. Agr. Handbook No. 60.

7 Wise, G., and D. L. Reddell. 1973. Waterquality of storm runoff from a Texas beeffeedlot. ASAE Paper No. 73-441. ASAE, St .Joseph, Mich. 49085.

1 9 7 2 : 5 5 5 .4 Jone s, D. D., D. L. Day, and U. S.

Garrigus. 1971. Oxidat ion di tch in a confinement beef bui lding. TRANSACTIONS of theASAE 14:825.

5 Larson, R. E. , and J. A. Moore, 19 71 .Beef wastes and the oxidat ion di tch todayand tomorrow. Livestock Waste Managementand Pol lut ion Abatement . ASAE Proceedingsof the Internat ional Symposium on LivestockWastes 1971:217, ASAE, St . Joseph, Mich.4 9 0 8 5 .

6 Lo eh r, R. C. 197 1. Liquid wastet reatment III the oxidat ion di tch. Cornel l University Conference on Agricultural WasteManagement 1971:72 .

7 Moore, J. A., R. E. Larson, R. O.Hegg, and E . R. Allred. 197 0. Beef confinement systems—oxidat ion di tch. ASAE PaperN o . 70-418, ASAE, S t . Joseph, Mich . 49085.

8 Nat ional Academy of Sciences. Subcommi t t ee on Feed Composi t i on , Nat ionalResearch Counci l , Uni ted States, and Commit tee on Feed Composi t ion, Department ofAgricul ture, Canada. 1 97 1. At las of nutri t ional data on Uni ted States and Canada feeds.Washington, D.C.

9 Tyrrel l , H. F. , and P. W. Moe. 19 72 .Net ener gy value for lacta tion of a high andlow concentrate rat ion containing corn si lage.J. Dairy Sci . 55:1106.

TRANSACTIONS of the ASAE—1975

analysis of runoff from southern great plains feedlots

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