Grazing Frequency Research Articles

Soil acidification and P, K, Ca and Mg budget as affected by sheep grazing and crop rotation in a long-term integrated crop-livestock system in southern Brazil

The insertion of the animal component into the crop production system can alter the nutrient dynamics and, consequently, the soil fertility status over time. This change occurs differently according to the arrangement adopted, depending on both, the intensity and frequency of animal grazing, as well as the crop rotation system. This study was carried out aiming to evaluate the effect of sheep grazing intensity and frequency during the winter period and the crop rotation in the summer period on the (i) temporal evolution and vertical distribution of soil chemical properties, and (ii) on the nutrient (phosphorus – P, potassium – K, calcium – Ca, and magnesium – Mg) budget. The experiment was established in 2003, in a subtropical Acrisol in southern Brazil, arranged in a randomized block design with split plots. The treatments were two grazing intensities (moderate and low), two stocking methods (continuous and rotational), subdivided into two crop rotation systems (monoculture - soybean/soybean and crop rotation soybean/maize). Temporal variation of soil pH, exchangeable aluminum (Al), Ca and Mg, available P and K, base saturation, Al saturation, and cation exchange capacity (CEC) were evaluated in samples collected in 2003, 2010, 2015 and 2017, corresponding to 0, 7, 12 and 14-years after the beginning of the experiment. The vertical distribution (0–5, 5–10, 10–20, 20–30 and 30–40 cm) of these chemical properties were also evaluated 14-years after the beginning of the experiment (2017). The nutrient budget in the soil was calculated based on the initial and final available/exchangeable contents in the 0–10 cm soil layer and the inputs (fertilizers) and outputs (exportation by grain and meat) of nutrients. >95% of P, K, Ca and Mg were exported by grains and <5% by sheep meat. There was an intense acidification of the soil over the 14-years of experiment as shown by the decrease of soil pH and base saturation, and the increase of Al saturation. Crop rotation with soybean/maize increased CEC up to 5 cm soil depth and increased the available K content up to 40 cm soil depth. The available K budget was more negative in soybean monoculture due to higher grain exportation. Integrated crop-livestock system involving low grazing intensities and rotational stocking methods, coupled with crop rotation in the summer, was more efficient in the use of nutrients.

Cattle select against the invasive grass tall fescue in heterogeneous pastures managed with prescribed fire

AbstractTall fescue (Festuca arundinacea) is a Eurasian forage grass extensively planted in the United States. However, an endophytic fungus in tall fescue, Epichloë coenophiala, causes health problems in cattle. We predicted that cattle prefer to graze alternative forages when available. We also predicted that cattle use tall fescue more intensively in recently burned areas, as fire can increase forage quality. We tested these predictions in four diverse‐forage pastures in Iowa, comparing use by cattle of tall fescue and four alternative forages (non‐fescue cool‐season grasses, native warm‐season grasses, non‐leguminous forbs and legumes) to their availabilities at the pasture scale. We also examined how tall fescue influences the distribution of grazing at a fine scale (0.1‐m2 quadrats). Tall fescue was the most abundant forage (46% of plants), but composed only 26% of grazed vegetation. In contrast, legumes composed 12% of available forage but 25% of grazed vegetation. Other forages were used in proportion to availability. At a fine scale, total grazing frequency (proportion of plants grazed) was lower in quadrats containing abundant tall fescue, and higher in quadrats with abundant warm‐season grasses. Grazing frequency of tall fescue and other cool‐season grasses was greatest in recently burned quadrats, but total grazing frequency did not increase after burning. Our results show that although cattle graze tall fescue, particularly following burns, they limit their use of this grass. Given that tall fescue is underused, creates health risks for cattle, and degrades wildlife habitat quality, it may be advisable to reduce tall fescue in pastures.

The short inventory of grazing (SIG): development and validation of a new brief measure of a common eating behaviour with a compulsive dimension

BackgroundGrazing, the repetitious and unplanned eating of small amounts of food with or without a sense of loss of control (LOC), is an eating pattern of recent interest which is highly prevalent in eating disorders and obesity. The current study aimed to (1) assess psychometric properties of a short inventory of grazing (SIG), consisting of a “grazing in general” item and a “compulsive/LOC grazing” item and (2) examine associations between compulsive and non-compulsive grazing and body mass index (BMI), eating disorder psychopathology, distress and health-related quality of life.MethodsParticipants recruited from a university and the community (n = 227; 75.3% female; age = 25.00 (9.88; 17.58–57.17) years; BMI = 23.24 (4.91, 14.20–46.06) kg/m2) completed an online test battery including the SIG. Parametric and non-parametric statistics were computed to assess internal consistency, test-retest reliability and construct validity, to test associations between the SIG and the other study variables, and to examine between-group differences.ResultsThe SIG demonstrated appropriate psychometric properties. Results indicated that both grazing in general and low-frequency LOC grazing are common; however, LOC grazing of moderate-severe frequency and/or associated with marked distress is unusual. Frequency of LOC grazing, but not grazing in general, was significantly associated with higher BMI, psychological distress, compensatory behaviours and lower mental health-related quality of life. The presence of compulsive grazing was also associated with eating disorder caseness and binge-type eating disorder diagnostic groups.ConclusionsResults support the positioning of “compulsive” LOC grazing on a continuum of problematic eating. The SIG is a parsimonious measure of this eating pattern of emergent interest.

A preliminary investigation comparing the frequency of grazing and movement behavior between a track paddock system and a conventional paddock system

A preliminary investigation comparing the frequency of grazing and movement behavior between a track paddock system and a conventional paddock system

Phenotypic Plasticity and Other Forage Responses to Grazing Management of Ecoturf Rhizoma Peanut

Forage–livestock systems in the southeastern United States are based on N‐fertilized perennial grass pastures, with minimal legume contribution. The legume rhizoma peanut (RP, Arachis glabrata Benth.) can persist and spread in grazed mixtures with C4 grasses, and Ecoturf RP is of particular interest because it is relatively decumbent and may vary its growth habit in response to defoliation management. The objective was to quantify effects of grazing frequency and intensity of Ecoturf on herbage accumulation (HA), canopy characteristics, storage organ mass, and total nonstructural carbohydrate (TNC) concentration. Treatments were the factorial combinations of three levels of regrowth interval (RI; 1, 4, and 7 wk) between grazing events and two levels of post‐grazing stubble height (SH; 4 and 8 cm). For the 4‐cm SH, HA increased from 8.4 to 10.5 Mg ha−1 in 2015 and from 9.8 to 13.6 Mg ha−1 in 2016 as RI decreased from 7 to 1 wk. The effect of RI was less pronounced for the 8‐cm SH. When grazed to a 4‐cm SH, herbage bulk density and post‐grazing leaflet mass increased linearly as RI decreased from 7 to 1 wk in both years. Changes in root‐rhizome mass and TNC pool during 2 yr of grazing were not affected by SH or RI. Ecoturf adapted to frequent, close grazing by increasing herbage bulk density and positioning leaves close to the soil surface, allowing rapid regrowth after defoliation without depleting reserves. Ecoturf is tolerant of a range of grazing strategies, showing promise for use in pastures.

Sensitivity of Winter-Active Lucerne (Medicago sativa L.) to Different Grazing Regimes

Lucerne (alfalfa; Medicago sativa L.) is the key forage for grazing in dryland temperate regions around the world. While rotational grazing of lucerne is recommended, in southern Australia the intervals between grazing events are often chosen in an opportunistic manner, to meet livestock production targets and utilise excessive spring and summer growth. To assess whether the persistence of lucerne is sensitive to variations in rotational grazing management practice, we report on an experiment with four sheep grazing treatments that was conducted for 2.5 years, including three summers, in southern New South Wales. The grazing management treatments were a crash-grazing control, frequent grazing, feed-based rotational grazing and time-based rotational grazing, replicated four times. The number of grazing events, percentage of time under grazing, lucerne top dry matter (DM) at the beginning and end of grazing periods and plant density were measured. The results relating to number of grazing events, percentage of time grazing and DM removed during grazing indicated that four grazing practices had been achieved. The treatments all had significant periods of rest for at least 73% of time and were empirically different in their approach but resulted in similar grazing pressures, in terms of overall pasture removed during grazing. Nevertheless, there was little difference in lucerne densities between grazing treatments over the life of the experiment. We conclude that there is flexibility in the rotational management of grazed lucerne provided adequate rest periods are part of the management program.

Attribution of explanatory factors for change in soil organic carbon density in the native grasslands of Inner Mongolia, China

The variation in soil organic carbon density (SOCD) has been widely documented at various spatial and temporal scales. However, an accurate method for examining the attribution of explanatory factors for change in SOCD is still lacking. This study aims to attribute and quantify the key climatic factors, anthropogenic activities, and soil properties associated with SOCD change in the native grasslands of Inner Mongolia, China, by comparing data between the 1960s and the 2010s. In 2007 and 2011, we resampled 142 soil profiles which were originally sampled during 1963–1964 in the native grasslands of Inner Mongolia. SOCD was determined in A horizon (eluvial horizon) of the soil. We selected the explanatory factors based on a random forest method, and explored the relationships between SOCD change and each of the explanatory factors using a linear mixed model. Our results indicated that the change in SOCD varied from the east to the west of Inner Mongolia, and SOCD was 18% lower in the 2010s than in the 1960s. The lower SOCD in the 2010s may primarily be attributed to the increasing in mean annual water surface evaporation, which explained approximately 10% and 50% of the total variation and explainable variation in the change in SOCD, respectively. The sand content of the soil is also a significant explanatory factor for the decrease in SOCD, which explained about 4% and 21% of the total variation and explainable variation in the change in SOCD, respectively. Furthermore, the collection of quantitative information on grazing frequency and duration may also help to improve our understanding of the anthropogenic factors that govern the change in SOCD.

Grazing every month minimizes size but boosts photosynthesis in Stipa grandis in the steppe of Inner Mongolia, China

In order to explore the effects of grazing frequency on functional traits and to test whether Stipa gandis has compensatory photosynthesis during the frequent grazing period, we investigated morphological traits, biomass allocation, photosynthetic traits, and chlorophyll fluorescence parameters of the species in Inner Mongolia, China. The grazing frequency treatments included fencing (T0), grazing in May and July (T1, i.e., two months per year) and grazing from May to September (T2, i.e., continuous five months per year). Results indicate that T1 and T2 treatments did not affect individual biomass, but T2 treatment negatively affected individual size, i.e., plant height, stem length, and leaf length. Physiological traits of S. grandis were significantly affected by grazing, year, and their interaction. In July 2014 (i.e., dry environment and low relative humidity), the photosynthetic rate, transpiration rate and water use efficiency were highest under T2 treatment, which was caused by the increase in stomatal conductance. However, in July 2015 (i.e., wet environment and high relative humidity), the photosynthetic rate and water use efficiency were higher under T1 and T2 treatments, which were caused by the increase in actual quantum efficiency and stomatal conductance. Our results implied that under frequent grazing treatment, S. grandis had small height and efficient compensatory photosynthesis, which promoted its resistance to severe grazing.

Effects of grazed stubble height and timing of grazing on resprouting of clipped oak seedlings

Although a number of studies have investigated the effects of grazing frequency and intensity on seedling resprouting, the influence of grazed stubble height and timing of grazing on oak seedlings is little known. In the present study, we aimed to explore the effects of grazed stubble height and timing of grazing on the seedling resprouting of twelve oak species. By imitating herbivory grazing, we artificially clipped the shoots to different stubble heights and at different development stages of seedlings to see the resprouting capability of 12 oak species. Our study showed that both grazed stubble height and timing of grazing posed significant influences on resprouting of clipped oak seedlings. Our results indicate that the attached cotyledons play an important role in supporting resprouting of the clipped oak seedlings. Moreover, oaks bearing larger acorns show higher ability to counter herbivory grazing than those producing smaller ones. Higher stubbles grazed by herbivores exert less negative impacts on resprouting of oak seedlings than lower stubbles. Earlier grazing is less harmful to damaged oak seedlings compared with later grazing by herbivory animals.

Effects of livestock grazing on rangeland biodiversity: A meta-analysis of grouse populations.

Livestock grazing affects over 60% of the world's agricultural lands and can influence rangeland ecosystem services and the quantity and quality of wildlife habitat, resulting in changes in biodiversity. Concomitantly, livestock grazing has the potential to be detrimental to some wildlife species while benefiting other rangeland organisms. Many imperiled grouse species require rangeland landscapes that exhibit diverse vegetation structure and composition to complete their life cycle. However, because of declining populations and reduced distributions, grouse are increasingly becoming a worldwide conservation concern. Grouse, as a suite of upland gamebirds, are often considered an umbrella species for other wildlife and thus used as indicators of rangeland health. With a projected increase in demand for livestock products, better information will be required to mitigate the anthropogenic effects of livestock grazing on rangeland biodiversity. To address this need, we completed a data‐driven and systematic review of the peer‐reviewed literature to determine the current knowledge of the effects of livestock grazing on grouse populations (i.e., chick production and population indices) worldwide. Our meta‐analysis revealed an overall negative effect of livestock grazing on grouse populations. Perhaps more importantly, we identified an information void regarding the effects of livestock grazing on the majority of grouse species. Additionally, the reported indirect effects of livestock grazing on grouse species were inconclusive and more reflective of differences in the experimental design of the available studies. Future studies designed to evaluate the direct and indirect effects of livestock grazing on wildlife should document (i) livestock type, (ii) timing and frequency of grazing, (iii) duration, and (iv) stocking rate. Much of this information was lacking in the available published studies we reviewed, but is essential when making comparisons between different livestock grazing management practices and their potential impacts on rangeland biodiversity.

Herbage accumulation, plant-part composition and nutritive value on grazed signal grass (Brachiaria decumbens) pastures in response to stubble height and rest period based on canopy light interception

Signal grass (Brachiaria decumbens cv. Basilisk, syn. Urochloa decumbens Stapf R.D. Webster) has been widely grown in the Brazilian tropics over the last 40 years, but management recommendations have been largely empirical and not based on canopy targets. This study was designed to characterise and explain the impact of canopy-based grazing strategies on herbage accumulation, plant-part composition, and nutritive value of signal grass. Treatments were factorial combinations of two stubble heights, 5 cm (SH5) and 10 cm (SH10), and two grazing frequencies, grazing initiated when 95% (LI95) and 100% (LI100) of incoming light was intercepted by the canopy. Rest periods were imposed during summer and autumn of both experimental years. Leaf blade accumulation was greater for LI100 than LI95 (9.5 v. 8.8 t/ha) associated with increased stem accumulation (4.6 v. 3.5 t/ha for LI100 v. LI95). The SH10 pastures produced more stem than SH5 pastures (4.4 v. 3.6 t/ha), with no difference in leaf blade accumulation. In general, SH10 pastures had more residual leaf blade mass post-graze, whereas SH5 pastures combined with higher grazing frequency (SH5-LI95) became more prostrate over time, increasing leaf blade proportion in post-graze forage. Over time, stubble height had more influence than grazing frequency on leaf blade proportion at pre-graze, and SH5 pastures had leafier canopies than SH10 pastures. Digestibility was less under LI100, especially when associated with SH5 stubble (SH5-LI100), regardless of season of the year. To provide optimal leaf blade yield and overall forage digestibility, particularly during warm, rainy seasons, defoliation of signal grass should include pre-graze height varying from 18 to 30 cm (95–100% of light interception) and mean stubble height close to 10 cm.

Improved grazing activity of dairy heifers in shaded tropical grasslands

ABSTRACT: Trees in the production systems can effectively reduce hot weather-induced stress in the Brazilian Midwest. High temperatures cause changes in animals daily routine, and trees into pastures can promote benefits. The aim of this research was to evaluate the behavior of dairy heifers in silvopastoral systems in the state of Mato Grosso, Brazil. A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein/Zebu), 350kg average weight, was evaluated over three seasons. Piatã grass was managed under three shade levels: full-sun, moderate-shade, and intensive-shade provided by 10 to 12m high Eucalyptus trees. Behavior data were collected every 15 minutes from 8:30h to 16h. Shade availability significantly impacted heifer behavior, mainly affecting grazing frequency and time during the hottest hours. Grazing behavior was affected by shade levels during the different seasons. Heifers showed preferred grazing times. Heifers in the intensive-shade system visited shady areas during the hottest hours throughout the seasons. Heifers in the full sun-system avoided grazing during the warmer times, ceasing feeding activities. Our results from the Brazilian Midwest showed that shade availability causes breed heifers to change their daily routine.

Nutritive value of Mulato grass under di erent grazing strategies

The objective of this study was to evaluate the e ect of grazing frequencies and intensities on herbage accumulation and nutritive value of Brachiaria hybrid 36061 cv. Mulato. Grazing frequencies of 14, 21 and 28 d and intensities of 9 to 11 and 13 to 15 cm were studied under a randomized block design in a 3x2 factorial arrangement with three replicates. Herbage accumulation, morphological components, in situ digestibility (DIGDM), crude protein (CP), neutral detergent ber (NDF) and acid detergent ber (ADF) were evaluated. Annual yield distribution was 55, 28 and 16 % during the rainy, northern cold-front and dry seasons, in the rst cycle, with the highest annual accumulation of 12 310 kg DM ha−1 obtained by grazing every 28 d. The highest DIGDM and PC were obtained by grazing at an intensity of 9 to 11 cm every 14 d in all seasons. However, grazing at an intensity of 13 to 15 cm every 28 d resulted in greater forage yield with a high concentration of NDF and ADF. In conclusion, the greatest herbage accumulation, NDF and ADF were recorded by grazing of 13 to 15 cm in height every 28 d in both cycles. DIGDM and CP had high values by grazing of 9 to 11 cm every 14 d.

Host plant density and patch isolation drive occupancy and abundance at a butterfly's northern range margin.

Marginal populations are usually small, fragmented, and vulnerable to extinction, which makes them particularly interesting from a conservation point of view. They are also the starting point of range shifts that result from climate change, through a process involving colonization of newly suitable sites at the cool margin of species distributions. Hence, understanding the processes that drive demography and distribution at high‐latitude populations is essential to forecast the response of species to global changes. We investigated the relative importance of solar irradiance (as a proxy for microclimate), habitat quality, and connectivity on occupancy, abundance, and population stability at the northern range margin of the Oberthür's grizzled skipper butterfly Pyrgus armoricanus. For this purpose, butterfly abundance was surveyed in a habitat network consisting of 50 habitat patches over 12 years. We found that occupancy and abundance (average and variability) were mostly influenced by the density of host plants and the spatial isolation of patches, while solar irradiance and grazing frequency had only an effect on patch occupancy. Knowing that the distribution of host plants extends further north, we hypothesize that the actual variable limiting the northern distribution of P. armoricanus might be its dispersal capacity that prevents it from reaching more northern habitat patches. The persistence of this metapopulation in the face of global changes will thus be fundamentally linked to the maintenance of an efficient network of habitats.

Re‐visiting historical semi‐natural grasslands in the Apennines to assess patterns of changes in species composition and functional traits

AbstractQuestionsTo what extent have semi‐natural grassland plant species composition and functional traits changed during the past five decades? Which are the main directions of change? Which environmental, management and landscape factors have determined these changes?LocationCentral and southern Apennines of Italy.MethodsIn 2013–2014, we used a stratified random sampling design to revisit 132 semi‐natural grasslands originally sampled between 1966 and 1992. The exact locations of the historical plots were not available but they were associated with detailed vegetation maps. Plots were divided in 17 groups based on study area and original community type. To assess changes in species composition we ran PERMANOVA and RDA. The extent of change was estimated by comparing each new plot with the quantitative species pool of the corresponding historical group; species composition changes were calculated using Bray‐Curtis coefficient, and shifts in functional traits were quantified as differences in community‐weighted means. These measures of change were used as response variables in mixed effects models including climate, topography, management and landscape metrics as explanatory variables.ResultsThe largest changes were related to successional dynamics, which occurred mainly in grasslands developing at low altitude and in the flattest sites where the soil organic horizon was relatively thick. Colonization by shrubs and trees was facilitated by high soil pH and amount of adjacent forests. Also, management factors affected the patterns of shifts in species composition and functional traits: grazing intensity was negatively related to the degree of compositional change as well as to the abundance of woody species, whereas the increase of species associated with frequent grazing disturbance was found at sites with higher values of soil salinity.ConclusionsApennine semi‐natural grasslands have undergone substantial changes in species composition and functional traits during recent decades. Compositional changes mainly indicated successional dynamics, likely following a decrease in grazing intensity, whereas some more accessible grasslands experienced an increase in disturbance‐tolerant species. The combination of the re‐visitation approach with functional traits allowed us to clarify different directions of changes in species composition, adding information on the ecological processes related to these changes.

Effects of holistic grazing management on milk production, weight gain, and visitation to grazing areas by livestock and wildlife in Laikipia County, Kenya

Grazing is an important management tool for maintaining healthy ecosystems and improving rangelands productivity. However, its effectiveness for this purpose is dependent on timing and frequency of grazing, as well as the type of animal. Understanding the effects of grazing management on rangeland ecosystems is critical in ensuring sustainable use of grazing resources and enhanced livestock production. This study assessed the effects of holistic grazing on animal productivity and range use pattern in Laikipia County of Kenya. The results revealed that the average milk yields (106 ± 20.1) of animals in holistic grazing areas (HGA) were significantly (p < 0.05) higher than those in traditional grazing areas (TGA) (101 ± 20.1).Weight gain of animals in HGA was significantly (0.13 ± 0.01) higher as compared to those in TGA (0.07 ± 0.01). The number of livestock grazing was significantly (p < 0.05) higher in HGA (74 ± 10 %) than those in TGA (57 ± 10 %). In addition, the number of wildlife grazing was significantly (p < 0.05) higher in HGA (74 ± 18 %) than in TGA (32 ± 18 %). The results indicate that holistic grazing management has the potential to improve animal performance, as well as condition of range areas as evident in the preference shown by frequent visits to HGA by both livestock and wildlife.

Performance of Limpograss Breeding Lines under Various Grazing Management Strategies

Limpograss [Hemarthria altissima (Poir.) Stapf et C.E. Hubb.] is a C4, perennial, stoloniferous grass that is well adapted to poorly drained soils and grows throughout frost‐free periods during winter in southern Florida. Its use has increased rapidly in recent decades, but nearly all area in cultivation is planted with one cultivar, ‘Floralta’. A breeding program was initiated to develop improved alternatives to Floralta, resulting in a group of breeding lines requiring evaluation under grazing. The objective of this research was to evaluate the performance of five limpograss breeding lines (1, 4F, 10, 32, and 34) under combinations of grazing frequency and intensity. During the 2012 and 2013 growing seasons, those lines, plus Floralta, were tested at two pre‐grazing canopy light interception levels (80 and 95%), that triggered the initiation of each grazing event, and two post‐grazing stubble heights (20 and 30 cm). Lines 4F and 10 had greater herbage accumulation, apparent herbage harvested, and persistence than Floralta. Initiation of grazing at 80% canopy light interception resulted in more frequent grazing events, a longer grazing season, shorter pre‐grazing canopy height, greater leaf percentage, less herbage bulk density, and greater herbage crude protein concentration compared with 95% canopy light interception. These data support cultivar release of breeding lines 4F and 10 and suggest that persistence and efficient utilization of limpograss under rotational stocking can likely be achieved by initiating grazing at a pre‐grazing canopy height of ∼60 cm, well before 95% canopy light interception, and by ending grazing at a post‐grazing canopy height of ∼30 cm.

Effects of past and present livestock grazing on herpetofauna in a landscape‐scale experiment

Livestock grazing is the most widespread land use on Earth and can have negative effects on biodiversity. Yet, many of the mechanisms by which grazing leads to changes in biodiversity remain unresolved. One reason is that conventional grazing studies often target broad treatments rather than specific parameters of grazing (e.g., intensity, duration, and frequency) or fail to account for historical grazing effects. We conducted a landscape-scale replicated grazing experiment (15,000 km2 , 97 sites) to examine the impact of past grazing management and current grazing regimes (intensity, duration, and frequency) on a community of ground-dwelling herpetofauna (39 species). We analyzed community variables (species richness and composition) for all species and built multiseason patch-occupancy models to predict local colonization and extinction for the 7 most abundant species. Past grazing practices did not influence community richness but did affect community composition and patch colonization and extinction for 4 of 7 species. Present grazing parameters did not influence community richness or composition, but 6 of the 7 target species were affected by at least one grazing parameter. Grazing frequency had the most consistent influence, positively affecting 3 of 7 species (increased colonization or decreased extinction). Past grazing practice affected community composition and population dynamics in some species in different ways, which suggests that conservation planners should examine the different grazing histories of an area. Species responded differently to specific current grazing practices; thus, incentive programs that apply a diversity of approaches rather than focusing on a change such as reduced grazing intensity should be considered. Based on our findings, we suggest that determining fine-scale grazing attributes is essential for advancing grazing as a conservation strategy.

Year-round horse grazing supports typical vascular plant species, orchids and rare bird communities in a dry calcareous grassland

Large herbivores, such as robust horse breeds, are increasingly used to develop and maintain open habitats. However, their use on calcareous grasslands has rarely been tested. On the one hand, conservationists fear an unequal use of the pasture with partial abandonment, encroachment or reduced ground light conditions, as well as partial over-grazing with negative effects as soil erosion, latrines, grazing lawns, disturbance to the ground or shrub nesting bird species due to enhanced trampling, or impairing of typical plant species. On the other hand, it is well known that large herbivore grazing is an economical alternative where traditional sheep grazing is no longer profitable. From 2010–2014, we studied horse activity (Koniks), habitat parameters (percent dung, shrub, short vegetation, and bare ground cover), and frequency of orchids and birds using a raster approach within a 90ha year-round pasture. Vegetation composition and structure was sampled on 25m2 plots from 2009 to 2014.All habitat parameters indicated a relatively equal horse utilization of the whole pasture and neither latrines nor partial abandonment were observed. After five years, shrub encroachment on the whole pasture was restricted from 13.7 (±17.0) to 12.0% (±15.3). Vegetation litter was reduced by 60% and the mean number of species typical for dry calcareous grasslands increased by one third on the 25m2 plots. The studied orchid species as well as the target bird species were not impaired by the grazers and plots not occupied by these species showed an equal or even lower grazing frequency. The positive grazing effects such as enhanced site conditions seem to outweigh the potentially negative effects through trampling or grazing. We conclude that in large-scale calcareous grasslands low-intensity year-round grazing with large herbivores is suitable for maintaining and even improving species diversity.

Sward Structure, Light Interception, and Rhizome‐Root Responses of Rhizoma Peanut Cultivars and Germplasm to Grazing Management

‘Florigraze’ rhizoma peanut (RP; Arachis glabrata Benth.) is a persistent forage legume for the US Gulf Coast, but peanut stunt virus (Cucumovirus spp.) reduces herbage accumulation (HA). Less susceptible germplasms and cultivars of RP have been released, but their responses to grazing management are not known. The objective was to quantify aboveground and belowground sward responses to grazing management of RP entries differing in growth habit to explain HA and persistence. Treatments were all combinations of four RP entries (Florigraze, ‘UF Peace’, ‘UF Tito’, and germplasm Ecoturf), two grazing intensities (50 and 75% removal of pre‐grazing canopy height), and two regrowth intervals (3 or 6 wk). UF Tito swards were the tallest and Ecoturf the shortest, but Ecoturf had greater herbage bulk density than any entry. Pre‐grazing leaf percentage was greatest for Ecoturf (61%); there were no differences among the upright entries (56–57%). Ecoturf (0.88) and UF Tito (0.76) had greater post‐grazing residual leaf area index than Florigraze (0.61). Ecoturf and UF Tito had greater rhizome‐root mass (4450 and 4110 kg ha‐1, respectively) than Florigraze and UF Peace (3490 and 3170 kg ha‐1, respectively). Pre‐grazing light interception was greater for the 6‐ than 3‐wk grazing frequency (85 vs. 70%, respectively), and rhizome‐root mass followed a similar pattern (3990 vs. 2730 kg ha‐1, respectively). Sward structure, leaf, and rhizome‐root data explain lack of differences among entries in HA, excellent persistence of Ecoturf and UF Tito, and generally greater HA and persistence for 6‐ vs. 3‐wk regrowth intervals.