10/2/07

Publication List Related to

Pasture Research

Publications and abstracts are listed in reverse chronological order. A
limited number of reprints are available, and can be requested by
referring to the NAEW number. Use your browser's "find" feature to
search for words of interest. For more information, please contact:

> Lloyd B. Owens
>
> Research Soil Scientist
>
> N. Appalachian Experimental Watershed
>
> PO Box 488
>
> Coshocton, Ohio 43812
>
> USA
>
> email: <lloyd.owens@ars.usda.gov>
>
> phone: 740-545-6349
>
> fax: 740-545-5125

Owens, L.B. and M.J. Shipitalo. **2006.** Surface and subsurface
phosphorus losses from fertilized pasture systems in Ohio. J. Environ.
Qual. 35:1101-1109. **(NAEW #430)**

Abstract:

Phosphorus is an essential plant nutrient and critical to agricultural
production, but it is also a problem when excessive amounts enter
surface waters. Summer rotational grazing and winter feeding beef
pasture systems at two fertility levels (56 and 28 kg available P
ha^-1^) were studied to evaluate the P losses from these systems via
surface runoff and subsurface flow using eight small (0.3-1.1 ha),
instrumented watersheds and spring developments. Runoff events from a
14-yr period (1974-1988) were evaluated to determine the relationships
between event size in mm, total dissolved reactive phosphorous (TDRP)
concentration, and TDRP transport. Most of the TDRP transported was via
surface runoff. There were strong correlations (r^2^ = 0.45-0.66)
between TDRP transport and event size for all watersheds, but no
significant (P = 0.05) correlations between TDRP concentration and event
size. Flow-weighted average TDRP concentrations from the pasture
watersheds for the 14-yr period ranged from 0.64 to 1.85 mg L^-1^. The
highest concentrations were in events that occurred soon after P
fertilizer application. Average seasonal flow-weighted TDRP
concentrations for subsurface flow were \<0.05 mg L^-1^. Applying P
fertilizer to pastures in response to soil tests should keep TDRP
concentrations in subsurface flow at environmentally acceptable levels.
Management to reduce runoff and avoidance of P fertilizer application
when runoff producing rainfall is anticipated in the next few days will
help reduce the surface losses of P.

Owens, L.B., and J.V. Bonta.  **2004**.  Reduction of nitrate leaching
with haying or grazing and omission of nitrogen fertilizer.  J. Environ.
Qual. 33:1230-1237. **(NAEW #401).** 

Abstract:

In some high-fertility, high-stocking-density grazing systems, nitrate
(NO~3~) leaching can be great, and ground water NO~3~-N concentrations
can exceed maximum contaminant levels. To reduce high N leaching losses
and concentrations, alternative management practices need to be used. At
the North Appalachian Experimental Watershed near Coshocton, OH, two
management practices were studied with regard to reducing NO~3~-N
concentrations in ground water. This was following a fertilized,
rotational grazing management practice from which ground water NO~3~-N
concentrations exceeded maximum contaminant levels. Using four small
watersheds (each approximately 1 ha), rotational grazing of a grass
forage without N fertilizer being applied and unfertilized grass forage
removed as hay were used as alternative management practices to the
previous fertilized pastures. Ground water was sampled at spring
developments, which drained the watershed areas, over a 7-yr period.
Peak ground water NO~3~-N concentrations before the 7-yr study period
ranged from 13 to 25.5 mg L^-1^. Ground water NO~3~-N concentrations
progressively decreased under each watershed and both management
practices. Following five years of the alternative management practices,
ground water NO~3~-N concentrations ranged from 2.1 to 3.9 mg L^-1^.
Both grazing and haying, without N fertilizer being applied to the
forage, were similarly effective in reducing the NO~3~-N levels in
ground water. This research shows two management practices that can be
effective in reducing high NO~3~-N concentrations resulting from
high-fertility, high-stocking-density grazing systems, including an
option to continue grazing.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **2003.**  Non-nitrogen
nutrient inputs and outputs for fertilized pastures in silt loam soils
in four small Ohio watersheds. Agric., Ecosyst. Environ. 97:117-130.
**(NAEW #383).** 

Abstract:

Evaluations of non-nitrogen nutrient budgets in pasture systems are
limited, and there needs to be greater knowledge of these budgets.
Although most nutrient budget studies from grasslands have focused
solely or primarily on N, maintenance of a proper nutrient balance is
important to healthy plant growth and reduction of potential water
quality problems. Budgets of non-nitrogen nutrients were studied in a
rotational pasture system during two treatment periods, which received
different levels of nitrogen (N) fertility. Rotationally grazed grass
pastures in Ohio (USA) received 56 kg N ha^-1^ as NH~4~NO~3~ for a
5-year period and then 168 kg N ha^-1^ for a 10-year period. A topsoil
pH of 6.0 and available P and K levels of 28 and 168 kg/ha,
respectively, were maintained. Cattle grazed four paddocks during the
summer and were fed hay in one of the paddocks during the winter. Inputs
of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium
(Na), and chlorine (Cl) from precipitation, fertilizer, and hay were
determined. Losses of these nutrients plus total organic carbon (TOC)
were measured in surface runoff and in water from springs draining each
area. The majority of the nutrients from the summer only grazed (SG)
paddocks were transported in subsurface flow. Hay was the major source
of P and K in the winter feeding/summer grazing (WF/SG) paddock, and
surface runoff was the major transport pathway for them and TOC. Most of
the transport of Ca, Mg, Na, and Cl from the WF/SG area occurred via
subsurface flow. Concentrations of P in subsurface flow were low; Na
concentrations changed little during the 15-year study; Mg, Ca, and Cl
concentrations increased slowly from the SG area but much more rapidly
from the WF/SG area. When large amounts of nutrients are brought into an
area with hay, there can be a soil buildup of P and K. This increases
the possibility for adverse water quality impacts. Nevertheless, the
evaluation of non-nitrogen nutrients in pasture systems showed that when
they are balanced and meet the plant requirements for the N fertility
level, the possibility of detrimental environmental impact is low.

Owens, L.B., G.C. Starr, and D.L. Lightell. 2002. Total organic carbon
losses in subsurface flow under two management practices. Journal of
Soil and Water Conservation 57(2):74-81. **(NAEW #376)**

Abstract:

Greenhouse gases and global warming have become major topics. Much of
the greenhouse gas discussion has dealt with carbon dioxide (CO~2~) and
methods to sequester or store atmospheric carbon in soils and forests.
The entire carbon cycle needs to be studied to better understand the
overall process. The major carbon transformations are loss of CO~2~ to
the atmosphere or the storage of carbon in sinks such as soil. Although
it is a minor pathway, carbon leached through the soil and into
groundwater needs to be quantified. Numerous carbon studies have been
performed, but concentrations and losses of total organic carbon (TOC)
moving through a soil profile have received little attention. Therefore,
this study was to assess TOC levels in subsurface flow under two
management practices. TOC was determined monthly in the percolate from
large soil blocks, called lysimeters, (2.4 m \[8 ft\] deep) with
undisturbed soils under row crops. Most of the TOC concentrations in the
percolate ranged from 0.5 to 6.0 mg/L with the corn/soybean-rye
rotation. Developed springs in two rotational grazing systems were
sampled for 10 years. TOC concentrations in the groundwater from the
springflow developments had less variability than in the lysimeter
percolate. Most TOC values from these pasture systems were in a
concentration range of 1 to 3 mg/L. Annual averages of TOC transport
were similar for the lysimeter percolate and groundwater springs,
ranging from 3.7 to 6.0 kg/ha (3.3 to 5.4 lb/ac).

Owens, L.B., W.M. Edwards, and R.W. Van Keuren.  **1999. ** Nitrate
leaching from grassed lysimeters treated with ammonium nitrate or slow
release nitrogen fertilizer.  J. Environ. Qual. 28(6):1810-1816.**(NAEW
#348).**

Abstract:

Nitrate leaching is a potential in humid regions when crops and forages
are fertilized. This study was conducted to compare NO~3~ leaching with
two different N fertilizer formulations applied to forages. For 11 yr,
ammonium nitrate (AN) was applied to a large (8.1 m^2^ surface area),
undisturbed, monolithic lysimeter Y101B at an annual rate of 168 kg N
ha^-1^, and methylene urea (MU), a slow-release fertilizer, was applied
to a similar lysimeter (Y101D) at the same rate. Nitrate-N
concentrations in the percolate from these 2.4 m-deep lysimeters were
measured weekly. Even though NO~3~-N levels increased steadily with the
AN applications, the greatest increases occurred during the eighth year
of treatment and reached levels above 20 mg L^-1^. With the MU, NO~3~-N
concentrations remained relatively constant until after 8 yr of
treatment, reaching concentrations of 6 mg L^-1^. The highest rates of
annual NO~3~-N transport in percolate were 42.3 and 12.1 kg ha^-1^ from
lysimeters treated with AN and MU, respectively. (Losses from NH~3~
volatilization were measured at 12.0 and 44.8 kg N ha^-1^ for An and MU,
respectively.) Nitrate-N transport in percolate varied seasonally with
the greatest amounts being moved during the late winter-early spring.
Following 11 yr, the NO~3~-N concentrations in each lysimeter declined
to approximately 1 mg L^-1^. Based on this study with a 168 kg N ha^-1^
annual application rate, less NO~3~-N leaching will occur when a
slow-release N fertilizer, such as MU, is applied to forages than when
AN is applied.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **1998. ** Budgets of
non-nitrogen nutrients in a high fertility pasture system.  Agric.,
Ecosyst. Environ. 70:7-18.**(NAEW #338).**

Abstract:

Concentrations and transport of non-nitrogen nutrients in surface runoff
and subsurface flow were determined under a high fertility pasture
system during a multi-year study. Most studies of nutrient loss from
grasslands have focused solely or primarily on nitrogen. Nevertheless,
maintaining a proper balance of other nutrients is important to healthy
plant growth, avoidance of toxicity problems from improper nutrient
balances, and reduction of potential water quality problems.
Rotationally grazed grass pastures received 224 kg N/ha annually as
NH~4~NO~3~ for a 5-year period and had a legume interseeded into the
grasses to be the N source during the following 8-year period. Part of
the pastures were grazed during the summer only. The other pastures were
used in the winter months with cattle eating fall regrowth and the hay
made on that area during the summer. Topsoil pH of 6.5 - 7.0 and
available P and K levels of 56 and 336 kg/ha, respectively, were
maintained by soil amendments. Concentrations of P, K, Na, Ca, Mg, Cl,
and TOC were measured in surface runoff collected from small watersheds
with automated samplers and in water from springs draining each area.
Nutrient concentrations in both surface runoff and subsurface flow were
strongly influenced by the amounts of fertilizer and lime applied. The
majority of P and K were transported via surface runoff. The
concentrations and transport of P and K were greater during the 8-year
period because of increased rates of application of these fertilizers.
Nutrient concentrations in subsurface flow did not vary greatly on a
monthly basis but there were some increases during the span of the
study. Concentrations of K and Na changed very little; Mg increased
slightly; and Ca and Cl had large increases during the 13 years.
Increased rates of KCl application during the 8-year period was a
primary cause for the increased Cl concentrations in the shallow
groundwater. Concentrations and transport of non-nitrogen nutrients from
a pasture system were little influenced by the summer vs. winter
management of this study or the change in N source form fertilizer to
legumes. The application of non-nitrogen fertilizers and lime was the
major factor of influence. In a pasture system where balances are
maintained, the possibility of detrimental environmental impacts from
non-nitrogen nutrients is low.

Owens, L. B., W. M. Edwards, and R. W. Van Keuren.  **1997.**  Runoff
and sediment losses resulting from winter feeding on pastures.  J. Soil
Water Conserv. 52:194-197. **(NAEW #332).**

Abstract:

Grazing is an important land use in the humid, eastern U.S. When the
grass is dormant, late fall through early sprint, the land is most
vulnerable to the pressures of livestock. Runoff and sediment losses
from a small pastured watershed (WS) in eastern Ohio have been studied
for 20 years. In Period 1, a beef cow herd grazed it rotationally during
the growing season for 12 years and was fed hay in this WS during the
dormant season (high animal density with feeding). During the next 3
years of this study (Period 2), there was summer rotational grazing
only. There was no animal occupancy on this WS during the last 5 years
(Period 3). Annual runoff was more than 10% of precipitation during
Period 1 (120 mm) and less than 2% during Periods 2 and 3 (14 and 6 mm,
respectively). The decrease in annual sediment loss was even greater
with the change in management, yielding 2259, 146, and 9 kg/ha for the
three respective periods. Over 60% of the soil loss during Period 1
occurred during the dormant season. In response to weather inputs, there
was considerable seasonal and annual variation in runoff and soil loss
within management periods. Low amounts of runoff and erosion from three
adjacent watersheds with summer-only grazing supported the conclusion
that the increased runoff and erosion during Period 1 resulted from the
non-rotational, winter feeding on pastures. When the management was
changed, the impacts of the previous treatment were not long lasting,
changing within a year.

Owens, L.B., W.M. Edwards, and R.W. Van Keuren.  **1996.**  Sediment
losses from a pastured watershed before and after stream fencing.  J.
Soil Water Conserv. 51:90-94. **(NAEW #322).**

Abstract:

Livestock induced sediment loss is one of the potential detrimental
impacts from grazing grasslands. Near Coshocton, Ohio, a 26-ha
unimproved pasture watershed was grazed year-around, and no fertilizer
was applied. A beef cow heard had access to the entire watershed study
area including the small stream that originated within the watershed,
i.e. there was no rotational grazing in the pasture. Sediment loss via
the stream was measured at the base of the watershed. Following 7 years
of this management practice, the stream and the wooded areas on the
sides of the stream were fenced so that the cattle no longer had access
to them. During the next 5 years, with the cattle fenced out of the
stream, the annual sediment concentration decreased by more than 50% and
the amount of soil lost decreased by 40%. Average annual soil losses
were reduced from 2.5 to 1.4 Mg/ha while annual precipitation averages
were similar during each management period.

Owens, L.B., W.M. Edwards, and R.W. Van Keuren.  **1994.**  Groundwater
nitrate level under fertilized grass and grass-legumes pastures.  J.
Environ. Qual. 23:752-758. **(NAEW #307).**

Abstract:

High levels of N fertilizer applied to pastures can result in NO~3~-N
concentrations in groundwater exceeding the USEPA potable water standard
of 10 mg N/L. This study was conducted to determine groundwater NO~3~-N
levels following a change in N source from fertilizer to a legume in a
grass-pasture grazed by beef cattle. For 5 yr, 224 kg N/ha was applied
annually to small watersheds with orchardgrass (*Dactylis glomerata* L.)
pastures used for summer-grazing and tall fescue (*Festuca arundinacea*
Schreb.) areas used for winter-grazing-feeding. At the beginning of the
sixth year, alfalfa (*Medicago sativa* L.) was interseeded into the
grass pastures and N fertilizer was no longer applied. Groundwater
samples from developed springs and surface runoff samples were collected
and analyzed for NH~4~-N, NO~3~-N, and total N for the 5-yr
fertilization period and for the following 10-yr period without applied
N fertilizer. Nitrogen in groundwater was present mainly in the NO~3~
form, and concentrations increased throughout the 5-yr period of
fertilizer application and reached levels that were usually in excess of
10 mg N/L. With the change from N fertilizer to legume N, the NO~3~-N
concentrations in groundwater dropped rapidly during a 2-yr period. In a
tall fescue-alfalfa area, NO~3~-N levels decreased from 17.7 to 9.3 mg
N/L. In two orchardgrass-alfalfa areas, NO~3~-N levels decreased from
11.2 to 2.7 and from 8.3 to 3.6 mg N/L. During the remainder of the
10-yr period, NO~3~-N concentrations declined to levels similar to those
before N fertilization. Although the amount of N lost via subsurface
flow decreased with decreasing concentrations, subsurface flow remained
the main pathway for N loss compared with surface runoff or
sediment-attached N.

Owens, L.B. and W.M. Edwards.  **1992.**  Long-term groundwater quality
changes from a one-time surface bromide application.  J. Environ. Qual.
21:406-410. **(NAEW #289).**

Abstract:

The purpose of this experiment was to use a conservative tracer to study
the impacts on groundwater quality of a one-time application of a water
soluble chemical. Potassium bromide was applied at a rate of 168 kg
Br^-^/ha to two 1.1-ha pasture watersheds in east-central Ohio. The
watersheds had well-drained residual silt loam soils and with slopes of
12 to 25%. A nearly impermeable clay layer under the watersheds created
a perched aquifer from which groundwater samples could be taken at
developed springs. There were seasonal variations in Br^-^
concentrations in the groundwater and the highest concentrations (9.2
mg/L maximum peak) occurred within 3 yr following the Br^-^ application.
Ten years following the Br^-^ application, Br^-^ concentration in the
groundwater was still slightly above initial baseline levels. Even with
a one-time application of a soluble chemical constituent on the surface
of a small aquifer system, a multiyear impact was produced on the
quality of groundwater.

Owens, L.B., W.M. Edwards, and R.W. Van Keuren.  **1992. ** Nitrate
levels in shallow groundwater under pastures receiving ammonium nitrate
or slow-release nitrogen fertilizer.  J. Environ. Qual.  21:607-613.
**(NAEW #292).**

Abstract:

This study examined the impact on groundwater quality of conventional
and slow-release N fertilizer to small, grazed watersheds in eastern
Ohio. Three small watersheds (each less than 1 ha) received 56 kg N/ha
annually as NH~4~NO~3~ for 5 yr. For the next 10 yr, one watershed
received 168 kg N/ha annually as NH~4~NO~3~ and two others received the
same amount of N as methyleneurea, a slow-release fertilizer. Shallow
groundwater samples were collected from springs and analyzed. After the
5-yr prestudy period, NO~3~-N levels in the groundwater from the three
watersheds were in a 3 to 5 mg/L range. Groundwater NO~3~-N
concentrations increased slightly during the first 3 yr at the higher N
fertilizer rate, though they remained in the 3 to 5 mg/L range.
Nitrate-N levels increased more sharply during the rest of the study.
Although these NO~3~-N levels varied more between the growing and
dormant seasons than when lower rates of fertilizer were applied, they
eventually reached a slower rate of increase. During the 9^th^ and
10^th^ yr of the high application, seasonal NO~3~-N levels in
groundwater ranged from 10 to 16 and 7 to 14 mg/L from the watersheds
receiving NH~4~NO~3~ and methylene urea, respectively. This study showed
that 168 kg N/ha was too much for this system, regardless of whether
conventional or slow-release N was used.

Owens, L.B., W.M. Edwards, and R.W. Van Keuren.  **1989.**  Sediment and
nutrient losses from an unimproved, all-year grazed watershed. J.
Environ. Qual.18:232-238.**(NAEW #268).**

Abstract:

A common practice for grazing land in the humid, eastern USA is
continuous grazing with little or no fertilizer use. Concentrations and
transport of nutrients from a 28-ha unimproved grassed watershed were
assessed in east-central Ohio for 2 yr without the presence of
livestock, for 3 yr with a 17-cow beef (*Bos Taurus)* herd grazing
during the summer months only, and for an additional 6-yr period with
all-year grazing with hay being brought in for winter feed. Nutrient
concentrations remained low during all three grazing levels. An
exception was K concentration, which increased with all-year grazing.
Concentrations of NO~3~-N, mineral-N, P, Ca, Mg, Na, and Cl were similar
to or less than the concentrations from a nearby 17.7-ha wooded
watershed that contained no pastured areas and received no agricultural
inputs. Nutrient concentrations showed no consistent seasonal variation.
Concentrations of organic-N, total organic C and sediment increased with
increased grazing pressure. Greatest sediment concentrations and
transport rates generally occurred during July and August regardless of
grazing system. Largest monthly average sediment concentrations were
0.8, 1.3, and 3.2 g/L for the three systems, respectively; annual
sediment losses were 0.2, 1.2, and 2.1 Mg/ha, respectively. All-year
cattle grazing/feeding on an unimproved pasture in this area would not
be expected to produce degradation of stream water quality from nutrient
concentrations or transport. **\
\
**

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **1985. ** Groundwater
quality changes resulting from a surface bromide application to a
pasture.  J. Environ. Qual. 14:543-548. **(NAEW #252).**

Abstract:

Potassium bromide was applied at a rate of 168 kg Br^-^/ha to two 1.1-ha
pasture watersheds in east-central Ohio to study the impacts on
groundwater quality of a one-time application of a soluble constituent.
The watersheds had well-drained residual silt loam soils and average
slopes of about 20%. A nearly impermeable clay layer under the
watersheds created a perched aquifer from which groundwater samples
could be taken at developed springs. Three monolith, grassed lysimeters
having soil profiles similar to the watersheds also received the Br^-^
treatment. The lysimeters, which were 8 m^2^ in surface area and had a
depth of 2.4 m, had shorter leaching pathways than the watersheds and
showed peak Br^-^ concentrations in percolation (24.0 mg/L maximum peak)
occurring 52 -- 78 weeks following the Br^-^ application. The Br^-^
concentration in the groundwater from the watersheds had lower peaks
(9.2 mg/L maximum peak) but occurred 84 to 104 weeks after the Br^-^
application. Because of variable leaching pathway lengths, including
pathways much longer than those in the lysimeters, the watershed
groundwater Br^-^ applications had shown no meaningful decrease by 2 yrs
after the Br^-^ application. A one-time application of a soluble,
nondegradable chemical constituent can have a multi-year influence on
groundwater quality.

Owens, L.B., W.M. Edwards, and R W. Van Keuren.  **1984. ** Peak
nitrate-nitrogen values in surface runoff from fertilized pastures.  J.
Environ. Qual. 13:310-312. **(NAEW #247).**

Abstract:

Pastured watershed on hill slopes in eastern Ohio were fertilized with
ammonium nitrate (NH~4~NO~3~) at two different levels for 5 years. The
pastures were rotationally grazed during either the growing season
(May-October) or the dormant season (November-April). Nitrate-N
concentrations were measured in surface runoff events \>0.1 mm from nine
watersheds. During the 5-year period, there were 890 runoff events.
Sixty-four of these events (7%) had NO~3~^-^ -N concentrations \>10
mg/L, and 48 of the 64 events occurred within a 30-d period following
fertilizer application. Ten events, \<2% of all of the runoff events,
exceeded 30 mg/L NO~3~^-^ -N, and all of these were within 17 d of
fertilization. Although all surface runoff events which closely followed
fertilizer applications did not have high NO~3~^-^ -N concentrations,
all surface runoff with high NO~3~^-^ -N was shortly preceded with a
fertilizer application. The closeness of the high NO~3~^-^ -N
concentration and fertilizations suggested that fertilizer was the major
contributor to high NO~3~^-^ -N in runoff as opposed to animal waste.

Owens, L.B., W.M. Edwards, and R.W. Van Keuren.  **1983.**  Surface
runoff quality comparisons between unimproved pasture and woodland.  J. 
Environ. Qual. 12:518-522.**(NAEW #242).**

Abstract:

The influence of pasturing on surface runoff water quality was studied
on a 26-ha, unimproved pasture watershed in east-central Ohio. Data were
collected for 2 y with no cattle in the pasture and for 3 y with summer
grazing by a 17-cow beef cattle herd. Because of springs and seep areas
in the pasture, a small stream (accessible to the cattle) in the
watershed flowed permanently. Samples of storm runoff were collected
with a rotating vane sampler. The concentrations of most of the measured
chemical parameters (NO~3~-N, mineral N, organic N, total P, K, Ca, Mg,
Na, S, Cl, HCO~3~, total organic C, salts) in the storm discharge water
were low and changed very little as a result of grazing. The weighted
annual NO~3~-N concentrations for the ungrazed period and grazed period
were 0.5 and 0.7 mg/L, respectively, and the highest event
concentrations were 1.2 and 3/8 mg/L, respectively.

A 17.7-ha, wooded watershed that contained no pastured areas and
received no agricultural chemical inputs, had concentrations of chemical
parameters in surface discharge that were greater than or equal to those
from the unimproved pasture during the grazing period.

Nutrient transport during storm runoff from the unimproved pasture was
greater during the 3-y period with summer grazing than during the 2-y,
ungrazed period. This largely resulted from increased precipitation and
subsequent increased surface runoff during the 3-y period. The transport
levels from the pasture during the 3-y period were similar to or less
than the transport levels from the wooded watershed during the same
period. The increase in sediment transport from the pastured area was
more than could be attributed solely to the increased surface runoff.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **1983.**  Hydrology
and soil loss from a high-fertility, rotational pasture program.  J.
Environ. Qual.  12:341-346. **(NAEW #239).**

Abstract:

Five small watershed (0.25-3.1 ha) on sloping uplands in eastern Ohio
were used to evaluate environmental effects of a beef management program
of rotational summer grazing on one area, and rotational winter
grazing/feeding with stored hay on another area. During the 5-y study,
annual precipitation was 1080 mm, which was 8-15% greater than the
long-term average. The surface runoff was measured by precalibrated
H-flumes, and automatically sampled using Coshocton wheels. Surface
runoff from watersheds with beef cattle management increased, compared
with the long-term averages when hay was grown on the watersheds.
Greater precipitation was the primary factor causing more runoff during
the growing season (May -- October), and the cattle management was a
major contributing influence on the runoff increase during the dormant
season (November -- April). Maintenance of good vegetative cover on the
study areas was a major factor in limiting annual average surface runoff
to \< 110 mm, which was a relatively small amount. The large runoff
events, although a small percentage of the total number of events,
produced most of the runoff volume. Soil loss from these pastures was
minimal.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **1983.**  Nitrogen
loss from a high-fertility, rotational pasture program.  J. Environ.
Qual. 12:346-350. **(NAEW #240).**

Abstract:

A beef cattle-pasturing system involving four rotationally grazed summer
pastures (SG) and four pastures used rotationally for winter
grazing/feeding (WGF) was studied on sloping upland watersheds in Ohio
to determine effects of livestock management on N levels in water. Both
summer and winter areas annually received 224 kg N/ha as NH~4~NO~3~
fertilizer. Surface runoff was collected automatically during runoff
events, and subsurface flow was sampled from spring developments on a
weekly basis. Although seasonal N concentration and transport in surface
runoff tended to be greater in the area occupied by the cattle, N
concentration and transport in runoff from the two areas were quite
similar and did not significantly impair water quality, based on U.S.
Public Health Standards. The NO~3~-N concentration in the subsurface
flow from the WGF area was higher than in the subsurface flow from the
SG area. The NO~3~-N concentration in the subsurface flow from both
areas increased progressively throughout the study period, and reached
levels as high as 18 mg/L. The subsurface flow provided the main pathway
for N transport, with the surface transport being approximately 20 and
14% of the total N transport from the SG and WGF areas, respectively.
The amount of sediment-N transported was very small because of low soil
loss.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **1982.** 
Environmental effects of a medium-fertility 12-month pasture program: 
I.  Hydrology and soil loss.  J. Environ. Qual. 11:236-240. **(NAEW
#231).\
\
**Abstract:

Four small, sloping upland watersheds in Ohio (0.5 -- 1.1 ha) were
studied for 5 years to investigate hydrologic and soil erosion changes
resulting from a beef cattle pasturing program. The cattle grazed all
four pastures rotationally during the summer (May -- October) and were
wintered on hay (November -- April) on the same pasture each year. The
long-term record for these pastures, which had been in meadow and light
pasturing during the previous years, showed average annual surface
runoff to be approximately 15 mm. During the 5 years of the grazing
project, the three summer-grazing-only pastures showed a slight increase
in surface runoff and a trace of soil loss. However, the
winter-feeding/summer-grazing area showed a large increase in surface
runoff (131 mm/year) and soil loss (1,355 kg/ha per year). Eighty-one
percent of the soil loss occurred during the dormant season. Large
runoff events, although a small percentage of the total number of
events, produced most of the runoff volume and most of the soil loss.
Water balance studies indicated that subsurface flow was relatively
unchanged by the grazing program. The increase in surface runoff was
offset by a decrease in the evapotranspiration.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards.  **1982.** 
Environmental effects of a medium-fertility 12-month pasture program: 
II.  Nitrogen.  J. Environ. Qual. 11:241-246. **(NAEW #232).**

Abstract:

Four small, medium fertility (56 kg/ha per year N) watersheds were used
in a rotational summer-grazing and winter-feeding program to determine
its effects on N levels in water. During a 5-year study on sloping
uplands in Ohio, the concentrations on NO~3~-N and NH~4~-N were
determined in precipitation, surface runoff, subsurface flow, and
sediment. Although the NO~3~-N concentration was generally higher in the
surface runoff from the summer-grazing/winter-feeding area than from the
summer-grazing-only areas, it usually resulted in no significant
impairment of water quality, except on a few occasions when the NO~3~-N
concentration exceeded 10 mg/liter. The N transported in the subsurface
flow from the summer-grazing only areas was approximately equal to that
transported from the winter-feeding area and to the amount of N received
in the precipitation. Both surface runoff transport and sediment
transport of N were much greater in the winter-feeding area than in the
summer-grazing-only areas because these latter areas yielded very little
surface runoff and only a trace of soil loss. Reduction of vegetative
cover and increased soil disturbance on the winter-feeding area resulted
in increased surface runoff and soil erosion and thus more N was
transported. Surface and subsurface losses of N from the winter-feeding
area were nearly equal. A large percentage of N was transported by the
large storms, which represented a small percentage of the total number
of storms.

Van Keuren, R.W., J.L. McGuinness, and F.W. Chichester.  **1979.** 
Hydrology and chemical quality of flow from small pastured watersheds: 
I. Hydrology.  J. Environ. Qual. 8:162-166. **(NAEW #217).**\
\
Abstract:

Surface runoff, soil loss, and subsurface flow were measured from four
rotationally grazed summer pastures. One of these pastures was also used
as a winter-feeding area. Surface runoff volumes and peak rates from the
three pastures used only for summer grazing were generally less as
compared with values for earlier years when the fields were in meadow
and light pasturing; however, runoff from the winter-feeding area was
markedly increased. Both before and after the initiation of grazing, the
areas used only for summer grazing had but a trace of soil loss. More
soil was lost from the winter-feeding area, particularly during the
dormant season. Water-balance studies indicated that during the growing
season surface runoff and subsurface outflow were higher and
evapotranspiration (ET) was less from the winter-feeding area than from
areas summer-grazed only. During the dormant season, surface runoff was
higher and subsurface outflow was lower from the winter-feeding area
than from the summer-grazed areas, whereas ET was similar.

Chichester, F.W., R.W. Van Keuren, and J.L. McGuinness.  **1979.** 
Hydrology and chemical quality of flow from small pastured watersheds: 
II. Chemical quality.  J. Environ. Qual. 8:167-171. **(NAEW #218).**

Abstract:

A beef cattle-pasturing system involving four rotationally grazed summer
pastures with winter-feeding on one pasture was studied on sloping
upland watersheds in Ohio to determine its effect on chemical quality of
water. The concentrations of chemicals in runoff from the pastures,
which were summer-grazed only, increased relative to that of incoming
precipitation but not enough to significantly impair water quality. No
measurable sediment was lost from the pastures used only for summer
grazing, allowing no chemical movement via that pathway. Much soil and
plant-cover disturbance on the pasture used for winter-feeding, however,
resulted in increased runoff, some surface erosion, and more chemical
movement as compared with the pastures grazed only in summer.
Considerably more chemicals moved in subsurface than in surface flow
from the summer pastures while amounts of chemicals transported from the
winter-feeding pasture were equally as great in surface runoff and
subsurface flow. Watershed surface management was a key factor in
determining the flow route of water in excess of that used for
evapotranspiration and, hence, the pathways and amounts of chemical
transport from the pastures.