High Stocking Rates Research Articles

Performance evaluation of Uruguayan dairy farming systems

In the last 20 years, the Uruguayan dairy sector has intensified and concentrated on higher cow productivity, maintaining the herd, smaller land, and fewer farms. The research aims are to identify, describe, and evaluate the economic performance of different types of dairy farms. A sample of 284 farms from the National Dairy Farm Survey 2019 was used (representing 2,021 dairies); using k-means Cluster analysis with the variables: cow productivity, stocking rate, land productivity, concentrate, roughage, and grass intake (per hectare). We identified six farm types, three with high participation of grass in the cows’ diets (HG, 60% or more of dry matter intake), and the other three focused on supplementation (HS); with three intensification levels (1-low, 2-intermediate and 3-high productivity per ha). For the 2018/19 season three types of farms presented the best economic performance (HS-3, HG-3, and HG-2), including those with the highest stocking rate and grass intake per hectare, and more than USD 225 Economic Farm Surplus (EFS) per hectare with the lower unitary cost. Other two types exhibited intermediate economic performance (HS-2 and HG-1) with EFS close to zero and unitary cost similar to price. And one type (HS-1) displayed the worst economic performance, with negative indicators and the largest number of farms with very low productivity.

A narrative review of factors affecting the welfare of dairy cows in larger Australasian pasture-based production systems

On the basis of current growth trajectories, pasture-based dairies of the future are likely to be bigger, have higher stocking rates and feed more concentrate to cows. This review uses the five-domains framework to consider risks to the welfare of dairy cows in these larger intensified pasture-based production systems. The factors considered in this review can be broadly categorised as (1) emerging welfare risks that can be managed, (2) emerging welfare risks that require research to be managed, or (3) persisting and/or exacerbated welfare risks. First, large herds could be subject to welfare risks associated with more stock per labour unit, longer milking times and longer distances walked to and from the dairy. To counter this, the time that cows in large herds spend off pasture can be reduced by splitting the herd into several more manageable groups, and animal-monitoring technologies can help identify health challenges with a reduced stockperson to animal ratio. Cow body condition and productivity can be maintained at high stocking rates by improving pasture production and feeding a higher proportion of concentrate. The risk of ruminal acidosis may then be reduced by appropriate transition feeding regimes and rumen buffers. Second, ensuring social stability and reducing competition may become difficult as herd sizes increase and feeding becomes more intensive. The resulting variability in feed intake, increased agonistic behaviour and social stress present emerging risks to cow welfare. Research is needed to better understand the social behaviour of cows in large intensive pasture-based herds, and how the design of the pre-milking area, the feeding pad and pasture feeding regimes (i.e. quantity and timing of pasture allocation) can improve accessibility for more vulnerable animals. Finally, intensive pasture-based dairies of the future will continue to face welfare challenges relating to lameness, mastitis and cull-cow management, whereas risks due to environmental exposure may be exacerbated by the removal of shelterbelts to facilitate irrigation. These require continued efforts in research (e.g. ways of incorporating shelter into intensive grazing systems), development (e.g. pathway to market for aged beef) and extension (e.g. improved record keeping and benchmarking of lameness and mastitis).

Bioeconomic and sustainability performance of dairy-beef steer and heifer production systems differing in stocking rate

There is little published research on dairy-beef heifer systems or comparisons of heifer and steer dairy-beef production. Furthermore, given its impact on the productivity and economics of dairy-beef systems, any comparison of gender must also consider potential interactions with stocking rate (SR). The objective of this study was to evaluate the variability of physical and economic performance, greenhouse gas emissions, feed-food competition and pasture land-use of dairy-beef production steer and heifer systems at differing stocking rates. Performance data from a two (gender: Steers and Heifers) x two (SR: Low and High) x two (breed-types: Early-maturing (EM) and Late-maturing (LM) factorial experiment was used to parameterize a bio-economic farm systems model. Low SR animals were heavier, had higher fat scores and better conformed at slaughter. High stocking rate resulted in greater carcass output per hectare and subsequently were, on average, 22 % more profitable than their Low SR counterparts. Late-maturing animals were found to be more profitable than early-maturing, and steers were more profitable than heifers. GHG emissions of the eight treatments investigated ranged from 10.7 to 17.7 kgs of carbon dioxide equivalents (kg CO2eq) per kilogram of carcass weight produced, with both High SR and heifer systems having lower GHG emissions per kg of product than their Low SR and steer counterparts. Human edible protein efficiency was only favorable for the steer systems. High SR systems had, on average, lower land use per kg of product than their Low SR counterparts. Results from this study indicate that no single treatment was optimal across the range of performance metrics considered.

Evolving Dairy Cattle Systems in Chile: Structural Shifts and Adaptation Strategies.

This study examines the structural and geographical changes in Chile's dairy cattle systems from 1997 to 2021, using data from agricultural censuses. It focuses on variables like animal stocks, herd sizes, pasture utilization, and stocking rates, analyzed through descriptive statistics, multivariable analysis, and geographical mapping. The findings show a significant decrease in dairy farms (-69%) and dairy cattle stocks (-25.4%), with regional disparities: southern farms increased in importance while central farms declined. There is a trend towards intensification, with higher stocking rates and larger herd sizes. Grassland utilization shifted, with a decrease in natural pastures and an increase in improved and sown pastures. The study identifies four typological groups based on stocking rates, dimensions, and pasture use, reflecting distinct evolutionary paths influenced by climate change, land use, economic dynamics, and technology. Geographical analyses highlight regional variations. This research provides insights into the dynamics of Chile's dairy farming sector and its sustainability challenges and opportunities amidst changing environmental and socioeconomic conditions.

Human-made small reservoirs alter dryland hydrological connectivity

Our research shed light on the distribution, number, and impact of small reservoirs (SRs) on rural dryland water availability and hydrology. We measured the storage capacity, relationship to environmental variables, and effects on the hydrology of all SRs (1225) found within a Sonoran Desert basin. SRs were predominantly associated with Tertiary conglomerates and Quaternary alluvium and were less common in extrusive rocks. A higher concentration of reservoirs was observed in woodlands and thornscrub, with fewer SRs in desertscrub than anticipated by chance. The average size of these small reservoirs was 5205 m2. All SRs reached full storage capacity during the rainy season, but only 20 % retained water throughout the year. Furthermore, our analysis revealed a significant impact on basin connectivity, with only 41 % of superficial drainage being connected. Notably, two large dams were found to disconnect 26 % of the basin. Despite their relatively small watershed footprint, SRs were found to be responsible for disconnecting 33 % of the total basin area. The magnitude of rainfall events played a crucial role in connectivity dynamics. Low-magnitude rainfall events led to sediment retention in SRs, reducing connectivity, while moderate events increased connectivity by repeatedly filling SRs. High-magnitude events reshaped channels, transported sediments, and enhanced overall connectivity. The concentration of SRs in the upper reaches of the basin coincides with higher stocking rates. SRs, are relatively recent additions to desert landscapes, impacting ecological dynamics. Their construction and use fragment an already disjointed basin, thereby restricting water retention by larger dams. These findings emphasize the intricate relationship between SRs, rainfall occurrences, and the overall connectivity of the basin. We underline that documenting the cumulative effects of SRs yields valuable insights for managing water resources in arid ecosystems.

Strategic control of the cattle tick Rhipicephlaus microplus applied to rotational and silvopastoral grazing systems in subtropical areas.

This work evaluated if strategic control based on no more than three or four annual treatments is useful to control Rhipicephalus microplus infestations on cattle when it is applied to intensive rotational grazing and silvopastoral systems with high stocking rates in subtropical areas. In the intensive rotational grazing system, three annual treatments with chemical acaricides were applied on cattle in two different schemes: between spring and early summer and from late winter and late spring. Strategic control based on three treatments with chemical acaricides from late winter to late spring plus an additional fourth treatment in summer was tested in the silvopastoral system. In the intensive rotational grazing systems, the control schemes allow to reach a significant reduction in the tick load on cattle considering a time interval from spring to autumn. However, the efficacy levels were not high enough in some specific moments, namely, the tick counts of summer and autumn (there were not significant differences between treated and control groups). The scheme evaluated in the silvopastoral grazing system yielded better results than those tested for the intensive rotational system, because significant differences in tick load between treated and control groups were observed in all post-treatment counts and when the analysis was performed for the whole study period. However, values of efficacy in the count-by-count comparison were disparate, ranging from 64.1 to 99.7. Although the efficacy values obtained in the silvopastoral system were better than those of the rotational grazing systems, the total tick load on treated cattle in autumn was not low enough (mean abundance values 25.14 and 38.14). Ticks were more evenly distributed among hosts in late summer and autumn than in spring or early summer, where few hosts carry most of the ticks. Some management strategies as intensive rotational systems or silvopastoral structures can lead to a more efficient forage use, but they imply greater tick challenge than in extensive grazing systems. In these situations, the schemes of strategic control bases on three or four annual treatments should be complemented with additional tactical treatments in late summer or autumn.

High stocking rates effects in continuous season long grazing reduces the contribution of microbial necromass to soil organic carbon in a semi-arid grassland in Inner Mongolia

Livestock grazing strongly influences the accumulation of soil organic carbon (SOC) in grasslands. However, whether the changes occurring in SOC content under different intensities of continuous summer long grazing are associated with the changes in microbially-derived necromass C remains unclear. Here, we established a sheep grazing experiment in northern China in 2004 with four different stocking rates. Soil samples were collected after 17 years of grazing and analyzed for physical, chemical, and microbial characteristics. Grazing decreased SOC and microbial necromass carbon (MNC). Notably, grazing also diminished contributions of MNC to SOC. MNC declined with decreasing plant carbon inputs with degradation of the soil environment. Direct reductions in microbial necromass C, which indirectly reduced SOC, resulted from reduced in plant C inputs and microbial abundance and diversity. Our study highlights the key role of stocking rate in governing microbial necromass C and SOC and the complex relationships these variables.

Effects of grazing and climate change on aboveground standing biomass and sheep live weight changes in the desert steppe in Inner Mongolia, China

CONTEXTThe Stipa breviflora desert steppe ecosystem is fragile and sensitive to climate change and grazing disturbance. Previous studies have reported the effects of climate change and grazing on aboveground standing biomass of the plant community and sheep live weight, however, the interaction between climate change and grazing remains unclear. Process models have become ideal tools for the evaluation of the effects of grazing management practices under climate change. OBJECTIVEWe used the Soil-Plant-Atmosphere Continuum System (SPACSYS) model to investigate aboveground standing biomass and the live weight of sheep in the desert steppe of Inner Mongolia under future climate change scenarios and different grazing management. The results will be used to inform adaptive management strategies. METHODSThe grazing experiment consisted of four treatments: no grazing (0 sheep ha−1 half year−1), light stocking rate (0.91 sheep ha−1 half year−1), moderate stocking rate (1.82 sheep ha−1 half year−1), and high stocking rate (2.71 sheep ha−1 half year−1). We used observed data on soil temperature, soil volumetric water content, changes to sheep live weight, and aboveground standing biomass of plant community to provide parameterization and validation for the SPACSYS model. We then predicted aboveground standing biomass of the plant community and sheep live weight changes for different grazing management under three representative concentration pathways (RCP) scenarios (RCP 2.6, RCP 4.5, and RCP 8.5) from 2021 to 2100. RESULTS AND CONCLUSIONSModerate and high stocking rates decreased aboveground standing biomass and sheep live weight changes more than the light stocking rate. A light stocking rate can maintain higher aboveground standing biomass and sheep live weight as well as meet production requirements. Therefore, a light stocking rate is a potentially effective management approach to improve food production security and combat global climate change in the desert steppe. SIGNIFICANCEThe model can inform management strategies for grazing in the desert steppe under climate change, supporting efforts to maintain the stability of the steppe ecosystem and increase economic benefits, while also providing a theoretical basis for adaptive management in the desert steppe.

The effects of pastoral hill country natural landscape features and land management practices on nitrate losses and its potential attenuation for improved water quality

AbstractPastoral farming on hill country landscapes influences nitrogen (N) dynamics and its losses to freshwater. This study reviewed the current literature identifying key effects of pastoral hill country landscape features and land management practices on nitrate losses to receiving waters. The review also highlighted the potential effects of inherent landscape features on nitrate attenuation pathways for better water quality outcomes. Intensive land use activities involving high rates of fertiliser application, higher stocking rates and cattle grazing, relative to sheep grazing, are more likely to increase nitrate loss, especially on lower slopes. However, soils with a high carbon (C) storage capacity such as allophanic soils potentially limit nitrate loss via denitrification in subsoil layers. Hill country seepage wetlands also offer an opportunity to attenuate nitrate loss, though their efficacy is largely impacted by hydrological variations in their inflows and outflows. By enhancing the natural nitrate attenuation capacity of seepage wetlands, mapping and strategic use of high subsoil denitrification potential, effective riparian management, efficient fertiliser and grazing practices and the incorporation of these farm management strategies into Freshwater Farm Plans (FWFPs), wider environmental and farm productivity/profitability goals, including improved water quality, would be achieved on pastoral hill country landscapes.

Confinamento e semiconfinamento de cordeiras em um sistema integrado de produção: impactos na produção, infecção por nematódeos gastrointestinais e em variáveis sanguíneas

ABSTRACT: This trial evaluated the production performance, gastrointestinal nematode infection (GIN), and selected blood analytes, in Corriedale lambs during the finishing phase in an integrated crop-livestock system (ICLS) with 2 stocking rates. Fifty-two Corriedale lambs were divided into 4 groups: a semi confinement system with a low stocking rate (T1) for 70 days; a semi confinement system with a high stocking rate (T2) for 70 days; confinement for 28 days, followed by semi confinement with a low stocking rate (T3) for 42 days; and confinement for 28 days, followed by semi confinement with a high stocking rate (T4) for 42 days. Body weight, dry matter intake, blood collection, and faecal analysis of nematode eggs were performed for each animal. The stocking rates did not influence body weight gain for the semiconfined lambs (T1 and T2) or for the confined/semiconfined lambs (T3 and T4). All treatments had lower EPG counts at the end of the experimental period. The nematode genera identified during the experiment trial were Haemonchus and Trichostrongylus. There were no significant differences (P > 0.05) for packed cell volume, total plasma protein, and eosinophil means between treatments. These results suggested that the confinement followed by semi confinement in an ICLS, was an option for lamb production during the finishing phase which could be useful in reducing GIN without affecting the production performance.

Grazing-driven shifts in soil bacterial community structure and function in a typical steppe are mediated by additional N inputs

Herbivore grazing and nitrogen (N) fertilization affect soil microbial diversity and community composition both in direct and indirect pathways (e.g., via alterations in soil microenvironment and plant communities); however, their combination effects are still largely unexplored. We carried out a field study to investigate how soil abiotic properties, plant community composition and functional traits altered soil bacterial community structure and function in response to a long-term herbivore grazing (17-year sheep grazing with four stocking rates) and anthropogenic N inputs (6-year N addition with four levels) experiment. We show that a high stocking rate of 8.7 sheep ha−1 (SR8.7) decreased soil bacterial α- and β-diversity, while α- and β-diversity showed hump-shaped and saddle-shaped responses, respectively, with increasing N addition rate, reaching tipping points at the N application rate of 10 g N m−2 year−1 (N10). The synergistic effects of grazing and N addition induced the highest soil bacterial α-diversity at SR2.7 with N10. The contrasting effects of grazing and N addition induced higher soil bacterial β-diversity at SR8.7 with N20. Plant factors (e.g., aboveground biomass of Stipa bungeana and community-weighted mean carbon [CWM_C]), edaphic factors (e.g., soil moisture, pH, NO3−-N, and C:nutrients ratios) and their interactions were the most significant factors affecting the diversity and community composition of bacteria. Our structure equation model (SEM) shows that grazing-induced negative effects on soil pH and plant community composition indirectly increased the β-diversity of soil bacteria, while grazing-induced decreased CWM_C had positive effects on bacterial α-diversity and community structure. However, N addition indirectly increased β-diversity of soil bacteria via changes in soil NO3−-N and plant community composition, while N addition had negative impacts on bacterial α-diversity and community structure via variations in CWM_C. The interaction of grazing and N addition increased the complexity and stability of the bacterial network. Based on the KEGG database, grazing and N addition could accelerate the soil functional potential of C and N cycling. Our findings suggest that N application at a rate of <10 g N m−2 year−1 with a stocking rate of <5.3 sheep ha−1 could maintain the development of soil bacteria in supporting the most important ecosystem functions and services. Complex responses of soil microbes to grazing and N addition indicate the need for deeper investigations of the impacts of global change on microbial involvement in biogeochemical cycles.

Grazing intensity and nitrogen fertilization timing to increase soil organic carbon stock and nitrogen in integrated crop-livestock systems

ABSTRACT Integrated crop-livestock systems (ICLS) foster synergistic relationships to increase nitrogen (N) cycling and soil organic carbon (SOC) accrual in agricultural setups. This study evaluated how the grazing intensity and N fertilization (rates and timing) affect both SOC and N fractions, and soil organic matter chemical composition in an ICLS managed under no-tillage in an Oxisol, six years after initiation. The ICLS was compared to a nearby pasture (PA) and a native forest (NF). The treatments consisted of two grazing intensities: Low Sward Height (LH) and High Sward Height (HH) were maintained with high and low stocking rates, respectively. The HH varied between 0.20 and 0.60 m, and LH between 0.10 and 0.30 m according to the plant forage species throughout the experiment. Fertilization using 200 kg ha -1 N-urea, not splitting up, was conducted at two timings, either at the winter pasture establishment (autumn), about 35 days after sowing or during the summer cash crop cycle (spring). Total N amount per year, including both phases, pasture and cash crop was the same for all treatments. The SOC and N contents were assessed in soil and particulate organic matter (POM), while carbon (C) and N stocks were specifically determined in the soil. Soil organic matter composition was characterized by FTIR. The combination of HH and N fertilization during the pasture phase increased the content of C from 36.1 to 39.9 ± 0.7 g C kg -1 and of N from 2.7 to 3.2 ± 0.1 g N kg -1 . The SOC stocks varied from 37.3 to 41.1 ± 0.7 Mg C ha -1 , and the N stocks from 2.1 to 3.3 ± 0.1 Mg N ha -1 at 0.0-0.10 m soil layer. The SOC content of the POM and the soil organic matter chemical composition determined by FTIR were mainly affected by the grazing intensity. The HH led to an increased in C content within the POM fraction, reaching values of 51.6 ± 1 and 49.2 g C kg -1 , respectively to N crop fertilization and N pasture fertilization. Land-use changed how organic functional groups were stored in soil organic matter fractions. The NF had a greater abundance of aliphatic and phenol in the MAOM, while pasture and ICLS systems had greater aliphatic in the POM fraction. In ICLS, SOC accrual was positively associated with more recalcitrant organic functional groups of phenol, aromatic, and carbonyl C-O. The HH increases SOC accrual, while N-fertilization on pasture ensures adequate nutrition of plants and animals during the winter ICLS phase, at the same time as providing greater residual N for subsequent cash crops through enhanced catalyzed by ruminants. Therefore, grazing and fertilization management strategies should be considered to promote sustainable agriculture intensification with ICLS.

Grazing cover crops: How does it influence soils and crops?

AbstractGrazing cover crops (CCs) can potentially generate economic benefits, but how this practice affects soils and crop production compared with non‐grazed CCs is not well understood. We reviewed all published literature up to June 30, 2023, on grazing CCs to evaluate how this practice impacts soils and crop production and discuss potential factors that may influence grazing CC effects. The emerging literature indicates that 18%–92% of CC biomass was removed when grazed. Grazing CCs increased soil bulk density and penetration resistance (compaction indicators) in 54% of cases (six of 11 studies). However, the increase in soil compaction as measured by penetration resistance generally remained below the root‐growth threshold level (&lt;2 MPa). Grazing CCs had small and mixed effects on soil C concentration, wet aggregate stability, water infiltration, water retention, and soil microbial biomass. In addition, grazing did not affect subsequent crop yields in 61% of cases (eight of 13 studies) or had variable effects. Grazing at high stocking rates or when soils are wet can result in soil compaction and potentially reduce subsequent crop yields. Additional long‐term (&gt;5 years) data are needed to better discern CC grazing implications for different climates, stocking rates, soil types, CC grazing infrastructure, and CC management practices. Particularly, data on CC grazing from water‐limited regions (i.e., semi‐arid regions) are scant. Success with CCs in water‐limited regions depends on timely precipitation input unless irrigated. Overall, grazing of CCs under proper management has small or no effects on soils and crop yields.

Extensive woodland pasturing supported Pitted Ware Complex livestock management systems: Multi-stable isotope evidence from a Neolithic interaction zone

Middle Neolithic Pitted Ware Complex (PWC) groups throughout the Baltic coastal areas of Scandinavia almost exclusively exploited marine resources for their subsistence. However, Pitted Ware communities inhabiting eastern Jutland (Denmark) also heavily relied on domesticated livestock, reflecting their close contacts and interactions with neighboring Funnel Beaker agriculturalists. Whether or not these domesticates were managed using husbandry practices designed to intensively enhance livestock production or herded using more extensive management strategies that may have better articulated with seal hunting, shellfish gathering, and fishing activities remains unknown. Here, multi-stable isotopic analyses conducted on bone collagen and enamel apatite from wild and domesticated animal species recovered from Pitted Ware sites in Djursland indicate that hunters regularly sought prey that roamed in deeply canopied forests but extensively pastured their livestock under lightly canopied woodlands while also grazing some animals in more open habitats at moderately high stocking rates. Cattle may have been grazed on crop stubble after the summer harvest but were not fed grassy hay or agricultural by-products during the winter season. Instead, they were provided with leaf fodder sourced from diverse woodland pastures. The use of extensive pasturing regimes for livestock by PWC groups fitted well with the intensive exploitation of marine mammals, fishes, and shellfish as part of a highly resilient, sustainable subsistence complex.

DESEMPEÑO PRODUCTIVO DE VACAS LECHERAS ALIMENTADAS CON PRADERAS DE KIKUYO SOBRESEMBRADAS CON CENTENO EN SISTEMAS DE PRODUCCIÓN DE LECHE EN PEQUEÑA ESCALA EN LOS VALLES ALTOS DE MÉXICO

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Small-scale dairy systems contribute to mitigate rural poverty as they provide a stable source of incomes to farming families, and also contribute with over 30% of national milk production. However, the dependency on external inputs affects their profitability and sustainability, which added to difficult agroclimatic conditions and limiting management factors as high stocking rate in pastures. It is therefore necessary to evaluate feeding strategies better adapted to conditions in these systems to improve cattle diets based on quality forages reducing external dependency and thus, costs. A means to increase herbage yields in pastures is overseeding with annual fast-growing cereals. &lt;strong&gt;Objective: &lt;/strong&gt;The objective was to evaluate the productive performance of dairy cows on two feeding strategies based on grazing, and the analysis of costs in small-scale dairy systems in the highlands of central Mexico. &lt;strong&gt;Methodology: &lt;/strong&gt;Eight Holstein cows were used on continuous day grazing (8 h/day) under on-farm research with a double cross-over design. Treatments ere: continuous intensive grazing of Kikuyu grass pastures (KY) or Kikuyu grass overseeded with rye (KYCEN) from 6:00 to 16:00 h, plus 4.5 kg DM/day of commercial concentrate. Two groups of four cows balanced for days in milk and daily milk yield were formed, and each group randomly assigned to one of the treatment sequences: KY-KYCEN-KY y KYCEN-KY-KYCEN, with three experimental periods of 14-day each, with 10 days for adaptation to diets and four days for sampling. Pastures were assessed with a split-plot design. Records were for milk yield and composition, live weight and body condition. A partial budget analysis was performed to compare income and feeding costs. &lt;strong&gt;Results: &lt;/strong&gt;There were no statistical differences (P&amp;gt;0.05) in productive performance, with mean 3.5% fat corrected milk yield of 17 kg/cow/day, with 36.6 g/kg, 28.5 g/kg and 43.4 g/kg for milk fat, protein and lactose respectively. There were no significant differences (P&amp;gt;0.05) between treatments for sward height or herbage mass, but there were significant differences (P&amp;lt;0.05) for DM and OM content between treatments, and for CP, NDF, ADF, IVDMD, and EM (P&amp;lt;0.05) between periods. &lt;strong&gt;Implications:&lt;/strong&gt; In the face of complex agroecological scenarios for small-scale dairy systems, it is necessary to assess forages better adapted for these conditions as the inclusion of a fast growing cereal as rye to increase pasture production and increase the forage base in the diets with farm resources as Kikuyo grass, in order to increase the profitability of farms. &lt;strong&gt;Conclusions: &lt;/strong&gt;Since there were no statistical differences in the productive performance of dairy cows, or in economic performance, the conclusion is that treatment KY is the recommended option for this season. Treatment KYCEN requires expenditures in seed and labour, so that it is not a viable option for small-scale dairy systems in this season.&lt;/p&gt;

Grazing effects on total carbon and nitrogen content of wind‐eroded soils in desert steppe

AbstractA high stocking rate can intensify wind erosion in grasslands, and strong wind can carry away soil surface particles, soil carbon (C), and nitrogen (N), which leads to soil barrenness. In this research, the dust flux, total carbon (TC) and total nitrogen (TN) contents, and fluxes of aeolian sediment were determined in the nongrowing season (mid‐October to mid‐April of the following year) and growing season (mid‐April to mid‐October) from 2017 to 2020 at a continuous grazing gradient experiment platform established in 2004 in a desert steppe in Inner Mongolia, China. The results were as follows: (1) As the stocking rate increased, fluxes of aeolian sediment at 10 cm (H10), 30 cm (H30), and 100 cm (H100) were greatly increased (p &lt; 0.05). Aeolian sediment fluxes followed the order control (CK) &lt; light stocking rate (LG) &lt; moderate stocking rate (MG) &lt; heavy stocking rate (HG). (2) The TC and TN contents of aeolian sediment decreased with an increase in stocking rate, and higher grazing intensity resulted in a difference in TC content, which decreased between the two seasons. The TC flux/aeolian sediment flux increased with an increase in stocking rate, and the ratio of TC flux increased between two seasons due to the influence of heavy grazing. Grazing disturbance had little effect on TN flux. As grazing intensity increased, wind erosion resulted in an increase in soil available carbon loss, and this loss was more severe in the nongrowing season. (3) The C/N ratio increased with increase in aeolian sediment flux. The aeolian sediment flux and C/N showed an inverse relationship with the increase in grazing intensity. Regression lines for the two seasons showed an intersecting trend, and the intersection points moved backward as height increased, indicating that higher stocking rates could reduce the influence of grassland vegetation on C/N. As height increased, the regression intercept increased, indicating that the loss of wind‐eroded soil changed from a low C/N loss to a high C/N loss. In general, high stocking rates aggravated soil wind erosion, resulting in more C pool loss than N loss in terms of soil elements and more available C loss in the nongrowing season. In the nongrowing season, vegetation characteristics are poor, coupled with grazing interference, and wind erosion in the nongrowing season is serious in general; however, the change law of C and N in wind‐eroded soil is directly related to its particle size. C and N content in fine particles is higher, and C content in soil is much higher than N, so the TC loss is relatively large; therefore, reducing the intensity of grazing can reduce the occurrence of soil wind erosion, and implementing measures to protect grassland in spring and other periods vulnerable to wind erosion would be conducive to the sustainable usage of grassland resources.

Intense game grazing shapes epigeic spider communities of pedunculate oak Quercus robur plantations in anthropogenic environments

Game browsing affects nature conservation because the interests of hunters and gamekeepers often lead to high game stocking rates. However, the compositional effects of game browsing on invertebrates are insufficiently understood. We addressed the dynamics of epigeic spider communities in oak stands planted in newly formed anthropogenic environments under the facultative pressure of browsing game. The study site consisted of an open-cast lignite mine and an overburden deposit in NW Czechia. Using pitfall traps, we examined five habitat types (four transects per habitat type): Quercus robur stands ≥ 25 years of age, 12–24 years of age, and 0–2 years of age; Q. robur stands 12–24 years of age that were heavily damaged by game browsing; and sites subject to spontaneous succession for 12–22 years. We captured 9459 individuals from 134 spider species distributed unevenly across the examined habitat types. The young stands were dominated by Pardosa agrestis, Pardosa monticola, and Oedothorax apicatus, whereas Pardosa prativaga, Pardosa lugubris, Pisaura mirabilis, and Alopecosa cuneata dominated the old stands. The stands damaged by browsing had the highest species richness and were dominated by Alopecosa pulverulenta, Xerolycosa miniata, A. cuneata, and Trochosa ruricola. All the oak stands were rich in threatened species, with most (26) found in habitats damaged by browsing, whereas the youngest stands hosted the lowest number of threatened species (11). The species dominating old stands still included species that prefer greater canopy openness, such as P. lugubris, whereas numerous species of central European climax oak forests were lacking. In conclusion, we identified oak stands heavily damaged by game browsing as a unique environment that shapes the community of epigeic spiders and that differs from epigeic spider communities of oak stands of various ages and those colonizing areas that are allowed to undergo spontaneous succession.

Sustainability of Animal Stocks in Traditional Pastoral Systems of the High-Altitude Andean Altiplano

The main traditional livelihood in the high Central Andes Plateau, locally known as the Puna, is pastoralism. This system is based on llamas (Lama glama) and sheep (Ovis aries), which graze on natural vegetation (shrub steppe, grasslands, and peatlands). So, the livelihood of Andean communities is strongly influenced by the spatial and temporal dynamics of vegetation. Most of the existing models on herbivory used to estimate sustainable livestock loads require information on the nutritional values and primary production of vegetation, which is lacking for the Argentine Puna. This work aimed to fill the gap by implementing a carrying capacity model using data on annual vegetation growth and herbivore feeding strategies collected in the field in different plant communities. The hypothesis that guided this work was that environmental heterogeneity affects management decisions and should be taken into account to model sustainable animal stocks in Andean pastoralist systems. We estimated carrying capacity based on the MSY logistic model, considering biomass and aboveground primary production of vegetation communities, climatic features, and herbivore selective responses. We compared the estimated carrying capacity with real animal stocks in four production units within the study site in 2013, 2014, and 2017. The results indicate that the carrying capacity presents high spatial and temporal variability. In three of the production units assessed, the livestock—mixed herds of sheep and llamas—were above or near the estimated carrying capacity, even when the stocking rates were reduced during dry periods. The high stocking rates, along with evidence of land degradation, may indicate moderate to severe overgrazing. This work demonstrates the usefulness of estimating the carrying capacity to monitor the pastoral systems at fine space and time scales. These monitoring techniques can facilitate decision making among Puna herders in a biocultural context of knowledge dialog that may foster sustainability in pastoralist livelihoods.

Grazing and fertilizer, compost or manure application effects on a meadow bromegrass pasture on a thick black chernozem I. Productivity and sustainability

Short duration, intensive grazing management with high stocking rates may result in sufficient turn-over of nitrogen (N) to compensate for production-limiting soil-N deficiencies for grass pasture. In central Alberta a 0.5 ha block was seeded to “Fleet” meadow bromegrass ( Bromus riparius Rehmann) in August 2002. Within this block, six fenced (9 m × 30 m) treatments were established in three replicates. They were (1) ungrazed—clip removal, (2) grazed—alone, (3) grazed—fertilizer, (4) grazed—fertilizer-compost, (5) grazed—hog manure, and (6) grazed—alfalfa ( Medicago sativa L.) grass. Measurements were conducted over a 4-year period between 2003 and 2006 and grazing occurred at identical times as vegetative mass permitted. Biomass was harvested before and after grazing for calculation of dry matter (DM) yield and biomass consumed. Sub-samples were used for determination of N concentration and in vitro digestibility. Mean herbage N-yield for grazed treatments was 131% of ungrazed and greatest for grazed-fertilizer and grazed-fertilizer plus compost. Grazed paddocks with no added N produced similar DM yield to those with added N. Estimated nitrogen fixation contributed an annual average of 82 kg ha−1 to herbage-N yield from the alfalfa-grass paddocks. Barley ( Hordeum vulgare L.) silage grown after termination of the grazed pastures produced 72% more herbage DM from grazed paddocks than ungrazed, but no significant ( P &lt; 0.05) differences occurred among amendments.

Influence of Pastoral Settlements Gradient on Vegetation Dynamics and Nutritional Characteristics in Arid Rangelands

An expansion of pastoral settlements in arid rangelands can increase pressure on fragile ecosystems. High stocking rates and inappropriate rangeland management can cause large, difficult-to-reverse changes in the composition and structure of rangeland ecosystems. This study aims to understand changes in vegetation composition (cover, density, biomass, richness, diversity) and nutritional characteristics of range vegetation along a gradient of increasing pastoral population in arid rangelands of Pakistan. Three sites were selected for sampling within three areas classified by their distance from settlement: Near, Away, Far (9 sites in total) belt transects (10 × 150 m). A total of 90 transects (30 each in classified sites) of size 10 × 150 m were placed at a distance of 100 m apart from each distance group. Results identified 28 species from nine plant families. We found a significant difference in vegetation characteristics along the gradient. Vegetation diversity increased along the settlement gradient, highest being in the far sites. Density, plant cover and biomass were greatest at the sites near pastoral communities and decreased as the distance from the settlements increased. Palatable species were characterized by low density and diversity near herder’s villages, but values increased as the distance from the villages increased. An increase in shrubs was observed near pastoral settlements, resulting in higher plant cover, biomass and density in these sites. This study identified anthropogenic impacts on rangeland structure and composition and found large shifts near communities. The frequent monitoring of vegetation resources is important, and the development of sustainable conservative strategies are recommended to ensure harmonious coexistence of pastoral populations in arid rangelands.