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AbstractGrazing is an important land use in the humid, eastern U.S. When the grass is dormant, late fall through early spring, 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.

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−1treatment. The lysimeters, which were 8 m2in surface area and had a depth of 2.4 m, had shorter leaching pathways than the watersheds and showed peak Br−1concentrations in percolation (24.0 mg/L maximum peak) occurring 52–78 weeks following the Br−1application. The Br−1concentration in the groundwater from the watersheds had lower peaks (9.2 mg/L maximum peak) but occurred 84 to 104 weeks after the Br−1application. Because of variable leaching pathway lengths, including pathways much longer than those in the lysimeters, the watershed groundwater Br−1applications had shown no meaningful decrease by 2 yrs after the Br−1application. A one‐time application of a soluble, nondegradable chemical constituent can have a multi‐year influence on groundwater quality.

Development of high levels of anthracnose (Colletotrichura trifoliiBain) resistance in alfalfa (Medicago sativaL.) in the early 1970's stimulated interest in obtaining estimates of the increased productivity associated with resistance. This paper reports the results of forage yield trials established at 24 locations in the eastern, midwestern, and western United States. Each trial included four pairs of anthracnose‐susceptible and anthracnose‐resistant bioindicator strains: 1) Glacier and Beltsville 1‐An4, 2) Saranac and Beltsville 2‐An4, 3) Vernal and Beltsville 3‐An4, and 4) Team and Arc. Forge yields were recorded for 3 years at 18 locations and for 2 years at six locations. Average annual forage yields were significantly higher for the resistant strains than for the susceptible strains at 15 of the 24 locations, averaging 1.1 mt/ha/year (10%) greater for the resistant than for the susceptible strains. A 0.8 mt/ha/year (7%) yield advantage of resistant strains over susceptible strains was obtained over all 24 locations. These results clearly indicate the value of anthracnose‐resistant alfalfa cultivars to U,S. agriculture.

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.

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 NH4NO3fertilizer. 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 NO3‐N concentration in the subsurface flow from the WGF area was higher than in the subsurface flow from the SG area. The NO3‐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.

Five small watersheds (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.

The influence of pasturing on surface runoff water quality was studied on a 26‐ha, unimproved pasture watershed in eastcentral 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 (NO3‐N, mineral N, organic N, total P, K, Ca, Mg, Na, S, Cl, HCO3, total organic C, salts) in the storm discharge water were low and changed very little as a result of grazing. The weighted annual NO3‐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.

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 fight pasturing; however, runoff from the winterfeeding 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.

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.

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 NO3‐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.

Frost heave of alfalfa (Medicago sativaL.) occurs periodically in northern areas of the United States, and frequently results in serious stand losses. Studies were conducted at Wooster, OH, to determine the effect of date of initial harvest, harvest frequency, and date of final harvest on yield and persistence of alfalfa on a Wooster silt loam (fine‐loamy, mixed, mesic Typic Fragiudalf), a frost heave susceptible soil. Late‐autumn harvests (late October) were a major factor associated with frost heave in this research. An average of 38 and 28% frost heave occurred in 1986 and 1987, respectively, compared to 5 and 7% with no late‐autumn harvests for the same years. The extent of frost heave was not related to average root weight, percent of roots branched, or percent total nonstructural carbohydrates. The two winters had high soil moisture, soil temperatures slightly below freezing, and no snow cover for relatively long periods, factors previously recognized as related to frost heave. Soil cover provided by leaving the autumn regrowth appeared to be the major effect in reducing the amount of frost heave that occurred by modifying the soil temperature. The practice of late‐autumn harvesting has become widespread in recent years. Producers with soils subject to heaving must consider the value of leaving the regrowth as protection against frost heave damage and potential loss of the alfalfa stand, against the value of the harvested forage.

High levels of N fertilizer applied to pastures can result in NO3‐N concentrations in groundwater exceeding the USEPA potable water standard of 10 mg N/L. This study was conducted to determine groundwater NO3‐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 glomerataL.) pastures used for summer‐grazing and tall fescue (Festuca arundinaceaSchreb.) areas used for winter‐grazing‐feeding. At the beginning of the sixth year, alfalfa (Medicago sativaL.) was interseeded into the grass pastures and N fertilizer was no longer applied. Groundwater sampies from developed springs and surface runoff samples were collected and analyzed for NH4‐N, NO3‐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 NO3form, 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 NO3‐N concentrations in groundwater dropped rapidly during a 2‐yr period. In a tall fescue‐alfalfa area, NO3‐N levels decreased from 17.7 to 9.3 mg N/L. In two orchard‐grass‐alfalfa areas, NO3‐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, NO3‐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.

The persistence of birds foot trefoil as a pasture legume grown with Kentucky bluegrass was studied for a 6‐year period. The inclined point quadrat was used to measure changes in the trefoil stands as influenced by grazing system, species of grazing animal, and plant growth habit. Trefoil was shown to be a long‐lived perennial. Rotational grazing was necessary for trefoil persistence under grazing; the trefoil stand was sharply reduced under continuous grazing. The species of grazing animal was not a major factor in trefoil persistence. Semiprostrategrowing ‘Empire’ was found to persist slightly better than upright‐growing ‘Viking’.

Southern and southeastern Ohio encomia pass a large area of hill land where the topography makes it necessary to devote a high proportion of the land to forage crops for soil protection. It is typical of the central Appalachian plateaus and the Ohio Valley. Beef cattle numbers are increasing in this area, primarily as cow-calf operations. The generally mild open winters of the area and the use of the natural protection of the hills and wooded ravines provide an opportunity for winter grazing of beef cows with minimum housing and feed storage needs.Earlier agronomic studies have shown that the soils respond well to fertilization and that good yields of forages can be expected. Initially, the soils are generally acid, low in phosphorus and high in potassium.An economic study of beef production in southeastern Ohio (Blosser, 1958) showed that with good management beef cow herds could yield a profitable return and pay for a major pasture improvement program.

Weaned beef calves wintered for 155 days at three levels of nutrition were subsequently placed on six kinds of irrigated pastures. As yearlings, the cattle were assigned at random from each of the wintering treatment groups to each of the pastures.Average daily gains by calves on the high, medium, and low wintering treatments were 1.29, 1.01, and 0.33 lb., respectively, at per-pound costs for feed of 13.15, 13.85, and 34.75 cents. There was no significant difference between the average daily gains made by the calves on the high and medium treatments. A significant difference was noted between the gains of the low treatment calves and those on each of the other two wintering treatments.Cattle grazing the grass-legume mixtures gained significantly faster than those grazing the grasses. There was also a significant difference between the pasture gains of the steers wintered at the low level and those wintered at medium and high levels. Average daily gains on pasture were 1.89, 1.91, and 2.45 lb. by the steers wintered at the high, medium, and low levels, respectively. A significant negative correlation was found between winter gains and subsequent pasture gains.Wintering treatment had no significant effect on feedlot performance of the cattle following the grazing season.

Results are presented from a randomized complete block design experiment in which progesterone-estradiol treatments were administered to yearling steers on three kinds of irrigated pastures. The responses of these animals were compared with others not implanted but grazing the same kinds of pastures.Daily gains and animal gains per acre were significantly increased by the hormone implant. Grain feeding erased the effect of implants on the rate of daily gain. Carrying capacity of the pastures grazed by implanted animals was not significantly lower than for the non-implanted.The implanted cattle apparently utilized their forage from 13 to 19% more efficiently than the non-implanted.There were no significant differences in grade, marbling, rib-eye area or lb. of carcass per sq. in. of rib-eye area between carcasses of implanted and non-implanted cattle. Intra-pasture differences were noted for carcass yield, fat cover and transit shrinkage.

A nylon-bag technique for in vivoestimation of forage dry matter digestibility is described. A uniformity trial with an alfalfa hay indicated very good repeatability with this procedure.An increase in percent dry matter digestibility of orchardgrass and sudangrass was found with each 24-hr, increase in length of time that the material remained in the rumen. Alfalfa and Ladino clover had a much higher digestibility for the first 24-hr. period than the grasses. Digestibility of alfalfa increased slightly through the 48- and 72-hr. periods. Digestibility of Ladino clover tended to level-off after the 48-hr. period.Fineness of grind of the samples did not affect percent digestibility. Generally, larger sample size resulted in lower digestibility for comparable periods of time in the rumen. These differences tended to disappear as length of time in the rumen increased.The dietary regimen of the fistulated animal appeared to influence digestibility of the forage samples.

The effect of grazing management on animal product per hectare and individual animal response from birdsfoot trefoil‐Kentucky bluegrass pastures was studied for a 6‐year period. The put‐and‐take grazing procedure was used with yearling steers and feeder lambs. Animal product per hectare, as measured by animal liveweight gains, was greater from a three paddock rotational grazing system than from continuous grazing. ‘Empire’ birdsfoot trefoil produced more total animal product per ha for the 6 years than did ‘Viking’ birdsfoot trefoil within grazing treatments. Individual animal response as measured by average daily gains was similar for grazing treatments as well as for Empire and Viking birdsfoot trefoils. Empire was found to be a more persistent pasture legume than Viking. Feeder lambs produced more animal product per hectare than yearling steers.