6 pp. / Originally published 09/2000. / The objectives of this article are to provide an overview of the major grazing systems that have been used on rangelands in the western U. S. and Canada, to summarize the conditions under which they may be applicable, and to highlight examples from the southwestern U. S. when relevant. Revised 12/2014. Originally published 09/2000.

Sheep producers in Victoria are applying more phosphorus (P) fertiliser and increasing stocking rates to increase production. At the same time, there is increasing awareness amongst research, community and producer groups that P-rich runoff water from agricultural land can contribute to the growth of undesirable algal blooms in surface waters. The loads, concentrations and forms of P in surface and subsurface hydrological flow pathways were estimated or measured directly on high and low P fertility hill slope plots in south-west Victoria to assess how this practice change could affect the P status of runoff and drainage water. Small plot rainfall simulator studies were also conducted to investigate pasture management treatment effects. The spatial and temporal distribution of P loss from hillslope pastures, and the processes of P mobilisation in runoff identified in this study were used to identify appropriate management practises to help minimise P losses in runoff. Runoff P concentrations were then related to properties of pasture soils and runoff at a range of locations across Victoria to identify whether simple models and/or soil P tests could be used to predict P concentrations in runoff.

Understanding the nutrient dynamics of pastures is essential to their profitable and sustainable management.  Tall fescue [Schendonorus phoenix (Scop.) Holub.] is the predominant forage species in Virginia pasturelands.  Although tall fescue pasture is common, little research has attempted to document how soil and herbage nutrient concentrations change through time.  This thesis summarizes two studies conducted within the context of a larger grazing systems project near Steele's Tavern, VA.  The objectives were to: (1) examine temporal changes in plant available soil nutrient concentrations in four grazing systems, (2) determine how hay feeding and use of improved forages affected soil and herbage nutrient concentrations (3) examine the relationship between and variability within soil and herbage nutrient concentrations, (4) analyze the seasonal variation in herbage mineral concentration with regard to beef cattle requirements, and (5) create a statistical model to predict variation in herbage mineral concentration across the growing season.  Analysis of plant and soil nutrients through 5 years of grazing produced several important findings.  Soil pH, P, and Ca, Mg, and B declined through five years of grazing.  Higher concentrations of herbage N and K and soil P, K, Fe, Zn, and Cu were measured in hay feeding paddocks.  Herbage nutrient concentrations showed less variability in P and K than did soil test results.  Fertility testing in pastures is important to monitor changing nutrient concentrations, and this study showed that herbage analysis may provide a more stable and accurate assessment of pasture fertility than soil testing.  Pasture herbage, grown without fertilization, contained sufficient concentrations of macronutrients to meet the requirements of dry beef cows through the growing season and to meet the requirements of lactating beef cows in April.  A model was developed using soil moisture and relative humidity that predicted (R2 = 0.75) variation in herbage mineral concentration throughout the growing season.  As described in this thesis, use of modeling to predict nutrient dynamics in pasture could allow for more efficient mineral supplementation strategies that lead to improved profitability, nutrient retention, and livestock health. / Master of Science

Tall fescue grasslands are the dominant form of grasslands in the North American transition zone, however, warm-season forages provide necessary forage for livestock in the summer. Pollinators require steady forage availability in the same fashion as cattle. Native warm-season grasses (NWSG) and wildflowers (WF) could be incorporated into tall fescue (TF) grasslands to improve pollinator resources within agricultural landscapes without sacrificing livestock production. This balance of ecosystem services can be considered bee-friendly beef. Previous establishment experiments suggests that bee-friendly beef is a possibility, although establishment and persistence of NWSG-WF stands warrants additional research. Three small plot experiments were conducted to evaluate different planting methods designed to optimize establishment of NWSG-WF stands. Additionally, a grazing study examined whether NWSG-WF pasture enhancement could improve animal performance in TF grazing systems. The small plot experiments experienced extreme weed competition in the establishment year, although plots with higher NWSG content had fewer weeds over time. Floral production was comparable across treatment, which suggests lower WF seeding rates can generate comparable pollinator resources. Major findings from these experiments suggested that spatial or temporal separation of NWSGWF was unnecessary to generate successful establishment, varying the ratio of NWSG-WF in seed mixtures produced similar establishment outcomes, and that adding companion crops to NWSG-WF mixtures did not improve establishment success appreciably. In the grazing experiment, animal performance was improved in the biodiverse grazing systems when heifers 3 had access to the NWSG. Biodiverse and shaded grazing systems modified animal behavior and reduced body temperature relative to control grazing systems, although only biodiverse grazing systems improved animal performance. Native WF species failed to establish within the biodiverse grazing system, but white clover provided all subsequent floral production. Establishing WF in pastures is challenging and warrants additional study on more effective weed control strategies and systems to ensure establishment success. Selecting WF for agronomic performance or breeding such plant material will be necessary to improve emergence and establishment dynamics. Ideally trait data can identify the optimal WF species for specific grazing systems. Biodiverse NWSG-WF can be highly effective at improving summer weight gain in beef cattle. Future studies should focus on finding a more optimal balance of NWSG, WF, and TF that can benefit beef cattle production, pollinator services, and ecosystem services regarding soil and water quality, as well as pasture resiliency to dynamic conditions. / Doctor of Philosophy / Tall fescue grasslands are the dominant form of grasslands in the North American transition zone, however, warm-season forages provide necessary forage for livestock in the summer. Pollinators require steady forage availability in the same fashion as cattle. Native warm-season grasses (NWSG) and wildflowers (WF) could be incorporated into tall fescue (TF) grasslands to improve pollinator resources within agricultural landscapes without sacrificing livestock production. This balance of ecosystem services can be considered bee-friendly beef. Previous establishment experiments suggests that bee-friendly beef is a possibility, although establishment and persistence of NWSG-WF stands warrants additional research. Three small plot experiments were conducted to evaluate different planting methods designed to optimize establishment of NWSG-WF stands. Additionally, a grazing study examined whether NWSG-WF pasture enhancement could improve animal performance in TF grazing systems. The small plot experiments experienced extreme weed competition in the establishment year, although plots with higher NWSG content had fewer weeds over time. Floral production was comparable across treatment, which suggests lower WF seeding rates can generate comparable pollinator resources. Major findings from these experiments suggested that spatial or temporal separation of NWSGWF was unnecessary to generate successful establishment, varying the ratio of NWSG-WF in seed mixtures produced similar establishment outcomes, and that adding companion crops to NWSG-WF mixtures did not improve establishment success appreciably. In the grazing experiment, animal performance was improved in the biodiverse grazing systems when heifers 3 had access to the NWSG. Biodiverse and shaded grazing systems modified animal behavior and reduced body temperature relative to control grazing systems, although only biodiverse grazing systems improved animal performance. Native WF species failed to establish within the biodiverse grazing system, but white clover provided all subsequent floral production. Establishing WF in pastures is challenging and warrants additional study on more effective weed control strategies and systems to ensure establishment success. Selecting WF for agronomic performance or breeding such plant material will be necessary to improve emergence and establishment dynamics. Ideally trait data can identify the optimal WF species for specific grazing systems. Biodiverse NWSG-WF can be highly effective at improving summer weight gain in beef cattle. Future studies should focus on finding a more optimal balance of NWSG, WF, and TF that can benefit beef cattle production, pollinator services, and ecosystem services regarding soil and water quality, as well as pasture resiliency to dynamic conditions.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The trial was accomplished in the Fundação Estadual de Pesquisa Agropecuária (FEPAGRO) in São Gabriel, RS, to evaluate the performance of sheep and lambs in natural grassland, managed with different grazing systems and, pasture improvement with fertilization and introduction of cool season species, and to verify the effects of those different managements on the dynamics of this grassland ´s floristic composition. The treatments were as follows: natural grassland improvement with introduction of annual ryegrass (Lolium multiflorum Lam cv. Comum), red clover (Trifolium pratense L. cv. E-116) and birdsfoot trefoil (Lotus corniculatus L. cv. São Gabriel) under rotative grazing (CNM); natural grassland under continuous grazing (CNC) and natural grassland under rotative grazing (CNR). The treatments were distributed in an entirely randomized design, with two replicates. There was a delay of the beginning of the use of the grassland in function of structural problems as the delay in fencing paddocks of the treatments with rotative grazing. The experimental period was from 11/01 to 12/23/2004. Grazing animals were ewes with lambs (males and females), of Corriedale breed. The data were submitted to multivariate analysis based in ordination and randomization testing. Significant difference was not observed between the treatments for the avarage values of pasture growth rate (P=0,3332) and total production of DM (P=0,3391). The averages forage allowances of 20,3 and 22,1 kg of DM/100 kg of live weight in CNM and CNR, respectively, were superior to 13,7 kg of DM/100 kg of live weight verified in CNC. Significant difference among the treatments was not observed in the values of DLG (Daily Liveweight Gain) for male (P=0,5724) and females (P=0,2488) lambs. For the analyses of botanical composition, in the first evaluation CNM differed (P=0,0001) from CNC and CNR, while in the second evaluation the observed difference (P=0,0017) was between CNM and CNC. The results of DLG and gain per area were affected by the delay of the beginning of the experiment and by the drought observed during the experimental period, especially in the natural grassland with introduction of cool season species. The results of DLG of lambs, obtained in the natural grassland under continuous grazing, permits to consider the reals allowance around 14% to correspond to the best potential of animal production in natural grassland. The effect of rotational grazing, introduction of species and fertilization is decisive for changes in the composition of the vegetation. / O trabalho foi realizado na Fundação Estadual de Pesquisa Agropecuária (FEPAGRO) em São Gabriel, RS, com o objetivo de avaliar o desempenho de ovelhas e seus cordeiros em pastagem natural, manejada com diferentes sistemas de pastejo e melhorada com adubação e introdução de espécies de estação fria, e verificar os efeitos desses diferentes manejos sobre a dinâmica da composição florística desta pastagem. Os tratamentos foram os seguintes: pastagem natural melhorada com introdução de azevém (Lolium multiflorum Lam. cv. Comum), trevo vermelho (Trifolium pratense L. cv. E-116) e cornichão (Lotus corniculatus L. cv. São Gabriel) sob pastejo rotacionado (CNM); pastagem natural sob pastejo contínuo (CNC) e pastagem natural sob pastejo rotacionado (CNR). Os tratamentos foram distribuídos em delineamento inteiramente casualizado, com duas repetições de área. Houve um atraso no início da utilização da pastagem em função de problemas estruturais como a demora na confecção da cerca que dividia os potreiros dos tratamentos com pastejo rotativo, sendo que o período experimental foi de 01/11 a 23/12/2004. Os animais utilizados foram ovelhas com cordeiros (machos e fêmeas), da raça Corriedale. Os dados foram submetidos a análise multivariada baseada em ordenação e testes de aleatorização. Não foi observada diferença significativa entre os tratamentos nos valores médios de taxa de acúmulo (P=0,3332) e produção total de MS (P=0,3391). As ofertas médias de forragem de 20,3 e 22,1 kg de MS/100 kg de peso vivo no CNM e CNR, respectivamente, foram superiores a 13,7 kg de MS/100 kg de peso vivo verificada no CNC. Não foi observada diferença significativa nos valores de GMD (Ganho Médio Diário) para cordeiros (P=0,5724) e cordeiras (P=0,2488) entre os tratamentos. Nas análises de composição botânica, no primeiro levantamento o CNM diferiu (P=0,0001) tanto do CNC quanto do CNR, enquanto no segundo levantamento foi observada diferença (P=0,0017) entre CNM e CNC. Os resultados de GMD e ganho por área foram condicionados pelo atraso do início do experimento e pela estiagem observada no período experimental, especialmente na pastagem natural com introdução de espécies de estação fria. Pelos bons resultados de GMD de cordeiros e cordeiras obtidos na pastagem natural sob pastejo contínuo, estima-se que ofertas reais em torno de 14% correspondam ao melhor potencial de produção animal da pastagem nativa. O efeito do pastejo rotativo, introdução de espécies e adubação é determinante para mudanças na composição da vegetação.

The increasing demand for food and fiber, the need for climate change mitigation and adaptation as well as for environmental protection impose severe challenges on land systems worldwide. Solutions to support the transformation towards a sustainable development of land systems are needed. One response to the multiple challenges is the introduction of policy options aimed at steering land use activities towards a bundle of societal goals. However, it is difficult to empirically foresee the effectiveness and unintended consequences of policy options prior to their deployment. A second response is environmental education because human consumption behavior, among other factors, strongly influences natural ecosystems. However, it is a non-trivial task to develop effective communication strategies for complex topics such as sustainable land management. In both cases, modeling can help to overcome the different obstacles along the way. In this thesis, dynamic process-based social-ecological models at the individual scale are developed and analyzed to study effectiveness and unintended side effects of policy options, which promote agricultural management strategies and were intentionally designed to cope with multiple societal challenges. Two case studies of political intervention are investigated: the promotion of perennial woody crops in European agricultural landscapes for a sustainable bioeconomy and governmental supplementary feeding programs to cope with climate risks in pastoral systems in drylands. These two case studies are complemented by the development of a serious online game on sustainable land management in general that bridges the gap between land use modeling and environmental education. Simulation results of this thesis provide insights into (i) the performance of the politically promoted agricultural management strategies in meeting various intended goals such as poverty alleviation or the maintenance of biodiversity and ecosystem services, (ii) the emergence of unintended (environmental and social) side effects such as land use conflicts, land degradation or cost explosion and (iii) the mitigation of such side effects by appropriately adjusting the design of the policy options. These insights are enabled by representing temporal as well as spatial variability in the developed models. Furthermore, different mechanistic approaches of transferability analyses based on stylized landscapes are developed and applied. They enable to check whether and in what respect policy impacts actually differ substantially between regional contexts, to identify what regional factors steer the impact and to derive indicators for grouping regions of similar policy impacts. Finally, based on a conducted survey-based evaluation and experiences from various applications, the value of the developed serious game for environmental education is revealed and discussed.Altogether, this thesis contributes to model-based decision support for steering transformation towards the sustainable development of land systems in an appropriate way. This is done by developing appropriate social-ecological modeling approaches, by performing specific policy impact analyses in two transformative agricultural systems using these models and by providing a model-based communication tool for environmental education.

This thesis at first discusses the importance of permanent grasslands, establishing and revival of pastures, further dividing agrobotanical groups, homogeneity of pastures and the treatment and fertilization of grasslands. The second part focuses on the breeding of cattle, commercial properties and targets in breeding herds. It deals with the Aberdeen angus beef, that is kept at monitored sites. In addition, the organization and the division of pastures. The third part contains observational monitoring of grassland. The effects of different grazing systems on pasture vegetation were observed at the selected pastures areas. Forage crop characteristics were measured and the suitable grazing system was designed and system of usage and treatment of pasture vegetation was designed. The observation was greatly complicated because of the excessive rainfall (floods) in the first third of the grazing season.