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Sample records for sward

  1. Imaging spectroscopy for characterisation of grass swards

    NARCIS (Netherlands)

    Schut, A.G.T.

    2003-01-01

    Keywords: Imaging spectroscopy, imaging spectrometry, remote sensing, reflection, reflectance, grass sward, white clover, recognition, characterisation, ground cover, growth monitoring, stress detection, heterogeneity quantification

    The potential of imaging spectroscopy as a tool for

  2. Influence of sward characteristics on grazing behaviour and short ...

    African Journals Online (AJOL)

    Relative to temperate systems, there has been few reported detailed assessments of sward characteristics and associated grazing behavior from natural and ... in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria.

  3. Hemiptera community and species responses to grassland sward islets

    OpenAIRE

    Helden, Alvin J.; Dittrich, Alex D. K.

    2016-01-01

    Sward islet is a term that has been used to describe a patch of longer vegetation in a pasture produced by a reduction in cattle grazing around their dung. They are known to affect the abundance and distribution of grassland arthropods. Hemiptera, like other groups, are found in higher densities within islets than the surrounding sward. Does this modify the community composition or is there just a density effect? Evidence from a paired (islets, non-islets) study at an Irish cattle-grazed site...

  4. The seasonal growth patterns of a Tall Grassveld sward | NFG ...

    African Journals Online (AJOL)

    The growth patterns of a Tall Grassveld sward measured with an inclined point and by clipping and weighing were determined by moisture conditions except in winter when temperature was limiting. The inclined point as a method of determining yield which might replace clipping and weighing, holds promise but is unlikely ...

  5. Productivity, utilization efficiency and sward targets for mixed pastures of marandugrass, forage peanut and tropical kudzu

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2012-03-01

    Full Text Available This study was carried out to evaluate the productivity and utilization efficiency of a mixed marandugrass (Brachiaria brizantha cv. Marandu, forage peanut (Arachis pintoi cv. Mandobi and tropical kudzu (Pueraria phaseoloides pasture, rotationally stocked at four daily forage allowance levels (6.6, 10.3, 14.3 and 17.9% of live weight, in order to define sward management targets for these mixtures. In each stocking cycle, dry matter (DM accumulation rates, defoliation intensity (%, grazing depth (% and grazed horizon (cm were evaluated. Sward targets were defined according to the sward condition that best conciliated the grass-legume balance and the equilibrium between forage production and utilization. Pastures submitted to higher forage allowance levels showed higher productivity, but were less efficiently utilized. It was not possible to establish sward management targets for marandugrass-tropical kudzu pastures. For marandugrass-forage peanut pastures the best sward state was set with forage allowance of 10.3% of live weight. Under rotational stocking, the following sward targets were suggested for these pastures in the Western Amazon: pre-grazing height of 30-35 cm (June to September or 45-50 cm (October to May and post-grazing sward height of 20-25 cm (June to September or 25-30 cm (October to May.

  6. Complementary effects of red clover inclusion in ryegrass-white clover swards for grazing and cutting

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Søegaard, Karen

    2014-01-01

    Increasing plant species diversity in grasslands may improve productivity and stability of yields. In a field experiment, we investigated the herbage dry-matter (DM) yield and crude protein content of two-species swards of perennial ryegrass–white clover (Lolium perenne L.–Trifolium repens L...... clover in sown swards are discussed. These may include higher nitrogen-use efficiency in ruminants, increased soil fertility and improved sward flexibility to cope with changing managements. The findings also suggest positive yield effects of alternating between cutting and grazing within the season...

  7. Carbon balance and water use efficiency of frequently cut Lolium perenne L. swards at elevated carbon dioxide

    NARCIS (Netherlands)

    Schapendonk, A.H.C.M.; Dijkstra, P.; Groenwold, J.; Pot, C.S.; Geijn, van de S.C.

    1997-01-01

    The impact of doubled atmospheric [CO2] on the carbon balance of regularly cut Lolium perenne L. swards was studied for two years under semi-field conditions in the Wageningen Rhizolab. CO2 and H2O vapour exchange rates of the swards were measured continuously for two years in transparent

  8. A note on the effects of paddock size on the white clover content of swards grazed by sheep

    NARCIS (Netherlands)

    Wolf, de P.L.; Schulte, R.P.O.; Lantinga, E.A.

    2004-01-01

    The maintenance of a high white clover content in mixed swards under sheep grazing has been a challenge to date. This paper presents the results of an experiment in which the effect of the length of a grazing period on the botanical composition of a mixed sward was studied. Paddocks ranging in size

  9. Relationship of bite mass of cattle to sward structure of four temperate grasses in short-term foraging sessions

    Science.gov (United States)

    Bite mass is a fundamental element of ruminant ingestive behavior and is highly influenced by sward structure. We compared the sward structure of four grasses and related structure to the bite mass of cattle grazing the grasses. Reed canarygrass (RCG; Phalaris arundinacea L), quackgrass (QG; Elytri...

  10. Imaging spectroscopy for early detection of nitrogen deficiency in grass swards

    NARCIS (Netherlands)

    Schut, A.G.T.; Ketelaars, J.J.M.H.

    2003-01-01

    The potential of an experimental imaging spectroscopy system with high spatial (0.16–0.28 mm²) ) and spectral resolution (5–13 nm) was explored for early detection of nitrogen (N) stress. From June through October 2000, a greenhouse experiment was conducted with 15 Lolium perenne L. mini-swards and

  11. Tiller size/density compensation in grazed Tifton 85 bermudagrass swards

    Directory of Open Access Journals (Sweden)

    Sbrissia André Fischer

    2003-01-01

    Full Text Available The objective of this study was to evaluate the occurrence of the tiller size/density compensation mechanism in Tifton 85 bermudagrass swards grazed by sheep under continuous stocking. Treatments corresponded to four sward steady state conditions (5, 10, 15, and 20 cm of sward surface height, maintained by sheep grazing. The experimental design was a complete randomized block with four replicates. Pasture responses evaluated include: tiller population density, tiller mass, leaf mass and leaf area per tiller, and herbage mass. Tiller volume, leaf area index, tiller leaf/stem ratio, and tiller leaf area/volume ratio were calculated and simple regression analyses between tiller population density and tiller mass were performed. Measurements were made in December, 1998, and January, April, and July, 1999. The swards showed a tiller size/density compensation mechanism in which high tiller population densities were associated with small tillers and vice-versa, except in July, 1999. Regression analyses revealed that linear coefficients were steeper than the theoretical expectation of -3/2. Increments in herbage mass were attributable to increases in tiller mass in December and January. Leaf area/volume ratio values of Tifton 85 tillers were much lower than those commonly found for temperate grass species.

  12. Ingestive behavior of supplemented Nellore heifers grazing palisadegrass pastures managed with different sward heights.

    Science.gov (United States)

    Vieira, Bruno Ramalho; Azenha, Mariana Vieira; Casagrande, Daniel Rume; Costa, Diogo Fleury Azevedo; Ruggieri, Ana Cláudia; Berchielli, Telma Teresinha; Reis, Ricardo Andrade

    2017-04-01

    Three sward heights (15, 25 and 35 cm) and three supplement types (energy, energy-protein, and a mineral mix supplement) were evaluated in a 3 × 3 factorial arrangement distributed in a completely randomized design to study changes in forage search patterns in Nellore heifers in a continuous grazing system. Pasture data were collected using two replicates (paddocks) per treatment over four periods during the rainy season. The behavior assessments were made in the first and fourth grazing seasons. It was hypothesized that supplements and pasture management would modify ingestive behavior, considering that animals would require less time grazing if they had energy requirements met through higher digestibility of better managed paddocks, or use of supplements high in energy. Total and green forage masses along with green : dead material ratio were greater in treatments managed with higher sward heights. Sward managed with 35 cm height resulted in lower leaf : stem ratio compared with 15 cm sward height treatments. The animals on the 15 cm pastures spent more time grazing overall and during each meal, but there were no differences observed in meal numbers in comparison to 35 cm treatments. Heifers fed protein and/or energy supplements spent less time grazing in the early afternoon, but overall grazing time was the same for all animals. © 2016 Japanese Society of Animal Science.

  13. Exchange of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) between air and a mixed pasture sward.

    Science.gov (United States)

    Barber, Jonathan L; Thomas, Gareth O; Bailey, Rebekah; Kerstiens, Gerhard; Jones, Kevin C

    2004-07-15

    To improve understanding of air-to-vegetation transfer of persistent organic pollutants (POPs), uptake and depuration of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) between grass sward and air was investigated. Pasture swards were placed in fanned (2 m s(-1) wind speed) and unfanned conditions for a period of 20 days and sampled at intervals. Depuration was carried out after a short (4 days) and a long (14 days) exposure period. Prior to contamination, a mixed pasture sward at a semi-rural location contained sigmaPCN concentrations 15-20% of the sigmaPCB concentration. Uptake of both PCBs and PCNs was broadly linear in fanned and unfanned conditions over the 20-day period, i.e., the pasture did not reach equilibrium with the air. Uptake rates (fluxes) were greater under the fanned conditions. The difference in uptake rates between fanned and unfanned conditions increased with degree of chlorination for both PCBs and PCNs, ranging between a factor of 2 for tri-chlorinated PCBs and PCNs and a factor 5 for octa-chlorinated PCBs. Depuration results over the first hours were very scattered, showing an initial period of loss, followed by an increase in concentrations, possibly as a result of re-volatilization of PCBs from the soil in the trays, with consequent recapture by the overlying sward. Rapid clearance was observed over the following days, but depuration of PCBs and PCNs was still incomplete after 14 days, with 20% of the initial concentration of the sigmaPCBs and 10% of the sigmaPCNs retained by the sward. There was no difference in the proportion of POPs retained in the sward between the 4- and 14-day contamination treatments. POP-specific differences in the amount of compound "trapped" in leaves after contamination were observed. The results show that, although changes in the rate of air movement around a pasture have an effect on the uptake rate of POPs into the vegetation, plant-side resistance controls both the air-to-pasture and

  14. Nitrogen fertilization of grass/clover swards under cutting or grazing by dairy cows

    DEFF Research Database (Denmark)

    Søegaard, Karen

    2009-01-01

    farms over a period of three years. Nitrogen was applied at four rates (0, 75, 150, and 225 kg N year-1) with cutting or grazing regime in Year 1 and Year 2, after establishment. A spring-only application of 150 kg N was compared with four applications during the season, which was the fertilization...... affected. The results indicate different possibilities for strategic fertilization both at farm and field level, and in swards with a high clover content it demonstrates how the clover content can be used as a buffer both for maximizing the N-response and for manipulating the production profile.......Intensively managed perennial ryegrass/white clover (Lolium perenne L. and Trifolium repens L.) swards receive relatively high levels of fertilizer N, and high N surpluses can subsequently be found. The N-fertilization effects on growth, yield, and herbage quality were therefore examined on three...

  15. Measurement of emission and deposition patterns of ammonia from urine in grass swards

    Science.gov (United States)

    Ross, C. A.; Jarvis, S. C.

    Currently, legislation is being considered to reduce NH3 emissions in the UK. The major sources of NH3 and their relative contributions are well known, however, the processes that control the rates of emission are still poorly defined. A series of wind-tunnel experiments has been carried out to determine the effects of various management practices on NH3 losses. The tunnels were modified to enable NH3 emission and subsequent deposition to the adjacent swards in the field to be measured. The wind-tunnels were used to examine the effects of herbage length, cutting and N status on rates of NH3 fluxes, which together with the prevailing environmental conditions affected the rates of NH3 emission and deposition. Results showed that between 20 and 60% of the NH3 emitted was deposited within 2 m. Compensation points of between 1.0 and 2.3 μg m-3 were calculated for the grass sward.

  16. Dynamics of sward condition and botanical composition in mixed pastures of marandugrass, forage peanut and tropical kudzu

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2012-03-01

    Full Text Available This study was carried out to evaluate the dynamics of sward condition and botanical composition of a mixed pasture of marandugrass (Brachiaria brizantha cv. Marandu, forage peanut (Arachis pintoi cv. Mandobi and tropical kudzu (Pueraria phaseoloides, rotationally stocked at four daily forage allowance levels (6.6, 10.3, 14.3 and 17.9% of live weight. Sward condition was characterized in each stocking cycle by measuring pre- and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, forage peanut, tropical kudzu and weeds was evaluated before each stocking period. Swards under smaller forage allowances presented lower height, forage mass and ground cover. This condition favored the growth of forage peanut, which constituted 21.1, 15.2, 8.4 and 3.8% of forage mass in the last quarter of the experimental period, from the lowest to the highest forage allowance, respectively. Tropical kudzu was sensitive to all forage allowance levels and its percentage in the botanical composition was strongly reduced along the experimental period, especially during the dry season (July to September. Forage peanut cv. Mandobi and marandugrass form a more balanced mixture when pre-grazing sward height is maintained shorter than 45 cm. Tropical kudzu is intolerant to intensive grazing management systems when associated to marandugrass.

  17. Effects of chicory/perennial ryegrass swards compared with perennial ryegrass swards on the performance and carcass quality of grazing beef steers.

    Directory of Open Access Journals (Sweden)

    Christina L Marley

    Full Text Available An experiment investigated whether the inclusion of chicory (Cichorium intybus in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne. Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36 were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011 in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.

  18. The combined effect of fertiliser nitrogen and phosphorus on herbage yield and change in soil nutrients of a grass/clover and grass-only sward

    NARCIS (Netherlands)

    Schils, R.L.M.; Snijders, P.J.M.

    2004-01-01

    The combined effect of reduced nitrogen ( N ) and phosphorus ( P ) application on the production of grass- only and grass/ clover swards was studied in a five- year cutting experiment on a marine clay soil, established on newly sown swards. Furthermore, changes in soil N, P and carbon ( C ) were

  19. Tiller size/population density compensation in grazed Coastcross bermudagrass swards

    Directory of Open Access Journals (Sweden)

    Sbrissia André Fischer

    2001-01-01

    Full Text Available Several compensatory mechanisms in pastures do not allow optimisation of responses from the processes of herbage production and utilisation. Compensation due to tiller size/density relationships is one of these mechanisms. This experiment evaluated this process for Coastcross bermudagrass and compared the responses to those reported for temperate forages. Treatments were "steady state" sward surface heights of 5, 10, 15, and 20 cm that were maintained from August, 1998, through July, 1999 by sheep grazing. The experimental design was a randomised complete block, replicated four times. Pasture responses were evaluated on four separate dates (15/12/1998, 25/01/1999, 07/04/1999 and 04/07/1999 with respect to: tiller population density, tiller weight, leaf mass and leaf area per tiller and herbage mass (biomass. Tiller volume, leaf area index (LAI, tiller leaf:stem ratio and tiller leaf area:volume ratio (R were calculated. Simple regression analyses between tiller population density and tiller weight were also performed. Coastcross swards showed a tiller size/density compensation mechanism where high tiller population densities were associated with small tillers and vice-versa; except on the last evaluation. However, regression analysis revealed linear coefficients of -3.83 to -2.05, which are lower than the theoretical expectation of -3/2. The lower R values observed, when compared to those reported for perennial ryegrass, suggest that Coastcross swards optimised their LAI via clonal integration among tillers in contrast with tillers of cool-season grasses that respond more as individuals. However, this hypothesis has yet to be experimentally verified.

  20. Dairy cow excreta patches change the boreal grass swards from sink to source of methane

    Directory of Open Access Journals (Sweden)

    Marja Elisa Maljanen

    2012-06-01

    Full Text Available We studied methane (CH4 flux rates from experimental excreta patches on a dairy pasture with a chamber technique during snow free seasons and with a gas gradient technique during winter from timothy-meadow fescue sward with mineral N fertilization (220 kg ha-1 and from grass-white clover mixture without fertilization. The dung and urine patches were applied in June or August two consecutive grazing seasons and the measurements were carried out for a year following each application. There were no significant differences in CH4 fluxes between plant species and emissions originated mainly from the fresh dung pats. The average annual CH4 fluxes from the control sites without excreta were -0.60±0.1 and with the excreta 0.47±0.3 kg CH4 ha-1. Thus, excreta originating from dairy cows can turn boreal swards from weak sinks to small sources of CH4. However, these emissions are only 0.2% of the total CH4 emissions from a dairy cow.

  1. Sward and milk production response to early turnout of dairy cows to pasture in Finland

    Directory of Open Access Journals (Sweden)

    P. VIRKAJÄRVI

    2008-12-01

    Full Text Available The timing of turnout is an important factor affecting the grazing management of dairy cows. However,its consequences are not well known in the short grazing season of northern Europe. Thus, the effect of the turnout date of dairy cows to pasture on sward regrowth, herbage mass production and milk production was studied in two experiments,1a grazing trial with 16 Holstein-Friesian dairy cows and 2a plot trial where the treatments simulated the grazing trial.The treatments were early turnout (1 Juneand normal turnout (6 June.Early turnout decreased the annual herbage mass (HM production in the plot trial (P =0.005,but due to a higher average organic matter (OMdigestibility (P 0.05. Although early turnout had no effect on milk yields it meant easier management of pastures.;

  2. Polyphenolic composition and antioxidant capacity of legume based swards are affected by light intensity in a Mediterranean agroforestry system.

    Science.gov (United States)

    Re, Giovanni Antonio; Piluzza, Giovanna; Sanna, Federico; Molinu, Maria Giovanna; Sulas, Leonardo

    2018-06-01

    In Mediterranean grazed woodlands, microclimate changes induced by trees influence the growth and development of the understory, but very little is known about its polyphenolic composition in relation to light intensity. We investigated the bioactive compounds and antioxidant capacity of different legume-based swards and variations due to full sunlight and partial shade. The research was carried out in a cork oak agrosilvopastoral system in Sardinia. The highest values of DPPH reached 7 mmol TEAC 100 g -1 DW, total phenolics 67.1 g GAE kg -1 DW and total flavonoids 7.5 g CE kg -1 DW. Compared to full sunlight, partial shade reduced DPPH values by 29 and 42%, and the total phenolic content by 23 and 53% in 100% legume mixture and semi natural pasture. Twelve phenolic compounds were detected: chlorogenic acid in 80% legume mixture (partial shade) and verbascoside in pure sward of bladder clover (full sunlight) were the most abundant. Light intensity significantly affected antioxidant capacity, composition and levels of phenolic compounds. Our results provide new insights into the effects of light intensity on plant secondary metabolites from legume based swards, underlining the important functions provided by agroforestry systems. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. Direct and carryover effect of post-grazing sward height on total lactation dairy cow performance.

    Science.gov (United States)

    Ganche, E; Delaby, L; O'Donovan, M; Boland, T M; Kennedy, E

    2013-08-01

    Grazing pastures to low post-grazing sward heights (PGSH) is a strategy to maximise the quantity of grazed grass in the diet of dairy cows within temperate grass-based systems. Within Irish spring-calving systems, it was hypothesised that grazing swards to very low PGSH would increase herbage availability during early lactation but would reduce dairy cow performance, the effect of which would persist in subsequent lactation performance when compared with cows grazing to a higher PGSH. Seventy-two Holstein-Friesian dairy cows (mean calving date, 12 February) were randomly assigned post-calving across two PGSH treatments (n = 36): 2.7 cm (severe; S1) and 3.5 cm (moderate; M1), which were applied from 10 February to 18 April (period 1; P1). This was followed by a carryover period (period 2; P2) during which cows were randomly reassigned within their P1 treatment across two further PGSH (n = 18): 3.5 cm (severe, SS and MS) and 4.5 cm (moderate, SM and MM) until 30 October. Decreasing PGSH from 3.5 to 2.7 cm significantly decreased milk (-2.3 kg/cow per day), protein (-95 g/day), fat (-143 g/day) and lactose (-109 g/day) yields, milk protein (-1.2 g/kg) and fat (-2.2 g/kg) concentrations and grass dry matter intake (GDMI; -1.7 kg dry matter/cow per day). The severe PGSH was associated with a lower bodyweight (BW) at the end of P1. There was no carryover effect of P1 PGSH on subsequent milk or milk solids yields in P2, but PGSH had a significant carryover effect on milk fat and lactose concentrations. Animals severely restricted at pasture in early spring had a higher BW and slightly higher body condition score in later lactation when compared with M1 animals. During P2, increasing PGSH from 3.5 to 4.5 cm increased milk and milk solids yield as a result of greater GDMI and resulted in higher mean BW and end BW. This study indicates that following a 10-week period of feed restriction, subsequent dairy cow cumulative milk production is unaffected. However, the substantial

  4. Características do pasto e acúmulo de forragem em capim-tanzânia submetido a alturas de manejo do pasto Sward characteristics and herbage accumulation of Tanzania grass submitted to sward heights

    Directory of Open Access Journals (Sweden)

    Marcos Weber do Canto

    2008-03-01

    Full Text Available O objetivo deste experimento foi avaliar alturas de manejo do pasto (20, 40, 60 e 80 cm em capim-tanzânia (Panicum maximum Jacq., em regime de lotação contínua, nas características do dossel e acúmulo de matéria seca. Os animais utilizados foram novilhos Nelore (Bos indicus, e a taxa de lotação foi variável. Foram avaliados: a massa de forragem, a massa de lâmina de folha verde, a razão folha:colmo, a composição morfológica e a taxa de acúmulo de matéria seca. O delineamento experimental foi inteiramente casualizado, com duas repetições. A massa de forragem aumentou linearmente com o aumento da altura do pasto. As médias de massa de forragem foram 2.767, 3.105, 3.657 e 4.436 kg ha-1, respectivamente, para as alturas de 20, 40, 60 e 80 cm. As taxas de acúmulo de matéria seca, a 20, 40, 60 e 80 cm, foram, respectivamente, 104, 108, 90 e 81 kg ha-1 por dia, o que indica que houve redução dessas taxas com a elevação da altura do pasto. A razão folha:colmo decresceu linearmente com o aumento da altura do pasto. Pastagens de capim-tanzânia, sob lotação contínua ao final da primavera e durante o verão, devem ser utilizadas entre 40 e 60 cm de altura.The objective of this experiment was to evaluate different sward height (20, 40, 60 e 80 cm in Tanzania grass (Panicum maximum Jacq. pastures managed under continuous stocking. The animals used were Nellore steers, and the control of sward height was done with put-and-take techniques. Evaluations were made for: forage mass, green leaf mass, leaf:stem ratio, morphological composition and dry matter accumulation rate. The experimental design was completely randomized with two replications. Forage mass increased linearly with sward height with overall mean of 2,767, 3,105, 3,657 and 4,436 kg ha-1 at sward heights 20, 40, 60 and 80 cm, respectively. Rates of dry matter accumulation decreased with increasing sward heights and were 104, 108, 90 and 81 kg ha-1 per day for sward

  5. The Impact of Tourist Traffic on the Condition and Cell Structures of Alpine Swards

    Directory of Open Access Journals (Sweden)

    Marlena Kycko

    2018-02-01

    Full Text Available This research focuses on the effect of trampling on vegetation in high-mountain ecosystems through the electromagnetic spectrum’s interaction with plant pigments, cell structure, water content and other substances that have a direct impact on leaf properties. The aim of the study was to confirm with the use of fluorescence methods of variability in the state of high-mountain vegetation previously measured spectrometrically. The most heavily visited part of the High Tatras in Poland was divided into polygons and, after selecting the dominant species within alpine swards, a detailed analysis of trampled and reference patterns was performed. The Analytical Spectral Devices (ASD FieldSpec 3/4 were used to acquire high-resolution spectral properties of plants, their fluorescence and the leaf chlorophyll content with the difference between the plant surface temperature (ts, and the air temperature (ta as well as fraction of Absorbed Photosynthetically Active Radiation (fAPAR used as reference data. The results show that, along tourist trails, vegetation adapts to trampling with the impact depending on the species. A lower chlorophyll value was confirmed by a decrease in fluorescence, and the cellular structures were degraded in trampled compared to reference species, with a lower leaf reflectance. In addition, at the extreme, trampling can eliminate certain species such as Luzula alpino-pilosa, for which significant changes were noted due to trampling.

  6. Species Diversity Effects on Productivity, Persistence and Quality of Multispecies Swards in a Four-Year Experiment

    DEFF Research Database (Denmark)

    Jing, Jingying; Søegaard, Karen; Cong, Wen-Feng

    2017-01-01

    ), neutral detergent fiber (NDF) and crude protein (CP), and a lower concentration of ash than the 10-mix and 12-mix. Slurry application increased annual yield production by 10% and changed the botanical composition, increasing the proportion of grass and decreasing the proportion of legumes. Compared......Plant species diversity may benefit natural grassland productivity, but its effect in managed grassland systems is not well understood. A four-year multispecies grassland experiment was conducted to investigate the effect of species diversity±legumes and non-leguminous forbs±on productivity...... increased sward production and yield persistence under cutting regime. The 12-mix had the highest yield from the second year onwards and no statistically significant yield reduction over four years, while annual yields in the 3-mix and 10-mix decreased significantly with increasing grassland age. The higher...

  7. THE FERTILIZATION EFFECT OF PERMANENT MEADOWS WITH SPENT MUSHROM SUBSTRATE ON THE UPTAKING OF MANGANESE, COPPER AND ZINC BY THE MEADOW SWARD

    Directory of Open Access Journals (Sweden)

    Beata Wiśniewska-Kadżajan

    2013-04-01

    Full Text Available The study was conducted in the years 1999–2001 in a meadow with the following fertilizer combinations: control object (without fertilizer, NPK mineral fertilization, fertilizing with manure, manure with NPK fertilization, fertilizing with spent mushroom substrate; spent mushroom substrate with NPK fertilization. The aim of the study was to determine the effect of permanent grassland fertilization both with spent mushroom substrate and the one supplemented with NPK on the uptaking of manganese, copper and zinc by the meadow sward. After the cultivation of mushrooms, in comparison to the standard manure, the substrate used in the experiment was characterized by more than twice higher amount of manganese and zinc. However, the amount of copper in the organic materials was similar. In spite of having supplied lager amount of manganese, zinc and similar amount of copper to the mushrooms substrate, it caused the reduction of the uptake of the elements in the meadow sward. In spite of supplying larger amounts of manganese, zinc and copper the reduction of their uptaking by meadow sward was observed in comparison to manure mushroom substrate. This may be connected with a slightly alkaline reaction of the soil environment, thus limiting the uptake of the studied micronutrients.

  8. Optimizing Radiometric Processing and Feature Extraction of Drone Based Hyperspectral Frame Format Imagery for Estimation of Yield Quantity and Quality of a Grass Sward

    Science.gov (United States)

    Näsi, R.; Viljanen, N.; Oliveira, R.; Kaivosoja, J.; Niemeläinen, O.; Hakala, T.; Markelin, L.; Nezami, S.; Suomalainen, J.; Honkavaara, E.

    2018-04-01

    Light-weight 2D format hyperspectral imagers operable from unmanned aerial vehicles (UAV) have become common in various remote sensing tasks in recent years. Using these technologies, the area of interest is covered by multiple overlapping hypercubes, in other words multiview hyperspectral photogrammetric imagery, and each object point appears in many, even tens of individual hypercubes. The common practice is to calculate hyperspectral orthomosaics utilizing only the most nadir areas of the images. However, the redundancy of the data gives potential for much more versatile and thorough feature extraction. We investigated various options of extracting spectral features in the grass sward quantity evaluation task. In addition to the various sets of spectral features, we used photogrammetry-based ultra-high density point clouds to extract features describing the canopy 3D structure. Machine learning technique based on the Random Forest algorithm was used to estimate the fresh biomass. Results showed high accuracies for all investigated features sets. The estimation results using multiview data provided approximately 10 % better results than the most nadir orthophotos. The utilization of the photogrammetric 3D features improved estimation accuracy by approximately 40 % compared to approaches where only spectral features were applied. The best estimation RMSE of 239 kg/ha (6.0 %) was obtained with multiview anisotropy corrected data set and the 3D features.

  9. Sistema de integração lavoura-pecuária: efeito do manejo da altura em pastagem de aveia preta e azevém anual sobre o rendimento da cultura da soja Crop-livestock integration system: effect of oat and italian ryegrass sward height management on soybean yield

    Directory of Open Access Journals (Sweden)

    Marília Lazzarotto Terra Lopes

    2009-08-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da altura de manejo em pastagem de aveia preta e azevém anual sobre o estabelecimento e o rendimento de grãos da cultura de soja. Os tratamentos utilizados foram quatro alturas de manejo do pasto: 10, 20, 30 e 40cm e um tratamento sem pastejo. Foram avaliados atributos referentes à pastagem (altura do pasto, oferta de forragem, massa de forragem, taxa de acúmulo, taxa de lotação animal e palhada residual e à cultura da soja (estande inicial de plantas e rendimento de grãos. As alturas reais do pasto ficaram próximas daquelas pretendidas, havendo um aumento linear da oferta de forragem e da massa de forragem quando foi observado aumento das alturas de manejo do pasto. A taxa de acúmulo não foi afetada pelos tratamentos. A taxa de lotação apresentou resposta linear decrescente com o aumento da altura do pasto. A massa de forragem remanescente aumentou na medida em que houve incremento na altura de manejo do pasto. Foi observada diferença entre os tratamentos para palhada residual e estande inicial de plantas de soja, porém essas diferenças não afetaram o rendimento de grãos da cultura. Os resultados sugerem que a presença dos animais não prejudica o cultivo subsequente, possibilitando aumento da renda do produtor pela oportunidade de utilização das áreas durante a entressafra da soja.This trial aimed to evaluate the effects of sward height management of pastures composed by black oat and Italian ryegrass upon soybean establishment and yield. The treatments were four sward management heights: 10, 20, 30 and 40cm; and no grazing control. Pasture (sward height, herbage allowance, herbage mass, stocking rate and post grazing herbage mass and soybean (initial stand of plants and yield attributes were evaluated. The observed sward heights were very similar to those previously intended. There was a linear increase in herbage allowance and herbage mass with increasing sward height

  10. Grazing management strategies for massaigrass-forage peanut pastures: 1. dynamics of sward condition and botanical composition Estratégias de manejo do pastejo para pastos consorciados de capim-massai e amendoim forrageiro: 1. dinâmica da condição do pasto e da composição botânica

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2006-04-01

    Full Text Available This study was carried out from October 2002 to December 2003 to evaluate the dynamics of sward condition and botanical composition of a mixed massaigrass (Panicum maximum x P. infestum, cv. Massai and forage peanut (Arachis pintoi Ac 01 pasture, intermittently stocked at three daily herbage allowance levels (9.0, 14.5 and 18.4% live weight. Sward condition was characterized in each grazing cycle in terms of the pre and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, legume and weeds was evaluated before each grazing period. Sward height and forage mass increased linearly with increasing herbage allowance (HA levels, and higher values were observed during the rainy season. Percentage of bare ground increased primarily at the lowest HA level. Percentage of forage peanut increased throughout the experimental period, primarily in the barest and shortest swards, under the lowest HA level. In the last quarter of 2003 the legume constituted 23.5, 10.6 and 6.4% of the pasture forage mass, respectively, from the lowest to the highest HA level. These results suggest that forage peanut can be successfully associated with massaigrass, as long as the pre-grazing sward height is maintained shorter than 65-70 cm, which will prevent excessive shading to the legume.Este estudo foi realizado com o objetivo de avaliar a dinâmica e a composição botânica de uma pastagem consorciada de capim-massai (Panicum maximum x P. infestum, cv. Massai e amendoim forrageiro (Arachis pintoi Ac 01, manejada sob lotação rotacionada em três níveis de oferta diária de forragem (9,0; 14,5 e 18,4% do peso vivo. A condição da pastagem foi caracterizada em cada ciclo de pastejo, em termos de altura, massa de forragem e porcentagem de solo descoberto (pré e pós-pastejo. A composição botânica da pastagem (gramínea, leguminosa e invasoras foi monitorada antes de cada período de ocupação. Houve aumento linear da altura

  11. Avaliação da composição química e da digestibilidade in vitro da mistura aveia IAPAR 61 (Avena strigosa Schreb + ervilha forrageira (Pisum arvense L. em diferentes alturas sob pastejo Evaluation of chemical composition and in vitro digestibility of mixture of oat IAPAR 61 (Avena strigosa Schreb cv IAPAR 61 + field pea (Pisum arvense L. under grazing in different sward heights

    Directory of Open Access Journals (Sweden)

    Márcia Mascarenhas Grise

    2001-06-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito das alturas (8,9; 10,0; 11,2; 11,8; 13,3; 13,6; 14,6; 18,2 cm de pastos consorciados de aveia IAPAR 61 (Avena strigosa Schreb cv IAPAR 61 com ervilha forrageira (Pisum arvense L. sob pastejo sobre a relação folha/colmo (F/C, os teores de proteína bruta (PB, fibra em detergente neutro (FDN e fibra em detergente ácido (FDA e a digestibilidade in vitro da matéria seca (DIVMS e da matéria orgânica (DIVMO. O delineamento experimental usado foi o inteiramente casualizado, com duas repetições. A relação F/C não foi influenciada pela altura do pasto, porém apresentou comportamento quadrático com o avanço na maturidade do pasto. Os teores de PB apresentaram comportamento quadrático ao longo do período experimental, devido à interação entre altura do pasto e o tempo. Os teores de FDN e FDA mostraram um comportamento quadrático ao longo do período experimental, ocorrendo uma diminuição dos mesmos quando as plantas se apresentavam mais baixas e, uma elevação, quando as plantas estavam mais altas, isto ocorreu em função da interação das variáveis tempo e altura. A DIVMS e a DIVMO tiveram incrementos lineares em função do aumento da altura do pasto, porém com comportamento quadrático no tempo (dias em todas as alturas, sendo mais elevadas nas alturas intermediárias do pasto.The objective of this work was to evaluate the effect of different sward heights (8.9, 10.0, 11.2, 11.8; 13.3; 13.6; 14.6; 18.2 cm in the mixture of black oat IAPAR 61 (Avena strigosa Schreb cv IAPAR 61 + field pea (Pisum arvense L., under grazing, on leaf/stem ratio (L/S, crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF contents and dry matter (DMIVD and of organic matter (OMIVD in vitro digestibility. A completely randomized experimental design with two replicates was used. L/S ratio was not influenced by sward height, although it presented quadratic behavior with the progress of

  12. The relationship between sward structure, ingestive behavior and ...

    African Journals Online (AJOL)

    Animals adjusted biting rates to compensate for changes in bite size and thus maintained rates of intake. Bite size and dietary CP were negatively correlated. It was argued that, in the present study, leaf table height, stemminess, leaf density and leaf % were the main determinants of dietary CP and ingestive behaviour.

  13. The influence of sward competition on shoot growth and ...

    African Journals Online (AJOL)

    In each of two seasons the growth form of Senecio retrorsus plants in Natal Tall Grassveld differed in accordance with the degree of utilization of the grasses and thus the degree of competition offered. In rested veld the main stems of seedlings and mature plants were long and spindly while those in frequently clipped veld ...

  14. Choice of grazed herbage or maize silage by lactating dairy cows: influence of sward height and concentrate level Preferência por pastagem ou silagem de milho por vacas leiteiras em lactação: influência da altura do pasto e do nível de concentrado

    Directory of Open Access Journals (Sweden)

    O. Hernandez-Mendo

    2010-10-01

    Full Text Available The preference of lactating dairy cows for grazed herbage or maize silage (MS, simultaneously offered ad libitum in the field, was examined at two sward heights (SH 4-6 and 8-10cm and two concentrate levels (CL 0 and 6kg day-1 in a 2x2 factorial arrangement within a completely randomised experimental design. The experiment lasted 35 days and was carried out in spring using 24 multiparous Holstein Friesian cows. On average, the cows proportionately spent more time grazing than eating MS (0.85:0.15 and even though the higher rate of intake (RI of dry matter (DM of MS compared with grazed herbage (76 versus 26g DM min-1, the proportion of total DM intake as herbage was higher compared to that of MS (0.56:0.44. The higher crude protein and low fibre content of grazed herbage appeared to have a higher priority of choice than RI, as the cows chose to graze for longer (grazing time 385 min, MS feeding time 67min despite the lower RI of herbage. The low proportion MS intake indicated that RI was a secondary factor of choice. Concentrate supplementation had a greater depressing effect on herbage intake than on MS intake. These results suggest that the animals reduce the intake of feed with lower RI when the labor associated to eat is decreased. The factors influencing the choice for herbage over maize silage remain unclear.A preferência de vacas leiteiras em lactação por pasto ou silagem de milho (SM oferecidas ad libitum simultaneamente no pasto foi avaliada quanto a duas alturas de pastagem (4-6 e 8-10cm e dois níveis de concentrado (0 e 6kg dia-1, em um arranjo fatorial 2x2 dentro de um delineamento inteiramente ao acaso. O experimento, com duração de 35 dias, foi executado na primavera utilizando 24 vacas multíparas da raça Holandesa. As vacas passaram, em média, proporcionalmente mais tempo pastando do que comendo SM (0,85:0,15 e, mesmo considerando a maior taxa de consumo (TC de matéria seca (MS de SM comparada com a da pastagem (76

  15. Plant mortality and natural selection may increase biomass yield in switchgrass swards

    Science.gov (United States)

    Switchgrass (Panicum virgatum L.) is an important candidate for bioenergy feedstock production, prompting significant efforts to increase the number of breeding programs and the output of those programs. The objective of this experiment was to determine the potential utility of natural selection for...

  16. Symbiotic dinitrogen fixation measurement in vetch-barley mixed swards using 15 N methodology

    International Nuclear Information System (INIS)

    Kurdali, F.; Sharabi, N.E.

    1995-01-01

    Field experiment on vetch and barley grown in monoculture and in mixed culture (3:1) under rain-fed conditions was conducted in 1991-1992 and 1992-1993 growing season. Three harvests were effectuated on one treatment throughout the growing season. While, other plots were harvested once at physiological maturity stage. Our results showed the importance of mixed cropping system of vetch and barley grown under rain fed conditions in terms of dry matter production, total nitrogen content and land use efficiency expressed as land equivalent ration (L.E.R). This advantage is clear in the plants harvested once at the end of the season. Therefore, it is important to grow legumes and cereals under rain fed conditions and to be left until late stage of growth and fed by animals directly. On the other hand, only two harvests could be done in the season with no additional harvests because this may weaken the plant growth, and as a result of the last approach we will obtained poor production due to unpredicated an appropriate rain fall after the second harvest (April). Nitrogen fixation efficiency in vetch measured by sup 1 sup 5 N isotop dilution method varied with the number of harvests and the procedure adopted in culture. Comparing the results of %Ndfa of vetch between monoculture and mixed culture showed that the values in most cases were higher in mixed culture. The competition between vetch and barley in the mixed stand for soil N-uptake made the barley supplements its N requirements from soil. The poor competitiveness of vetch capability for soil N-uptake enhanced it to fix more nitrogen. On the other hand, N residual after harvest was higher in the mixed treatment than the others. Positive and high final nitrogen balance were observed with the inclusion of vetch in the mixture. We excluded, under the current experimental conditions, the possibility of N-transfer from vetch to barley due to the insignificant differences in the value of sup 1 sup 5 N atom excess for barley between the two types of farming. (author). 35 refs., 2 figs., 15 tabs

  17. Dinitrogen fixation estimates in Vetch-barley swards using {sup 15} N-methodology

    Energy Technology Data Exchange (ETDEWEB)

    Kurdali, F; Sharabi, N E [Atomic Energy Commission, P.O.Box 6091, Damascus, (Syrian Arab Republic)

    1995-10-01

    N 2- fixation in vetch (Vicia Sativa) grown alone and in mixture with barley (hordeum vulgare) in pots was evaluated using {sup 15} N isotope dilution method. Two harvests were made over the growing season. The proportion of the above-ground N, derived from atmospheric N 2 (% Ndfa) in mixed vetch was significantly higher than that of vetch in pure culture for the different harvests. However, this increase was not accompanied with the amount of N 2-fixation. On the other hand, no significant differences were observed in N-content or in N-derived from soil between barley grown in mixture and in monoculture, in spite of the difference in the number of plants between the tow cropping systems. These results indicate a high competing capacity of barley for soil nitrogen in mixed culture. Barley grown together with vetch had lower atom % 15 N excess than barley grown in mono-culture because it may have received some of their N from N-released by the legume in the second herbage but not in the first. Overall, results obtained from this experiment indicate the importance of mixed crops for forage production. Based on these results, further investigation must carried out in the field. 1 fig.

  18. Tall swards and small grazers : competition, facilitation and coexistence of different-sized grazers

    NARCIS (Netherlands)

    Heuermann, N.

    2007-01-01

    Differences in body mass are assumed to be a major factor leading to resource partitioning and the reduction of competition between species within a guild. To study the effects of body mass on foraging behaviour of grazers independently of morphological adaptations we used intra-specific size

  19. Evaluation of a Rising Plate Meter for Use in Multispecies Swards

    Directory of Open Access Journals (Sweden)

    S. Leanne Dillard

    2016-11-01

    Full Text Available The rising plate meter (RPM provides rapid estimates of herbage mass (HM. Accurate calibration of the RPM is difficult due to variability in forage management, growth, and species composition. The RPM is typically calibrated by linear regression of HM and RPM height; however, the is usually low. Curvilinear regression, with the intercept set to zero, could provide a more robust calibration equation and decrease variability in RPM estimates. Three Pennsylvania organic dairy farms grazing lactating dairy cattle on multispecies pastures were used to determine measured HM and estimated HM using a RPM. Removal of the intercept increased the adjusted of all equations between 42.8 and 89.0%. Use of quadratic and cubic regression only resulted in 0.01 to 0.02 increase in adjusted . Linear regression remains the simplest and preferred method of calibration; however, error can be reduced by setting calibration equations so that zero RPM height is associated with zero HM.

  20. Symbiotic dinitrogen fixation measurement in vetch-barley mixed swards using {sup 15} N methodology

    Energy Technology Data Exchange (ETDEWEB)

    Kurdali, F; Sharabi, N E [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Radiation Agriculture

    1995-01-01

    Field experiment on vetch and barley grown in monoculture and in mixed culture (3:1) under rain-fed conditions was conducted in 1991-1992 and 1992-1993 growing season. Three harvests were effectuated on one treatment throughout the growing season. Our results showed the importance of mixed cropping system of vetch and barley grown under rain fed conditions in terms of dry matter production, total nitrogen content and land use efficiency expressed as land equivalent ration (L.E.R). This advantage is clear in the plants harvested once at the end of the season. Therefore, it is important to grow legumes and cereals under rain fed conditions and to be left until late stage of growth and fed by animals directly. On the other hand, only two harvests could be done in the season with no additional harvests because this may weaken the plant growth, and as a result of the last approach we obtained poor production due to unpredicated an appropriate rain fall after the second harvest (April). Nitrogen fixation efficiency in vetch measured by {sup 1 5} N isotope dilution method varied with the number of harvests and the procedure adopted in culture. Comparing the results of %Ndfa of vetch between monoculture and mixed culture showed that the values in most cases were higher in mixed culture. The competition between vetch and barley in the mixed stand for soil N-uptake made the barley supplements its N requirements from soil. The poor competitiveness of vetch capability for soil N-uptake enhanced it to fix more nitrogen. On the other hand, N residual after harvest was higher in the mixed treatment than the others. Positive and high final nitrogen balance were observed with the inclusion of vetch in the mixture. We excluded, under the current experimental conditions, the possibility of N-transfer from vetch to barley due to the insignificant differences in the value of {sup 1 5} N atom excess for barley between the two types of farming. 35 refs., 2 figs., 15 tabs.

  1. The response of sward-dwelling arthropod communities to reduced grassland management intensity in pastures

    Directory of Open Access Journals (Sweden)

    Helden Alvin J.

    2015-12-01

    Full Text Available We compared arthropod taxon richness, diversity and community structure of two replicated grassland husbandry experiments to investigate effects of reduced management intensity, as measured by nutrient input levels (390, 224 and 0 kg/ha per year N in one experiment, and 225 and 88 kg/ha per year N in another. Suction sampling was used to collect Araneae, Coleoptera, Hemiptera and Hymenoptera, with Araneae and Coleoptera also sampled with pitfall trapping. Univariate analyses found no significant differences in abundance and species density between treatments. However, with multivariate analysis, there were significant differences in arthropod community structure between treatments in both experiments.

  2. Fatty acid, tocopherol and carotenoid content in herbage and milk affected by sward composition and season of grazing

    DEFF Research Database (Denmark)

    Larsen, Mette Krogh; Fretté, Xavier; Kristensen, Troels

    2012-01-01

    BACKGROUND: The aim of the present work was to study to what extent grazing large amounts ofwhite clover (WCL), red clover (RCL), lucerne (LUC) or chicory (CHI) was suitable for production of bovine milk with a high milk fat content of tocopherols, carotenoids, α-linolenic acid and conjugated......), carotenoids (6 μg g−1) and α-tocopherol (21 μg g−1 milk fat). There were minor differences between herbage types and periods, but multivariate analysis of these data showed no clear grouping. Chemical composition of herbage varied with species as well as period, but it was not possible to relatemilk and feed...... contents of specific fatty acids, carotenoids or tocopherols. CONCLUSION: All four herbages tested were suitable for production of milk with a high content of beneficial compounds. Thus any of these herbages could be used in production of such differentiated milk based on a large proportion of grazing...

  3. Estimating the content of clover and grass in the sward using a consumer camera and image processing

    DEFF Research Database (Denmark)

    Mortensen, Anders Krogh; Karstoft, Henrik; Søegaard, Karen

    the dry matter ratio of clover and grass in clover grass fields from sparse close up images. First, the light conditions is determined, which is used for selecting model parameters to estimate the coverage of both clover and grass. Next, the clover and grass coverage are transformed to give the dry matter...

  4. Sward characteristics and performance of dairy cows in organic grass-legume pastures shaded by tropical trees.

    Science.gov (United States)

    Paciullo, D S C; Pires, M F A; Aroeira, L J M; Morenz, M J F; Maurício, R M; Gomide, C A M; Silveira, S R

    2014-08-01

    The silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate pasture characteristics, herbage intake, grazing activity and milk yield of Holstein×Zebu cows managed in two grazing systems (treatments): SPS dominated by a graminaceous forage (Brachiaria decumbens) intercropped with different leguminous herbaceous forages (Stylosanthes spp., Pueraria phaseoloides and Calopogonium mucunoides) and legume trees (Acacia mangium, Gliricidia sepium and Leucaena leucocephala), and open pasture (OP) of B. decumbens intercropped only with Stylosanthes spp. Pastures were managed according to the rules for organic cattle production. The study was carried out by following a switch back format with 12 cows, 6 for each treatment, over 3 experimental years. Herbage mass was similar (P>0.05) for both treatments, supporting an average stocking rate of 1.23 AU/ha. Daily dry matter intake did not vary (P>0.05) between treatments (average of 11.3±1.02 kg/cow per day, corresponding to 2.23±0.2% BW). Milk yield was higher (P0.05) in subsequent years. The highest (P0.05) milk yields. Low persistence of Stylosanthes guianensis was observed over the experimental period, indicating that the persistence of forage legumes under grazing could be improved using adapted cultivars that have higher annual seed production. The SPS and a diversified botanical composition of the pasture using legume species mixed with grasses are recommended for organic milk production.

  5. Effect of the type of silage on milk yield, intake and rumen metabolism of dairy cows grazing swards with low herbage mass.

    Science.gov (United States)

    Ruiz-Albarrán, Miguel; Balocchi, Oscar A; Noro, Mirela; Wittwer, Fernando; Pulido, Rubén G

    2016-07-01

    The aim of this study was to evaluate the effect of herbage allowance (HA) and type of silage supplemented (TS) on milk yield, dry matter intake (DMI) and metabolism of dairy cows in early lactation. Thirty-six Holstein-Friesian dairy cows were allocated to four treatments derived from an arrangement of two HA (LHA = 17 or HHA = 25 kg of DM/cow/day) and two TS (grass (GS) or maize (MS)). Herbage allowance had no effect on DMI or milk yield. Rumen pH and NH3 -N concentration were not affected by HA. The efficiency of microbial protein synthesis in the rumen (microbial protein (MP)) was affected by HA with 21.5 and 23.9 g microbial nitrogen per kg ruminal digestible organic matter for LHA and HHA, respectively (P content by 0.10 % (P < 0.023) and herbage DMI by 2.2 kg/cow/day, and showed lower values for milk urea compared to GS (P < 0.001). The former results suggest that TS had a greater effect on milk yield, total feed intake and energy intake than increase in herbage allowance; however, increase in HA had greater effects on MP than TS. © 2015 Japanese Society of Animal Science.

  6. Nitrate leaching and residual effect in dairy crop rotations with grass-clover leys as influenced by sward age, grazing, cutting and fertilizer regimes

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Rasmussen, Jim

    2015-01-01

    Intensive dairy farming, with grass-arable crop rotations is challenged by low N use efficiency that may have adverse environmental consequences. We investigated nitrate leaching and N fertility effects of grass–clover leys for five years in two organic crop rotations with different grassland...... with the 2-yr-old leaching the most (36–46 kg N ha−1), and (4) high leaching (>50 kg N ha−1) with lupin and maize, where especially maize was consistently high in all five years (average 81 kg N ha−1). Great care should be taken during all phases of the dairy crop rotation where grasslands cause considerable...... build-up of fertility. With due care and the best management practice, nitrate leaching losses may be reduced to low levels....

  7. Effect of strategies regarding concentrate supplementation and day-time grazing on N utilization at both field and dairy cow level

    DEFF Research Database (Denmark)

    Lund, Peter; Søegaard, Karen; Weisbjerg, Martin Riis

    2008-01-01

    N utilization at cow and field level was examined over two grazing periods of 30 days with 64 Holstein dairy cows. At cow and field level the effect of sward type (diploid vs. tetraploid perennial ryegrass, both mixed with white clover) and compressed sward height (6 vs. 10 cm) was examined....

  8. Perennial ryegrass for dairy cows: effects of cultivar on herbage intake during grazing

    NARCIS (Netherlands)

    Smit, H.J.

    2005-01-01

    Keywords:Perennial ryegrass, Lolium perenne , sward morphology, sward cutting, n-alkanes, herbage intake, selection, preference.Perennial ryegrass ( Lolium perenne L.) is the most important species for feeding dairy cows. The majority of the farmers in the Netherlands graze their

  9. Effect of pasture botanical composition on milk composition in organic production

    DEFF Research Database (Denmark)

    Adler, S.; Dahl, A.V.; Vae, A.H.

    2010-01-01

    Milk samples from sixteen Norwegian Red dairy cows grazing mixed swards of either grass-red clover (GR) or mixed swards of sown and unsown species of grass, clover and other herbs (GCH) were collected during four periods. Both pastures were organically managed. Pasture botanical composition had...

  10. Effect of application timing and grass height on the nitrogen fertilizer replacement value of cattle slurry applied with a trailing-shoe application system

    NARCIS (Netherlands)

    Lalor, S.T.J.; Schroder, J.J.; Lantinga, E.A.; Schulte, R.P.O.

    2014-01-01

    This study investigated the effect of using a trailing-shoe system to apply cattle slurry, under different conditions of grass height (low [LG]: freshly cut sward [4–5 cm height] vs. high [HG]: application delayed by 7–19 d and applied to taller grass sward [4–11 cm] height) and month of application

  11. The nutritive value, yield and botanical composition of irrigated ...

    African Journals Online (AJOL)

    The performances of grass and grass/legume swards at three levels of nitrogen were compared under irrigation over a three-year period. The swards were grazed by dairy cows and the influence of nitrogen on dry matter yield, protein content, protein yield and botanical composition was measured. Keywords: ...

  12. Time of mowing and burning veld: short term effects on production ...

    African Journals Online (AJOL)

    In a comparison of mowing and burning as removal treatments in the Natal Tall Grassveld, mowing proved to be superior to burning in terms of sward productivity in the season following the removal treatment, but burning was responsible for a sward of higher protein content, at least during the early part of the season.

  13. Ecology of grazing lawns in Africa

    CSIR Research Space (South Africa)

    Hempson, GP

    2014-09-01

    Full Text Available otherwise outcompete lawn species for light. Regular grazing that prevents shading and maintains sward quality is thus the cornerstone of grazing lawn dynamics. The strong interplay between abiotic conditions and disturbance factors, which are central...

  14. The Impact of Harvest Frequency on Herbage Yield and Quality of ...

    African Journals Online (AJOL)

    User

    This can be achieved by maximising forage production through appropriate harvest management .... seasons and T1 was to estimate DM yield if sward remains undisturbed until the ... was the above ground biomass yield (ton ha-1). Harvested ...

  15. Assessment of some macromineral concentration of a grass/ legume ...

    African Journals Online (AJOL)

    Assessment of some macromineral concentration of a grass/ legume sward in ... Bulletin of Animal Health and Production in Africa ... The study aimed to determine the concentration of some macromineral elements in the grass/legume pasture ...

  16. Canopy characteristics, animal behavior and forage intake by goats grazing on Tanzania-grass pasture with different heights - doi: 10.4025/actascianimsci.v34i4.14544

    Directory of Open Access Journals (Sweden)

    Maurílio Souza dos Santos

    2012-10-01

    Full Text Available This study evaluated the influence of Tanzania-grass sward height (30, 50, 70 and 90 cm on the morphological characteristics of the canopy, grazing behavior and forage intake by adult Anglo Nubian female goats. A completely randomized experimental design was employed, with two replicates in space and two replicates in time. Six animals were used to assess the grazing behavior, and four, the ingestion process. The rise in sward height increased the forage and leaf mass, the percentages of stem and dead material, and reduced the leaf stem-1 ratio. Above 50 cm there was an increase in grazing time and a decrease in leisure time. A positive linear correlation was detected between sward height and bite depth. The consumed forage mass, ingestion rate and daily intake were higher at 50 cm, indicating that the other heights reduced the intake process. The sward height was negatively correlated to the bite rate and positively to the bite time. The sward height of 50 cm presents the best combination of features, favoring the grazing and ingestive behavior of female adult goats.

  17. Dinitrogen fixation in white clover grown in pure stand and mixture with ryegrass estimated by the immobilized 15N isotope dilution method

    DEFF Research Database (Denmark)

    Jørgensen, F.V.; Jensen, E.S.; Schjørring, J.K.

    1999-01-01

    Dinitrogen fixation in white clover (Trifolium repens L.) grown in pure stand and mixture with perennial ryegrass (Lolium perenne L.) was determined in the field using N-15 isotope dilution and harvest of the shoots. The apparent transfer of clover N to perennial ryegrass was simultaneously...... assessed. The soil was labelled either by immobilizing N-15 in organic matter prior to establishment of the sward or by using the conventional labelling procedure in which N-15 fertilizer is added after sward establishment. Immobilization of N-15 in the soil organic matter has not previously been used...

  18. Herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Meijs, J.A.C.

    1981-01-01

    An extensive review of the literature is given of
    - nine possible methods for estimating herbage intake by grazing ruminants, with special attention to the sward-cutting and indirect animal methods
    - the factors determining the herbage intake by grazing ruminants.

    The

  19. Lidar-derived variables as a proxy for fungal species richness and composition in temperate Northern Europe

    DEFF Research Database (Denmark)

    Thers, Henrik; Brunbjerg, Ane Kirstine; Læssøe, Thomas

    2017-01-01

    . Lidar-derived variables performed best in predicting fungal richness and the first ordination axis, interpreted as a gradient from low and open herb-dominated communities over closed swards and scrubs to closed-canopy forests (cross validated r2 of 0.50 and 0.81, respectively). The number of red...

  20. Cultivar effects of perennial ryegrass on herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.

    2006-01-01

    Perennial ryegrass is the most abundant grass species in temperate climates. An increased herbage intake of dairy cows by breeding new cultivars could have a large potential impact on agriculture. The effects of cultivars on sward structure, nutritive value, physical characteristics and disease

  1. Water-soluble carbohydrates and in vitro digestibility of annual ryegrass (Lolium ridigum Gaudin) sown at varying densities

    NARCIS (Netherlands)

    Smouter, H.; Simpson, R.J.; Pear, G.R.

    1995-01-01

    An experiment is described in which the tiller density of microswards of Lolium rigidum was varied by altering planting density. The treatments were expected to alter the interplant competition for light and thus affect the concentration of water-soluble carbohydrates (WSC) of the grass swards.

  2. Effect of stocking pressure on selected diet quality, intake and ...

    African Journals Online (AJOL)

    ABUBAKER

    with quality, sward structure, availability and the type, size and productivity of the animal ... 1997), and determine grazing animal productivity and efficiency of production. ... This is important for pasture maintenance and improving animal performance. .... which would influence the quality of the overall diet of the lambs.

  3. Appreciation of the functions of grasslands by Irish stakeholders

    NARCIS (Netherlands)

    Hennessy, D.; Pol-van Dasselaar, van den A.

    2014-01-01

    The European project MultiSward studied the appreciation of different functions of grasslands by European stakeholders. This paper describes the importance of grasslands for stakeholders in Ireland. Ireland currently has approximately 4.6 million ha of grassland, which is 90% of the total utilized

  4. Alpha-tocopherol and β-carotene in legume-grass mixtures as influenced by wilting, ensiling and type of silage additive

    DEFF Research Database (Denmark)

    Lindqvist, H; Nadeau, E; Jensen, Søren Krogh

    2012-01-01

    Effects of wilting, ensiling and type of additive on α-tocopherol and β-carotene contents in legume–grass mixtures were examined. Swards of birdsfoot trefoil + timothy (Bft + Ti), red clover + timothy (Rc + Ti) and red clover + meadow fescue (Rc + Mf) were harvested as a first regrowth in August...

  5. Experimental Evidence Shows the Importance of Behavioural Plasticity and Body Size under Competition in Waterfowl

    Science.gov (United States)

    Zhang, Yong; Prins, Herbert H. T.; Versluijs, Martijn; Wessels, Rick; Cao, Lei; de Boer, Willem Frederik

    2016-01-01

    When differently sized species feed on the same resources, interference competition may occur, which may negatively affect their food intake rate. It is expected that competition between species also alters behaviour and feeding patch selection. To assess these changes in behaviour and patch selection, we applied an experimental approach using captive birds of three differently sized Anatidae species: wigeon (Anas penelope) (~600 g), swan goose (Anser cygnoides) (~2700 g) and bean goose (Anser fabalis) (~3200 g). We quantified the functional response for each species and then recorded their behaviour and patch selection with and without potential competitors, using different species combinations. Our results showed that all three species acquired the highest nitrogen intake at relatively tall swards (6, 9 cm) when foraging in single species flocks in the functional response experiment. Goose species were offered foraging patches differing in sward height with and without competitors, and we tested for the effect of competition on foraging behaviour. The mean percentage of time spent feeding and being vigilant did not change under competition for all species. However, all species utilized strategies that increased their peck rate on patches across different sward heights, resulting in the same instantaneous and nitrogen intake rate. Our results suggest that variation in peck rate over different swards height permits Anatidae herbivores to compensate for the loss of intake under competition, illustrating the importance of behavioural plasticity in heterogeneous environments when competing with other species for resources. PMID:27727315

  6. Nitrogen distribution as affected by stocking density in a combined production system of energy crops and free-range pigs

    DEFF Research Database (Denmark)

    Jørgensen, Uffe; Thuesen, Janni; Eriksen, Jørgen

    2018-01-01

    Free-range pig production is typically associated with high risks of nitrogen (N) leaching due to the pigs excretory behaviour creating nitrogen ‘hotspots’ and rooting behaviour destroying the grass sward. This challenge is reinforced at high animal densities causing high nitrogen deposition. A c...

  7. Volume 9 Number 2

    African Journals Online (AJOL)

    OLUWOLE

    insufficient energy reserves for regrowth (Jung et al., 1994). ... temperature, solar radiation, relative humidity, ... Hydrogen. 3.2. Aluminium. 0.8. C.E.C.. 8.4. Month. Jan. Feb. March. Apr. May .... the year, the pure verano stylo swards produced.

  8. PROTEIN AND/OR ENERGY SUPPLEMENTATION OF LACTATING ...

    African Journals Online (AJOL)

    intake of a lactating beef cow and the chemical composttion of'the grass sward, it was cstimated that the veld supplred 90 per ccnt.65 ... (iv) a low calcium and phosphate content of the veld ... cent for those on a high energy-low protein diet.

  9. The Potch System: An approach to the management of semi-arid ...

    African Journals Online (AJOL)

    A host of grassland management systems have been published and recommended. Whereas earlier approaches to grassland management emphasized the systematic resting aspect, the systems published since 1966 have tended to stress the degree of utilization of the grassland sward. In an attempt to accommodate the ...

  10. RESEARCH NOTE THE PERFOR]\\IANCE DURING WINTER, OF ...

    African Journals Online (AJOL)

    THE PERFOR]\\IANCE DURING WINTER, OF HETFERS FED GRASS SILAGE, MADE UNDER. UNFAVOURABLE WEATHER CONDITIONS AND E. curvula HAY, PRODUCED. FROM THE SAME SWARD. Receipt of MS: 06-10-1981. A. van Niekerk. Cedara Agriculrural Research Station, PlBag X9059, Pietermaritzburg ...

  11. Fatty acid profile in vertical strata of elephant grass subjected to intermittent stocking

    Directory of Open Access Journals (Sweden)

    KAMILA M. DIAS

    2017-08-01

    Full Text Available ABSTRACT The milk and meat from animals with a pasture-based diet have higher proportions of CLA and C18:3 and lower omega-6:omega-3 ratios than products from animals with diets based on corn silage and concentrate. However, most of the published studies have evaluated fatty acid profiles in temperate climate grasses and the literature with tropical grasses is scarce. Thus, the aim of this study was to evaluate the morphological and fatty acid compositions in the vertical strata of elephant grass (Pennisetum purpureum Schum. swards subjected to grazing heights (90 or 120 cm pre-grazing heights and levels of defoliation (50% or 70% removal of the initial pre-grazing height. There were no interactions among pre-grazing height, the level of defoliation and grazing stratum. However, higher proportion of C18:3 (58% and 63% was found in the 90-cm swards and in the half upper stratum. A higher proportion of C18:3 was associated with a higher leaf proportion and crude protein content. Thus, the upper stratum of sward or a grazing management scheme (e.g. first-last stocking resulting in a higher proportion of leaves and crude protein both provide higher proportions of C18:3 to animals grazing in elephant grass swards.

  12. Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

    DEFF Research Database (Denmark)

    Schulze, A.K.S.; Nørgaard, P.; Byskov, M.V.

    2015-01-01

    The physical structure value of conserved grass/clover forages of spring harvest was evaluated by assessing effects of harvest time, conservation method, iNDF/NDF ratio and NDF intake (NDFI) per kg BW on chewing activity and fecal particle size in dairy heifers. A mixed sward consisting of ryegrass...

  13. The effect of fire, with and without subsequent defoliation on the ...

    African Journals Online (AJOL)

    On plots where the burn was followed by an 8-weekly clipping treatment, a slower biomass accumulation rate of the sward as a whole was recorded than on burnt plots allowed unchecked post-fire regrowth. The lowest rate was recorded on unburnt plots allowed unchecked growth. The burn plus 8-weekly clipping reduced ...

  14. Establishing vegetation on Kimberlite mine tailings: 2. Field trials. | N ...

    African Journals Online (AJOL)

    A series of field experiments were carried out on Kimberlite mine tailing located at Cullinan in the Transvaal. The most successful species in pure sward were Chloris gayana, Cynodon aethiopicus, Eragrostis curvula, E. tef, Pennisetum purpureum, Melilotus alban and Medicago sativa. Growth of grasses in the absence of ...

  15. Possibilities and constraints for grazing in high output dairy systems

    NARCIS (Netherlands)

    Hennessy, D.; Delaby, L.; Pol, van den A.; Shalloo, L.

    2015-01-01

    In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of

  16. Spatial ecology and habitat selection of Little Owl Athene noctua during the breeding season in Central European farmland

    Czech Academy of Sciences Publication Activity Database

    Šálek, Martin; Lövy, M.

    2012-01-01

    Roč. 22, č. 3 (2012), s. 328-338 ISSN 0959-2709 Institutional support: RVO:68081766 Keywords : Little Owl * home range size * habitat use * compositional analysis * grasslands * short-sward vegetation Subject RIV: EG - Zoology Impact factor: 1.074, year: 2012

  17. Bulletin of Animal Health and Production in Africa

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... Log in or Register to get access to full text downloads. ... Assessment of some macromineral concentration of a grass/ legume sward in relation to ... Single nucleotide polymorphisms in two TLR genes and their effects on ...

  18. Effect of processed cereal grains as a supplement on grass intake, rumen pool sizes, ruminal kinetics and the performance of grazing lactating dairy cows

    NARCIS (Netherlands)

    Tothi, R.; Zhang, R.H.; Chilibroste, P.; Boer, H.; Tamminga, S.

    2003-01-01

    Five multiparous lactating Holstein-Friesian dairy cows fitted with rumen cannula were allowed to graze perennial ryegrass swards. Next to a control treatment of grazing only, pelleted barley (PB), pelleted maize (PM), toasted and subsequently pelleted barley (TPB), and toasted and subsequently

  19. Tensile fracture properties of seven tropical grasses at different phenological stages

    NARCIS (Netherlands)

    Jacobs, A.A.A.; Scheper, J.A.; Benvenutti, M.A.; Gordon, I.J.; Poppi, D.P.; Elgersma, A.

    2011-01-01

    The intake of forage grasses by grazing ruminants is closely related to the mechanical fracture properties of grasses. The relationship between the tensile fracture properties of grasses and foraging behaviour is of particular importance in tropical reproductive swards composed of both stems and

  20. Comparison of techniques for estimating herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.; Taweel, H.Z.; Tas, B.M.; Tamminga, S.; Elgersma, A.

    2005-01-01

    For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments in 2002 and 2003 with the recently developed n-alkanes technique and with the net energy method. The first method estimates herbage intake by the difference between the herbage

  1. The performance of lambs on kikuyu as influenced by stocking rate ...

    African Journals Online (AJOL)

    C.C.&Graham,. M. Proc. of a workshop held in Ottawa, Canada, p. 49. WRIGHT, W.A. & RUSSEL, A.J.F., 1987. The effect of sward height on beef cow performance and on the relationship between calf milk and herbage intake. Anim. P rutd.

  2. Gradients in fracture force and grazing resistance across canopy layers in seven tropical grass species

    NARCIS (Netherlands)

    Jacobs, A.A.A.; Scheper, J.A.; Benvenutti, M.A.; Gordon, I.J.; Poppi, D.P.; Elgersma, A.

    2013-01-01

    In reproductive swards, stems can act as a barrier that affects the grazing behaviour of ruminant livestock. The barrier effect of stems is closely associated with both the force required to fracture the stems and the density of these stems (in combination, these make up grazing resistance), and

  3. Assessment of the disc pasture meter on natural veld in the False ...

    African Journals Online (AJOL)

    The use of the standard disc pasture meter is found to be a reliable technique for estimating the yield of the densely tufted grass swards found in the False Thornveld of the Eastern Province. It compares favourably with traditional methods of yield estimation in the veld type and its attractiveness lies in the rapidity with which ...

  4. Estimating grass fuel loads with a disc pasture meter in the Kruger ...

    African Journals Online (AJOL)

    Reports the results of a study conducted to assess the efficiency of a new calibration procedure for the disc pasture meter, used for estimating the fuel load available for combustion during fires; The major portion of the fuel load in the savanna areas comprises surface fuels in the form of the standing grass sward. The disc ...

  5. Tree growth studies on uranium mill tailings

    International Nuclear Information System (INIS)

    Murray, D.R.; Turcotte, M.

    1982-01-01

    Coniferous trees planted in 1974 and deciduous species that have volunteered since 1970 on uranium mill tailings that had been stabilized to varying degrees using limestone and vegetation were evaluated. Their survival and growth rates were compared with those from other investigations. Competition for light appears to be a major contributor to mortality. Differences in soil moisture conditions under a tree stand as compared to those under a grass sward are potentially significant enough to affect the tailings hydrology and effluent contamination. Recommendations include planting seeds of deciduous species or deciduous and coniferous seedlings on strips of freshly disturbed tailings. The disturbed strips would provide reduced competition for the initial year and assist in tree survival. The planting of block stands of coniferous or deciduous trees would be useful for evaluating the hydrological impact of the trees as compared to the present grass sward

  6. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman

    2016-01-01

    with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N......A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized...... carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground...

  7. High-Order Numerical Methods for the Simulation of Linear and Nonlinear Waves: High-Frequency Radiation and Dynamic Stability

    Energy Technology Data Exchange (ETDEWEB)

    Nicholls, David P. [UIC-MSCS

    2014-04-23

    Over the past four years the Principal Investigator (PI) David Nicholls has worked on several projects in connection with award DE-SC0001549. Of the greatest import has been the continued supervision of ve Ph.D. students (Robyn Canning, Travis McBride, Andrew Sward, Zheng Fang, and Venu Tammali). Canning and McBride defended their theses and graduated in May 2012, while Sward defended his thesis and graduated in May 2013. Both Fang and Tammali plan to defend their theses within the year and graduate in May 2015. Fang is now a very experienced graduate researcher with one paper accepted for publication and another in preparation. Tammali is nearly to the point of writing a paper and will work this summer as an intern at Argonne National Laboratory in the Mathematics and Computer Science Division under the supervision of Paul Fischer.

  8. Revegetation of metalliferous mine spoil contaminated by lead and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M S; McNeilly, T; Putwain, P D

    1977-04-01

    Plant growth and development on metalliferous mine spoil is restricted by the high concentrations of phytotoxic metals and by the low levels of macronutrients in the substrates. Swards established on innocuous amendments applied to the surface of mine spoil deteriorate when roots penetrate to the underlying toxic substratum. This deterioration is attributed to the accumulation of toxic metals. The rate of decline is determined by the inherent fertility of the amendment and the depth to which it is applied. Results of field trials on calcareous and acidic lead/zinc spoils indicate that inert amendments may be more suitable where revegetation is for amenity or recreational purposes. Legumes are essential components of low-maintenance swards established on substrates of low nutrient status.

  9. Effects of species diversity on seasonal variation in herbage yield and nutritive value of seven binary grass-legume mixtures and pure grass under cutting

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2016-01-01

    Intensively managed sown temperate grasslands are generally of low species diversity, although swards based on grass-legume mixtures may have superior productivity and herbage quality than grass-only swards. We conducted a cutting experiment over two years to test the effect of species composition...... and diversity on herbage yield, contents of N, neutral detergent fibre (NDF) and in vitro organic matter digestibility (IVOMD). Perennial ryegrass (PR, Lolium perenne) was sown alone and with each of four forage legumes: red clover (RC, Trifolium pratense), lucerne (LU, Medicago sativa), birdsfoot trefoil (BT......, Lotus corniculatus) and white clover (WC, Trifolium repens); WC was also sown with hybrid ryegrass (HR, Lolium × boucheanum), meadow fescue (MF, Festuca pratensis) and timothy (TI, Phleum pratense). Herbage productivity was lowest in pure PR followed by PR/BT, and highest in PR/RC; this mixture had...

  10. Bite frequency measured by head pitch movements in grazing experiment

    DEFF Research Database (Denmark)

    Oudshoorn, Frank W.; S. Nadimi, Esmaeil; Jørgensen, Rasmus Nyholm

    2010-01-01

    . ECPLF      2007 Skiathos, Greece. p 111-116 Pulido, R.G. & Leaver, J.D., 2001. Quantifying the influence of sward height, concentrate level and initial      milk yield on the milk production and grazing behaviour of continuously stocked dairy cows. Grass      and Forage Science 56, 57-67.    ...

  11. On mobility of cesium-137, sodium, potassium in various types of soils and prediction of cesium-137 cumulation in agricultural plants

    International Nuclear Information System (INIS)

    Ashkinazi, Eh.I.

    1990-01-01

    Mobility of cesium-137, sodium and potassium in the natural environment in podzolic gray and chernozem medium-loamy, sward podzolic sandy soils and chernozem has been studied. Durability of fixation of cesium-137 increases in a number of soils and increase of the level of metabolic potassium. Coefficient of transition of level of metabolic cesium-137 by potassium and sodium, and of sodium by potassium. The mentioned above coefficients can be used for the prediction of cesium-137 cumulation in plants

  12. Strategic grazing management towards sustainable intensification at tropical pasture-based dairy systems.

    Science.gov (United States)

    Congio, Guilhermo F S; Batalha, Camila D A; Chiavegato, Marília B; Berndt, Alexandre; Oliveira, Patrícia P A; Frighetto, Rosa T S; Maxwell, Thomas M R; Gregorini, Pablo; Da Silva, Sila C

    2018-05-01

    Agricultural systems are responsible for environmental impacts that can be mitigated through the adoption of more sustainable principles. Our objective was to investigate the influence of two pre-grazing targets (95% and maximum canopy light interception during pasture regrowth; LI 95% and LI Max , respectively) on sward structure and herbage nutritive value of elephant grass cv. Cameroon, and dry matter intake (DMI), milk yield, stocking rate, enteric methane (CH 4 ) emissions by Holstein × Jersey dairy cows. We hypothesized that grazing strategies modifying the sward structure of elephant grass (Pennisetum purpureum Schum.) improves nutritive value of herbage, increasing DMI and reducing intensity of enteric CH 4 emissions, providing environmental and productivity benefits to tropical pasture-based dairy systems. Results indicated that pre-sward surface height was greater for LI Max (≈135 cm) than LI 95% (≈100 cm) and can be used as a reliable field guide for monitoring sward structure. Grazing management based on LI 95% criteria improved herbage nutritive value and grazing efficiency, allowing greater DMI, milk yield and stocking rate by dairy cows. Daily enteric CH 4 emission was not affected; however, cows grazing elephant grass at LI 95% were more efficient and emitted 21% less CH 4 /kg of milk yield and 18% less CH 4 /kg of DMI. The 51% increase in milk yield per hectare overcame the 29% increase in enteric CH 4 emissions per hectare in LI 95% grazing management. Thereby the same resource allocation resulted in a 16% mitigation of the main greenhouse gas from pasture-based dairy systems. Overall, strategic grazing management is an environmental friendly practice that improves use efficiency of allocated resources through optimization of processes evolving plant, ruminant and their interface, and enhances milk production efficiency of tropical pasture-based systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Post Gliphosate treatments establishment of some grasses

    OpenAIRE

    Ioan ROTAR; Mariana RUSU; Fl. PRICA

    1997-01-01

    The sward dominated by Festuca rubra/Agrostis tenuis was treated to reduce the Nardus component and others weed by spraying with Gliphosate. Treatments were applied in the autumn of 1993. In the spring of 1994 a mixture of Phleum pratense, Fesuca rubra, Dactylis glomerata, Trifolium repens and Lotus corniculatus was oversown. Establishment of each species and botanical composition of the pasture were measured over the next three years. Nardus and weed was largely replaced by Phleum/Festuca mi...

  14. Spatial variation in spoil and vegetative characteristics of pastures on reclaimed surface mined land

    International Nuclear Information System (INIS)

    Teutsch, C.D.; Collins, M.; Ditsch, D.C.

    1999-01-01

    Kentucky has large areas of reclaimed surface mined land that could provide grazing for livestock. Research is needed to determine optimal stocking densities and to evaluate the sustainability of such grazing systems for this region. A long-term grazing study was initiated in 1997 on 151 ha of reclaimed land near Chavies, KY to determine spatial and temporal variation with stocking densities of 0, 0.28, 0.42, or 0.83 beef cow-calf units/ha. Global Positioning System and GIS technologies were used to establish pasture boundaries, locate permanent sampling markers at a density of 1 per 0.4 ha, and interpolate maps of physical, spoil, and vegetable pasture characteristics. Herbage and spoil samples were collected around the permanent markers in May of 1997. Stepwise regression was used to determine factors affecting the vegetative characteristics of the sites. Biomass density ranged from 0 to 2500 kg/ha with a mean of 570 kg/ha. Factors affecting biomass included legume and weed proportions in the sward, grazing activity, soil potassium, elevation, and potential acidity, cumulatively accounting for 32% of the variation. Ground cover ranged from 10 to 100% with an average of 74%. Soil pH, potassium, and grass in the sward accounted for 14% of the variation in ground cover. Legumes made up 0 to 61% of the sward with a mean of 13% over the pasture area. Variables affecting the amount of legume in the sward included biomass density, slope, elevation, pH, and stocking density, together accounting for 21% of the variation. Spatial variation in the physical, spoil, and vegetative characteristics of the pastures was large. Overall, regression accounted for a limited amount of the variation in the vegetative characteristics of the site indicating that other important variables exist

  15. The spectrum and occurrence of entomopathogenic fungi in soils from apple orchards

    Directory of Open Access Journals (Sweden)

    Barbara Marjańska-Cichoń

    2012-12-01

    Full Text Available The spectrum and occurrence of entomopathogenic fungi in orchard soil and arable soil were evaluated using an "insect bait method". Soil samples taken in autumn and spring from sward, herbicides fallow and arable soil were baited with Galleria mellonella larvae. Entomopathogenic fungi Beauveria bassiana (Bals. Vuill., Metarhizium anisopliae (Metsch. Sorok. and Paecilomyces fumosoroseus (Wize Brown et Smith were isolated from three species of orchards soil and adjacent arable soil. Infection levels of G. mellonella larvae were depended from species of soil . M. anisoopliae caused most frequent infections of bait insects in light loamy sand and P. fumosoroseus in alluvial silt and coarse sand. B. bassiana was dominated in alluvial silt. It was established that M. anisopliae and B. bassiana infected more larvae in autumn than in spring. In case of P. fumosoroseus an opposite tendency was observed. Generaly in arable soil and sward number of infected larvae was higher than other stands. In case of light loamy sand more infections of G. mellonella larvae were found in samples from herbicides fallow. Irrespective of soil type B. bassiana was the dominated species isolated from herbicides fallow, M. anisopliae from sward and P. fumosoroseus - from arable soil.

  16. Tillering dynamics in pastures of guinea grass subjected to grazing severities under intermittent stocking

    Directory of Open Access Journals (Sweden)

    Denise Baptaglin Montagner

    2012-03-01

    Full Text Available This experiment was carried out to analyze the tillering dynamics of the species Panicum maximum cv. Mombaca subjected to three post-grazing heights: residue of 30 cm (30; residue of 50 cm (50; and residue of 50 cm during spring and summer, lowered to 40 cm in the first fall season grazing and to 30 cm in the following grazing cycle, resuming to 50 cm after the first grazing of the following spring season (50-30. Grazings were initiated whenever the swards intercepted 95% of the incident light. The post-grazing heights were allocated in the experimental units in a completely randomized block design with three replications. The density of basal tillers did not vary between the residual heights evaluated. Swards managed with variable residual height (50-30 presented higher rates of appearance and mortality of basal tillers during the summer of 2007, indicating high tiller renovation. Regardless of the post-grazing height evaluated, lower rates of appearance of basal tillers were found in the spring of 2006. The stability index of guinea grass cv. Mombaca was close to 1.0 throughout the experimental period. Swards managed with variable post-grazing present structural changes able to improve the regrowth vigor, which may be important to maximize the use of the forage species in the production system.

  17. Effect of Cutting Pattern and Fertilization Level on Species Diversity and Evaluation of Grassland Quality

    Directory of Open Access Journals (Sweden)

    Josef Raus

    2014-01-01

    Full Text Available The effects of fertilization level and cutting pattern on the species diversity and quality of a meadow stand were assessed in 2004–2012 in the small plot trial established in 2003 in Vatín, Vysočina Region, Czech Republic. Four levels of fertilization (none; N0 + P30 + K60 kg∙ha−1; N90 + P30 + K60 kg∙ha−1; N180 + P30 + K60 kg∙ha−1 were combined with four treatments of exploitation intensity (4 cuts per year, first cut on 15th May, every next after 45 days; 3 cuts per year, first cut on 30th May, every next after 60 days; 2 cuts per year, first cut on 15th June, next after 90 days; 2 cuts per year, first cut on 30th June, next after 90 days. Numbers of species, Simpson’s diversity index and evaluation of grassland quality according to Novák (2004 were evaluated. Numbers of species and Simpson’s diversity index were significantly affected by both fertilization level and cutting pattern. Species richness decreased along with increasing fertilization rates from 29.4 (no fertilization to 27.8 (N180PK. When comparing cutting pattern treatments the highest species richness was found in four-cut swards (29.6 in average of fertilization levels and it declines towards late double-cut regime (27.2. The Simpson’s index generally increased from two-cut swards to four-cut and from fertilized treatments to control. Grassland quality was significantly affected by cutting pattern. Values increased from four-cut swards (38.1 to two-cut ones (43.8 and 44.0 in early and late harvest respectively.

  18. Fate of 15N and 14C from labelled plant material

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Gjettermann, Birgitte; Eriksen, Jørgen

    2008-01-01

    strength of labelled plant residues in dissolved inorganic N (DIN) and dissolved organic N (DON) in pore water from the plough layer, and (ii) the plant uptake of organically bound N. Litterbags containing 14C- and 15N-labelled ryegrass or clover roots or leaves were inserted into the sward of a ryegrass......–clover mixture in early spring. The fate of the released 14C and 15N was monitored in harvested biomass, roots, soil, and pore water percolating from the plough layer. No evidence of plant uptake of dual-labelled organic compounds from the dual-labelled residues could be observed. N in pore water from the plough...

  19. Flächenproduktivität in Öko-Milchviehbetrieben in unterschiedlichen Standorten und Regionen

    OpenAIRE

    Edmund, Leisen; Ferdi, Mersch

    2013-01-01

    The productivity of forage land and of dairy cow pastures has been investigated in Organic dairy farms in North Germany and the Netherlands. The energy yields of the forage land varied between the farms from 18030 to 62707 MJ NEL per ha. The yields clearly indicate regional differences between the farms. In 2011 the grazing time lasted more than 200 days per year and is partly due to the application of the continuous grazing system with short grass swards. As milk and energy yields are concer...

  20. Comparison of herbage yield, nutritive value and ensilability traits of three ryegrass species evaluated for the Irish Recommended List

    Directory of Open Access Journals (Sweden)

    Burns G. A.

    2015-06-01

    Full Text Available This study examined 169 of the newest varieties of three ryegrass species, perennial (Lolium perenne L., Italian (Lolium multiflorum Lam. and hybrid (Lolium boucheanum Kunth, from Recommended List trials in Ireland. The traits examined were yield, dry matter concentration, three nutritive value traits (in vitro dry matter digestibility, water-soluble carbohydrate on a dry matter basis and crude protein concentration and two ensilability traits (buffering capacity and water soluble carbohydrate concentration on an aqueous phase basis. Varietal monocultures of each species underwent a six cut combined simulated grazing and silage management in each of two years following sowing. Perennial ryegrass yielded less than both other species in one-year-old swards, but less than only Italian ryegrass in two-year-old swards, but generally had the higher in vitro dry matter digestibility and crude protein values. Italian ryegrass displayed the most favourable ensilability characteristics of the three species with perennial ryegrass less favourable and hybrid ryegrass intermediate. Overall, despite the high yields and favourable nutritive value and ensilability traits recorded, the general differences between the three ryegrass species studied were in line with industry expectations. These findings justify assessing the nutritive value and ensilability of ryegrass species, in addition to yield, to allow farmers select species that match farming enterprise requirements.

  1. Influence of different combinations of cultivation techniques and a number of ameliorants on radiocesium contents in crop products grown in meadows

    International Nuclear Information System (INIS)

    Bystritskij, V.S.; Klimov, O.V.; Karnafel', P.V.; Kostyushko, P.V.

    1992-01-01

    The investigations have been performed at the meadows where soils are sandy, sod-podzolic, the area under investigation being the zone of strict radiation monitoring. The density of soil contamination with radiocesium was 20-25 Ci/sq.km. 4 cultivation techniques and 6 procedures of soil amelioration have been studied. It has been proved that Cs-134, -137 content reduces by a factor of 3.0 to 3.5 under conditions of standard plowing (down to 18 to 20 cm) and by a factor of 5 to 6 under conditions of deep plowing (down to 35 to 40 cm). For deep plowing when radiocontaminated sward was buried, radionuclide accumulation in crop products reduces by a factor of 1.5 as compared to standard plowing. When burial of radiocontaminated sward mixed with peat was provided, the radionuclide content has reduced by a factor of 2.0 to 2.5. When the radiocontaminated sword mixed with potassium chloride and lime was buried, the radionuclide content in crop products has reduced by a factor of 3. 5 tabs

  2. Effect of forage supplements on the incidence of bloat in dairy cows grazing high clover pastures.

    Science.gov (United States)

    Phillips, C J; James, N L; Murray-Evans, J P

    1996-08-17

    The effect of offering forage supplements of different compositions was examined in two experiments with cows grazing high clover swards. In the first experiment strawmix supplements of high or low energy content (11 and 9 MJ metabolisable energy/kg dry matter [DM]) and high or low crude protein content (17 and 4 g/kg DM) were offered for periods of three weeks. The energy and protein contents were varied by the content of molasses and soyabean meal, respectively. The high energy, high protein supplement increased the incidence of bloat, and the low energy, high protein supplement reduced it, compared with grazing alone. Bloat was most evident in the first two weeks of each feeding period, suggesting that the cows partially adapted to the diets within three weeks. In the second experiment silage supplements reduced the incidence of bloat among cows grazing both tall and short swards. The most suitable forages to feed when there is a risk of bloat are those that are slowly fermented in the rumen but are eaten in sufficient quantity to reduce periods of rapid herbage intake.

  3. Sewage sludge fertiliser use: implications for soil and plant copper evolution in forest and agronomic soils.

    Science.gov (United States)

    Ferreiro-Domínguez, Nuria; Rigueiro-Rodríguez, Antonio; Mosquera-Losada, M Rosa

    2012-05-01

    Fertilisation with sewage sludge may lead to crop toxicity and environmental degradation. This study aims to evaluate the effects of two types of soils (forest and agronomic), two types of vegetation (unsown (coming from soil seed bank) and sown), and two types of fertilisation (sludge fertilisation and mineral fertilisation, with a no fertiliser control) in afforested and treeless swards and in sown and unsown forestlands on the total and available Cu concentration in soil, the leaching of this element and the Cu levels in plant. The experimental design was completely randomised with nine treatments and three replicates. Fertilisation with sewage sludge increased the concentration of Cu in soil and plant, but the soil values never exceeded the maximum set by Spanish regulations. Sewage sludge inputs increased both the total and Mehlich 3 Cu concentrations in agronomic soils and the Cu levels in plant developed in agronomic and forest soils, with this effect pronounced in the unsown swards of forest soils. Therefore, the use of high quality sewage sludge as fertiliser may improve the global productivity of forest, agronomic and silvopastoral systems without creating environmental hazards. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Defoliation patterns in signal grass tillers with varying heights in the same pasture - doi: 10.4025/actascianimsci.v35i3.14376

    Directory of Open Access Journals (Sweden)

    Simone Pedro da Silva

    2013-07-01

    Full Text Available The experiment was carried out to evaluate the patterns of defoliation in plants of various heights in the same pasture of Brachiaria decumbens cv. Basilisk under continuous stocking with cattle. Four plant heights were evaluated (10, 20, 30 and 40 cm in the same managed sward, with mean height equal to 25 cm. A randomized blocks design was used, with two replications. Defoliation frequency increased linearly along with plant height in the same pasture. Defoliation intensity, number of defoliations in leaf blade and percentage of leaf blade grazed per tiller also increased linearly along with plant height. The defoliation interval decreased linearly according to plant height. The quadratic model was adequately fitted into grazing efficiency data, reaching the highest value (98% at the sward site with 35 cm plants. The percentage variation in signal grass height showed a negative linear response with initial plant height. The structure of the pasture, characterized by the diversity in plant heights, is simultaneously the cause and consequence of the variability in defoliation patterns in individual tillers, which occur on the horizontal plane of the pasture.  

  5. Influência de variáveis químicas e estruturais do dossel sobre a taxa de ingestão instantânea em bovinos manejados em pastagens tropicais Influence of structural characteristics and chemical composition of tropical grasses on the instantaneous forage intake rate

    Directory of Open Access Journals (Sweden)

    Fabíola Cristine de Almeida Rego

    2006-06-01

    - altura capim-marandu, PBL - PB lâminas de capim-marandu.Steer forage intake rate (IR was evaluated in pastures of Brachiaria brizantha, Panicum maximum cv. Tanzania, Arachis pintoi and a mixed of Brachiaria brizantha with Arachis pintoi. The objectives were to define sward structural characteristics and chemical composition nutrients of each pasture most determinant of forage intake rate by grazing steers. The steers grazed in pairs, passing through all grass species maintained at different sward heights in successive days. After three hours fast the animals were allowed to graze each experimental area for 60 minutes and had their grazing time and bite numbers registered. Forage intake was estimated by the double sampling technique. Sward structural characteristics used in the model for estimation of IR were: average sward height, morphological component proportion (%, morphological component mass (ton DM/ha and density of morphological components (kg DM/ha/cm. The chemical composition was expressed as crude protein (CP and neutral detergent fiber (NDF. Sward variables were selected using the stepwise statistical procedure. The IR equations defined from the studied characteristics were: Marandu grass: IR = 59,8980 + 0,7299 GL + 3,5777 DMA - 1,2459 NDFL + 0,2882 SH (GL - proportion of green leaves, FM - forage mass, NDFL - NDF of leaves, SH - average sward height. Tanzania grass: IR = 111,762 -4,1532 CPL + 0,3469 GL - 0,5207 NDFL (CP of leaves, GL - proportion of green leaves, NDFL - NDF of leaves. Peanut forage: IR = -196,589 + 12,1978 CPS + 8,3406 DMA + 1,1060 GS +17,3669 GLA (CPS - stem CP, DMA - dry matter availability, GLA - green leaves availability. Mixed pasture: IR= -7,25 + 1,15HA -0,22HI + 18,49AA -9,88GLA + 0,49HM + 1,00CPL (HA - Peanut forage height, HI - weed species height, AA - Arachis availability, GLA - green leaf availability of Marandu grass, HB - marandugrass sward height, CPL - CP of leaves of marandugrass.

  6. Evaluation of the biological nitrogen fixation (N{sub 2}) contribution in several forage legumes and the transfer of N to associated grasses; Avaliacao da contribuicao da fixacao biologica de N{sub 2} em varias leguminosas forrageiras e transferencia de N para uma graminea consorciada

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, M S.V.

    1991-12-01

    The objective of experiment 1 was to compare two different techniques for labelling the soil mineral nitrogen with {sup 15} N, for studies to quantify the contribution of biological nitrogen fixation (BNF) to forage legumes using the {sup 15} N isotope dilution technique. The two techniques for labelling the soil were: incorporation a {sup 15} N labelled organic compost (slow release treatment), and split applications of {sup 15} N labelled ammonium sulphate. The evaluation of the techniques was through the quantification of BNF in the Itaguai Hybrid of Centrosema using two non-Na- fixing control plants (P. maximum K K-16 and Sorghum bicolor). The objective of experiment 2 was to quantify the contribution of BNF to forage legumes and the transfer of fixed nitrogen to associated grasses in mixed swards again using the {sup 15} N isotope dilution technique. This study was conducted on a red podzolic soil (Typic Hapludult), with 7 forage legumes and 3 grasses in monoculture, and 3 mixed swards of Brachiaria brizantha with the Centrosema hybrid, Galactia striata and Desmodium ovalifolium, respectively, with varying ratios of grass to legume (4:1 to 1:4). In order to quantify the BNF contributions to the legumes and the transfer of fixed N to the B. brizantha, the plots were amended 8 times with doses of 0.01 g {sup 15} N m{sup -2} of {sup 15} N labelled ammonium sulphate (12.5 atom % {sup 15} N) each 14 days, giving a total of 0.08 g {sup 15} N m{sup -2} of {sup 15} N during the 97 days of the experiment. In monoculture the different forage legumes obtained the equivalent of between 43 and 100 kg N ha{sup -1} from BNF. Stylosanthes guianensis showed the greatest contributions from BNF at 100 Kg N ha{sup -1}. In mixed swards with Brachiaria brizantha the proportion of N derived from BNF in the three legumes studied (Centrosema hybrid, G. striata and D. ovalifolium) was significantly greater than when they were grown in monoculture. (author). 197 refs, 9 figs, 19 tabs.

  7. Evaluation of the biological nitrogen fixation (N2) contribution in several forage legumes and the transfer of N to associated grasses

    International Nuclear Information System (INIS)

    Vargas, M.S.V.

    1991-12-01

    The objective of experiment 1 was to compare two different techniques for labelling the soil mineral nitrogen with 15 N, for studies to quantify the contribution of biological nitrogen fixation (BNF) to forage legumes using the 15 N isotope dilution technique. The two techniques for labelling the soil were: incorporation a 15 N labelled organic compost (slow release treatment), and split applications of 15 N labelled ammonium sulphate. The evaluation of the techniques was through the quantification of BNF in the Itaguai Hybrid of Centrosema using two non-Na- fixing control plants (P. maximum K K-16 and Sorghum bicolor). The objective of experiment 2 was to quantify the contribution of BNF to forage legumes and the transfer of fixed nitrogen to associated grasses in mixed swards again using the 15 N isotope dilution technique. This study was conducted on a red podzolic soil (Typic Hapludult), with 7 forage legumes and 3 grasses in monoculture, and 3 mixed swards of Brachiaria brizantha with the Centrosema hybrid, Galactia striata and Desmodium ovalifolium, respectively, with varying ratios of grass to legume (4:1 to 1:4). In order to quantify the BNF contributions to the legumes and the transfer of fixed N to the B. brizantha, the plots were amended 8 times with doses of 0.01 g 15 N m -2 of 15 N labelled ammonium sulphate (12.5 atom % 15 N) each 14 days, giving a total of 0.08 g 15 N m -2 of 15 N during the 97 days of the experiment. In monoculture the different forage legumes obtained the equivalent of between 43 and 100 kg N ha -1 from BNF. Stylosanthes guianensis showed the greatest contributions from BNF at 100 Kg N ha -1 . In mixed swards with Brachiaria brizantha the proportion of N derived from BNF in the three legumes studied (Centrosema hybrid, G. striata and D. ovalifolium) was significantly greater than when they were grown in monoculture. (author). 197 refs, 9 figs, 19 tabs

  8. Influence of tree canopy on N{sub 2} fixation by pasture legumes and soil rhizobial abundance in Mediterranean oak woodlands

    Energy Technology Data Exchange (ETDEWEB)

    Carranca, C., E-mail: corina.carranca@iniav.pt [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Castro, I.V.; Figueiredo, N. [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Redondo, R. [Laboratorio de Isotopos Estables, Universidade Autonoma, Madrid (Spain); Rodrigues, A.R.F. [Centro de Estudos Florestais, ISA/UL, Tapada Ajuda, 1349-017 Lisboa (Portugal); Saraiva, I.; Maricato, R. [INIAV, Qta Marquês, 2784-505 Oeiras (Portugal); Madeira, M.A.V. [Centro de Estudos Florestais, ISA/UL, Tapada Ajuda, 1349-017 Lisboa (Portugal)

    2015-02-15

    Symbiotic N{sub 2} fixation is of primordial significance in sustainable agro-forestry management as it allows reducing the use of mineral N in the production of mixed stands and by protecting the soils from degradation. Thereby, on a 2-year basis, N{sub 2} fixation was evaluated in four oak woodlands under Mediterranean conditions using a split-plot design and three replicates. {sup 15}N technique was used for determination of N{sub 2} fixation rate. Variations in environmental conditions (temperature, rainfall, radiation) by the cork tree canopy as well as the age of stands and pasture management can cause great differences in vegetation growth, legume N{sub 2} fixation, and soil rhizobial abundance. In the present study, non-legumes dominated the swards, in particular beneath the tree canopy, and legumes represented only 42% of total herbage. A 2-fold biomass reduction was observed in the oldest sown pasture in relation to the medium-age sward (6 t DW ha{sup −1} yr{sup −1}). Overall, competition of pasture growth for light was negligible, but soil rhizobial abundance and symbiotic N{sub 2} fixation capacity were highly favored by this environmental factor in the spring and outside the influence of tree canopy. Nitrogen derived from the atmosphere was moderate to high (54–72%) in unsown and sown swards. Inputs of fixed N2 increased from winter to spring due to more favorable climatic conditions (temperature and light intensity) for both rhizobia and vegetation growths. Assuming a constant fixation rate at each seasonal period, N{sub 2} fixation capacity increased from about 0.10 kg N ha{sup −1} per day in the autumn–winter period to 0.15 kg N ha{sup −1} per day in spring. Belowground plant material contributed to 11% of accumulated N in pasture legumes and was not affected by canopy. Size of soil fixing bacteria contributed little to explain pasture legumes N. - Highlights: • Legumes fixation in oak woodlands was quantified in terms of biomass and N

  9. Flowering catch crops used as forage plants for dairy cows: influence on fatty acids and tocopherols in milk.

    Science.gov (United States)

    Kälber, T; Meier, J S; Kreuzer, M; Leiber, F

    2011-03-01

    The effect of several flowering dicotyledonous catch crop plants (dicots) on milk fat quality in cows was investigated to test the hypothesis that their phenolic compounds may inhibit ruminal biohydrogenation and thus enhance the transfer to milk of intact, plant-derived polyunsaturated fatty acids. Berseem clover (Trifolium alexandrinum), buckwheat (Fagopyrum esculentum), and phacelia (Phacelia tanacetifolia) were sown in mixture with ryegrass (Lolium multiflorum; intended biomass proportion of 0.2) on 1ha. For comparison, nonflowering chicory (Cichorium intybus, also sown in mixture with ryegrass) and pure ryegrass were cultivated. Realized biomass proportions (wet weight) were 91% for berseem clover, 69% for buckwheat, 54% for phacelia, and 51% for chicory. At the start of flowering (or from d 47 after sowing onward), cultures were harvested daily and fed for 20 d ad libitum to groups of 6 midlactation cows each. Additionally, 1 kg each of energy and protein concentrate and pure ryegrass hay were fed. Individual intake and milk yield of the cows were measured daily. Milk samples were obtained twice daily 5 d before and from 11 to 20 d after the start of treatment feeding. Feed samples were drawn twice a week from the fresh feeds. Apart from standard traits, feeds and milk were analyzed for fatty acids, tocopherols, and phenolic fractions. Only a few substantial treatment effects on intake and performance were observed. All diets based on dicots increased α-linolenic acid (ALA) concentrations in milk fat compared with the ryegrass diet even though the corresponding swards were not generally richer in ALA. The highest ALA concentration in milk fat (1.3 g/100g of fatty acids) occurred with the berseem clover diet. Transfer rate of ALA from feed to milk was highest with the buckwheat diet (0.09) and lowest with ryegrass (0.05). This was congruent with the differences in total extractable phenols, being high in the buckwheat sward (2.6% of dry matter) and low in the

  10. Dose soil adhesion matter when predicting radiocaesium transfer to animals?

    International Nuclear Information System (INIS)

    Crout, N.M.J.; Beresford, N.A.; Howard, B.J.

    1993-01-01

    A sward will often have significant amounts of soil adhered to the vegetation surfaces which will be ingested by grazing animals. If the soil is contaminated by radioactive fallout then it can serve as a dietary source of radionuclides, in addition to any root uptake by the plants. This study is an attempt to quantitatively assess the importance of soil adhesion as a source of radiocaesium to sheep using the RUINS model which simulates radiocaesium transfer in grazing systems. The method of simulating the contamination of vegetation surfaces used by the RUINS model is described, and the importance of the availability of radiocaesium associated with adhered soil relative to plant incorporated radiocaesium discussed. Two sets of simulations are presented : one in which the soil is treated as a medium providing a uniform availability of radiocaesium, and the second in which account is taken of the partitioning of radiocaesium in the soil between 'fixed' and 'labile' phases. (author)

  11. Evaluation of physical structure value in spring-harvested grass/clover silage and hay fed to heifers

    DEFF Research Database (Denmark)

    Schulze, A.K.S.; Nørgaard, P.; Byskov, M.V.

    2015-01-01

    The physical structure value of conserved grass/clover forages of spring harvest was evaluated by assessing effects of harvest time, conservation method, iNDF/NDF ratio and NDF intake (NDFI) per kg BW on chewing activity and fecal particle size in dairy heifers. A mixed sward consisting of ryegrass...... of 315, 436, 414 and 503 g/kg DM, respectively. Forages were fed as sole feed to four Jersey heifers of 435±30 kg BW in a 4×4 Latin square experiment. Feeding level was 90% of individual ad libitum intake, divided equally across two daily meals offered at 0800 and 1530 h. Chewing activity was estimated...... from recorded jaw movements (JM) oscillations continuously logged for 96 h and summarized per 24 h as mean effective rumination time and eating time. Eating behavior was further observed during four 20-min test meals. Weight proportion of large feces particles (>1.0 mm) and geometric mean fecal...

  12. Radiation and temperature influence on forage grasses yield

    International Nuclear Information System (INIS)

    Vadell, J.; Medrano, H.

    1986-01-01

    Biomass production has been studied in forage plants, as well as the temperature and radiation effects on plant growth. Four cultivars of grasses: Lolium multiflorum var westerwoldicum cv Promenade, Lolium perenne cvs Combi and Compas and Bromus inermis were growing as microswards in a growth chamber with constant temperature and outdoors. A field assay was done also with the same cultivars. L. multiflorum was the highest productive genotype anywhere showing also more active growth at low temperatures. Total production showed significant differences among genotypes. It was also a clear correspondence among microswards and field productions. Highest efficiency values (in % of PAR accumulated as dry matter) was obtained in 6th cut (April) achieving to 5.18 % in L. multiflorum. Biomass production variations through the growth period show a low correlation with <> and very high correlation with total irradiation received by the sward between consecutive cuts [es

  13. Dairy cows increase ingestive mastication and reduce ruminative chewing when grazing chicory and plantain.

    Science.gov (United States)

    Gregorini, P; Minnee, E M K; Griffiths, W; Lee, J M

    2013-01-01

    Although the nutritive value of chicory (Cichorium intybus L.) and plantain (Plantago lanceolata L.) has been thoroughly studied, little is known about the grazing behavior of cattle feeding on chicory and plantain swards. The objective of the present study was to assess and describe the grazing behavior of dairy cows as affected by dietary proportions of chicory and plantain fed as monocultures for part of the day. Ninety Holstein-Friesian cows (489±42 kg of body weight; 4.1±0.3 body condition score, and 216±15 d in milk) were randomly assigned to 15 groups (6 cows per group) and grazed according to 7 treatments: control (CTL, 3 groups), perennial ryegrass (Lolium perenne L.) dominant sward (24-h pasture strip); 3 chicory treatments comprising 20, 40, and 60% of the diet, strip-grazing a monoculture of chicory to a fixed postgrazing residual before strip-grazing a perennial ryegrass dominant sward (2 groups of cows per treatment); and 3 plantain treatments comprising 20, 40, and 60% of the diet, strip-grazing a monoculture of plantain to a fixed postgrazing residual before strip-grazing a perennial ryegrass dominant sward (2 groups of cows per treatment). Four focal animals per group were equipped with 3-dimensional motion sensors, which provided the number of steps taken at each minute of the day. These cows were also fitted with automatic jaw-movement recorders that identified bites, mastication during ingestion, chewing during rumination, and determined grazing, rumination and idling times and bouts. Daily grazing time and bouts were not affected by treatments but rumination time differed and was reduced by up to 90 min when cows were allocated to chicory and plantain as 60% of their diet. Ruminative chewing was reduced in cows grazing chicory and plantain by up to 20% in cows allocated to the 60% treatments. Compared with perennial ryegrass, as the dietary proportion of chicory and plantain increased, cows spent more time idling and less time ruminating

  14. High resolution 14C dating of surface peat using the AMS technique

    International Nuclear Information System (INIS)

    Tolonen, K.; Possnert, G.; Jungner, H.; Sonninen, E.; Alm, J.

    1992-01-01

    In an AMS (Accelerator Mass Spectrometric) determination of 14 C from moss-increment dated samples from a Sphagnum fuscum hummock, a clear peak representing the time of high 14 C activity in the atmosphere due to nuclear bomb tests was found. The C-14 activities in the peat profile at deeper levels, corresponding to the period down to 1600 Bp, showed similar variations as the atmospheric values. The time scale obtained from radiocarbon dating fitted well with results from moss-increment counting, pollen analysis and dendrochronological dating of a fire horizon. Using the bomb layers and refixing into growing peat was estimated. The fraction of soil carbon dioxide taken up by the contemporary Sphagnum Sward was thus found to be in the order of 20 %. (orig.). (15 refs., 5 figs., 2 tabs.)

  15. Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen

    2012-01-01

    -term mean. The experiment was initiated in a 4-yr-old grass-clover sward in south Denmark. Three treatments were as follows grazing only (G), spring cut followed by grazing (CG) and both spring and autumn cuts with summer grazing (CGC). Nitrate leaching was calculated by extracting water isolates from 80 cm......Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long...... depth using ceramic suction cups. Because of considerable variation in measured nitrate concentrations, the 32 installed suction cups per treatment were insufficient to reveal differences between treatments. However, weighted nitrate leaching estimations for G, CG and CGC showed estimated mean nitrate N...

  16. Energy and carbon balances in cheatgrass, an essay in autecology. [Shortwave radiation, radiowave radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hinds, W.T.

    1975-01-01

    An experiment to determine the fates of energy and carbon in cheatgrass (Bromus tectorum L.) was carried out on steep (40/sup 0/) north- and south-facing slopes on a small earth mound, using many small lysimeters to emulate swards of cheatgrass. Meteorological conditions and energy fluxes that were measured included air and soil temperatures, relative humidity, wind speed, incoming shortwave radiation, net all-wave radiation, heat flux to the soil, and evaporation and transpiration separately. The fate of photosynthetically fixed carbon during spring growth was determined by analysis of the plant tissues into mineral nutrients, crude protein, crude fat, crude fiber, and nitrogen-free extract (NFE) for roots, shoots, and seeds separately. (auth)

  17. Flowering does not decrease vegetative competitiveness of Lolium perenne

    DEFF Research Database (Denmark)

    Thiele, Jan; Bagger Jørgensen, Rikke; Hauser, Thure Pavlo

    2009-01-01

    as reduced flowering could free resources and increase productivity. But if so, less-flowering cultivars might be more competitive and invade natural swards. We tested for costs of sexual reproduction on vegetative propagation and competitiveness of the perennial grass Lolium perenne, one of the most...... treatments were successful in producing clones with largely differing degrees of flowering. However, we found no negative correlation between flowering and vegetative propagation and competitiveness. Early and strongly flowering southern provenances showed less clonal growth and higher mortality, but within...... provenances the response of clone diameter to flowering was positive or neutral. We conclude that investment of resources into flowering has no measurable costs on vegetative propagation and competitiveness of L. perenne. The apparent lack of costs of sexual reproduction could be explained by bet...

  18. Effects of Shepherd’s Purse (Capsella bursa pastoris (L. Medic. on the Chemical Composition of Lucerne (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Tsvetanka Dimitrova

    2008-01-01

    Full Text Available A study was conducted in a pure stand of lucerne (variety Viktoria under natural weed infestation with shepherd’s purse (Capsella bursa pastoris (L. Medic. on a slightly leached chernozem soil under nonirrigated conditions in the experimental field of the Institute ofForage Crops – Pleven during the 2006-2007 period. The effect of shepherd’s purse Capsella bursa pastoris (L. Medic. on the chemical composition of lucerne Medicago sativa (L. was analyzed.Statistically significant (P<0.05 functional relations were found between the chemical characteristics and percentage of Capsella bursa pastoris (L. Medic. participation in the lucerne sward, and forage quality. These relations indicated a multiple practical relevance and a necessity to control Capsella bursa pastoris (L. Medic. in lucerne stands in order to decrease weed density and improve forage quality.

  19. Inter and intra-specific variation in photosynthetic acclimation response to long term exposure of elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M. [Univ. of Essex, Colchester (United Kingdom)]|[Writtle Coll. (United Kingdom)

    1996-08-01

    The response of intra and interspecific variation in photosynthetic acclimation to growth at elevated atmospheric CO{sub 2} concentration (600{micro}mol mol-l) in six important grassland species was investigated. Plants were grown in a background sward of Lolium perenne and measurements were made after four years of growth at elevated C{sub a}. Elevated CO{sub 2} was maintained using a FACE (Free-Air Carbon Enrichment) system. Significant intra and interspecific variation in acclimation response was demonstrated. The response of adaxial and abaxial stomatal conductance to elevated CO{sub 2} was also investigated. The stomatal conductance of both the adaxial and abaxial leaf surfaces was found to be reduced by elevated C{sub a}. Significant asymmetric responses in stomatal conductance was demonstrated in D. glomerata and T. pratense. Analysis of stomatal indices and densities indicated that the observed reductions in stomatal conductance were probably the result of changes in stomatal aperture.

  20. Biological reduction of dust nuisance on power station waste dumps

    Energy Technology Data Exchange (ETDEWEB)

    Kozel, J

    1978-01-01

    The results of pot trials and succeeding field trials carried out in 1966-72 to find out the best method of reclamationand stabilishing the fly ash and cinder waste dump at the Melnik power station are summarised. The material consists mainly of fine particles with a size range of less than 1 micron to 0.16 mm in diam., and creates a source of blown dust in dry weather. Treatment of the waste material before sowing grass and legume species, the species tested, sowing rates, applied fertilizers, irrigation and treatment of the resulting swards are discussed. The most suitable species were Festuca rubra, F. ovina, perennial ryegrass and Italian ryegrass; the cost of stabilising the dump was lowest with Italian ryegrass. (In English)

  1. Componentes morfológicos e produção de forragem de pastagem de aveia e azevém manejada em diferentes alturas Morphological components and forage production of oat (Avena strigosa, Schreb and annual ryegrass (Lolium multiflorum, Lam pasture managed at different heights

    Directory of Open Access Journals (Sweden)

    Angelo Antonio Queirolo Aguinaga

    2008-09-01

    Full Text Available Avaliou-se a dinâmica de produção de forragem em pastagem de aveia-preta (Avena strigosa Schreb e azevém (Lolium multiflorum Lam manejada em diversas alturas de manejo com o objetivo de evidenciar as potencialidades dessa mistura em sistemas de integração lavoura-pecuária. Os tratamentos consistiram de quatro alturas de manejo da pastagem (10; 20; 30 e 40 cm, medidas com bastão graduado e avaliadas em blocos casualizados com três repetições. O método de pastejo foi contínuo, com taxa de lotação variável. Utilizaram-se bezerros de corte mestiços com 10 meses de idade e peso médio inicial de 210 kg, respectivamente. As características da pastagem estudadas foram: massa de forragem (MF; taxa de acúmulo de forragem (TAC; produção total de forragem (PTMS; e quantificação dos componentes morfológicos da pastagem (colmo, lâmina e material morto. A massa de forragem aumentou de forma linear de acordo com a altura do pasto, uma vez que, para cada cm de aumento na altura superior a 10 cm, a matéria seca aumentou aproximadamente 90 kg/ha. Não houve efeito das alturas da pastagem sobre a TAC ou sobre a PTMS, cujos valores médios foram de 66,8 kg/ha/dia de MS e 10.721 kg/ha de MS, respectivamente. A porcentagem de folhas de azevém foi maior que a de folhas de aveia nos três períodos de avaliação e, na altura de 10 cm, foi superior à obtida nas demais alturas na última avaliação (em torno de 20% da participação total da massa de forragem. A aveia apresenta rápido desenvolvimento inicial e diminuição na produção nos períodos posteriores de desenvolvimento.Forage growth dynamic in an Oat (Avena strigosa, Schreb + Ryegrass (Lolium multiflorum, Lam pasture managed at different grazing heights was evaluated in order to access the mixed-sward potential in a crop-livestock integrated system. Treatments were four sward grazing heights (10, 20, 30, and 40 cm, measured with a sward-stick. The experimental design was a

  2. Intervalo e intensidade de desfolhação nas taxas de crescimento, senescência e desfolhação e no equilíbrio de gramíneas em associação Interval and intensity of defoliation on the growth, senescence and defoliation fluxes and equilibrium of associated grasses

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    Andréa Machado Groff

    2002-09-01

    Full Text Available O experimento foi realizado no INRA (Institut National de la Recherche Agronomique em Theix, França. Duas gramíneas (azevém perene e festucaforam semeadas em caixas (0,13 m² e submetidas a três intervalos (3,5, 7 e 14 dias e três intensidades (160, 320 e 640 bocados.m-2 a cada desfolhação de desfolhação, com quatro repetições por tratamento. Quatro meses após a semeadura, a cada data de desfolhação, as caixas foram oferecidas, individualmente, a quatro ovelhas secas e retiradas após a realização de um determinado número de bocados. Para cada gramínea foram estudadas as taxas de crescimento, senescência e desfolhação. Os resultados mostraram que o intervalo e a intensidade de desfolhação tiveram efeitos diferenciados nas taxas de crescimento, senescência e desfolhação e no equilíbrio da associação.The experiment was carried in INRA (Institut National de la Recherche Agronomique at Theix, France. Two grasses (perennial ryegrass and tall fescue were grown in sward boxes (0,13 m² and submitted to three defoliation intervals (3,5, 7 and 14 days between two successive defoliation and three defoliation intensities (160, 320 and 640 bites.m-2 at each defoliation. Four months after sowing, at defoliation date, sward boxes were offered to four individual dry ewes and removed after a given number of bites had been taken. For each grass species, the growth, senescence and defoliation fluxes were studied. The results showed that the interval and the intensity of grazing had distinct effects on the growth, senescence and defoliation fluxes as well as on the equilibrium of grass mixtures.

  3. Contemporary floristic changes in the Karkonosze Mts.

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    Jerzy Fabiszewski

    2014-01-01

    Full Text Available The paper presents the transformations of species composition in the main plant communities of the Karkonosze Mts. subalpine and alpine belts during the last 35 years. The investigations of floristic changes were performed in associations: Carici (rigidae-Nardetum, Carici-Festucetum supinae, Crepidi-Calamagrostietum villose and Empetro-Vaccinietum. Signalized are also some vegetation transformations in the remaining belts. The progressing floristic degradation of plant communities in the subalpine and alpine belts consists in: (a expansion of grasses, (b decline of rare vascular plants, and (c elimination of terricolous bryophytes and lichens. In spruce forest belts declining are species connected with old-growth spruce forests like: Listera cordata and Moneses uniflora. The changes of plant communities of low mountain swards (Nardetalia caused by cessation of pasture and mowing in the cause of retreat of many rare plants, like e.g., Arnica montana. The main cause of the still lasting in the Karkonosze Mts. community transformations is the changes in soil environment connected with anthropogenic nitrogen fertilization. The large inflow of mineral nitrogen from the atmosphere (1138 mg/m2 sum for vegetation season is the reason of accelerated rate of decomposition of organic matter and intensified nitrification. The high content of nitrates in soil (5 times higher than in the Tatra Mts. swards is the reason of expansion of graminoids, mainly Deschampsia flexuosa, Calamagrostis villosa and Carex bigelowii subsp. rigida. The overfertilisation of habitats causes the retreat of rare high mountain vascular plants and the decline of terricolous bryophytes and lichens.

  4. The pasture-type approach for mountain pasture description and management

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    Giovanni Argenti

    2012-10-01

    Full Text Available The study of pastoral resources can take different approaches with the main goal of characterizing pasture vegetation and its potential carrying capacity. In recent times, the pasture-type approach has been developed in several Alpine areas – on a regional and on a district scale – starting from sward surveys carried out taking the approach formerly developed by the French pastoral school. The pasture-type approach may play an important role in defining the management of mountain and marginal environments where grazing pressure reduction remarkably affects the agro-ecosystems functions (production, landscape, wildlife, recreation, etc.. This approach is based on the concept of pasture type, which could be defined as a semi-natural vegetation (mainly exploited by grazing animals, rather homogeneous in terms of botanic composition and influenced by environmental factors and agro-pastoral management. This paper presents the pasture-type approach by discussing the results of two large studies carried out in two areas of the south side of the Alps (Piedmont and Veneto. In order to identify pasture types, the vegetation composition was assessed with a point quadrat method. It allowed the computation of species-specific contribution, and of sward forage value and carrying capacity, after a multivariate statistical procedure for type classification and ordination. The site conditions (altitude, slope, aspect and other environmental variables were surveyed. Moreover, to characterize the pasture types from the point of view of the ecological and management factors affecting vegetation composition, the Landolt indicators were used. The results achieved in the two areas were synthesised and organised into reference technical tools with the aim of using the pasture-type approach for pastoral planning. For each study area an identification key to recognize pasture types was drafted, and a handbook containing the technical sheets for pasture type

  5. Field studies on the behaviour of radiocaesium in agricultural environments after the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, K

    1996-05-01

    This thesis deals with the occurrence of Chernobyl {sup 137}Cs and {sup 134}Cs in cultivated, semi-natural and natural agricultural areas of five Swedish counties. The investigations were carried out under field conditions 1986 to 1995 on farms where transfer to grass and milk during the first years were high. Vertical migration rate in soil profiles, the practical value of countermeasures to reduce transfer to feed and food and the impact of passing time were important aims for the study. The transfer of Cs was higher on permanent pasture than on temporary grassland and much lower to barley grain. Stubble and grass swards kept Cs available for transfer to grass. High organic matter contents in the surface soil also caused high transfer during a lag period of some years. Soil texture, grass sward, K-fertilization and growth dilution explained the variation in Cs transfer and its reduction rate. A case study on transfer of Cs to vegetation and to grazing lambs was made on a mountain farm. High transfer to vegetation was found, 510-2260 Bq/kg d.w.. Mean transfer soil to plant (TFg,m{sup 2}/kg) was 67 and plant to muscle 0.7 during 1990-1993. The effect of K-fertilization on soil-plant transfer was studied on 15 soils. A dose of 100 to 200 kg/ha K decreased the transfer on sandy soils with a factor of up to 10. Liming was effective on soils that were originally low in pH. Adding zeolite on the surface of pastures did not reduce the root uptake of Cs. Ploughing down the contaminated surface was effective in reducing the transfer. Downward migration of Cs was usually less on mineral soils than or organic or podsolized soils. 68 refs, 9 figs, 13 tabs.

  6. Marandu palisade grass intercropped with densely spaced teak in silvopastoral system

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    Carlos Eduardo Avelino Cabral

    2017-08-01

    Full Text Available This study was conducted to evaluate two systems of production: integration between teak and forage (silvopastoral system and forage only (monoculture. The forage species used was Marandu palisade grass (Urochloa brizantha cv. Marandu. In January 2009, part of the pasture was desiccated and the teak (Tectona grandis was implemented in a 3 × 4 m spacing arrangement, and at every five rows, a space between rows of 6 m was established, providing a population of 750 trees per hectare. Alongside the development of the trees, the Marandu palisade grass pasture was reestablished. In February 2015, the animals were removed from the experimental area and, in March, the pasture degradation, the density and the mass of tillers was assessed. The following variables were evaluated: sward height; forage mass, percentage of leaf blade, stem+sheath and senescent material; leaf blade:stem+sheath ratio; and live:dead material ratio. The experimental design was completely randomized, with 12 replicates. Treatments consisted of two systems (silvopastoral and monoculture. The total forage accumulation was higher in the monoculture system. The sward height and the percentage of stem+sheath were higher in the integrated system, while the percentage of leaf blade and the leaf blade:stem+sheath ratio were higher in the system exclusively with forage. In conclusion, Marandu palisade grass tolerates shading in a high density spacing silvopastoral system, but the degradation process is more intense compared to grass in monoculture, and the use of Marandu palisade grass in silvopastoral systems changes the forage mass and the structure of the produced forage.

  7. Tillering of Marandu palisadegrass maintained at fixed or variable heights throughout the year

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    Denis D. Pessoa

    2016-05-01

    Full Text Available Satisfactory tillering is the basic attribute to ensure stability and productivity of a grass population. We aimed to develop an understanding of tillering in Urochloa brizantha syn. Brachiaria brizantha cv. Marandu (Marandu palisadegrass maintained at constant or variable heights during the various seasons of the year and to identify defoliation strategies that optimize tillering. In an experiment conducted in Uberlândia, Minas Gerais, Brazil, 3 defoliation strategies were studied: sward kept at 30 cm during the whole year (constant height; kept at 15 cm in fall/winter, 30 cm in spring and 45 cm in summer (increasing height; and kept at 45 cm in fall/winter, 30 cm in spring and 15 cm in the summer (decreasing height. The experiment was completely randomized, with 4 replicates. The following variables were evaluated: tiller appearance (TAR, mortality (TMR and survival (TSR rates; the balance (BAL between TAR and TMR; tiller population stability (TPS; and number of tillers/m2 (NT. In winter and late spring, TAR and BAL were low, while in early spring, the sward with decreasing height showed high TAR, BAL and TPS. The NT was higher when managed with increasing height than with other height strategies. Lowering pasture height from 45 to 30 cm after the winter increased TAR in early spring. Grazing studies seem warranted to assess how these results can be reproduced under grazing and how pasture yield and quality plus animal performance compare with those under the fixed grazing height regimen. Keywords: Defoliation, grazing management, pasture height, tillers, Urochloa brizantha.DOI: 10.17138/TGFT(4101-111 Normal 0 false false false PT-BR X-NONE X-NONE

  8. Field studies on the behaviour of radiocaesium in agricultural environments after the Chernobyl accident

    International Nuclear Information System (INIS)

    Rosen, K.

    1996-05-01

    This thesis deals with the occurrence of Chernobyl 137 Cs and 134 Cs in cultivated, semi-natural and natural agricultural areas of five Swedish counties. The investigations were carried out under field conditions 1986 to 1995 on farms where transfer to grass and milk during the first years were high. Vertical migration rate in soil profiles, the practical value of countermeasures to reduce transfer to feed and food and the impact of passing time were important aims for the study. The transfer of Cs was higher on permanent pasture than on temporary grassland and much lower to barley grain. Stubble and grass swards kept Cs available for transfer to grass. High organic matter contents in the surface soil also caused high transfer during a lag period of some years. Soil texture, grass sward, K-fertilization and growth dilution explained the variation in Cs transfer and its reduction rate. A case study on transfer of Cs to vegetation and to grazing lambs was made on a mountain farm. High transfer to vegetation was found, 510-2260 Bq/kg d.w.. Mean transfer soil to plant (TFg,m 2 /kg) was 67 and plant to muscle 0.7 during 1990-1993. The effect of K-fertilization on soil-plant transfer was studied on 15 soils. A dose of 100 to 200 kg/ha K decreased the transfer on sandy soils with a factor of up to 10. Liming was effective on soils that were originally low in pH. Adding zeolite on the surface of pastures did not reduce the root uptake of Cs. Ploughing down the contaminated surface was effective in reducing the transfer. Downward migration of Cs was usually less on mineral soils than or organic or podsolized soils. 68 refs, 9 figs, 13 tabs

  9. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings. Copyright © 2015. Published by Elsevier B.V.

  10. Monitoring and assessment of ingestive chewing sounds for prediction of herbage intake rate in grazing cattle.

    Science.gov (United States)

    Galli, J R; Cangiano, C A; Pece, M A; Larripa, M J; Milone, D H; Utsumi, S A; Laca, E A

    2018-05-01

    Accurate measurement of herbage intake rate is critical to advance knowledge of the ecology of grazing ruminants. This experiment tested the integration of behavioral and acoustic measurements of chewing and biting to estimate herbage dry matter intake (DMI) in dairy cows offered micro-swards of contrasting plant structure. Micro-swards constructed with plastic pots were offered to three lactating Holstein cows (608±24.9 kg of BW) in individual grazing sessions (n=48). Treatments were a factorial combination of two forage species (alfalfa and fescue) and two plant heights (tall=25±3.8 cm and short=12±1.9 cm) and were offered on a gradient of increasing herbage mass (10 to 30 pots) and number of bites (~10 to 40 bites). During each grazing session, sounds of biting and chewing were recorded with a wireless microphone placed on the cows' foreheads and a digital video camera to allow synchronized audio and video recordings. Dry matter intake rate was higher in tall alfalfa than in the other three treatments (32±1.6 v. 19±1.2 g/min). A high proportion of jaw movements in every grazing session (23 to 36%) were compound jaw movements (chew-bites) that appeared to be a key component of chewing and biting efficiency and of the ability of cows to regulate intake rate. Dry matter intake was accurately predicted based on easily observable behavioral and acoustic variables. Chewing sound energy measured as energy flux density (EFD) was linearly related to DMI, with 74% of EFD variation explained by DMI. Total chewing EFD, number of chew-bites and plant height (tall v. short) were the most important predictors of DMI. The best model explained 91% of the variation in DMI with a coefficient of variation of 17%. Ingestive sounds integrate valuable information to remotely monitor feeding behavior and predict DMI in grazing cows.

  11. Caracterização da estrutura da vegetação numa pastagem natural do Bioma Pampa submetida a diferentes estratégias de manejo da oferta de forragem Structural characterization of a natural pasture vegetation from Pampa Biome under different herbage allowance management strategies

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    Fabio Pereira Neves

    2009-09-01

    Full Text Available Os objetivos neste trabalho foram descrever e investigar a dinâmica espaço-temporal de sítios alimentares em diferentes faixas de massa de forragem e altura do pasto, assim como o percentual de área efetivamente pastejada, a taxa de acúmulo de forragem e a produção de matéria seca de uma pastagem natural do Bioma Pampa. O delineamento utilizado foi o de blocos ao acaso com duas repetições, com três ofertas de forragem fixas (8, 12 e 16% e três ofertas de forragem variáveis ao longo do ano (8-12%, 12-8% e 16-12%, com o primeiro valor correspondendo à primavera. Na oferta fixa de forragem de 8%, observou-se maior percentual de área efetivamente pastejada, porém os valores médios de altura e massa de forragem foram inferiores aos das demais ofertas. As maiores ofertas de forragem, 16 e 16-12%, apresentaram altura média do pasto superior, 9,0 cm e massa de forragem de 2.000 kg/ha de matéria seca, porém, com área efetivamente pastejada inferior às observadas nas ofertas de 8 e 8-12%. Mesmo estratégias de manejo tão distintas, aproximadamente 60 a 70% dos sítios alimentares ocorreram em faixas consideradas limitantes ao potencial de ingestão de forragem por bovinos, com exceção dos tratamentos 16% e 16-12%, nos quais se observou menor frequência de sítios alimentares na faixa inferior a 6,0 cm de altura. Os sítios alimentares, em geral, se concentraram em faixas com altura The objective of this trial was to investigate the spatio-temporal dynamics of feeding sites stratified by strips of herbage mass and sward height, and the percentage of effectively grazed area, herbage growth rate and dry matter yield of a natural pasture from Pampa Biome managed with different herbage allowance management strategies. A randomized block design with two replications was used with three fixed herbage allowance (8, 12 and 16% and three herbage allowance variables throughout the year (8-12%, 12-8%, and 16-12%, with first value

  12. Elucidating source processes of N2O fluxes following grassland-to-field-conversion using isotopologue signatures of soil-emitted N2O

    Science.gov (United States)

    Roth, G.; Giesemann, A.; Well, R.; Flessa, H.

    2012-04-01

    Conversion of grassland to arable land often causes enhanced nitrous oxide (N2O) emissions to the atmosphere. This is due to the tillage of the sward and subsequent decomposition of organic matter. Prediction of such effects is uncertain so far because emissions may differ depending on site and soil conditions. The processes of N2O turnover (nitrification, production by bacterial or fungal denitrifiers, bacterial reduction to N2) are difficult to identify, however. Isotopologue signatures of N2O such as δ18O, average δ15N (δ15Nbulk) and 15N site preference (SP = difference in δ15N between the central and peripheral N positions of the asymmetric N2O molecule) can be used to characterize N2O turnover processes using the known ranges of isotope effects of the various N2O pathways. We aim to evaluate the impact of grassland-to-field-conversion on N2O fluxes and the governing processes using isotopic signatures of emitted N2O. At two sites, in Kleve (North Rhine-Westphalia, Germany, conventional farming) and Trenthorst (Schleswig-Holstein, Germany, organic farming), a four times replicated plot experiment with (i) mechanical conversion (ploughing, maize), (ii) chemical conversion (broadband herbicide, maize per direct seed) and (iii) continuous grassland as reference was started in April 2010. In Trenthorst we additionally established a (iv) field with continuous maize cultivation as further reference. Over a period of two years, mineral nitrogen (Nmin) content was measured weekly on soil samples taken from 0-10 cm and 10-30 cm depth. Soil water content and N2O emissions were measured weekly as well. Gas samples were collected using a closed chamber system. Isotope ratio mass spectrometry was carried out on gas samples from selected high flux events to determine δ18O, δ15Nbulk and SP of N2O. δ18O and SP of N2O exhibited a relatively large range (32 to 72 ‰ and 6 to 34 ‰, respectively) indicating highly variable process dynamics. The data-set is grouped

  13. Spatially dependent biotic and abiotic factors drive survivorship and physical structure of green roof vegetation.

    Science.gov (United States)

    Aloisio, Jason M; Palmer, Matthew I; Giampieri, Mario A; Tuininga, Amy R; Lewis, James D

    2017-01-01

    Plant survivorship depends on biotic and abiotic factors that vary at local and regional scales. This survivorship, in turn, has cascading effects on community composition and the physical structure of vegetation. Survivorship of native plant species is variable among populations planted in environmentally stressful habitats like urban roofs, but the degree to which factors at different spatial scales affect survivorship in urban systems is not well understood. We evaluated the effects of biotic and abiotic factors on survivorship, composition, and physical structure of two native perennial species assemblages, one characterized by a mixture of C 4 grasses and forbs (Hempstead Plains, HP) and one characterized by a mixture of C 3 grasses and forbs (Rocky Summit, RS), that were initially sown at equal ratios of growth forms (5:1:4; grass, N-fixing forb and non-N-fixing forb) in replicate 2-m 2 plots planted on 10 roofs in New York City (New York, USA). Of 24 000 installed plants, 40% survived 23 months after planting. Within-roof factors explained 71% of variation in survivorship, with biotic (species identity and assemblage) factors accounting for 54% of the overall variation, and abiotic (growing medium depth and plot location) factors explaining 17% of the variation. Among-roof factors explained 29% of variation in survivorship and increased solar radiation correlated with decreased survivorship. While growing medium properties (pH, nutrients, metals) differed among roofs there was no correlation with survivorship. Percent cover and sward height increased with increasing survivorship. At low survivorship, cover of the HP assemblage was greater compared to the RS assemblage. Sward height of the HP assemblage was about two times greater compared to the RS assemblage. These results highlight the effects of local biotic and regional abiotic drivers on community composition and physical structure of green roof vegetation. As a result, initial green roof plant

  14. Densidade e qualidade dos estratos de forragem do capim Tanzânia (Panicum maximum Jacq. Cv. Tanzânia-1 manejado em diferentes alturas, sob pastejo Density bulk and quality of Tanzania grass layers (Panicum maximum Jacq.cv. Tanzania-1, at different heights in grazing

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    Geraldo Tadeu dos Santos

    2001-05-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito de diferentes alturas (24; 26; 43; 45; 52; 62; 73 e 78 cm do pasto sobre a qualidade de forragem e estrutura do perfil do capim-Tanzânia, (Panicum maximum Jacq. cv. Tanzânia – 1 (Poaceae. Foram utilizados novilhos da raça Nelore sob pastejo com carga animal variável, por meio da técnica put and take. O delineamento experimental utilizado foi inteiramente casualizado, com duas repetições. A densidade de matéria seca total (DMT aumentou com o avanço no período experimental, enquanto a densidade de matéria seca de lâminas (DML não foi influenciada pelo período e pela altura do pasto. O estrato superior da pastagem foi a porção de maior qualidade, apresentando maior DML e maior teor de PB. Os estratos inferiores apresentaram menor qualidade, devido à maior DMT e menor DML, acarretando em maiores valores de FDA e FDN e menores teores de PB. O conteúdo de minerais das lâminas foi superior aos colmos, mantendo-se inalterado com relação aos estratos da pastagem.The effect of different sward heights (24; 26; 43; 45; 52; 62; 73 and 78 cm on forage quality and profile structure Tanzania grass, Panicum maximum Jacq. cv. Tanzania – 1 (Poaceae is provided. Nelore steers were used in grazing at variable stocking rates with put and take technique. The experimental design was completely randomized, with two replications. Total dry matter bulk densitity (TDMD increased during experimental period, while the leaf blade dry matter bulk density (LDMD was not influenced by period on by sward height. The upper layers had the best quality with higher LDMD and CP levels. Lower layers had the worst quality, due the higher TDMD and lower LDMD. This fact caused higher ADF and NDF levels and lower CP levels. Leaf blade mineral content was higher than that of stem, and remained unaltered in relation to the different layers.

  15. On the formation and evolution of the Pannonian basin: constraints derived from the orogenic collapse recorded at the junction between Carpathians and Dinarides

    Science.gov (United States)

    Matenco, L. C.; Radivojevic, D.

    2012-04-01

    Formation and evolution of back-arc basins is related to the evolution of subduction zones, resulting geometries being dependent on the interplay between the velocity of retreating slabs and boundary conditions that often limit rapid subduction systems. Classical models of evolution in the Alps-Carpathians-Dinaridic domain assume that the formation of the Pannonian back-arc basin is related to the rapid roll-back of an European slab and the invasion of Tisza-Dacia and ALCAPA upper plate blocks into the so-called Carpathians embayment starting at ~20Ma. The general mechanism assumes a gradual evolution, an initial mechanical phase of extensional detachments being recognized near the transition between the Alps and the Pannonian basin was subsequently followed by upper crustal normal faulting and a thermal phase during the Middle-late Miocene times that affected the central part of the Pannonian basin. A key area of the entire system often neglected by kinematic studies is the connection between South Carpathians and Dinarides. Here, regional seismic lines traversing the entire Serbian part of the Pannonian basin were calibrated with well data in order to derive an evolutionary model. The deformation is dominantly expressed by the formation of extensional (half-)grabens that are the brittle expression of large-scale extensional detachments. In contrast with previous interpretation restricting the syn-rift phase to the Middle Miocene, the geometry of normal faults and the associated syn-kinematic sedimentation allows the definition of a continuous Early to Late Miocene extensional evolution that was followed by the formation of isolated uplifted areas during the subsequent Pliocene - Quaternary inversion. The orientation of these (half-)grabens changes gradually from W-E to NW-SE and then to N-S, suggesting that the present-day strike of faults is the effect of a clockwise rotational mechanism of South Carpathians and Apuseni Mountains in respect to Dinarides. The S-ward

  16. Grazing ecology of female lambs on Italian ryegrass plus red clover pasture under different defoliation intensities Ecologia do pastejo por cordeiras em pastagem de azevém e trevo-vermelho sob diversas intensidades de desfolha

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    Carine Lisete Glienke

    2010-01-01

    Full Text Available The relationship between pasture dynamics and ingestive behavior of female lambs was studied on Italian ryegrass (Lolium multiflorum Lam. plus red clover (Trifolium pratense L. mixture under a range of defoliation intensities. Rotational grazing was used and the grazing interval was determined by the thermal sum of 313 degree days. The initial pre-grazing canopy height disappearance values were 65 (very high, 58 (high, 47 (medium and 37% (low. The sward vertical structure was similar among defoliation intensities. The forage allowance decreased linearly as defoliation intensities increased, with 0.35 bite/minute reduction for each 1% increase in forage allowance. The bite rate and number of bites/feeding station decreased with reduced contribution of leaves in the sward structure. It was associated, respectively, with an increase and a decrease of NDF and CP levels in forage as grazed by female lambs. The pasture cycle proves to be more important than defoliation intensities as a source for changes in feeding stations and displacement patterns of female lambs.Estudou-se a relação entre a dinâmica do pasto e o comportamento ingestivo de cordeiras em pastagem de azevém (Lolium multiflorum Lam. e trevo-vermelho (Trifolium pratense L. em diferentes intensidades de desfolha. O pastejo foi rotacionado e o intervalo entre pastejos foi determinado pela soma térmica de 313 graus-dia. Os valores de desaparecimento da altura do dossel no pré-pastejo foram de 65 (muito alta, 58 (alta, 47 (média e 37% (baixa, respectivamente. A estrutura vertical do pasto foi semelhante entre as intensidades de desfolha testadas. A oferta de forragem diminuiu linearmente com o aumento da intensidade de desfolha, com redução de 0,35 bocado/minuto a cada 1% a mais na oferta de forragem. A taxa de bocados e o número de bocados/estação alimentar reduziram com a diminuição da contribuição de folhas na estrutura da pastagem, acompanhada do aumento do teor de FDN e

  17. Respostas do capim-Tifton 85 à aplicação de nitrogênio: cobertura do solo, índice de área foliar e interceptação da radiação solar Responses of the grass Tifton 85 to the application of nitrogen: soil cover, leaf area index, and solar radiation interception

    Directory of Open Access Journals (Sweden)

    A.P.P. Oliveira

    2010-04-01

    Full Text Available Estudaram-se os efeitos da adubação nitrogenada sobre o crescimento do capim Tifton 85 (Cynodon spp. cv. Tifton 85, em termos de ocorrência de plantas e altura do dossel, índice de área foliar e interceptação de radiação fotossinteticamente ativa. O estudo foi desenvolvido sobre um planossolo de ocorrência em campo experimental. Os tratamentos consistiram de níveis de N (0; 150; 300; 450 e 600kg/ha de N-ureia, aplicados em duas vezes, arranjados em um desenho experimental de blocos inteiramente ao acaso, com quatro repetições. As avaliações foram realizadas semanalmente, entre 10 e 40 dias após o corte. Tanto a ocorrência de plantas como a altura do dossel responderam à adubação nitrogenada, conforme um padrão de resposta que variou, sazonalmente, em função das doses de N em interação com as condições ambientais. A expansão da área foliar e a interceptação da radiação fotossinteticamente ativa associada, também foram controladas direta e proporcionalmente pelas doses de N aplicadas, sendo maximizadas a valores de índice de área foliar em torno de 4,0.The effects of nitrogen (N fertilization levels on the growth patterns of the grass Tifton 85 (Cynodon spp. cv.Tifton 85 were studied in terms of occurrence of plants, sward height, leaf area index, and photosynthetically active radiation interception (PARint. The field trial was made in an experimental area. Treatments consisted of N levels (0; 150; 300; 450; and 600kg/ha N-urea, split in two applications arranged in an experimental design of entirely randomized blocks with four repetitions. Plots were weekly sampled, from the day 10th to 40th after cutting. Both occurrence of plants as well as sward height were responsive to nitrogen fertilization according to a response pattern that seasonally varied, depending on N rates and environmental conditions; thus, demonstrating their sensitivity as indicators of growth conditions and canopy structure. Leaf expansion

  18. Leaf dynamics of Festulolium and Dactylis glomerata L. at the end of the growing season

    Directory of Open Access Journals (Sweden)

    Jiří Skládanka

    2008-01-01

    Full Text Available The paper is focused on the assessment of leaf extension rate (LER, leaf appearance rate (LAR and leaf senescence rate (LSR in the Festulolium (Festuca arundinacea Schreb. × Lolium multiflorum Lam. and in the Dactylis glomerata L. at the end of the growing season from the end of September to the beginning of December. In summer, the swards were used for a single cut (beginning of June or for a double cut (beginning of June and end of July. Measurements were made in three periods from 14 Sept. to 11 Oct., from 11 Oct. to 29 Oct., and from 29 Oct. to 6 Dec. In the first period, LER was higher in Dactylis glomerata L. (3.770 mm tiller−1 d−1 than in Festulolium (2.376 mm tiller−1 d−1. In the second and third period, LER was higher in Festulolium (0.859 resp. 0.271 mm tiller−1 d−1 than in Dactylis glomerata L. (0.694, resp. 0.199 mm tiller−1 d−1. LAR values measured in Festulolium in the studied pe­riods were 0.277 leaf tiller−1 d−1, 0.079 leaf tiller−1 d−1 and 0.038 leaf tiller−1 d−1 and LAR values of Dactylis glomerata L. were 0.225 leaf tiller−1 d−1, 0.054 leaf tiller−1 d−1 and 0.027 leaf tiller−1 d−1. In the course of the whole pe­riod of study, LSR showed the highest values in Dactylis glomerata L. (7.869 mm til­ler−1 d−1, 5.947 mm til­ler−1 d−1 and 4.757 mm tiller−1 d−1 while the LSR values of Festulolium were lower (2.904 mm tiller−1 d−1, 2.375 mm tiller−1 d−1 and 1.205 mm tiller−1 d−1. The influence of both the species and the period of measurement on the LER, LAR and LSR values was statistically highly significant (P < 0.01 to very highly significant (P < 0.001. The interaction between the species and the period of measurement was very highly significant (P < 0.001 in the LER characteristic. The influence of the intensity of sward use in summer on the LSR values was very highly significant (P < 0.001, too.

  19. Forage intake and behavior of goats on Tanzania-grass pasture at two regrowth ages - doi: 10.4025/actascianimsci.v35i1.16035 Forage intake and behavior of goats on Tanzania-grass pasture at two regrowth ages - doi: 10.4025/actascianimsci.v35i1.16035

    Directory of Open Access Journals (Sweden)

    Wellington Kelson Alvarenga Silva

    2013-01-01

    Full Text Available Normal 0 21 false false false The forage mass, sward structure, the ingestive and grazing behavior and forage intake by goats grazing on Tanzania-grass at 22 and 37 days of regrowth were evaluated. A completely randomized experimental design was used, with eight replications for evaluating the pasture and bite depth, and six replications for evaluating intake, feeding and grazing behavior. The forage canopy height ranged from 64.1 to 92.7 cm. Higher forage mass was observed at 37 days, and the best leaf/stem ratio, at 22 regrowth days. The bite depth did not differ between regrowth ages. The biting rate for the 22 regrowth days (23.07 bites min.-1 was higher than at 37 days (19.06 bites min.-1. The grazing time was longer at the regrowth age of 22 days (5.58h than at 37 days (4.51h. The average feed intake was 2.75% of the body weight and was not different between regrowth ages.  The forage mass, sward structure, the ingestive and grazing behavior and forage intake by goats grazing on Tanzania-grass at 22 and 37 days of regrowth were evaluated. A completely randomized experimental design was used, with eight replications for evaluating the pasture and bite depth, and six replications for evaluating intake, feeding and grazing behavior. The forage canopy height ranged from 64.1 to 92.7 cm. Higher forage mass was observed at 37 days, and the best leaf/stem ratio, at 22 regrowth days. The bite depth did not differ between regrowth ages. The biting rate for the 22 regrowth days (23.07 bites min.-1 was higher than at 37 days (19.06 bites min.-1. The grazing time was longer at the regrowth age of 22 days (5.58h than at 37 days (4.51h. The average feed intake was 2.75% of the body weight and was not different between regrowth ages.  

  20. Disentangling the role of management, vegetation structure, and plant quality for Orthoptera in lowland meadows.

    Science.gov (United States)

    Schirmel, Jens; Gerlach, Rebekka; Buhk, Constanze

    2017-08-17

    Seminatural grasslands provide habitats for various species and are important for biodiversity conservation. The understanding of the diverse responses of species and traits to different grassland management methods is therefore urgently needed. We disentangled the role of grassland management (fertilization and irrigation), vegetation structure (biomass, sward height) and plant quality (protein and fiber content) for Orthoptera communities in lowland hay meadows in Germany. We found vegetation structure to be the most important environmental category in explaining community structure of Orthoptera (species richness, total individuals, functional diversity and species composition). Intensively used meadows (fertilized, irrigated, high plant biomass) were characterized by assemblages with few species, low functional diversity, and low conservation value. Thereby, the relatively moderate fertilizer inputs in our study system of up to ∼75 kg N/ha/year reduced functional diversity of Orthoptera, while this negative effect of fertilization was not detectable when solely considering taxonomic aspects. We found strong support for a prominent role of plant quality in shaping Orthoptera communities and especially the trait composition. Our findings demonstrate the usefulness of considering both taxonomic and functional components (functional diversity) in biodiversity research and we suggest a stronger involvement of plant quality measures in Orthoptera studies. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  1. Predation risk of artificial ground nests in managed floodplain meadows

    Science.gov (United States)

    Arbeiter, Susanne; Franke, Elisabeth

    2018-01-01

    Nest predation highly determines the reproductive success in birds. In agricultural grasslands, vegetation characteristics and management practices influences the predation risk of ground breeders. Little is known so far on the predation pressure on non-passerine nests in tall swards. Investigations on the interaction of land use with nesting site conditions and the habitat selection of nest predators are crucial to develop effective conservation measures for grassland birds. In this study, we used artificial nests baited with quail and plasticine eggs to identify potential predators of ground nests in floodplain meadows and related predation risk to vegetation structure and grassland management. Mean daily predation rate was 0.01 (±0.012) after an exposure duration of 21 days. 70% of all observed nest predations were caused by mammals (Red Fox and mustelids) and 17.5% by avian predators (corvids). Nest sites close to the meadow edge and those providing low forb cover were faced with a higher daily predation risk. Predation risk also increased later in the season. Land use in the preceding year had a significant effect on predation risk, showing higher predation rates on unmanaged sites than on mown sites. Unused meadows probably attract mammalian predators, because they provide a high abundance of small rodents and a more favourable vegetation structure for foraging, increasing also the risk of incidental nest predations. Although mowing operation is a major threat to ground-nesting birds, our results suggest that an annual removal of vegetation may reduce predation risk in the subsequent year.

  2. Supplementation of Nellore young bulls on Marandu grass pastures in the dry period of the year

    Directory of Open Access Journals (Sweden)

    Marcella de Toledo Piza Roth

    2013-06-01

    Full Text Available The objective of this study was to evaluate performance and daytime ingestive behavior of 84 Nellore young bulls in the post-weaning phase kept on Brachiaria brizantha cv. Marandu pastures during the dry season. Treatments were protein mineral supplementation (1 g/kg body weight and protein+energy mineral supplementation (3 g/kg body weight. The experimental area comprised 12 paddocks in a total area of 27.36 ha, divided in two blocks of six paddocks each, having three replications per treatment in each block, with 42 animals/treatment. The data were subjected to variance analysis with repeated measures over time via procedure PROCMIXED of SAS (Statistical Analysis System, version 9.0 and means were compared by the Tukey test at 5% probability. The initial average weight of animals was 204.8 kg; final weights were 260.9 and 276.9 kg for animals that received protein and protein+energy supplement, respectively. The forage availability, sward height and stocking rate values did not differ with supplementation, but they showed difference between the experimental periods. The average time spent grazing during daylight of animals fed protein+energy supplement was shorter as compared with those which consumed protein supplement. Animals kept under the same pasture conditions during the dry season show better performance when they receive protein+energy supplement than protein supplement.

  3. Multiscale approach to pest insect monitoring: random walks, pattern formation, synchronization, and networks.

    Science.gov (United States)

    Petrovskii, Sergei; Petrovskaya, Natalia; Bearup, Daniel

    2014-09-01

    Pest insects pose a significant threat to food production worldwide resulting in annual losses worth hundreds of billions of dollars. Pest control attempts to prevent pest outbreaks that could otherwise destroy a sward. It is good practice in integrated pest management to recommend control actions (usually pesticides application) only when the pest density exceeds a certain threshold. Accurate estimation of pest population density in ecosystems, especially in agro-ecosystems, is therefore very important, and this is the overall goal of the pest insect monitoring. However, this is a complex and challenging task; providing accurate information about pest abundance is hardly possible without taking into account the complexity of ecosystems' dynamics, in particular, the existence of multiple scales. In the case of pest insects, monitoring has three different spatial scales, each of them having their own scale-specific goal and their own approaches to data collection and interpretation. In this paper, we review recent progress in mathematical models and methods applied at each of these scales and show how it helps to improve the accuracy and robustness of pest population density estimation. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Impact of cover crops in vineyard on the aroma compounds of Vitis vinifera L. cv Cabernet Sauvignon wine.

    Science.gov (United States)

    Xi, Zhu-Mei; Tao, Yong-Sheng; Zhang, Li; Li, Hua

    2011-07-15

    This study compared the influence of different cover crops with clean tillage on wine aroma compounds of 5-year-old Cabernet Sauvignon vines. White clover, alfalfa, and tall fescue were used in the vineyard and compared with clean tillage. Aroma compounds of wine were analysed by solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC/MS). Forty-seven volatile compounds were identified and quantified. Wines made from grapes grown with various cover crops had higher levels of aroma compounds. Ethyl acetate, isoamyl acetate, ethyl octanoate, ethyl hexanoate, phenylethyl acetate, isoamyl alcohol, linalool, citronellol, β-damascenone, α-ionone, and 5-amyl-dihydro-2(3H)-furan were the impact odorants of sample wines. Wines from cover crop also had higher contents of these impact odorants than the control. For different cover crops, alfalfa sward yielded the highest levels, followed by the tall fescue treatment. According to the data analysis of aroma compounds and sensory assess, permanent cover crop may have the potential to improve wine quality. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  5. Herbicides in environmental pollution

    International Nuclear Information System (INIS)

    Qureshi, M.J.; Haq, A.; Maqbool, U.

    1997-01-01

    Herbicide effectiveness on the most pernicious weeds including cyperus rotundus may be limited because spray droplets are not well retained or because penetration and/or translocation is restricted. As a result, chemical pollute the environment and is hazardous to the human health. Monitoring studies ad undertaken to check that the flate and environmental effects of herbicides under field condition are consistent with prediction. Studies on /sup 14/-glyphosate in Cyperus rotundus using radiotracer methods indicated that out of five formulations studies formulation No.3 was the best from penetration point of view of the chemical whereas formulation No. 4 with the high dose showed effective retention and uniform translocation of the chemical after five days of the treatment. Cuticular penetration and translocation of glyphosate in the formulations with or without surfactants have also been studied in C. rotundus. It is also concluded that synperonic surfactants, diesel oil or glycerol did not influence the translocation of glyphosate within the weed. The translocation mainly occurred down swards and accumulated in the plant parts located below the treated zone. (author)

  6. Early lactation feed intake and milk yield responses of dairy cows offered grass silages harvested at early maturity stages

    DEFF Research Database (Denmark)

    Randby, A T; Weisbjerg, M R; Nørgaard, P

    2012-01-01

    was available in automatic feed stations. Intake of grass silage when fed as the sole feed was 16.9 kg of DM on average for lactation wk 1 to 16. When H1 was supplemented with 4 or 8 kg of concentrates, silage DM intake did not change, but total DM intake increased to 20.6 and 23.7 kg/d, respectively. Energy......The main objective was to evaluate the potential of grass silages of very high quality to support a high milk yield with a low or moderate, or even without concentrate supplementation. Production responses to increased levels of concentrate supplementation with 3 primary growth grass silages...... differing in digestibility were studied using 66 Norwegian Red dairy cows. Roundbale silage was produced from a timothy-dominated sward at very early (H1), early (H2), and normal (H3) stages of crop maturity. Crops were rapidly wilted (h) and a formic acid-based additive was applied. All silages were...

  7. The estimation of some wild flowers seed material from the natural-valuable meadow habitats

    Directory of Open Access Journals (Sweden)

    Janicka Maria

    2016-12-01

    Full Text Available The restoration of the species composition of the meadow habitats is often linked to the introduction of the typical species’ seeds. The effectiveness of that treatment requires getting the acquired detailed knowledge of the germination biology of peculiar species. Eight typical plant species of four non-forest habitats of the river valleys, representing the following types: Cnidion dubii (6440, Molinion (6410, Arrhenatherion (6510 and Festuco-Brometea (6210 were investigated. The diasporas were collected in the years 2014–2015 on the meadows of PLH 140016 protection area near Mniszew (Kozienice county, Mazovian voivodeship. The ability of seeds’ germination in the laboratory conditions was studied. It was stated that Cnidion and Molinion meadows’ species require pre-chilling to break the seeds’ dormancy, while the Arrhenatherion meadows and xerotermophilous swards do not require such treatment. The Allium angulosum, Plantago lanceolata, Achillea millefolium and Eryngium planum were characterized by high vigour and germination capability as well as the low share of dead seeds. The extremely drought in 2015 caused the decreasing in germination capability and increasing in the dead seeds’ share. The preliminary studies, presented in this paper, show that Cnidion and Molinion meadows may be most difficult to restore because of the necessity of breaking the seeds’ dormancy and higher sensitiveness for the unfavourable weather conditions during the seed ripening stage. The studies have practical significance for the works connected with the floristic diversity’ increasing of threatened communities and the restoration of the destroyed meadow habitats.

  8. Human gastric cancer, Helicobacter pylori and bracken carcinogens: A connecting hypothesis.

    Science.gov (United States)

    Oliveros-Bastidas, Alberto; Calcagno-Pissarelli, María Pía; Naya, Marlene; Ávila-Núñez, Jorge Luis; Alonso-Amelot, Miguel E

    2016-03-01

    Long term infection of Helicobacter pylori (Hp) virulent strains is a key factor in the genesis of human gastric cancer, and so are certain dietary proinflammatory and genotoxic compounds. Carcinogenic bracken fern (Pteridium spp.) is one of these. Toxins from this plant are consumed as bracken culinary preparations, through milk and meat of bracken-exposed livestock, and drain waters from bracken swards. Bracken toxin ptaquiloside (PtQ), a suspected human carcinogen, elicits complex responses in animals leading to death. PtQ and Hp might cooperate in gastric pathologies. This paper presents an hypothesis on PtQ-Hp association leading to the enhancement of carcinogenesis in the human gastric environment that might explain the high gastric cancer incidence and death rates among Hp-infected people living in bracken zones at two levels: (1) The macroscopic scale comprising the flow of PtQ in the human diet. (2) the microscopic scale encompassing (A) gastric luminal medium; (B) gastric mucus structure and mucin degradation elicited by Hp; (C) bacterial pH gradient modification of the gastric mucosa that favors PtQ survival and its penetration into epithelial tissue; (D) combined PtQ/Hp effects on gastric immune and inflammatory responses; (E) PtQ-Hp complementary activity at selected cell signaling cascades and genome disturbance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Anaerobic mono-digestion of lucerne, grass and forbs – Influence of species and cutting frequency

    DEFF Research Database (Denmark)

    Wahid, Radziah; Feng, Lu; Cong, Wenfeng

    2018-01-01

    but it was not possible to ascertain whether this was due to organic overload alone or if high ammonia levels during Lu-4 digestion were contributing to the reduced performance. It was found that four cuts per year was suitable for a lab-scale mono-digestion system as the substrate was less fibrous and has lower dry......In the present study, biogas potentials of multispecies swards including grass, lucerne, caraway, ribwort plantain and chicory from two- and four-cut regimes (Mix-2 and Mix-4) for mono-digestion applying batch and continuous modes under lab-scale conditions were investigated. The gas yields...... confirmed with continuous experiments, during which the reactor digesting Mix-4 was stable throughout the experiment with low ammonia and volatile fatty acid (VFA) concentration. Meanwhile, mono-digestion of Lu-4 led to elevated VFA levels, even at a comparatively low organic loading rate of 1.76 g L−1 d−1...

  10. Carbon and nitrogen cycling in an integrated soybean-beef cattle production system under different grazing intensities

    Directory of Open Access Journals (Sweden)

    Joice Mari Assmann

    2015-10-01

    Full Text Available Abstract:The objective of this work was to evaluate the effect of grazing intensity on the decomposition of cover crop pasture, dung, and soybean residues, as well as the C and N release rates from these residues in a long-term integrated soybean-beef cattle system under no-tillage. The experiment was initiated in 2001, with soybean cultivated in summer and black oat + Italian ryegrass in winter. The treatments consisted of four sward heights (10, 20, 30, and 40 cm, plus an ungrazed area, as the control. In 2009-2011, residues from pasture, dung, and soybean stems and leaves were placed in nylon-mesh litter bags and allowed to decompose for up to 258 days. With increasing grazing intensity, residual dry matter of the pasture decreased and that of dung increased. Pasture and dung lignin concentrations and C release rates were lower with moderate grazing intensity. C and N release rates from soybean residues are not affected by grazing intensity. The moderate grazing intensity produces higher quality residues, both for pasture and dung. Total C and N release is influenced by the greater residual dry matter produced when pastures were either lightly grazed or ungrazed.

  11. Evolution of revegetated ski slopes in different environments

    Directory of Open Access Journals (Sweden)

    Argenti G

    2011-12-01

    Full Text Available Revegetation of ski slopes is a useful technique to limit soil erosion, reduce the visual impact of the tracks and lengthen the duration of snow cover. Restoration is often performed with commercial forage mixtures with the aim of creating a fast soil cover, then allowing the natural recolonization of artificial swards in the mid-long term. To investigate on the recolonization dynamics, data were collected from 21 different plots from the Alps and the Apennines (Valtellina, Plan de Corones, Sappada, Cimone. Knowledge of both the original mixtures used for restoration and the timespan since intervention (ranging from 1 to 21 years allowed to throw light on the naturalization process for the studied plots. Ground cover, floristic richness and relative presence of sown and native species were measured along linear transects established on the analyzed ski tracks. Results showed the effectiveness of plant restoration, in terms of soil coverage and (in some cases persistence of species of the original mixtures. Recovery of autochthonous species was strongly affected by site elevation and time elapsed since restoration. Moreover, the distance of ski lanes from forest edges seems to influence the dynamics of recolo­nisation process. Renaturalization was remarkably faster in the lower-altitude Apennine study plot. Application of a regression analysis revealed that elevation and timespan since restoration may be considered useful predictors of the level of naturalization of the restored canopies.

  12. Predicting soil acidification trends at Plynlimon using the SAFE model

    Directory of Open Access Journals (Sweden)

    B. Reynolds

    1997-01-01

    Full Text Available The SAFE model has been applied to an acid grassland site, located on base-poor stagnopodzol soils derived from Lower Palaeozoic greywackes. The model predicts that acidification of the soil has occurred in response to increased acid deposition following the industrial revolution. Limited recovery is predicted following the decline in sulphur deposition during the mid to late 1970s. Reducing excess sulphur and NOx deposition in 1998 to 40% and 70% of 1980 levels results in further recovery but soil chemical conditions (base saturation, soil water pH and ANC do not return to values predicted in pre-industrial times. The SAFE model predicts that critical loads (expressed in terms of the (Ca+Mg+K:Alcrit ratio for six vegetation species found in acid grassland communities are not exceeded despite the increase in deposited acidity following the industrial revolution. The relative growth response of selected vegetation species characteristic of acid grassland swards has been predicted using a damage function linking growth to soil solution base cation to aluminium ratio. The results show that very small growth reductions can be expected for 'acid tolerant' plants growing in acid upland soils. For more sensitive species such as Holcus lanatus, SAFE predicts that growth would have been reduced by about 20% between 1951 and 1983, when acid inputs were greatest. Recovery to c. 90% of normal growth (under laboratory conditions is predicted as acidic inputs decline.

  13. Signal grass structure at different sites of the same pasture under three grazing intensities - doi: 10.4025/actascianimsci.v35i1.11801

    Directory of Open Access Journals (Sweden)

    Ronan Lopes Albino

    2013-01-01

    Full Text Available The experiment was conducted to evaluate Brachiaria decumbens cv. Basilisk at different sites of the same pasture featuring varying grazing intensities (under grazed, properly grazed and overgrazed. The pasture was managed under continuous stocking using 200-kg cattle and grass height kept at about 25 cm. The randomized block design was used, with three replications. Sward height (38.0 cm and extended plant height (85.2 cm were greater at the under grazed site. The falling index was lower at the properly grazed site (1.28. At the under grazed site, the masses of green leaf blade (3442 kg ha-1 DM, green stem (8370 kg ha-1 DM, green forage (11812 kg ha-1 DM and total forage (14137 kg ha-1 DM were higher when compared to the overgrazed and properly grazed sites. Dead material mass was higher at the properly grazed (3422 kg ha-1 DM and under grazed (2324 kg ha-1 DM sites. At the under grazed sites, there was a higher occurrence of tillers taller than 40 cm. Tillers with sizes between 10 and 30 cm predominated in properly grazed sites. In overgrazed site there was a higher share of tillers with sizes smaller than 20 cm. There is spatial variability of vegetation in the same pasture of Brachiaria decumbens cv. Basilisk due to uneven grazing by cattle.

  14. Tiller density and tillering on Brachiaria brizantha cv. Marandu pastures inoculated with Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    B.C. Pedreira

    Full Text Available ABSTRACT The objective of this study is to verify the population density and the dynamics of tillering in the Marandu palisade grass sward subjected to nitrogen (N fertilization strategies, characterized by the N supply via urea or bacterial inoculant (Azospirillum brasilense. The treatments comprised of four nitrogen fertilization strategies: (A Without fertilization, (B 80 kg N/ha, (C inoculant (A. brasilense, and (D 80 kg N/ha + inoculant, distributed in a randomized complete block design, with three replications. The nitrogen supply strategies were evaluated during six periods: October, November, and December (2012 as well as January, March, and April (2013. The nitrogen dose or inoculant had no effect on the tiller appearance rate (TAR, tiller mortality rate (TMR, tiller survival rate (TSR, or tiller population density (TPD. However, these variables were influenced by the season. The TAR and TSR were higher at the beginning of the experimental period (October and lower towards the end of the period (March-April, whereas, TMR and TPD exhibited the opposite behavior, with lower values in October and higher from January onward. Neither the nitrogen nor the inoculant influenced the population dynamics of the tillers in Marandu palisade grass.

  15. Effects of forage types on digestibility, methane emissions, and nitrogen utilization efficiency in two genotypes of hill ewes.

    Science.gov (United States)

    Zhao, Y G; Annett, R; Yan, T

    2017-08-01

    Thirty-six nonpregnant hill ewes (18 pure Scottish Blackface and 18 Swaledale × Scottish Blackface) aged 18 mo and weighing 48 ± 4.8 kg were allocated to 3 forage treatments balanced for genotype and BW. Each genotype was offered 3 forages (pelleted ryegrass, fresh lowland grass, and fresh hill grass) ad libitum with 6 ewes for each of the 6 genotype × diet combination treatments. Pelleted ryegrass was sourced from a commercial supplier (Drygrass South Western Ltd, Burrington, UK). Fresh lowland grass was harvested daily in the morning from a third regrowth perennial ryegrass () sward. Fresh hill grass was harvested from a seminatural hill grassland every 2 d and stored in plastic bags at 4 to 5°C until offered. The animals were individually housed in pens and offered experimental diets for 14 d before being transferred to 6 individual respiration chambers for a further 4 d, during which feed intake, fecal and urine outputs, and CH emissions were measured. There was no interaction between genotype and forage types on any variable measured. In a comparison of effects of the 3 forages, pelleted ryegrass had the greatest ( reduce CH emissions per kilogram DMI. These equations add new information in predicting enteric CH emissions and N utilization efficiency and can be used to quantify the environmental footprint of hill sheep production systems.

  16. Seedling Performance Associated with Live or Herbicide Treated Tall Fescue

    Directory of Open Access Journals (Sweden)

    Jonathan J. Halvorson

    2015-01-01

    Full Text Available Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L, or an herbicide killed (K tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E− or legumes (alfalfa, red clover, and white clover. After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover and tall fescue (especially MaxQ were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions.

  17. The photosynthetic acclimation response of Lolium perenne to four years growth in a free-air CO{sub 2} enrichment (FACE) facility

    Energy Technology Data Exchange (ETDEWEB)

    Creasey, R. [Univ. of Essex (United Kingdom)

    1996-11-01

    In this study, the photosynthetic responses of field grown Lolium perenne to ambient (354 {mu}mol mol{sup -1}) and elevated (600 {mu}mol mol{sup -1}) C{sub a} were measured. The experiment utilized the FACE facility at Eschikon, Switzerland; here the L. Perenne swards had been grown at two nitrogen treatments, with six cuts per year, for 4 years. The study revealed a significant decrease in Rubisco activity (Vcmax) in the low nitrogen FACE plots; this is consistent with the theories of source-sink imbalance resulting in feedback inhibition and down-regulation. Such negative acclimation was not wholly supported by diurnal investigations which revealed an average stimulation of 53.38% and 52.78% in the low and high nitrogen, respectively. However, light response curves and AI investigations also suggested down-regulation, especially in the low nitrogen. SI is expected to decrease in response to elevated C{sub a}, if any change is seen. This was indeed observed in the high nitrogen plots but for the low nitrogen a significant increase was found. Conclusions drawn from this project center around the implications of negative acclimation to future crop productivity. For instance, inter-specific differences in response to elevated C{sub a} may result in ecosystem changes and new management techniques may be necessary. However, real predictions cannot be made from leaf level studies alone as these may not represent the overall changes at the whole plant level.

  18. Effect of grazing intensity and applied fertilizers on pasture production and animal gain

    International Nuclear Information System (INIS)

    Sigurbjoernsson, B.; Gudmundsson, O.; Arnalds, A.; Thorsteinsson, I.; Eiriksson, T.

    1983-01-01

    A 5-year study was conducted to determine the effect of grazing intensity and fertilizers on the production of twin lambs in Iceland. Three sites were selected: dry highland, dry lowland and lowland bog. Although increasing the stocking rate reduced the daily gain and carcass weight per lamb, these factors were markedly increased per unit area. Tritiated water was used to establish the body composition and water turnover rates in the lambs. The criteria for optimum use of a pasture could best be established by considering the condition of the sward. Fertilizer (78 to 92 kg N/ha and 18 to 80 kg P/ha) increased the carcass weight by a factor of three on the lowland bog, but by a factor of ten on the less productive highlands. Fertilizer increased standing vegetation by a factor of 11 to 18 and also increased forage quality by markedly increasing the protein and phosphorus content and the digestibility. Fertilizer restored and improved the species composition of the pasture in addition to its productivity. (author)

  19. Dynamics of production and forage utilization on elephant grass pastures managed with different post-grazing heights

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    Braulio Maia de Lana Sousa

    2012-08-01

    Full Text Available This study was conducted to evaluate the daily production of forage and its morphological components, as well as the potential of forage utilization in pastures of Pennisetum purpureum cv. Napier managed with three post-grazing heights (30, 50 and 70 cm. Two experiments were carried out: one from February to May 2009 and another from December 2009 to May 2010, characterizing months of summer and fall. The experimental design was of completely randomized blocks with three replicates. The grazing was performed by crossbred heifers of approximately 270 kg body weight, when the sward intercepted 95% of the incoming light. In both experiments, the pastures managed with post-grazing height of 30 cm, in the summer months (December to March, presented lower daily production of leaves and stems, as well as less daily leaf senescence, which resulted in lower daily forage production and accumulation in comparison with those managed at 70 and 50 cm. In the period from February to March 2009 (experiment 1 and December 2009 to March 2010 (experiment 2, pastures presented greater daily production of leaves and forage, greater daily forage accumulation and more daily leaf senescence in relation to the months of April and May 2009 and 2010. On the other hand, the daily production of stems was higher in the fall, in comparison with the summer. Therefore, elevation in the post-grazing height, especially in the summer, increases the regrowth vigor of elephant grass cv. Napier.

  20. Morphogenesis in guinea grass pastures under rotational grazing strategies

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    Denise Baptaglin Montagner

    2012-04-01

    Full Text Available This study was conducted in order to evaluate the morphogenetic and structural characteristics of guinea grass cv. Mombasa under three post-grazing heights (intense - 30 cm, lenient - 50 cm and variable - 50 in spring-summer and 30 cm in autumn-winter when sward light interception reached 95% during regrowth. Post-grazing heights were allocated to experimental units (0.25 ha in a completely randomized block design with three replications. Post-grazing heights affected only leaf elongation rate and the number of live leaves. Pastures managed with variable post-grazing height showed higher leaf elongation rate in the summer of 2007. This management strategy also resulted in a higher number of live leaves. During the spring of 2006, plants showed lower leaf elongation rate, leaf appearance rate and number of live leaves, and greater phyllochron and leaf lifespan. In contrast, during the summer of 2007, the leaf appearance rate, leaf elongation rate, number of live leaves, and final leaf length were greater while phyllochron, stem elongation rate, and leaf senescence rate were lower. The management of the guinea grass cv. Mombasa with intense or variable post-grazing height throughout the year seems to represent an interesting management target, in terms of leaf appearance rate and number of live leaves.

  1. Brazilian scientific progress in pasture research during the first decade of XXI century Progresso científico em pastagem na primeira década do século XXI

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    Valéria Pacheco Batista Euclides

    2010-07-01

    Full Text Available This paper aims to discuss the scientific progress obtained in the past ten years in genetics and plant breeding, soil fertility and plant nutrition and the importance of target sward conditions for planning, controlling and recommending management grazing of tropical grasses. In addition, progress in crop-livestock integration systems and management alternatives for mitigation of greenhouse gas emission by beef cattle production systems, two very important areas related to sustainable production systems, will also be discussed.O objetivo neste trabalho é discutir os progressos científicos obtidos nos últimos dez anos em genética e melhoramento de plantas, fertilidade do solo e nutrição de plantas, além da importância dos objetivos concernentes a condições de pasto para planejamento, controle e recomendações de manejo de pastejo de gramíneas tropicais. Além disso, também serão discutidos o progresso nos sistemas de integração lavoura-pecuária e as alternativas de gestão para a mitigação das emissões de gases de efeito estufa em sistemas de produção de gado de corte, duas áreas muito importantes associadas a sistemas de produção sustentável.

  2. Ingestive behavior of cattle kept in Brachiaria brizantha cv. Xaraés grass managed under different grazing heights

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    Marco Aurélio Alves de Freitas Barbosa

    2014-02-01

    Full Text Available This experiment was conducted to evaluate the effect of grazing heights on daytime behavioral activities of Nellore beef cattle in the rainy season. The experimental area was 12 hectares divided into paddocks of one hectare each. The treatments consisted of four defoliation heights (15, 30, 45 and 60 cm in pastures of Brachiaria brizantha cv. Xaraés with three replicates each. It was used the continuos grazing method, with variable stocking rate. Forage samples collected on the plots were sent to the laboratory for separation of the botanical components, weighing and determination of dry matter, with the material collected by simulated grazing. The variables: grazing time, idle time and ruminating time were evaluated for 12 consecutive hours on days 15 and 16 February 2011, considering the morning and afternoon periods. It was used a completely randomized design. The height of the canopy significantly influenced the daily grazing time and ruminating time, with a quadratic response as a function of time of defoliation. The bite rate decreased as a function of heights studied. However the chemical composition of the material collected by simulated grazing did not differ between treatments. Xaraés grass swards grazed at around 45 cm height provide greater ease of apprehension by grazing cattle.

  3. Voluntary intake, digestibility and nitrogen utilization by sheep fed ensiled grass clover mixture harvested at three stages of maturity

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    Marina Vranić

    2008-12-01

    Full Text Available The objective of this experiment was to study the effects of grass maturity at harvest on silage ad libitum intake, in vivo digestibility and N retention in wether sheep. The sward was harvested at the stem elongation, tasseling and flowering growth stages of orchardgrass (Dactylis glomerata. Three silages were offered to four Charolais wether sheep in an incomplete change over design with four periods. As the crop matured, there was an increase (P<0.001 in dry matter (DM, organic matter (OM and acid detergent fiber (ADF concentration and a decrease in crude protein (CP concentration (P<0.001. Increasing maturity of grass ensiled showed a linear decrease (P<0.01 in voluntary silage intake of DM, OM, neutral detergent fiber (NDF, a linear decrease (P<0.01 in digestibility of silage DM, OM, NDF, ADF, CP, and a linear decrease in nitrogen balance (P<0.01. No quadratic response was recorded in silage intake, digestibility or N balance. The results suggest that grass maturity at harvest influences the nutritive value of grass silage, in terms of ad libitum intake, in vivo digestibility and N retention in sheep, as a result of changes in chemical composition.

  4. Comportamento ingestivo de equinos e a relação com o aproveitamento das forragens e bem-estar dos animais Equine feeding behavior and its relation with forage use and animal welfare

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    João Ricardo Dittrich

    2010-07-01

    , but it is a complex system which interferes on the horse's decision while it is grazing. The appropriate horse's feeding management depends on the comprehension of their behavior patterns. As the sward is heterogeneous and the plants' structure vary in height, density, types of leaves, stems and reproductive parts, the horses select the sward. This selection allows them to ingest some important nutrients, vital for their maintenance and development. Stocking rate and grazing time, both results of horse management in stables, limit their selectivity. The forages supply nutrients and prevent clinical disorders and behavior stereotypic. Inputs of researches about pasture use are able to show the importance of horses' relationship with environment and the need of appropriate management can provide a better life quality for horses.

  5. Herbage Production, Nutritive Value and Grazing Preference of Diploid and Tetraploid Perennial Ryegrass Cultivars (Lolium perenne L. Producción de Fitomasa, Calidad Nutritiva y Preferencia de Pastoreo de Cultivares Diploides y Tetraploides de Ballica Perenne (Lolium perenne L.

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    Oscar A Balocchi

    2009-09-01

    Full Text Available The objective of this study was to determine, under the soil and climatic conditions of Southern Chile, the effect of the ploidy of perennial ryegrass (Lolium perenne L. cultivars on herbage production, nutritive value, grazing preference and utilization of pasture produced. This study was conducted in southern Chile, Valdivia Province, and was evaluated for 3 years. The tetraploid cultivars used were Quartet (4n, Gwendal (4n, Pastoral (4n and Napoleon (4n. The diploid cultivars were Anita (2n, Jumbo (2n, Aries (2n, and Yatsyn 1 (2n.When the average sward height reached 20 cm, all plots were simultaneously grazed by dairy cows for a period of 24 h. Before and after grazing, sward height, dry matter availability and nutritive value were evaluated. Grazing preference was visually assessed every 5 min for a period of 2.5 h after the afternoon milking. During the 3-year period 20 grazing events were evaluated. A randomized complete block design, with eight cultivars and three replicates, was used. Diploid cultivars showed greater herbage mass accumulation than tetraploid cultivars (P ≤ 0.05. No significant differences were obtained in the annual average crude protein content. Nevertheless, tetraploid cultivars showed a greater D value than diploid cultivars, except during the third year when the difference was not statistically significant. Dairy cows grazed more time on tetraploid cultivars. Considering, additionally, the residual herbage mass after grazing and the percentage of pasture utilization, diploid cultivars were less intensively grazed, suggesting a lower consumption by the cows.El objetivo de este estudio fue determinar, bajo las condiciones edafoclimáticas del sur de Chile, el efecto de la ploidía de cultivares de ballica perenne (Lolium perenne L. sobre el rendimiento de fitomasa, calidad nutricional, preferencia de pastoreo y porcentaje de utilización del forraje producido. El ensayo se realizó en el sur de Chile, provincia de

  6. Desenvolvimento e migração de larvas infectantes de ciatostomíneos (Nematoda: Cyathostominae em gramínea coast cross (Cynodon dactylon em clima tropical, na Baixada Fluminense, RJ, Brasil Development and migration of cyathostome infective larvae (Nematoda: Cyathostominae in bermuda grass (Cynodon dactylon in tropical climate, in Baixada Fluminense, RJ, Brazil

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    Melissa C. M. do Couto

    2009-06-01

    Full Text Available Esse estudo foi realizado no período de julho de 2003 a novembro de 2004, para avaliar o desenvolvimento, a sobrevivência, a migração das larvas infectantes em gramínea "coast cross" (Cynodon dactylon e o horário de maior disponibilidade, em condições de clima tropical, na Baixada Fluminense, RJ, Brasil. De julho de 2003 a setembro de 2004, massas fecais de equinos naturalmente infectados foram depositadas mensalmente sobre a gramínea. Sete dias após, amostras de fezes e gramínea foram coletadas semanalmente em diferentes horários (8, 13 e 17 horas, pesadas e processadas pela técnica de Baermann. O desenvolvimento, a sobrevivência e a migração das larvas infectantes nas fezes e na gramínea foram observados durante todo o período. A sobrevivência das L3 foi de até 15 semanas nas fezes e 12 semanas na gramínea no período seco e de nove e oito semanas, respectivamente, para o período chuvoso. No período chuvoso, maior número de L3 foi recuperado nas fezes e, no período seco, na gramínea. Condições climáticas influenciaram diretamente o número larvas infectantes. Pela análise multivariada, ficou demonstrado uma forte relação entre o tempo e o número de L3 nas fezes, sendo esta relação menos acentuada para a gramínea. Não se observou diferença significativa entre os horários de coleta.A study following the development and migration of Cyathostominae infective larvae was conducted from July 2003 to November 2004 in tropical climate, Baixada Fluminense, RJ, Brazil. Samples of naturally infected feces were placed on 12 m² plot each month on a cyathostomin-free "Bermuda grass" pasture (Cynodon dactylon. After Seven days, samples of feces and grass were collected every week at 8 a.m, 1 and 5 p.m., weighed and processed by Baermann technique. Higher survival of L3 was found at dry season, 15 and 12 weeks on feces and sward respectively, at rainy season the survival was smaller. The multivariable analysis of main

  7. Comportamento ingestivo de novilhas de corte submetidas a estratégias de suplementação em pastagens de aveia e azevém Ingestive behavior of beef heifers submitted to strategies of supplementation on oats and ryegrass pastures

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    Carolina Bremm

    2008-07-01

    BO and IR pasture receiving 0.9% of LW of supplement; and 'decreasing' - animals on BO and IR pasture receiving decreasing (1.5, 1.2, and 0.9% of LW levels of supplement. Structural sward characteristics (herbage mass, green herbage mass, herbage allowance, leaf blade allowance, leaf:stem ratio, and proportion of oats leaf blade and stem + sheath and proportion of ryegrass leaf blade and stem + sheath and nutritive value (crude protein concentration, in vitro organic matter digestibility, total digestible nutrients, and neutral detergent fiber were similar among strategies of supplementation and varied with pasture utilization periods. Daily grazing time, ruminating time, idling time, time spent near the trough (min/day, and bite mass (g OM/bite varied with strategies of supplementation and sward characteristics. The biting rate/min was influenced only by grazing cycle.

  8. Evaluation of silage diets offered to reindeer calves intended for slaughter. I. Feeding of silage and barley from September to March

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    Anna Nilsson

    1996-01-01

    Full Text Available An experiment involving 75 male reindeer calves (mean initial live weight 39.6 kg, SD=3.7 intended for slaughter was undertaken to study the effect of proporrion of barley to silage in the diets on animal performance. The calves were alloted to five groups including one group slaughtered at the start of the experiment in September. The remaining groups were offered diets containing either, 30% (LB, or 60% (HB rolled barley, based on the dry matter (DM content, until slaughter in November (LB and HB or in March (HB. The silage (43% DM was made from the primary growth of a predominantly grass sward preserved as plastic-wrapped big bales. Small amounts of lichens were mixed with the rations during rhe first two weeks of the experiment and the calves adapted well to the experimental diets. However, health problems and deaths occurred on borh rarions after five weeks of feeding. Since the animals fed the LB diet lost live weight and condition the experimental feeding of these calves were interrupted at the slaughter in November. Calves fed the LB diet had significantly lower daily DM intake (P<0.01. They also had lower live weighr gain (not significant, greater losses of carcass weight and fat in the abdominal cavity relative to those offered the HB diet. During the second period of the study the remaining animals offered the HB diet showed no signs of ill-health and increased live weight, carcass weighr, and fat in the abdominal cavity. The results of the presenr experiment indicate that when silage of the investigated quality is fed to reindeer calves rhe proportion of silage should not exceed 40% of the DM.

  9. Milk quality as affected by grazing time of day in Mediterranean goats.

    Science.gov (United States)

    Avondo, Marcella; Bonanno, Adriana; Pagano, Renato I; Valenti, Bernardo; Grigoli, Antonio Di; Luigia Alicata, M; Galofaro, Vittorio; Pennisi, Pietro

    2008-02-01

    We evaluated the effect of grazing time of day on goat milk chemical composition, renneting properties and milk fatty acid profile in a Mediterranean grazing system. Sixteen lactating Girgentana goats were divided into two experimental groups and housed in individual pens, where they received 500 g/d of barley grain. For 5 weeks the two groups were left to graze in two fenced plots on a ryegrass sward as follows: morning group (AM), from 9.00 to 13.00; afternoon group (PM), from 12.00 to 16.00. In selected herbage, water-soluble carbohydrates (WSC) increased in the afternoon (204 v. 174 g/kg dry matter, DM; P=0.01), whereas crude protein (CP) and linolenic acid decreased (respectively, 16.7 v. 19.8% DM; Ptitrable acidity ( degrees SH) increased in the PM group (respectively 3.56 v. 3.42%; P=0.01; 3.55 v. 3.22 degrees SH/50 ml; P=0.01). In contrast, milk urea content was significantly higher in the AM group (381 v. 358 mg/l; P=0.037). The results seem to indicate that an improvement in ruminal efficiency might be obtained by shifting grazing time from morning to afternoon, as a consequence of a more balanced ratio between nitrogenous compounds and sugars. Indeed, the higher linolenic acid and the lower conjugated linoleic acid (CLA) (respectively 1.02 v. 0.90, P=0.037; 0.71 v. 0.81% of total fatty acids, P=0.022) in the milk of goats grazing in the afternoon seem to indicate a reduced biohydrogenation activity in the PM group.

  10. Surface coal mine land reclamation using a dry flue gas desulfurization product: Short-term and long-term water responses.

    Science.gov (United States)

    Chen, Liming; Stehouwer, Richard; Tong, Xiaogang; Kost, Dave; Bigham, Jerry M; Dick, Warren A

    2015-09-01

    Abandoned coal-mined lands are a worldwide concern due to their potential negative environmental impacts, including erosion and development of acid mine drainage. A field study investigated the use of a dry flue gas desulfurization product for reclamation of abandoned coal mined land in USA. Treatments included flue gas desulfurization product at a rate of 280 Mg ha(-1) (FGD), FGD at the same rate plus 112 Mg ha(-1) yard waste compost (FGD/C), and conventional reclamation that included 20 cm of re-soil material plus 157 Mg ha(-1) of agricultural limestone (SOIL). A grass-legume sward was planted after treatment applications. Chemical properties of surface runoff and tile water (collected from a depth of 1.2m below the ground surface) were measured over both short-term (1-4 yr) and long-term (14-20 yr) periods following reclamation. The pH of surface runoff water was increased from approximately 3, and then sustained at 7 or higher by all treatments for up to 20 yr, and the pH of tile flow water was also increased and sustained above 5 for 20 yr. Compared with SOIL, concentrations of Ca, S and B in surface runoff and tile flow water were generally increased by the treatments with FGD product in both short- and long-term measurements and concentrations of the trace elements were generally not statistically increased in surface runoff and tile flow water over the 20-yr period. However, concentrations of As, Ba, Cr and Hg were occasionally elevated. These results suggest the use of FGD product for remediating acidic surface coal mined sites can provide effective, long-term reclamation. Copyright © 2015. Published by Elsevier Ltd.

  11. Evolution of body size in Galapagos marine iguanas.

    Science.gov (United States)

    Wikelski, Martin

    2005-10-07

    Body size is one of the most important traits of organisms and allows predictions of an individual's morphology, physiology, behaviour and life history. However, explaining the evolution of complex traits such as body size is difficult because a plethora of other traits influence body size. Here I review what we know about the evolution of body size in a group of island reptiles and try to generalize about the mechanisms that shape body size. Galapagos marine iguanas occupy all 13 larger islands in this Pacific archipelago and have maximum island body weights between 900 and 12 000g. The distribution of body sizes does not match mitochondrial clades, indicating that body size evolves independently of genetic relatedness. Marine iguanas lack intra- and inter-specific food competition and predators are not size-specific, discounting these factors as selective agents influencing body size. Instead I hypothesize that body size reflects the trade-offs between sexual and natural selection. We found that sexual selection continuously favours larger body sizes. Large males establish display territories and some gain over-proportional reproductive success in the iguanas' mating aggregations. Females select males based on size and activity and are thus responsible for the observed mating skew. However, large individuals are strongly selected against during El Niño-related famines when dietary algae disappear from the intertidal foraging areas. We showed that differences in algae sward ('pasture') heights and thermal constraints on large size are causally responsible for differences in maximum body size among populations. I hypothesize that body size in many animal species reflects a trade-off between foraging constraints and sexual selection and suggest that future research could focus on physiological and genetic mechanisms determining body size in wild animals. Furthermore, evolutionary stable body size distributions within populations should be analysed to better

  12. The estimation of Adonis vernalis populations in chosen patches of Lublin Upland

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    Bożena Denisow

    2012-12-01

    Full Text Available The number of Adonis vernalis populations, their size and abundance in xerothermic communities of the Lublin Upland have decreased significantly in the last 40-50 years, which indicates that there is a real risk of species extinction in the studied area. The paper is an attempt to indicate the possible factors which influence the decrease of Adonis vernalis populations. Detailed studies were carried out in six sites differing habitat conditions, land use and the size of Adonis vernalis populations. Observations were made of the abundance of blooming and the number of anthers per flower. The ability for reproduction was estimated indirectly by the mass of pollen delivered and its biological value. The populations of Adonis vernalis differ in number of anthers per flower (94.4 - 131.5, on average, the mass of pollen delivered (0.83 mg - 3.18 mg per 100 anthers, on average, the biological value of pollen and the size of pollen grains. Generally, stronger populations were characterized by better quality and a higher quantity of pollen. Potential energy of pollen in flowers from Pliszczyn and Łabunie was 69-72%, compared to 36%-47% in the remaining populations. Grass burning did not cause a reduction of potential biological value of Adonis vernalis pollen. Xerothermic swards in Pliszczyn and Kąty regularly burnt developed strong, most abundant populations of Adonis vernalis with favorable pollen. The development of the shrub layer, if it is out of control, stands in the way of satisfactory reproduction of halophilous Adonis vernalis.

  13. Foliar contamination of plants with aerosols of 137Cs, 85Sr, 133Ba and 123mTe: influence of rain

    International Nuclear Information System (INIS)

    Madoz-Escande, C.; Bonhomme, T.; Poncet-Bonnard, D.

    2004-01-01

    Different types of plants (lettuce, radish and grass sward) were contaminated by dry deposition of radioactive aerosols ( 137 Cs, 85 Sr, 133 Ba and 123m Te). Due to the rain efficiency in decreasing radiological contamination of crops, a range of rain scenarios was applied on these three types of plants. These experiments aimed at improving the prediction of the consequences on agricultural products of a nuclear accident occurring on a PWR, and also at improving the understanding of the different processes occurring between the contamination and the first harvest. For a plant species at a given stage of its growth cycle, interception of the four radionuclides was identical and varied from 68% for radish to 84% for grass. The interception of aerosols by lettuce was intermediary with 75% (at the middle of ripeness stage) or 78%(at the mature plant stage). By the use of a conceptual model, the predominance between the two processes: washing-off the leaves and absorption through the leaves cuticles that allows the translocation, was evidenced. For Cs, Sr and Ba,, for the lettuce and the radish the washing-off process on the foliar cover of lettuce and radish was the most significant during the first rain. The absorption process inside the plant became dominant only from the third rain event. Tellurium had a particular behaviour: it was non-mobile and stayed put on the leaves. The values of the washing-off and absorption coefficients were estimated. For the grass, during the washing-off, radionuclides had a tendency to accumulate in the basal parts of plant first and the root matt later. Moreover, grass cuts came in between the rains. The global transfer factor values were dependant on both the radionuclides and the plant species, nevertheless the higher value was obtained for the cesium, whatever the plant and the rain (from 0,06 m 2 .kg fresh -1 for radish to 0,1 m 2 .kg fresh -1 for whole lettuce). (author)

  14. Influence of high-altitude grazing on bone metabolism of growing sheep.

    Science.gov (United States)

    Liesegang, A; Hüttenmoser, D; Risteli, J; Leiber, F; Kreuzer, M; Wanner, M

    2013-02-01

    The objective of this study was to identify the effect of high alpine grazing, associated with varying pasture grass qualities and more pronounced exercise on typically steep slopes, on bone metabolism by improving bone density and enhancing bone turnover in growing sheep. Twenty-four 5-month-old sheep were randomly assigned to two groups. One group was kept at high altitude (HA; 2000-2200 m a.s.l.) for 3 months, and the other group (C; control) remained in the lowlands (400 m a.s.l.). Both groups were kept in grazing pastures with access to good-quality swards. Before the start of the experiment, blood samples were taken, the sheep were weighed, and the left metatarsus of each animal was analysed by quantitative computer tomography. After 1 month, blood samples were taken and body weight was measured, followed by biweekly sampling. Finally, the animals were slaughtered, and the bones were collected for analysis of various bone parameters. Body weight development did not differ between the groups. Concentrations of 25-OH-Vitamin D, carboxy-terminal telopeptide of type I collagen and activities of bone-specific alkaline phosphatase were always higher in the HA group than in the C group, except on the last two sampling dates. Bone mineral content and density increased in both groups during the experiment, but more intensively in the HA group. In addition, the cortical thickness of the HA group increased. The present study demonstrates an increase in bone turnover and mineral content of the bones of the growing sheep grazing in high alpine pastures. The factors associated with HA grazing, therefore, clearly seem to improve bone composition. © 2011 Blackwell Verlag GmbH.

  15. Effect of fertilization and harvest frequency on floristic composition and yields of meadow stand

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    Josef Raus

    2012-01-01

    Full Text Available The effect of fertilization and the harvest frequency on production and floristic characteristics of a meadow stand were assessed in a small plot trial established in 2003 in Vatín, Vysočina Region, the Czech Republic. Four levels of fertilization (none; N0 + P30 + K60 kg∙ha−1; N90 + P30 + K60 kg∙ha−1; N180 + P30 + K60 kg∙ha−1 were combined with four treatments of exploitation intensity (4 cuts per year, first cut on 15th May, every next after 45 days; 3 cuts per year, first cut on 30th May, every next after 60 days; 2 cuts per year, first cut on 15th June, next after 90 days; 2 cuts per year, first cut on 30th June, next after 90 days. Production of dry matter and proportions of guilds (grasses, legumes, and other species were evaluated. Data from 2009–2011 were used in this paper. Yields of the dry matter increased along with increasing amounts of nutrients supplied and ranged from 3.8 t∙ha−1 (non-fertilized to 9.1 t∙ha−1 (N180PK. The nutrition level had a significant effect on spread of grasses, which reached maximal proportion of 52.3 % under N180PK fertilization compared to 42.1% on non-fertilized plots. On the contrary, legumes flourished well in treatments without N-supply, attaining proportion of 6.8 % and 5.1 % on PK-fertilized and non-fertilized plot, respectively. With regard to the exploitation intensity grasses profited from extensive management by contrast to the group of other species which reached its maximum in swards harvested four times a year. Proportions of legumes did not show significant dependence on the cutting frequency.

  16. Germination characteristics of Rhinanthus minor influence field emergence, competitiveness and potential use in restoration projects.

    Science.gov (United States)

    Marin, M; Laverack, G; Matthews, S; Powell, A A

    2018-02-10

    The facultative root hemi-parasite Rhinanthus minor is often used in grassland habitat restoration projects to regulate ecosystem structure and function. Its impact on community productivity and diversity as a function of resource supply, sward composition and management has been widely investigated. However, there is a lack of information about the possible influence of seed quality on the efficacy of the hemi-parasite. Ten seed lots from commercial sources were sown in the field and their germination characteristics were investigated in the laboratory. Seeds from four lots were also germinated and sown in pots alongside plants of two host species, Lotus corniculatus and Holcus lanatus. Plant establishment, height and flowering density were evaluated for the hemi-parasite, while plant biomass was measured for both R. minor and its host. Two aspects of seed quality influenced the field emergence of seed lots of R. minor, the radicle emergence (%) and the length of the lag period from the beginning of imbibition to germination (mean germination time), which indicates seed vigour. A longer lag period (lower vigour) was associated with higher levels of seedling mortality and lower plant vigour, in terms of plant height and biomass accumulation and was also reflected in the parasitic impact of the seed lots. Seed quality, specifically germination and vigour, can influence the establishment, survival, subsequent plant productivity and parasitic impact of R. minor in vegetation restoration projects. Seed quality is discussed as a key factor to consider when predicting the impact of the hemi-parasite on community productivity and diversity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Effects of pasture management and off-stream water on temporal/spatial distribution of cattle and stream bank characteristics in cool-season grass pastures.

    Science.gov (United States)

    Schwarte, K A; Russell, J R; Morrical, D G

    2011-10-01

    A 2-yr grazing experiment was conducted to assess the effects of grazing management on cattle distribution and pasture and stream bank characteristics. Six 12.1-ha cool-season grass pastures in central Iowa were allotted to 1 of 3 treatments: continuous stocking with unrestricted stream access (CSU), continuous stocking with stream access restricted to 4.9-m-wide stabilized crossings (CSR), or rotational stocking with stream access restricted to a riparian paddock (RP). Pastures were stocked with 15 fall-calving Angus cows (Bos taurus L.) from mid-May to mid-October for 153 d in 2008 and 2009. A global positioning system (GPS) collar recording cow position every 10 min was placed on at least 1 cow per pasture for 2 wk of each month from May through September. Off-stream water was provided to cattle in CSU and CSR treatments during the second of the 2 wk when GPS collars were on the cattle. A black globe temperature relative humidity index (BGTHI) was measured at 10-min intervals to match the time of the GPS measurements. Each month of the grazing season, forage characteristics (sward height, forage mass, and CP, IVDMD, and P concentrations) and bare and fecal-covered ground were measured. Stream bank erosion susceptibility was visually scored in May, August, and October (pre-, mid-, and post-stocking). Cattle in RP and CSR treatments spent less time (P CSR treatment reduced the probability (P CSR and RP treatments in the stream and streamside zones in September and October and in July and September. Streams in pastures with the CSU treatment had less stable banks (P CSR treatments. Results show that time spent by cattle near pasture streams can be reduced by RP or CSR treatments, thereby decreasing risks of sediment and nutrient loading of pasture streams even during periods of increased BGTHI.

  18. Quantifying Beetle-Mediated Effects on Gas Fluxes from Dung Pats

    Science.gov (United States)

    Penttilä, Atte; Slade, Eleanor M.; Simojoki, Asko; Riutta, Terhi; Minkkinen, Kari; Roslin, Tomas

    2013-01-01

    Agriculture is one of the largest contributors of the anthropogenic greenhouse gases (GHGs) responsible for global warming. Measurements of gas fluxes from dung pats suggest that dung is a source of GHGs, but whether these emissions are modified by arthropods has not been studied. A closed chamber system was used to measure the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from dung pats with and without dung beetles on a grass sward. The presence of dung beetles significantly affected the fluxes of GHGs from dung pats. Most importantly, fresh dung pats emitted higher amounts of CO2 and lower amounts of CH4 per day in the presence than absence of beetles. Emissions of N2O showed a distinct peak three weeks after the start of the experiment – a pattern detected only in the presence of beetles. When summed over the main grazing season (June–July), total emissions of CH4 proved significantly lower, and total emissions of N2O significantly higher in the presence than absence of beetles. While clearly conditional on the experimental conditions, the patterns observed here reveal a potential impact of dung beetles on gas fluxes realized at a small spatial scale, and thereby suggest that arthropods may have an overall effect on gas fluxes from agriculture. Dissecting the exact mechanisms behind these effects, mapping out the range of conditions under which they occur, and quantifying effect sizes under variable environmental conditions emerge as key priorities for further research. PMID:23940758

  19. Acidification of pig slurry effects on ammonia and nitrous oxide emissions, nitrate leaching, and perennial ryegrass regrowth as estimated by N-urea flux

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    Sang Hyun Park

    2018-03-01

    Full Text Available Objective The present study aimed to assess the nitrogen (N use efficiency of acidified pig slurry for regrowth yield and its environmental impacts on perennial ryegrass swards. Methods The pH of digested pig slurry was adjusted to 5.0 or 7.0 by the addition of sulfuric acid and untreated as a control. The pig slurry urea of each treatment was labeled with 15N urea and applied at a rate of 200 kg N/ha immediately after cutting. Soil and herbage samples were collected at 7, 14, and 56 d of regrowth. The flux of pig slurry-N to regrowth yield and soil N mineralization were analyzed, and N losses via NH3, N2O emission and NO3− leaching were also estimated. Results The pH level of the applied slurry did not have a significant effect on herbage yield or N content of herbage at the end of regrowth, whereas the amount of N derived from pig slurry urea (NdfSU was higher in both herbage and soils in pH-controlled plots. The NH4+-N content and the amount of N derived from slurry urea into soil NH4+ fraction (NdfSU-NH4+ was significantly higher in in the pH 5 plot, whereas NO3− and NdfSU-NO3− were lower than in control plots over the entire regrowth period. Nitrification of NH4+-N was delayed in soil amended with acidified slurry. Compared to non-pH-controlled pig slurry (i.e. control plots, application of acidified slurry reduced NH3 emissions by 78.1%, N2O emissions by 78.9% and NO3− leaching by 17.81% over the course of the experiment. Conclusion Our results suggest that pig slurry acidification may represent an effective means of minimizing hazardous environmental impacts without depressing regrowth yield.

  20. Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay

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    Roberto Gratton

    2012-06-01

    Full Text Available Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH4 emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM basis and G pasture with 75% grasses on DM basis. Milk production and CH4 emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6 tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71 and HOMI (15.7 kg OM were not affected by pasture composition. Milk production (20.3 kg/d, milk fat yield (742 g/d and milk protein yield (667 g/d were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d or expressed as methane yield (6.6% of Gross Energy Intake (GEI was not affected by treatments. In conclusion, at high herbage allowance, the quality of the diet selected by grazing cows did not differ between pastures rich in legumes or rich in grasses, and therefore there was no effect on milk or methane production.

  1. Methane Emission and Milk Production of Dairy Cows Grazing Pastures Rich in Legumes or Rich in Grasses in Uruguay.

    Science.gov (United States)

    Dini, Yoana; Gere, José; Briano, Carolina; Manetti, Martin; Juliarena, Paula; Picasso, Valentin; Gratton, Roberto; Astigarraga, Laura

    2012-06-08

    Understanding the impact of changing pasture composition on reducing emissions of GHGs in dairy grazing systems is an important issue to mitigate climate change. The aim of this study was to estimate daily CH₄ emissions of dairy cows grazing two mixed pastures with contrasting composition of grasses and legumes: L pasture with 60% legumes on Dry Matter (DM) basis and G pasture with 75% grasses on DM basis. Milk production and CH₄ emissions were compared over two periods of two weeks during spring using eight lactating Holstein cows in a 2 × 2 Latin square design. Herbage organic matter intake (HOMI) was estimated by chromic oxide dilution and herbage organic matter digestibility (OMD) was estimated by faecal index. Methane emission was estimated by using the sulfur hexafluoride (SF6) tracer technique adapted to collect breath samples over 5-day periods. OMD (0.71) and HOMI (15.7 kg OM) were not affected by pasture composition. Milk production (20.3 kg/d), milk fat yield (742 g/d) and milk protein yield (667 g/d) were similar for both pastures. This may be explained by the high herbage allowance (30 kg DM above 5 cm/cow) which allowed the cows to graze selectively, in particular in grass sward. Similarly, methane emission expressed as absolute value (368 g/d or 516 L/d) or expressed as methane yield (6.6% of Gross Energy Intake (GEI)) was not affected by treatments. In conclusion, at high herbage allowance, the quality of the diet selected by grazing cows did not differ between pastures rich in legumes or rich in grasses, and therefore there was no effect on milk or methane production.

  2. Transpiration and CO2 fluxes of a pine forest: modelling the undergrowth effect

    Directory of Open Access Journals (Sweden)

    V. Rivalland

    2005-02-01

    Full Text Available A modelling study is performed in order to quantify the relative effect of allowing for the physiological properties of an undergrowth grass sward on total canopy water and carbon fluxes of the Le-Bray forest (Les-Landes, South-western France. The Le-Bray forest consists of maritime pine and an herbaceous undergrowth (purple moor-grass, which is characterised by a low stomatal control of transpiration, in contrast to maritime pine. A CO2-responsive land surface model is used that includes responses of woody and herbaceous species to water stress. An attempt is made to represent the properties of the undergrowth vegetation in the land surface model Interactions between Soil, Biosphere, and Atmosphere, CO2-responsive, ISBA-A-gs. The new adjustment allows for a fairly different environmental response between the forest canopy and the understory in a simple manner. The model's simulations are compared with long term (1997 and 1998 micro-meteorological measurements over the Le-Bray site. The fluxes of energy, water and CO2, are simulated with and without the improved representation of the undergrowth vegetation, and the two simulations are compared with the observations. Accounting for the undergrowth permits one to improve the model's scores. A simple sensitivity experiment shows the behaviour of the model in response to climate change conditions, and the understory effect on the water balance and carbon storage of the forest. Accounting for the distinct characteristics of the undergrowth has a substantial and positive effect on the model accuracy and leads to a different response to climate change scenarios.

  3. Soil properties and clover establishment six years after surface application of calcium-rich by-products

    Energy Technology Data Exchange (ETDEWEB)

    Ritchey, K.D.; Belesky, D.P.; Halvorson, J.J. [USDA ARS, Beaver, WV (US). Appalachian Farming Systems Research Center

    2004-12-01

    Calcium-rich soil amendments can improve plant growth by supplying Ca and reducing detrimental effects of soil acidity, but solubility and neutralizing capacity of Ca sources vary. Our objectives were to evaluate effects of calcitic dolomite and several coal combustion by-products on soil properties at various depths 6 yr after surface application and their influence on grass-clover herbage accumulation. Calcium and Mg soil amendments were surface-applied to an acidic grassland in 1993, and orchardgrass (Dactylis glomerata L.) and tall fescue (Lolium arundinaceum (Schreb.) Darbyshire) were oversown in 1994. In 1998, amendment treatment plots were split to accommodate sod seeding with red clover (Trifolium pratense L.) or white clover (T. repens L.) as well as a nonseeded control. No N fertilizer was applied after sod seeding. Six years after amendment application, reductions in soil Al and Mn and increases in Ca and pH from 4654 kg ha{sup -1} calcitic dolomite, 15 000 kg ha{sup -1} fluidized bed combustion residue, or 526 kg ha{sup -1} MgO amendment were greatest in the surface 2.5 cm while rates of gypsum as high as 32 000 kg ha{sup -1} left little residual effect except for decreases in Mg. Percentage clover in the sward tripled as pH increased from 4.3 to 5.0 while herbage mass increased 75% as clover percentage increased. Herbage mass was generally more closely correlated with properties of soil samples collected from the surface 2.5 cm than from deeper samples.

  4. Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems

    Energy Technology Data Exchange (ETDEWEB)

    Ladd, J N [Commonwealth Scientific and Industrial Research Organization, Glen Osmond (Australia). Div. of Soils

    1981-01-01

    The results of this experiment indicate that the use of the technique described, (based on the degree of /sup 15/N-labelling of an N/sub 2/ fixer and a non-fixer), may be of value in assessing N/sub 2/ fixation in the field by legumes, but it is apparent that there are some problems to be overcome. Analyses of the whole plant are necessary, since the proportions of legume N due to N/sub 2/ fixation vary with the plant part. The extent to which legumes take up available N from the soil obviously will vary with soil profile and plant properties; and they will be affected by sward density and competition from other plants. These latter factors will increase the difficulty of using this method for assessing N/sub 2/ fixation by legumes in grazed pastures, but probably they would not be big problems when applying the method to grain legume crops. It is important that, in comparing the extent of labelling of the N of fixing and non-fixing plants, both types of plants should have access to soil inorganic-N of the same enrichment. This will be difficult to achieve under field conditions. However soils which contain relatively stable /sup 15/N-labelled organic residues may yield NO/sub 3/-N of tolerably constant enrichments. An experiment is in progress at Avon in which soils, amended 15 months previously with /sup 15/N-labelled legume residues and then cropped to wheat, will remain in situ and will be sown with fixing and non-fixing plants during the 1980 and 1981 seasons. These soils may prove to be suitable for measuring N/sub 2/ fixation in the field.

  5. Carbon balance of renovated grasslands: input- or output-driven?

    Science.gov (United States)

    Choncubhair, Órlaith Ní; Osborne, Bruce; Lanigan, Gary

    2015-04-01

    Temperate grasslands constitute over 30% of the Earth's naturally-occurring biomes and make an important contribution towards the partial mitigation of anthropogenic greenhouse gas emissions by terrestrial ecosystems. In permanent temperate grasslands, biomass production and sward quality can deteriorate over time and periodic renovation activities, involving soil tillage and reseeding, are commonly carried out to halt this decline. Long-term cultivation of agricultural land has been associated with soil aggregate degradation and reduced soil carbon storage. However, the impact of these single tillage disturbances on C cycling in grasslands is less clear. This study evaluated gaseous and dissolved organic carbon (DOC) losses following a single tillage event by subjecting grassland lysimeters with contrasting soil drainage characteristics to simulated conventional inversion or minimum tillage. Field-scale CO2 emissions after conventional tillage were also quantified and empirically modelled over short- and medium-term timeframes to delineate the ecosystem response to environmental variables. Soil moisture was the limiting determinant of ecosystem carbon release following conventional tillage. Freshly-tilled soils were associated with reduced water retention and increased sensitivity to soil moisture, which was particularly pronounced following rewetting events. Significantly elevated but ephemeral CO2 effluxes were detected in the hours following inversion ploughing, however tillage disturbance did not generate significantly enhanced C emission rates in the medium term. Equally, DOC losses were not significantly amplified by conventional tillage compared with conservative minimum tillage and were predominantly controlled by soil drainage across tillage regimes. Our results suggest that a net ecosystem source of 120 to 210 g C m-2 over an approximately two-month period was most likely a consequence of reduced productivity and C input rather than enhanced soil CO2

  6. Evaluation of silage diets offered to reindeer calves intended for slaughter. II. Feeding of silage and concentrate from January to March

    Directory of Open Access Journals (Sweden)

    Anna Nilsson

    1996-01-01

    Full Text Available An experiment involving 56 male reindeer calves, with a mean initial live weight of 39 kg (SD=4.6, was undertaken to evaluate the effect of the concentrate:silage ratio on the performance during feeding to slaughter. Forty four of the calves were divided in four groups, two groups each being allotted to diets with low, 60% (LC, or high, 80% (HC proportions of a commercial pelleted feed. The remaining twelve calves were slaughtered at the start of the experiment. The experimenral period lasted from January to March. The proportions of concentrate to silage were based on the dry matter (DM content. The silage, 44% DM, was made from the primary growth of a predominantly grass sward preserved as plastic-wrapped big bales. Animal health was good throughour the experimenr. Small amounts of lichens were mixed into the diets during the first rwo weeks of feeding and may have contributed to the lack of adapta-tionai problems. The mean daily intakes of DM and metabolisable energy were higher (P<0.01 for calves offered the HC-diet. Despite the higher feed intakes, the increased proportion of concentrate in the diet did not significantly alter live weight gains or carcass weight gains. However, the greater fat deposition (P<0.05 and better carcass gradings indicated a better condition of the animals at slaughtet when less silage was fed. This experiment was the the final part of a three year study of silage based diets for reindeer intended for slaughter and the general conclusion is that the best role of grass silage of this quality is as a limited part of the ration. The silage may, however, play an important role during the adaptation period and further detailed studies are needed to evaluate the applicability of silage as a part of the diet to reindeer.

  7. Effect of planting density and cutting frequency on forage and grain yields of kochia (Kochia scoparia under saline water irrigation

    Directory of Open Access Journals (Sweden)

    mseou ziyaeii

    2009-06-01

    Full Text Available AField experiment was conducted at Research Farms of Center of Excellence for Special Crops, Ferdowsi University of Mashhad, Mashhad, Iran, in 2006 to evaluate the effect of planting density on forage and grain yield of kochia (Kochia scoparia. Experimental design was a randomized complete block with split-plot arrangement of treatments,with three replications, where different planting densities (10, 20, 30 and 40 plant m-2 were assigned to main plots and number of cutting (including a single cutting, two cutting and no cutting i.e. allowing the crop to grow until maturity allocated to sub-plots. At each harvest date (cutting the biological yield, leaf and stem dry weight, plant height, number of branches and the individual plant biomass were measured. Grain yield and thousand seed weight were also determined at the end of growing season. Result showed the highest biological yield and leaf and stem dry weights for kochia obtaind at 30 plant m-2. The total biomass, leaf and stem dry weights, plant height, number of branches were greater for the first cutting as compared to the second cutting. Planting density and cutting number interacted to affect the leaf dry weight. At physiological maturity stage there were no significant differences among planting densities for plant height and number of branches. The best planting density, in terms of biomass production and leaf and stem dry weight, was found as 30 plant m-2, while for grain production a planting density of 20 plant m-2 could be recommended. Key words: Kochia, planting density, sward, biological yield, grain production.

  8. Transpiration efficiency of three Mediterranean annual pasture species and wheat.

    Science.gov (United States)

    Bolger, T P; Turner, N C

    1998-06-01

    Attempts to improve water use efficiency in regions with Mediterranean climates generally focus on increasing plant transpiration relative to evaporation from the soil and increasing transpiration efficiency. Our aim was to determine if transpiration efficiency differs among key species occurring in annual pastures in southern Australia. Two glasshouse experiments were conducted with three key pasture species, subterranean clover (Trifolium subterraneum L.), capeweed [Arctotheca calendula (L.) Levyns] and annual ryegrass (Lolium rigidum Gaudin), and wheat (Triticum aestivum L.). Transpiration efficiency was assessed at the levels of␣whole-plant biomass and water use (W), leaf gas exchange measurements of the ratio of CO 2 assimilation to leaf conductance to water vapour (A/g), and carbon isotope discrimination (Δ) in leaf tissue. In addition, Δ was measured on shoots of the three pasture species growing together in the field. In the glasshouse studies, annual ryegrass had a consistently higher transpiration efficiency than subterranean clover or capeweed by all methods of measurement. Subterranean clover and capeweed had similar transpiration efficiencies by all three methods of measurement. Wheat had W values similar to ryegrass but A/g and Δ values similar to subterranean clover or capeweed. The high W of annual ryegrass seems to be related to a conservative leaf gas exchange behaviour, with lower assimilation and conductance but higher A/g than for the other species. In contrast to the glasshouse results, the three pasture species had similar Δ values when growing together in mixed-species swards in the field. Reasons for these differing responses between glasshouse and field-grown plants are discussed in terms of the implications for improving the transpiration efficiency of mixed-species annual pasture communities in the field.

  9. Influence of the compound effect between nitrogen and zinc on the resource of nitrogen of herbage in mixed and pure culture

    International Nuclear Information System (INIS)

    He Zhongjun; Hua Luo

    2002-01-01

    Under pot culture, the influence of compound effect between nitrogen and zinc on the resource of nitrogen of ryegrass in mono-culture and ryegrass/clover in mixture were studied on yellow brown earth which collected from sub-tropic mountain sward of southern China. The result showed as follows: (1) The percentage of nitrogen derived from atmosphere (% Ndfa) was decreased by nitrogen application in early growth stage and suitable amount of nitrogen application increased it in later growth stage. The % Ndfa of white clover in mixture was the highest with 6 mg/kg zinc application in all nitrogen levels. The transfer of fixed nitrogen by white clover to ryegrass was decreased by nitrogen application and increased by low amount of zinc application. (2) The percentage of nitrogen derived from fertilizer (% Ndff) was significantly increased by nitrogen application, of which the treatments with 6-20 mg/kg zinc application was higher than other zinc application treatments on ryegrass in monoculture, and the treatments with 6-20 mg/kg zinc application on white clover/ryegrass in mixture was lower than other zinc treatments at the range from 30 to 90 mg/kg nitrogen application. (3) The percentage of nitrogen derived from soil (% Ndfs) of ryegrass both in pure and in mixture was significantly decreased as the increasing of the levels of nitrogen application, of which ryegrass in mono-culture was not obviously influenced by zinc application, and ryegrass/clover in mixture was decreased by 6-20 mg/kg zinc application under all nitrogen levels

  10. Comportamento ingestivo de novilhos mestiços em pastagens tropicais manejadas em diferentes alturas Chewing behavior of crossbred beef steers on tropical pasture managed at different heights

    Directory of Open Access Journals (Sweden)

    Fabíola Cristine de Almeida Rego

    2006-08-01

    Full Text Available Foi avaliado o comportamento ingestivo de novilhos mestiços em pastagens exclusivas de capim-marandu (Brachiaria brizantha Stapf Hoesch cv. Marandu, capim-tanzânia (Panicum maximum Jacq. cv. Tanzânia e amendoim forrageiro (Arachis pintoi cv. Amarillo e em pastagem consorciada de capim-marandu e amendoim forrageiro, em resposta à altura do relvado. As parcelas foram reguladas em seis alturas nas pastagens de gramíneas e, naquelas de amendoim forrageiro e consorciada, foram rebaixadas simulando o pastejo intermitente. A quantidade de forragem ingerida pelo animal foi determinada pela técnica de dupla pesagem. A taxa de ingestão (TI, g MS/minuto foi estudada em função da altura da pastagem (A e da massa de folhas (MFV, denominadas variável Z no modelo: TI = TImax (1 - e(-K x Z; em que: TImax é o parâmetro que representa a taxa de ingestão potencial máxima (g MS/min; k é o parâmetro que representa a variação em TI para cada unidade de variação em Z. A TI variou conforme a altura da pastagem para todas as espécies, mas, para a MFV, variou apenas nas pastagens de amendoim forrageiro e capim-marandu. A TI potencial em função da altura da pastagem foi de 66,49 g MS/minuto, independentemente da pastagem avaliada, e foi mais sensível à variação na altura para o amendoim forrageiro, em comparação às demais pastagens (k = 0,09 vs 0,039. A fração tempo despendido/g MS ingerido/bocado foi maior para o capim-tanzânia e a pastagem consorciada, com valores de 3,16 e 2,83 segundos, respectivamente. Para manipulação do capim-marandu e do amendoim forrageiro, o tempo despendido foi 0,80 e 0,68 segundo, respectivamente. A estratégia do animal para manter a TI elevada na pastagem de amendoim forrageiro foi aumentar a taxa de bocados e, nas demais pastagens, aumentar a ingestão por bocado.The chewing behavior of crossbred beef steers grazing pure swards of marandugrass (Brachiaria brizantha Stapf Hoesch cv. Marandu, tanzaniagrass

  11. Mixed grazing systems of goats with cattle in tropical conditions: an alternative to improving animal production in the pasture.

    Science.gov (United States)

    d'Alexis, S; Periacarpin, F; Jackson, F; Boval, M

    2014-08-01

    Mixed grazing systems combining sheep and cattle have shown better growth performance for one or both species. This observation has been attributed to their complementary feeding behaviour and the reduced host infection by gastrointestinal nematodes. Less attention has been paid to mixed grazing systems combining goats and cattle. Here, continuously grazing goats mixed with cattle (M) were compared with control goats reared alone (C) under tropical conditions. The comparison was conducted with gastrointestinal nematode-infected (I) and non-infected (nI) goats. Thus, the four treatments were cattle with gastrointestinal nematode-infected goats (MI), gastrointestinal nematode-infected goats alone (CI), cattle with non-infected goats (MnI) and non-infected goats (CnI). Average daily gain (ADG, g/day) and grass production were measured for the four groups of animals (six goats and two heifers treated with MI or MnI) grazing for 3 months on 4 subplots. Monthly measurements were performed over 5-day periods. This pattern was replicated in space for a second set of four subplots and in time for six successive cohorts of animals (bands 1 to 6). The ADG of goats in mixed grazing conditions was higher than controls irrespective of the infection status (32.6 v. 18.4 g/day for MI v. CI; 44.2 v. 33.5 g/day for MnI v. CnI). Concomitantly, the average biomass was lower for mixed grazing animals compared with controls (174 v. 170 for MI and MnI; 235 v. 208 for CI and CnI, respectively), suggesting better use of the sward. For daily BW gain (g/kg DM), mixed grazing also yielded better results than the control (1.88 v. 0.52 g BW/kg DM per day for MI v. CI; 2.08 v. 1.47 g BW/kg DM per day for MnI and CnI). Mixed grazing of goats and heifers offers a promising alternative for increasing goat and overall animal production as well as improving the management of pastures.

  12. The use of sustainable 'biochar compost' for remediation of contaminated land

    Science.gov (United States)

    Ryan, Aoife; Street-Perrott, Alayne; Eastwood, Daniel; Brackenbury, Sion

    2014-05-01

    South Wales (UK) has a long industrial history which, since the collapse of the coal-mining industry, has left a large number of contaminated former colliery sites. Bio-remediation of these areas by re-vegetation with native grasses aims to prevent erosion and leaching of pollutants into drainage waters. However, acid pH, low organic-matter content and unsuitable soil structure have limited the success of re-vegetation and prompted research into the development of artificial soils. This study aims to assess the value of creating an artificial soil cover by adding "biochar compost" to the top 10cm of a large volume of contaminated colliery spoil (high in As and Cu) to be moved during construction of a flood-alleviation barrage in Cwm Dulais (Swansea). It is proposed to use biochar, manufactured from chipped biomass sourced from a local stand of invasive Rhododendron ponticum using a BiGchar 1000 fast pyrolysis-gasification unit, in combination with locally produced BSI PAS100-certified Pteridium aquilinum (bracken) compost, to remediate a large area (2.3ha) of landscaped colliery waste and re-establish a cover of native grasses suitable for sheep grazing. Pot and field trials are being used to determine the most appropriate biochar:compost mix. In a 90-day outdoor pot trial, a commercial acid-grassland seed mix was grown in screened (remediation trial at Ffos-y-Frân (Jarvis & Walton, WRAP Report, 2011). Varying application rates of biochar (0%, 2%, 5%, 10% or 20%v/v) were employed. Additional benefits of adding mycorrhizal inoculant or Trifolium repens (white clover) seed were also tested. Six-fold replication was used, with appropriate controls. The performance of each treatment was assessed from its maximum sward height and final above-ground dry phytomass. To evaluate the quality of the resulting grassland for sheep grazing, grass samples are being analysed for nutrients, heavy metals and metalloids by elemental analysis (EA) and X-ray fluorescence spectroscopy

  13. Effect of energy restriction and re-alimentation in Belgian Blue double-muscled beef cows on digestibility and metabolites.

    Science.gov (United States)

    Fiems, L O; Vanacker, J M; De Boever, J L; van Caelenbergh, W; Aerts, J M; De Brabander, D L

    2007-02-01

    Four groups of five non-lactating and non-pregnant Belgian Blue double-muscled (BBDM) cows were used to investigate the effect of energy level (E) on digestion, and blood and urine metabolites. The energy levels of the groups, applied indoors during a 140-day restriction period, were 100%, 90%, 80% or 70% of their energy requirements (E100, E90, E80, E70) respectively. Afterwards, animals grazed on the same swards for 203 days (re-alimentation period). Balance trials were conducted at the end of the restriction period (BT1) and at the end of the re-alimentation period (BT2). Blood was sampled at the end of these trials. Diets consisted of maize silage and straw (80/20 on a dry matter basis) and a mineral-vitamin premix, fed at the appropriate E during BT1, or maize silage and a mineral-vitamin premix, fed at 125% of the maintenance requirements, during BT2. Significant increases of the digestibility coefficients were found during BT1 when E decreased, resulting in a better net energy capture of 7% for E70 compared with E100 (p < 0.05). Slightly, but non-significantly higher digestibility coefficients were observed for decreasing E during BT2. Plasma concentrations of glucose and creatinine did not differ between treatments during BT1, while differences were found for triacylglycerols and alpha-amino nitrogen. A tendency for a linear increase was observed for non-esterified fatty acids with decreasing E. Differences in blood metabolite concentrations disappeared in BT2. Urinary creatinine excretion was not affected by E, while body nitrogen loss increased linearly with energy restriction in BT1. No differences were found during BT2, suggesting that non-lactating and non-pregnant BBDM cows are able to adapt to a cyclic change of body weight and body reserves. These data show that restricted cows mobilized body fat as well as body protein. It is concluded that the qualitative aspects of metabolism during energy restriction are comparable in double-muscled cows with

  14. 238U, and its decay products, in grasses from an abandoned uranium mine

    Science.gov (United States)

    Childs, Edgar; Maskall, John; Millward, Geoffrey

    2016-04-01

    Bioaccumulation of radioactive contaminants by plants is of concern particularly where the sward is an essential part of the diet of ruminants. The abandoned South Terras uranium mine, south west England, had primary deposits of uraninite (UO2) and pitchblende (U3O8), which contained up to 30% uranium. When the mine was active uranium and radium were extracted but following closure it was abandoned without remediation. Waste rock and gangue, consisting of inefficiently processed minerals, were spread around the site, including a field where ruminants are grazed. Here we report the activity concentrations of 238U, 235U 214,210Pb, and the concentrations of selected metals in the soils, roots and leaves of grasses taken from the contaminated field. Soil samples were collected at the surface, and at 30 cm depth, using an auger along a 10-point transect in the field from the foot of a waste heap. Whole, individual grass plants were removed with a spade, ensuring that their roots were intact. The soils and roots and grass leaves were freeze-dried. Activity concentrations of the radionuclides were determined by gamma spectroscopy, following 30 days incubation for development of secular equilibrium. Dried soils, roots and grasses were also digested in aqua regia and the concentrations of elements determined by ICP techniques. Maximum activity concentrations of 238U, 235U, 214Pb and 210Pb surface soils were 63,300, 4,510, 23,300 and 49,400 Bq kg-1, respectively. The mean 238U:235U ratio was 11.8 ± 1.8, an order of magnitude lower than the natural value of 138, indicating disequilibrium within the decay chain due to mineral processing. Radionuclides in the roots had 5 times lower concentration and only grass leaves in the vicinity of the waste heap had measureable values. The mean soil to root transfer factor for 238U was 36%, the mean root to leaf was 3% and overall only 0.7% of 238U was transferred from the soil to the leaves. The roots contained 0.8% iron, possibly as

  15. Comportamento ingestivo de cordeiros em três sistemas de produção em pastagem de Tifton 85 - DOI: 10.4025/actascianimsci.v31i3.6014 Intake behavior of lambs in three production systems on Tifton 85 pasture - DOI: 10.4025/actascianimsci.v31i3.6014

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    Sergio Rodrigo Fernandes

    2009-09-01

    Full Text Available O objetivo deste estudo foi avaliar o comportamento ingestivo de cordeiros em pastagem de Tifton-85 (Cynodon spp. em três sistemas de produção: cordeiros desmamados aos 60 dias de idade e mantidos em pastagem; cordeiros mantidos com suas mães em pastagem; e cordeiros mantidos com suas mães em pastagem e suplementados em creep feeding. O delineamento foi em blocos ao acaso com três repetições, utilizando quatro cordeiros-teste por repetição. Na pastagem, avaliou-se a altura, a massa, a composição morfológica e bromatológica da forragem. Na avaliação do comportamento ingestivo registrou-se, do nascer ao pôr do sol, o tempo despendido nas atividades de pastejo, ruminação, ócio, amamentação e alimentação no creep feeding. Avaliou-se, também, a taxa de bocados ao pastejo. Os cordeiros permaneceram maior tempo em pastejo, e os suplementados despenderam menor (p creep feeding alterou (p The objective of this study was to evaluate the intake behavior of lambs on Tifton 85 pasture (Cynodon spp. in three production systems: sixty-days-old weaned lambs kept on pasture; lambs kept with their mother on pasture; lambs kept with their mother on pasture in creep feeding. Systems were allocated in a completely randomized blocks design with three replicates and four lambs per replicate. Pasture sward surface height, forage dry matter, and morphological and nutritional characters were assessed. Intake behavior was observed from dawn to dusk. The study assessed the time animals spent in the following activities: grazing, ruminating, idling, suckling, and staying in creep feeding. Bite rate was also evaluated. Lambs spent most of their time grazing, but the supplemented ones spent less time (p creep feeding altered (p < 0.05 distribution of grazing and rumination, indicating a substitutive effect of pasture by concentrate. Sheep production systems affected the intake behavior of lambs, but did not affect the bite rate.

  16. Reaction of cocksfoot (Dactylis glomerata L. in grass-clover mixture on N fertilization and grazing

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    Marcela Andreata-Koren

    2009-09-01

    Full Text Available Grazing is the most common way of using a hill and mountain areas because of their specific agro-ecological conditions. Cocksfoot is a grass with high productivity and quality, and it is very good for sowing in the sward for grazing. Because of its good adaptability to different growing conditions, especially in very dry and cold areas, it is excellent in relation to some other good grasses, which can not be raised in such areas. The aim of the experiment was to determine effect of N application (0-N0 and 150 kg ha-1 year-1-N150 and rotational grazing by cattle (C and sheep (S, and their interaction on the cocksfoot sown in a mixture of smooth-stalked meadow grass (Poa pratensis L. and white clover (Trifolium repens L. in hill mountain areas. In a three-year average, the application of 150 kg ha-1 N had significant impact on cocksfoot population density (number of tillers m-2, and it was 51.4 % higher than the recorded one before grazing (P<0.05 and 42.2 % higher after grazing (P<0.01 in comparison to N0. The application of 150 kg ha-1 N resulted in significantly higher cocksfoot dry matter (DM yield for 38.6 % (P<0.01 and 15.3 % higher cocksfoot share in the total mixture in relation to N0 (P<0.01. Grazing management and grazing management interaction with N rate did not significantly affect the population density of individual years. However, in the three-year average, grazing management significantly affected cocksfoot DM (P<0.01 and its percentage in the total DM mixture (P<0.01. Cattle grazing resulted in 9.9 % higher cocksfoot DM yield and 15.2 % higher cocksfoot percentage in pasture. Interaction of grazing management and N-level had significant influence on the percentage of cocksfoot DM in grass-clover mixture. On cattle grazed areas fertilized with 150 kg ha-1 N, the percentage of cocksfoot DM was the highest (74. 07%, while the lowest percentage of cocksfoot DM was recorded on the sheep grazed areas without N (55.12%.

  17. Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

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    Magnússon, B.; Magnússon, S. H.; Ólafsson, E.; Sigurdsson, B. D.

    2014-10-01

    Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca

  18. Média diária do déficit de pressão de saturação do vapor d'água do ar e sua influência na vapotranspiração de referência pelo modelo de penman-monteith (FAO 56 em Piracicaba - SP Daily average of the saturation-vapor-pressure deficit of the air and its influence upon the reference evapotranspiration by penman-monteith model (FAO56 in Piracicaba, SP, Brazil

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    Gustavo B. Lyra

    2004-08-01

    Full Text Available Utilizando-se como padrão as medidas lisimétricas de um gramado, avaliaram-se os resultados de estimativas de ETo obtidas com Dar_méd oriundos de 14 métodos para seu cálculo. Tais comparações permitiram separar os métodos de cálculo de Dar_méd em três grupos, ou seja: um grupo resultou sempre em superestimativa de ETo; em outro, a tendência foi de sempre subestimar, e no último a tendência foi de superestimar valores baixos (The results of the evapotranspiration obtained with the Dair_avg proceeding from 14 methods were evaluated, by using the lysimetric measures of a sward. These comparisons allowed to separate the Dar_avg calculating methods into three groups: a group always resulted into an overestimate ETo; in other one always tended to underestimating the ETo; and in the last tended to overestimating the low values (<4.5 mm day-1, while underestimating the high values of ETo. No significant statistical differences were observed (t test; p <0.05 in ETo as a function of the Dair_avg methods, when using the hourly average of the temperature and/or the air relative humidity in relation to those determined with the average of the maximum and minimum values of these elements. Among the methods proposed by paper FAO56, just the one using the average relative humidity to calculate the actual pressure (e a showed a satisfactory estimate. The best estimates of ETo were obtained with the Dair_avg methods using the average of the air temperature in the determination of the saturation pressure (e s and the average of the relative humidity for the actual pressure (e a. The use of saturation-vapor-pressure deficit of the air at a single time (from 9 or 10 a.m. local as a representative of Dair_avg showed to be a satisfactory alternative in estimating the ETo under the climatic conditions of Piracicaba, SP, Brazil.

  19. Effect of concentrate feed level on methane emissions from grazing dairy cows.

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    Jiao, H P; Dale, A J; Carson, A F; Murray, S; Gordon, A W; Ferris, C P

    2014-11-01

    Although the effect of nutrition on enteric methane (CH4) emissions from confined dairy cattle has been extensively examined, less information is available on factors influencing CH4 emissions from grazing dairy cattle. In the present experiment, 40 Holstein-Friesian dairy cows (12 primiparous and 28 multiparous) were used to examine the effect of concentrate feed level (2.0, 4.0, 6.0, and 8.0 kg/cow per day; fresh basis) on enteric CH4 emissions from cows grazing perennial ryegrass-based swards (10 cows per treatment). Methane emissions were measured on 4 occasions during the grazing period (one 4-d measurement period and three 5-d measurement periods) using the sulfur hexafluoride technique. Milk yield, liveweight, and milk composition for each cow was recorded daily during each CH4 measurement period, whereas daily herbage dry matter intake (DMI) was estimated for each cow from performance data, using the back-calculation approach. Total DMI, milk yield, and energy-corrected milk (ECM) yield increased with increasing concentrate feed level. Within each of the 4 measurement periods, daily CH4 production (g/d) was unaffected by concentrate level, whereas CH4/DMI decreased with increasing concentrate feed level in period 4, and CH4/ECM yield decreased with increasing concentrate feed level in periods 2 and 4. When emissions data were combined across all 4 measurement periods, concentrate feed level (2.0, 4.0, 6.0, and 8.0 kg/d; fresh basis) had no effect on daily CH4 emissions (287, 273, 272, and 277 g/d, respectively), whereas CH4/DMI (20.0, 19.3, 17.7, and 18.1g/kg, respectively) and CH4-E/gross energy intake (0.059, 0.057, 0.053, and 0.054, respectively) decreased with increasing concentrate feed levels. A range of prediction equations for CH4 emissions were developed using liveweight, DMI, ECM yield, and energy intake, with the strongest relationship found between ECM yield and CH4/ECM yield (coefficient of determination = 0.50). These results demonstrate that

  20. Increasing milk solids production across lactation through genetic selection and intensive pasture-based feed system.

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    Coleman, J; Pierce, K M; Berry, D P; Brennan, A; Horan, B

    2010-09-01

    The objective of the study was to quantify the effect of genetic improvement using the Irish total merit index, the Economic Breeding Index (EBI), on overall performance and lactation profiles for milk, milk solids, body weight (BW), and body condition score (BCS) within 2 pasture-based systems of milk production likely to be used in the future, following abolition of the European Union's milk quota system. Three genotypes of Holstein-Friesian dairy cattle were established from within the Moorepark dairy research herd: LowNA, indicative of animals with North American origin and average or lower genetic merit at the time of the study; HighNA, North American Holstein-Friesians of high genetic merit; and HighNZ, New Zealand Holstein-Friesians of high genetic merit. Animals from within each genotype were randomly allocated to 1 of 2 possible pasture-based feeding systems (FS): 1) The Moorepark pasture (MP) system (2.64 cows/ha and 344 kg of concentrate supplement per cow per lactation) and 2) a high output per hectare (HC) system (2.85 cows/ha and 1,056 kg of concentrate supplement per cow per lactation). Pasture was allocated to achieve similar postgrazing residual sward heights for both treatments. A total of 126, 128, and 140 spring-calving dairy cows were used during the years 2006, 2007, and 2008, respectively. Each group had an individual farmlet of 17 paddocks and all groups were managed similarly throughout the study. The effects of genotype, FS, and the interaction between genotype and FS on milk production, BW, and BCS across lactation were studied using mixed models with factorial arrangements of genotype and FS accounting for the repeated cow records across years. No significant genotype by FS interaction was observed for any of the variables measured. Results show that milk solids production of the national average dairy cow can be increased across lactation through increased EBI. High EBI genotypes (HighNA and HighNZ) produced more milk solids per cow and

  1. Relationship between Remote Sensing Data, Plant Biomass and Soil Nitrogen Dynamics in Intensively Managed Grasslands under Controlled Conditions.

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    Knoblauch, Christoph; Watson, Conor; Berendonk, Clara; Becker, Rolf; Wrage-Mönnig, Nicole; Wichern, Florian

    2017-06-23

    The sustainable use of grasslands in intensive farming systems aims to optimize nitrogen (N) inputs to increase crop yields and decrease harmful losses to the environment at the same time. To achieve this, simple optical sensors may provide a non-destructive, time- and cost-effective tool for estimating plant biomass in the field, considering spatial and temporal variability. However, the plant growth and related N uptake is affected by the available N in the soil, and therefore, N mineralization and N losses. These soil N dynamics and N losses are affected by the N input and environmental conditions, and cannot easily be determined non-destructively. Therefore, the question arises: whether a relationship can be depicted between N fertilizer levels, plant biomass and N dynamics as indicated by nitrous oxide (N₂O) losses and inorganic N levels. We conducted a standardized greenhouse experiment to explore the potential of spectral measurements for analyzing yield response, N mineralization and N₂O emissions in a permanent grassland. Ryegrass was subjected to four mineral fertilizer input levels over 100 days (four harvests) under controlled environmental conditions. The soil temperature and moisture content were automatically monitored, and the emission rates of N₂O and carbon dioxide (CO₂) were detected frequently. Spectral measurements of the swards were performed directly before harvesting. The normalized difference vegetation index (NDVI) and simple ratio (SR) were moderately correlated with an increasing biomass as affected by fertilization level. Furthermore, we found a non-linear response of increasing N₂O emissions to elevated fertilizer levels. Moreover, inorganic N and extractable organic N levels at the end of the experiment tended to increase with the increasing N fertilizer addition. However, microbial biomass C and CO₂ efflux showed no significant differences among fertilizer treatments, reflecting no substantial changes in the soil

  2. Economic feasibility of four grazing intensities of Tanzania grass for beef cattleViabilidade econômica de quatro intensidades de pastejo do capim Tanzânia na pecuária de corte

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    Valter Harry Bumbieris Júnior

    2012-02-01

    Full Text Available Were evaluated the economic effects of four grazing heights (20, 40, 60 and 80 cm of Tanzânia grass for beef cattle. The total area was 12 acres divided into paddocks of one hectare, with three replications. We used three animals, males, Nelore per paddock, as more animals need additional adjustment to the height you want. The reduction in sward height allowed higher stocking rate, which, even with a reduction in individual performance, there was more beef production per area. The interest rate on capital given the property represented the largest share in the final cost of production. The participation of fixed variables showed a positive linear function of the increase in height from grazing, showing significant reduction of the production scale. A reduction in cost of production per hectare per year with increasing grazing height. No differences were found in certain economic indicators, and the four systems remunerate the capital invested.Foram avaliados os efeitos econômicos de quatro alturas de pastejo (20; 40; 60 e 80 cm do capim Tanzânia para bovinos de corte. A área total foi de 12 hectares divididos em piquetes de um hectare, com três repetições. Foram utilizados três bovinos, machos, Nelore por piquete, mais animais adicionais conforme necessidade de ajuste para as alturas pretendidas. A redução da altura do pasto permitiu maior taxa de lotação, onde, mesmo com redução no desempenho individual, houve maior produção por área. A taxa de juros atribuída sobre o capital do imóvel representou a maior parcela no custo final de produção. A participação das variáveis fixas apresentou comportamento linear positivo em função do aumento na altura dos pastos, se mostrando sensível à redução da escala de produção. Houve redução do custo de produção anual por hectare com aumento da altura de pastejo. Não foram detectadas diferenças nos indicadores econômicos determinados, e os quatro sistemas remuneraram o

  3. The Aegean/Cycladic and the Basin and Range Extensional Provinces - A Tectonic and Geochronologic Perspective

    Science.gov (United States)

    Stockli, D. F.

    2017-12-01

    The Aegean/Cycladic region (AC) and the Basin and Range Province (B&R) are two of the most famous Cenozoic extensional provinces and have greatly influenced our thinking about syn-convergent back-arc extension, core complex formation, syn-extensional magmatism, and kinematic transitions. They share numerous tectonic and structural similarities, such as a syn-convergent setting, previous contractional deformation, and core complex formation, but fundamental geological ambiguities remain, mainly centering around timing. The B&R affected a previously contractional belt (Sevier) and voluminous continental magmatic arc that created a pre-extensional orogenic highland. Extension was long-lived and complex, driven by both gravitational collapse and temporally distinct kinematic boundary condition changes. The B&R was also affected by massive, largely pre-extensional regional magmatic flare-ups that modified both the thermal and crustal composition. As the B&R occupies an elevated interior plateau, syn-extensional basin deposits are exclusively continental in character. In contrast, the AC is a classic marine back-arc extensional province that affected an active subduction margin with numerous accreted oceanic and continental ribbons, exhuming an early Cenozoic HP-LT subduction complex. Exhumation of the HP-LT complex, however, was accommodated both by vertical extrusion and crustal extension. Late Cenozoic extensional faulting was contemporaneous with S-ward sweeping arc magmatism and affected by little to no kinematic changes. As both the AC and B&R experienced contractional deformation during K-Cz subduction and J-K shortening, respectively, it is critical to differentiate between contractional and extensional structures and fabrics. The lack of temporal constraints hampers the reconstructions of pre-extensional structural anatomies and extensional strain magnitudes or even the attribution of structures to specific geodynamic settings. Novel methodologies in

  4. Estrutura do capim-braquiária em relação à planta daninha - doi: 10.4025/actascianimsci.v33i3.10439 Structure of signalgrass in relation to weeds - doi: 10.4025/actascianimsci.v33i3.10439

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    Guilherme Portes Silva

    2011-06-01

    cm prevailed. The presence of weeds caused an increase in sward height and light interception by the canopy. The masses and volumetric densities of living leaf, stem, living and dead material were lower in the site near the weeds in relation to the remote site. The occurrence of S. sisymbrifolium causes spatial variability of vegetation in B. decumbens pasture.

  5. Estrutura do capim-braquiária em relação à planta daninha = Structure of signalgrass in relation to weeds

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    Manoel Eduardo Rozalino Santos

    2011-07-01

    prevailed. The presence of weeds caused an increase in sward height and light interception by the canopy. The masses and volumetric densities of living leaf, stem, living and dead material were lower in the site near the weeds in relation to the remote site. The occurrence of S. sisymbrifolium causes spatial variability of vegetation in B. decumbens pasture.

  6. Forage accumulation in brachiaria grass under continuous grazing with single or variable height during the seasons of the year

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    Manoel Eduardo Rozalino Santos

    2013-05-01

    Full Text Available The objective of this study was to evaluate grazing management strategies of Brachiaria decumbens cv. Basilisk managed with different heights under continuous grazing with cattle. Two grazing management strategies were evaluated: maintenance of pasture with an average height of 25 cm throughout the experimental period and maintenance of pasture on the average of 15 cm in height during winter, up to 25 cm from the beginning of spring. The split-plot scheme and the randomized block design with four replications were adopted. The grazing management strategies corresponded to the primary factor, while the seasons (winter, spring and summer corresponded to secondary factor. The reduction of the average sward height to 15 cm in the winter resulted, when compared with pasture maintained at 25 cm, in overall higher growth rates (95 kg/ha.day DM and leaf blade (66.1 kg/ha.day DM, as well as higher rates of total accumulation (81.5 kg/ha.day DM and leaf blade (52.6 kg/ha.day DM. The accumulated forage production (from winter to summer was higher in the pasture lowered to 15 cm in winter (25.6 t/ha DM compared with that managed with an average height of 25 cm (22.2 t/ha DM. Regarding the seasons of the year, in the winter, there were lower rates of overall growth (6.4 kg/ha.day DM, leaf blade (5.6 kg/ha.day DM and pseudostem (0.8 kg/ha.day DM, and also lower total (-6.6 kg/ha.day DM and leaf blade (-7.5 kg/ha.day DM accumulation rates. In the spring there was a higher rate of leaf senescence (22.4 kg/ha.day DM. The accumulation of forage is incremented when the pasture of B. decumbens is lowered to 15 cm during the winter, and in the spring and summer, its average height is increased to 25 cm.

  7. Invasive mammals and habitat modification interact to generate unforeseen outcomes for indigenous fauna.

    Science.gov (United States)

    Norbury, Grant; Byrom, Andrea; Pech, Roger; Smith, James; Clarke, Dean; Anderson, Dean; Forrester, Guy

    2013-10-01

    Biotic invasions and habitat modification are two drivers of global change predicted to have detrimental impacts on the persistence of indigenous biota worldwide. Few studies have investigated how they operate synergistically to alter trophic interactions among indigenous and nonindigenous species in invaded ecosystems. We experimentally manipulated a suite of interacting invasive mammals, including top predators (cat Felis catus, ferret Mustela furo, stoat M. erminea), herbivores (rabbit Oryctolagus cuniculus, hare Lepus europaeus), and an insectivore (hedgehog Erinaceus europaeus occidentalis), and measured their effects on indigenous lizards and invertebrates and on an invasive mesopredator (house mouse Mus musculus). The work was carried out in a grassland/shrubland ecosystem that had been subjected to two types of habitat modification (widespread introduction of high-seed-producing pasture species, and areas of land use intensification by fertilization and livestock grazing). We also quantified food productivity for indigenous and invasive fauna by measuring pasture biomass, as well as seed and fruit production by grasses and shrubs. Indigenous fauna did not always increase following top-predator suppression: lizards increased on one of two sites; invertebrates did not increase on either site. Mesopredator release of mice was evident at the site where lizards did not increase, suggesting negative effects of mice on lizard populations. High mouse abundance occurred only on the predator-suppression site with regular production of pasture seed, indicating that this food resource was the main driver of mouse populations. Removal of herbivores increased pasture and seed production, which further enhanced ecological release of mice, particularly where pasture swards were overtopped by shrubs. An effect of landscape supplementation was also evident where nearby fertilized pastures boosted rabbit numbers and the associated top predators. Other studies have shown that

  8. Soil acidification and liming in grassland production and grassland soil fertility in Slovenia

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    Jure ČOP

    2015-12-01

    Full Text Available This paper reviews the evidences on grassland soil acidity and liming in relation to soil processes and herbage production. There is also an outline of the present state of soil acidity and acidity-related traits – contents of organic matter (OM, phosphorus (P and potassium (K in Slovene grassland. In grassland, soil acidification is an ongoing process under humid climate conditions. It is mainly driven by leaching of nutrients, net loss of cations due to retention in livestock products, use of physiologically acid fertilizers, acid rain and N2 fixation. This process is reduced by strong pH buffering capacity of the soil and by physiologically basic fertilizers. Acid grassland soils in Slovenia are widely distributed in spite of the fact that 44% of the total land has developed from a carbonate parent material. Of the 1713 grassland soil samples analysed during 2005-2007 45% were regarded as acid ones (pH < 5.5; in KCl, 57% as soils with very low P status (˂ 6 mg P2O5/100 g soil and 22% as soils with very low K status (˂ 10 mg K2O/100 soil. Increased content of soil organic matter was identified for alpine pastures (˃ 10 % OM in 44% of samples, mainly as a result of low decomposition rate. Liming of acid grassland soils did not always reflect in a higher herbage yield. The cause for this inefficiency is plant composition of grassland. Thus, many grassland plants with relatively high production potential have adapted to acid soil conditions. To illustrate the inconsistent liming effect three researches are reviewed. In the first two researches liming along with fertilizer application did not increase the yield comparing to the fertilized control while in the third research the increase amounted 26 %. Liming improves considerably botanical composition of the acid grassland (e.g. sward where Common Bent – Agrostis tenuis Sibth. – prevails and thus indirectly affects palatability and nutritive value of herbage. Grassland liming has a weak

  9. Does delaying the first mowing date benefit biodiversity in meadowland?

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    Humbert Jean-Yves

    2012-07-01

    Full Text Available Abstract Background Meadows are regularly mown in order to provide fodder or litter for livestock and to prevent vegetation succession. However, the time of year at which meadows should be first mown in order to maximize biological diversity remains controversial and may vary with respect to context and focal taxa. We carried out a systematic review and meta-analysis on the effects of delaying the first mowing date upon plants and invertebrates in European meadowlands. Methods Following a CEE protocol, ISI Web of Science, Science Direct, JSTOR, Google and Google Scholar were searched. We recorded all studies that compared the species richness of plants, or the species richness or abundance of invertebrates, between grassland plots mown at a postponed date (treatment vs plots mown earlier (control. In order to be included in the meta-analysis, compared plots had to be similar in all management respects, except the date of the first cut that was (mostly experimentally manipulated. They were also to be located in the same meadow type. Meta-analyses applying Hedges’d statistic were performed. Results Plant species richness responded differently to the date to which mowing was postponed. Delaying mowing from spring to summer had a positive effect, while delaying either from spring to fall, or from early summer to later in the season had a negative effect. Invertebrates were expected to show a strong response to delayed mowing due to their dependence on sward structure, but only species richness showed a clearly significant positive response. Invertebrate abundance was positively influenced in only a few studies. Conclusions The present meta-analysis shows that in general delaying the first mowing date in European meadowlands has either positive or neutral effects on plant and invertebrate biodiversity (except for plant species richness when delaying from spring to fall or from early summer to later. Overall, there was also strong between

  10. Vegetation of the eastern communal conservancies in Namibia: II. Environmental drivers

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    Ben J. Strohbach

    2014-11-01

    assist in understanding savanna dynamics. With the threat of global climate change, we postulate that the vegetation will gradually change from the present mesophyll to a microphyll savanna, but that the grass sward will probably not develop very well. Shrub and tree removal (‘bush harvesting’ is likely to speed up the desertification process within this area.

  11. and the quality of silage

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    Liisa Syrjälä-Qvist

    1984-09-01

    Full Text Available Five silages having different proportions of red clover and timothy (100/0, 75/25, 50/50, 25/75 and 0/100 were preserved in five glass-fibre silos of 0.4 m 3. Chopped red clover and timothy were mixed during ensiling and preserved with AIV II solution (80 % formic acid and 2 % orthophosphoric acid, applied at the rate of 6 l/1000kg fresh material. The timothy sward was fertilized with 100kg N/ha and the red clover with 15kg N/ha. The dry matter content in red clover was 14.5 % and in timothy 18.6%, and the crude protein content of DM 22.9 % and 11.5 %, respectively. True protein formed 75—76 % of crude protein in both herbages and the proportion of watersoluble N in total N was 32 % in red clover and 36 % in timothy. The rumen degradability of protein during the first two hours was under 10 % in both herbages; after 18 and 24h ours it was 76 % and 87 % in red clover, and 65 % and 70 % in timothy. In red clover the contents of lysine, methionine and cysteine were 5.7 g, 0.4 g and 0.9 g/16 g N, respectively, the corresponding values for timothy being 4.8 g, 0.7 g and 1.4g/16 g N. In red clover the content of water-soluble carbohydrates was 10.6 % of DM and in timothy 16.5 %; the contents of plant acids were 6.7 % and 3.5 % of DM, respectively. Red clover contained 10.9g Ca/kg DM and timothy 3.1 g Ca. The total amount of inorganic constituents was also higher in red clover than in timothy. Although the chemical composition of red clover was less suitable for ensiling than the composition of timothy, the quality of all the silages was good. During ensiling the decrease in the proportion of true protein in crude protein and the increase in the proportion of watersoluble N in total N were smaller in red clover than in timothy silage. These changes were reflected in the ruminal protein degradation, which seemed to be slower when they were small. The amino acid profile of the protein did not alter during ensiling. The ensiling losses were higher in

  12. Effect of forage conservation method on ruminal lipid metabolism and microbial ecology in lactating cows fed diets containing a 60:40 forage-to-concentrate ratio.

    Science.gov (United States)

    Halmemies-Beauchet-Filleau, A; Kairenius, P; Ahvenjärvi, S; Crosley, L K; Muetzel, S; Huhtanen, P; Vanhatalo, A; Toivonen, V; Wallace, R J; Shingfield, K J

    2013-04-01

    The effect of forage conservation method on ruminal lipid metabolism and microbial ecology was examined in 2 complementary experiments in cows. Treatments comprised fresh chopped grass, barn-dried hay, or untreated (UTS) or formic acid-treated silage (FAS) prepared from the same grass sward. Preparation of conserved forages coincided with the collection of samples from cows offered fresh grass. In the first experiment, 5 multiparous Finnish Ayrshire cows (229 d in milk) were used to compare the effects of feeding diets based on grass followed by hay during 2 consecutive 14-d periods separated by a 5-d transition during which extensively wilted grass was fed. In the second experiment, 5 multiparous Finnish Ayrshire cows (53 d in milk) were assigned to 1 of 2 blocks and allocated treatments according to a replicated 3×3 Latin square design with 14-d periods to compare the effects of hay, UTS, and FAS. Cows received 7 or 9 kg/d of the same concentrate in experiments 1 and 2, respectively. Conservation of grass by drying, but not ensiling, decreased forage fatty acid content primarily due to losses of 18:2n-6 and 18:3n-3. Compared with grass, feeding hay had no effect on dry matter intake (DMI), rumen pH, or fermentation characteristics, other than increasing ammonia content, but lowered whole-tract organic matter and fiber digestibility (experiment 1). Relative to hay, silage increased DMI, rumen volatile fatty acid (VFA) concentrations, and molar proportions of butyrate, and decreased molar acetate proportions (experiment 2). Compared with UTS, FAS increased DMI, had no effect on rumen ammonia or VFA concentrations, but tended to lower rumen pH and the molar ratio of lipogenic to glucogenic VFA. Conservation method had no substantial effect on ruminal or whole-tract digestibility coefficients. Compared with fresh grass and silages, hay decreased lipolysis and biohydrogenation (BH) of dietary unsaturates in the rumen, resulting in similar flows of 18:2n-6 and 18:3n-3

  13. Performances of legume-grass mixtures under different cutting managements in mediterranean environments

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    Pasquale Martiniello

    2011-02-01

    clovers and vetch showed higher adaptability to cutting treatments particularly at Cagliari. Our results showed that the forage species associations studied can be grown successfully under simulated grazing treatment during the winter season and under the double land-use system (integrated grazing and cutting adopted at Cagliari. These treatments provide a reasonably economical means of assessing mixtures under diverse farming conditions. However, as a fraction of the plant population in swards of this experiment diminished over time, particularly at one site, the optimum of species present in these forage species associations have yet to be determined.

  14. Short communication: grazing pattern of dairy cows that were selected for divergent residual feed intake as calves.

    Science.gov (United States)

    Gregorini, P; Waghorn, G C; Kuhn-Sherlock, B; Romera, A J; Macdonald, K A

    2015-09-01

    The aim of this study was to investigate and assess differences in the grazing pattern of 2 groups of mature dairy cows selected as calves for divergent residual feed intake (RFI). Sixteen Holstein-Friesian cows (471±31kg of body weight, 100 d in milk), comprising 8 cows selected as calves (6-8 mo old) for low (most efficient: CSCLowRFI) and 8 cows selected as calves for high (least efficient: CSCHighRFI) RFI, were used for the purpose of this study. Cows (n=16) were managed as a single group, and strip-grazed (24-h pasture allocation at 0800h) a perennial ryegrass sward for 31 d, with measurements taken during the last 21 d. All cows were equipped with motion sensors for the duration of the study, and jaw movements were measured for three 24-h periods during 3 random nonconsecutive days. Measurements included number of steps and jaw movements during grazing and rumination, plus fecal particle size distribution. Jaw movements were analyzed to identify bites, mastication (oral processing of ingesta) during grazing bouts, chewing during rumination, and to calculate grazing and rumination times for 24-h periods. Grazing and walking behavior were also analyzed in relation to the first meal of the day after the new pasture was allocated. Measured variables were subjected to multivariate analysis. Cows selected for low RFI as calves appeared to (a) prioritize grazing and rumination over idling; (b) take fewer steps, but with a higher proportion of grazing steps at the expense of nongrazing steps; and (c) increase the duration of the first meal and commenced their second meal earlier than CSCHighRFI. The CSCLowRFI had fewer jaw movements during eating (39,820 vs. 45,118 for CSCLowRFI and CSCHighRFI, respectively), more intense rumination (i.e., 5 more chews per bolus), and their feces had 30% less large particles than CSCHighRFI. These results suggest that CSCLowRFI concentrate their grazing activity to the time when fresh pasture is allocated, and graze more efficiently

  15. A farm platform approach to optimizing temperate grazing-livestock systems: metrics for trade-off assessments and future innovations

    Science.gov (United States)

    Harris, Paul; Takahashi, Taro; Blackwell, Martin; Cardenas, Laura; Collins, Adrian; Dungait, Jennifer; Eisler, Mark; Hawkins, Jane; Misselbrook, Tom; Mcauliffe, Graham; Mcfadzean, Jamie; Murray, Phil; Orr, Robert; Jordana Rivero, M.; Wu, Lianhai; Lee, Michael

    2017-04-01

    data on hydrology, emissions, nutrient cycling, biodiversity, productivity and livestock welfare/health for 2 years (April 2011 to March 2013). Since April 2013, the platform has been progressively modified across three distinct ca. 22 ha farmlets with the underlying principle being to improve the sustainability (economic, social and environmental) by comparing contrasting pasture-based systems (permanent pasture, grass and clover swards, and reseeding of high quality germplasm on a regular cycle). This modification or transitional period ended in July 2015, when the platform assumed full post-baseline status. In this paper, we summarise the sustainability trade-off metrics developed to compare the three systems, together with the farm platform data collections used to create them; collections that can be viewed as 'big data' when considered in their entirety. We concentrate on the baseline and transitional periods and discuss the potential innovations to optimise grazing livestock systems utilising an experimental farm platform approach.

  16. Milk production and composition, nitrogen utilization, and grazing behavior of late-lactation dairy cows as affected by time of allocation of a fresh strip of pasture.

    Science.gov (United States)

    Vibart, R E; Tavendale, M; Otter, D; Schwendel, B H; Lowe, K; Gregorini, P; Pacheco, D

    2017-07-01

    Eighty late-lactation dairy cows were used to examine the effects of allocating a new pasture strip of a sward based on ryegrass (Lolium perenne L.) in the morning (a.m.; ∼0730 h) or in the afternoon (p.m.; ∼1530 h) on milk production and composition, nitrogen (N) utilization, and grazing behavior. Cows grazed the same pasture strips for 24 h and were offered the same daily herbage allowance. Herbage composition differed among treatments; p.m. herbage had greater dry matter (DM; 22.7 vs. 19.9%), organic matter (OM; 89.5 vs. 88.9%), and water-soluble carbohydrate (10.9 vs. 7.6%) concentrations and lesser crude protein (20.5 vs. 22.2%) and neutral detergent fiber (48.8 vs. 50.4%) concentrations compared with a.m. herbage. Total fatty acids (FA), α-linolenic acid, and polyunsaturated FA (PUFA) were greater in a.m. herbage, whereas monounsaturated FA were greater in p.m. herbage. Estimates of herbage DM intake did not differ among treatments. Daily milk yields and milk fat and milk protein concentrations were similar among treatments, whereas milk fat (684 vs. 627 g/cow), milk protein (545 vs. 505 g/cow), and milk solids (milk fat + milk protein) yields (1,228 vs. 1,132 g/cow) tended to be greater for cows on p.m. herbage. Rumenic acid and total PUFA in milk were greater for cows on a.m. herbage, whereas oleic acid was greater for cows on p.m. herbage. Estimates of urinary N excretion (g/d) did not differ among treatments, but urinary N concentrations were greater for cows on a.m. herbage (5.85 vs. 5.36 g/L). Initial herbage mass (HM) available (kg of DM/ha) and instantaneous HM disappearance rates (kg of DM/ha and kg of DM/h) did not differ, but fractional disappearance rates (0.56 vs. 0.74 per hour for a.m. vs. p.m., respectively) differed. Under the current conditions, timing of pasture strip allocation altered the herbage nutrient supply to cows; allocating a fresh strip of pasture later in the day resulted in moderate increases in milk and milk solids yields

  17. Chosen aspects of flowering of Ranunculaceae representatives in Poland

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    Bożena Denisow

    2016-04-01

    Full Text Available The family Ranunculaceae consists of numerous widespread species occuring from lowlands to subalpine or alpine zones. In Poland, the species grow in different types of habitats, including xerothermic swards (Adonido-Brachypodietum, Brachypodio- Teucrietum, Thalictro-Salvietum, Seslerio- Scorzoneretum and decidous forests (Tilio- Carpinetum. Many species are popular ornamentals cultivated fro their esthetic value. Ranunculaceans vary remarkably in the phenology of blooming. Among them, there are early spring blooming species like Eranthis hyemalis, Ficaria verna, Isopyrum thalictroides, Anemone nemorosa, A. ranunculoides, and those that start to bloom in autumn, e.g. Aconitum carmichaelli. The overall flowering duration may differ significantly between years – for example, in Anemone sylvestris the disparities reached more than three weeks. The occurrence and the length of each blooming phase may vary considerably between sites, e.g. in Adonis vernalis 10-15-day dissimilarities in the occurrence of blooming stages were recorded. Additionally, the duration of the full blooming stage varied from 10 to 30 days. The diurnal pattern of blooming among Ranunculaceae members was proved to be highly species-specific. Flowers of Aquilegia vulgaris started opening at approx. 5.00 (GMT+2, which was 2-3 hours earlier than those of Adonis vernalis. Significant differences in the diurnal flowering dynamics can be found even in the same genus: flowers of Aconitum lycoctonum began opening at 5.00 (with the peak between 6.00-9.00, while flowers of Aconitum carmichaelii started opening at 8.00 and peaked between 11.00-13.00. The flowering abundance may differ among populations of the same species. The management type was found to have an impact on the individuals’ density of Adonis vernalis occurring in xerothermic grasslands. The control of shrub encashment has already been designated as the factor determining the flowering abundance of Adonis vernalis in

  18. Biological N2 fixation by chickpea in inter cropping system on sand soil

    International Nuclear Information System (INIS)

    Ismail, M. M.; Moursy, A. A. A.; Kotb, E. A.; Farid, I. M.

    2012-12-01

    A field experiment was carried out at the plant nutrition and fertilization unit, Soils and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Inshas, Egypt on wheat and chickpea incorporating. The benefits of N 2 fixation by legumes to cereals growing in inter crops or to grasses growing in mixed swards are high clear. In cases the benefit to the N status of cereals has bee seen when they are inter cropped with legumes, where benefit is found, it is mainly due to sparing of soil N rather than direct transfer from the legume. Inter cropped wheat, has a high grains yield as compared to those recorded under sole crop. The application of inter cropping system an increase of wheat grain yield against the sole system, regardless the cultivation system, the over all means of fertilizer rates indicated (50% MF + 50% OM) treatment was superiority (100% OM) and (75% MF + 25% OM) or those recorded with either un fertilizer when wheat grain yield considered. Comparison heed between or gain sources reflected the superiority of compost under sole cultivation, while chickpea straw was the best under inter cropping. Inter cropped has a high grain N uptake compared to soil systems. While totally organic materials had accumulates more N in grains than those of untreated treated control. In the some time, the overall mean indicated the superiority of compost treatment combined with 50% mineral fertilizer under inter cropping system over those of either only organic materials treatment or those combined with 75% mineral fertilizer. Plants treated of chickpea straw and compost, achieved the best value of straw weight. A mong the organic manure treatments, chickpea straw and compost seem to be the best ones. Nitrogen derived from air (%Ndfa) shoots and seeds of chickpea plants: In case of cow manure and maize stalk, the best value of nitrogen derived from air was detected followed by compost, while the lowest value was recorded with wheat straw. In general

  19. Biological N2 Fixation by Chickpea in inter cropping System on Sand Soil

    International Nuclear Information System (INIS)

    Ismail, M. M.; Moursy, A. A. A.; Kotb, E. A.; Farid, I. M.

    2012-12-01

    A field experiment was carried out at the plant Nutrition and Fertilization Unit, Soils and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Inshas, Egypt on wheat and chickpea inter cropping. The benefits of N 2 fixation by legumes to cereals growing in inter crops or to grasses growing in mixed swards are high clear. in cases the benefit to the N status of cereals has bee seen when they are inter cropped with legumes , where benefit is found ,it is mainly due to sparing of soil N rather than direct transfer from the legume. inter cropped wheat has a high grains yield as compared to those recorded under sole crop. The application of inter cropping system induced an increase of wheat grain yield against the sole system. regardless the cultivation system, the over all means of fertilizer rates indicated (50% MF + 50% OM) treatment was superiority (100% OM) and (75% MF + 25% OM) or those recorded with either un fertilizer when wheat grain yield considered. Comparison heed between organic sources reflected the superiority of under sole cultivation, while chickpea straw was the best under inter cropping. Inter cropped has a high grain N uptake compared to soil system. While totally organic materials had accumulates more N in grain than those of underrated treated control. In the same time, the overall mean indicated the superiority of compost treatment combined with 50% mineral fertilizer under inter cropping system over those of either only organic materials treatment or those combined with 75% mineral fertilizer. Plants treated of chickpea straw and compost, achieved the best value of straw weight. Among the organic manure treatments, chickpea straw and compost seem to be the best ones. Nitrogen derived from air (% Ndfa) shoots and seeds of chickpea plant: In case of cow manure and maize stalk, the best value of nitrogen derived from air was detected followed by compost, while the lowest value was recorded with wheat straw. In general

  20. Respostas morfológicas do capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia-1 irrigado à intensidade de desfolha sob lotação rotacionada Morphological responses of irrigated Tanzaniagrass (Panicum Maximum Jacq. cv. Tanzania-1 to grazing intensity under rotational stocking

    Directory of Open Access Journals (Sweden)

    Alexandre Carneiro Leão de Mello

    2004-04-01

    2=2,500, and T3=4,000 kg green dry mass/ha, in a randomized complete block design with four replications. During the grazing season (eight 36-d cycles; three days of grazing followed by 33 days rest, the following measurements were taken: mean sward height, leaf area index (LAI, light interception (LI, mean leaf angles, all measured on four occasions (1, 11, 22, and 33 days after grazing of each rest period. Partial correlation analysis indicated the existence of correlation between height and LI, as well as between LAI and LI. As the grazing season progressed from spring-summer to autumn-winter, mean LAI declined. Mean critical LAI (95% LI was 3.6 (T1, 4.0 (T2, and 4.5 (T3 and was always reached around the 22nd day after grazing. Over the season, hard grazing (lower residual mass altered the sward structure causing shifts in plant architecture, as shown by reduced leaf angles (more horizontal, as plants begun to intercept more light per unit of leaf area. Critical LAI values suggest that relatively short rest periods may be advantageous for Tanzania grass pastures managed intensively under rotational stocking and irrigation.

  1. Acúmulo de forragem durante a rebrotação de capim-xaraés submetido a três estratégias de desfolhação Herbage accumulation during regrowth of Xaraés palisadegrass submitted to rotational stocking strategies

    Directory of Open Access Journals (Sweden)

    Bruno Carneiro e Pedreira

    2009-04-01

    -graze forage, although total pre-graze FM was lower. Forage produced in paddocks grazed at 100% LI had lower pre-graze leaf percentage, indicating that the higher forage accumulation in that treatment was a result of higher stem elongation, likely due to light competition within the canopy. Rest periods beyond the point where swards achieved 95% LI (100% LI or 28-d during the summer resulted in higher accumulation and higher pre-graze FM, although this corresponded mainly to large amounts of stem and dead material, which could negatively affect the nutritive value of the forage produced and animal performance.

  2. Produção de forragem do capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia-1 pastejado em diferentes alturas Forage production of Tanzaniagrass (Panicum maximum Jacq. cv. Tanzania-1 grazed at different heights

    Directory of Open Access Journals (Sweden)

    Clovenilson Cláudio Perissato Cano

    2004-12-01

    Full Text Available Objetivou-se, com este experimento, avaliar a massa de forragem (MF, massa de lâmina verde (MLV, massa de colmo + bainha verde (MCV, massa de material morto (MMM, massa de forragem verde (MFV, relação folha/colmo (F/C, taxa de acúmulo de massa seca (TAMS, acúmulo de massa de forragem (AMF, índice de área foliar (IAF, porcentagem de solo descoberto (SD e porcentagem de solo coberto com liteira (SCL em pastagem de capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia-1 manejada em quatro alturas do dossel forrageiro (20, 40, 60 e 80 cm. O método de pastejo utilizado foi o de lotação contínua e taxa de lotação variável, com novilhos da raça Nelore com peso médio de 340 kg. Utilizou-se o delineamento experimental inteiramente casualizado com duas repetições e realizaram-se cinco avaliações. MLV, MCV, MMM, MFV, MF, IAF, TAMS e AMF aumentaram com o avanço da altura do dossel, sendo que a porcentagem de SD, SCL e material morto diminui em pastos mais altos. O manejo do capim-Tanzânia nas alturas de 40 e 60 cm, apresentou as melhores respostas de composição morfológica, garantindo boa oferta de folhas, de cobertura do solo e taxa de acúmulo de massa seca. As alturas de 20 e 80 cm não devem ser recomendadas para o manejo do capim-Tanzânia quando o objetivo for produção com qualidade e quantidade.This experiment was conducted out to evaluate the forage mass (FM, green leaf lamina mass (GLLM, green stem + leaf sheath mass (GSSM, mass of dead material (MDM, green forage mass (GMF, total forage mass (TFM, leaf/stem ratio (L/S, dry matter accumulation rate (DMAR, leaf area index (LAI, % of bare soil (BS and litter cover percentage (LCP in Tanzaniagrass pasture (Panicum maximum Jacq. cv. Tanzania-1 managed at four different sward heights (20, 40, 60 and 80 cm. The grazing method was the continuous stocking with variable stocking rate, and the grazing animals were Nellore steers with average weight of 340 kg. The completely

  3. Sistemas de alimentação para a recria de ovinos a pasto: avaliação do desempenho animal e características da forragem Feeding systems for sheep rearing on pasture: evaluation of animal performance and forage characteristics

    Directory of Open Access Journals (Sweden)

    Marcos da Silva Brum

    2008-02-01

    Full Text Available Um experimento foi conduzido na Fundação Estadual de Pesquisa Agropecuária (FEPAGRO, em São Gabriel, Rio Grande do Sul (RS, com objetivo de avaliar o desempenho de cordeiras em recria, as características da pastagem, a composição química e a cinética de degradação nas alternativas: pastagem cultivada de milheto (Pennisetum americanum (L. Leeke (PCM, pastagem natural (PN e pastagem natural melhorada (PNM, que constituíram os tratamentos. O período de pastejo foi de 29 de janeiro a 14 de abril de 2005, sendo este caracterizado por uma forte estiagem. A PNM apresentou valores médios de massa de forragem superiores aos demais tratamentos, pela grande quantidade de material morto de azevém presente na forragem disponível. A PCM apresentou maior proporção de folhas em relação à PN e à PNM. A carga animal média de 914kg de PV ha-1 da PCM foi superior à de 261kg de PV ha-1 e de 467kg de PV ha-1 da PN e da PNM, respectivamente. O ganho médio diário (GMD no tratamento PCM (0,151kg dia-1 foi superior ao da PN (0,053kg dia-1 e da PNM (0,058kg dia-1, proporcionando maior peso vivo final (36kg de PV.animal-1 e escore corporal final (3,7 unidades na PCM. Foram observados maiores valores de proteína bruta e menores de FDA e FDN na PCM em relação à PN e à PNM. O volume final de gás, a taxa de degradação e o tempo de colonização refletiram com precisão a composição química e os ganhos de peso observados, sendo melhores para a PCM.A trial was conducted at Fundação Estadual de Pesquisa Agropecuária (FEPAGRO in São Gabriel, Rio Grande do Sul (RS, aiming to evaluate female lambs performance in rearing, sward characteristics, the chemical composition and the degradation kinetics of pearl millet (Pennisetum americanum (L. Leeke (MP; natural grassland (NG and natural grassland improved (ING, that constituted the treatments. The grazing period was from January 29 to April 14, 2005, being characterized by a strong drought. ING

  4. Número de perfilhos do capim-braquiária em regime de lotação contínua - doi: 10.4025/actascianimsci.v33i1.10440 Tiller number in signalgrass under continuous stocking systems - doi: 10.4025/actascianimsci.v33i1.10440

    Directory of Open Access Journals (Sweden)

    Simone Pedro da Silva

    2011-02-01

    . In spring and summer, the balance and number of vegetative tillers were higher and did not differ. The lowering of pasture in winter resulted in greater balance between TAR and TMR and higher number of tillers in relation to management on sward fixed at 25 cm. There were greater numbers of reproductive and dead tillers in summer and winter, respectively. The pastures with fixed height of 25 cm contained a higher number of dead tiller. Under continuous stocking, the lowering of B. decumbens pasture in winter and its increase to 25 cm in spring and summer optimizes turnover of tillers.

  5. Incorporating a prediction of postgrazing herbage mass into a whole-farm model for pasture-based dairy systems.

    Science.gov (United States)

    Gregorini, P; Galli, J; Romera, A J; Levy, G; Macdonald, K A; Fernandez, H H; Beukes, P C

    2014-07-01

    The DairyNZ whole-farm model (WFM; DairyNZ, Hamilton, New Zealand) consists of a framework that links component models for animal, pastures, crops, and soils. The model was developed to assist with analysis and design of pasture-based farm systems. New (this work) and revised (e.g., cow, pasture, crops) component models can be added to the WFM, keeping the model flexible and up to date. Nevertheless, the WFM does not account for plant-animal relationships determining herbage-depletion dynamics. The user has to preset the maximum allowable level of herbage depletion [i.e., postgrazing herbage mass (residuals)] throughout the year. Because residuals have a direct effect on herbage regrowth, the WFM in its current form does not dynamically simulate the effect of grazing pressure on herbage depletion and consequent effect on herbage regrowth. The management of grazing pressure is a key component of pasture-based dairy systems. Thus, the main objective of the present work was to develop a new version of the WFM able to predict residuals, and thereby simulate related effects of grazing pressure dynamically at the farm scale. This objective was accomplished by incorporating a new component model into the WFM. This model represents plant-animal relationships, for example sward structure and herbage intake rate, and resulting level of herbage depletion. The sensitivity of the new version of the WFM was evaluated and then the new WFM was tested against an experimental data set previously used to evaluate the WFM and to illustrate the adequacy and improvement of the model development. Key outputs variables of the new version pertinent to this work (milk production, herbage dry matter intake, intake rate, harvesting efficiency, and residuals) responded acceptably to a range of input variables. The relative prediction errors for monthly and mean annual residual predictions were 20 and 5%, respectively. Monthly predictions of residuals had a line bias (1.5%), with a proportion

  6. Estimating N2O processes during grassland renewal and grassland conversion to maize cropping using N2O isotopocules

    Science.gov (United States)

    Buchen, Caroline; Well, Reinhard; Flessa, Heinz; Fuß, Roland; Helfrich, Mirjam; Lewicka-Szczebak, Dominika

    2017-04-01

    Grassland break-up due to grassland renewal and grassland conversion to cropland can lead to a flush of mineral nitrogen from decomposition of the old grass sward and the decomposition of soil organic matter. Moreover, increased carbon and nitrogen mineralisation can result in enhanced nitrous oxide (N2O) emissions. As N2O is known to be an important greenhouse gas and a major precursor for ozone depletion, its emissions need to be mitigated by adjusting agricultural management practices. Therefore, it is necessary to understand the N2O processes involved, as well as the contribution of N2O reduction to N2. Apart from the widely used 15N gas flux method, natural abundance isotopic analysis of the four most abundant isotopocules of N2O species is a promising alternative to assess N2O production pathways. We used stable isotope analyses of soil-emitted N2O (δ18ON2O, δ15NN2Obulk and δ15NN2OSP= intramolecular distribution of 15N within the linear N2O molecule) with an isotopocule mapping approach to simultaneously estimate the magnitude of N2O reduction to N2 and the fraction of N2O originating from the bacterial denitrification pathway or fungal denitrification and/or nitrification. This approach is based on endmember areas of isotopic values for the N2O produced from different sources reported in the literature. For this purpose, we calculated two main scenarios with different assumptions for N2O produced: N2O is reduced to N2 before residual N2O is mixed with N2O of various sources (Scenario a) and vice versa (Scenario b). Based on this, we applied seven different scenario variations, where we evaluated the range of possible values for the potential N2O production pathways (heterotrophic bacterial denitrification and/or nitrifier denitrification and fungal denitrification and/or nitrification). This was done by using a range of isotopic endmember values and assuming different fractionation factors of N2O reduction in order to find the most reliable scenario

  7. Peculiarities of the imago Coleoptera (Insecta groups overwintering in various substrata of the Reserve «Galichya Gora»

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    Mikhail N. Tsurikov

    2016-05-01

    Full Text Available During the 1997–2006 and 2010–2011winter seasons, in the area of Morozova Gora (the nature reserve "Galichya Gora", in Russia, 1200 samples of various substrata were taken, most of which were 4500 cm3 in volume. In total, 41,854 specimens of 690 species belonging to 52 Coleoptera families were registered at overwintering sites. The analysis of the peculiarities of imago Coleoptera groups in the major winter habitats showed that in most of the investigated substrata representatives of the Staphylinidae family prevailed both in terms of species diversity and number. It is only under the bark of trees and in deadwood that Carabidae are the most numerous, whereas Latridiidae are prevalent in tinder fungi. Turf has the maximal species saturation during the winter season (the highest percentage of species referring to 18 families was registered here, as well as plant litter (10 families, with turf being the preference of 8 families richest in species diversity. The imagos of a number of families relatively rich in species – Cantharidae, Malachiidae, Melandryidae, Mordellidae, Oedemeridae, Meloidae, Scraptiidae and Anthribidae – were not found at overwintering sites, which is explained by the preimaginal overwintering of most representatives of the abovementioned families. It was shown that in substrata which are the least suitable for the overwintering of the imago of most Coleoptera species, the highest percentage of the predominant species was registered since more accessible substrata are used as overwintering sites by the same species from different habitats, which decreases the concentration of imago beetles of certain species there. A study of the peculiarities of species distribution (with no less than 30 specimens among overwintering sites showed that the largest number of stenotopic species was registered in droppings (9 species. Then follow the substrata (in decreasing order: turf (5, hay (grass sward, haymow, meadow (4, decomposing

  8. N-P-K balance in a milk production system on a C. nlemfuensis grassland and a biomass bank of P. purpureum CT-115 clone

    Science.gov (United States)

    Crespo, G.; Rodriguez, I.; Martinez, O.

    2009-04-01

    In very intensive milk production systems in Europe and America with the use of high amounts of chemical fertilizers, the nutrient recycling models consider the losses by leaching and N volatilization, as well as the hydro physical characteristics of the soil affecting the performance of this element (10; 6). However, in more extensive milk production systems, low input agriculture forming the natural cycle occurring within each farm, is of vital importance to potentate nutrient recycling for a stable animal production. The objective is the determination of the values of N, P and K inputs and outputs in a dairy farm with a sward composed by 60% of C. nlemfuensis and 40% of P. purpureum CT-115, associated with legumes in 28% of the area and the balance of these nutrients in the system using the "Recycling" software proposed by Crespo et al (2007). The grassland covered an area of 53.4 ha, composed by C. nlemfuensis (60%), P. purpureum CT-115 (40%) and L. leucocephala and C. cajan legumes intercropped in 28% of the area. The dairy herd consisted of 114 cows, 35 replacement heifers and 24 calves. There was a milk yield of 100 000 litters and the animals consumed 825 t DM from pastures and 75.1 t DM from other supplementary feeds. Nutrients extracted by pastures, nutrients intake by animals from pastures, symbiotically N fixation by legumes and N, P and K determinations outside the system due to animal production were determined (3-11). Volatilized ammonia, nutrient input and litter accumulated in the paddocks were measured once each season of the year. In the whole system the balance indicates negative values of N, P and K. Out of the total amount of nutrients consumed, animals used only 16 kg N, 5 Kg P and 4 Kg K for milk production, LW gain and calf production, the remainder returned to the system through excretions. Hence, more than 90% of the N and K, and approximately 81% of the P consumed by the animals were recycled to the system through the excretions. These

  9. Características morfológicas, estruturais e produtividade do capim-braquiária e do amendoim forrageiro submetidos ao sombreamento Morphological and structural characteristics and productivity of Brachiaria grass and forage peanut submitted to shading

    Directory of Open Access Journals (Sweden)

    Kátia Fernanda Gobbi

    2009-09-01

    levels (0, 50 and 70%. A randomized complete block design was used with four replications. Three and two harvests for signalgrass and forage peanut were made, respectively. Forage peanut showed significant reduction in dry matter production with shading, only in the second harvest. Dry matter production of signalgrass decreased linearly in the first and second harvest. In all the harvests evaluated, average sward height, petiole length, and stem and leaf blade length increased significantly with shading. Increasing shade levels promoted linear reduction in the tiller population density of signalgrass, in the three harvests evaluated. On the other hand, mean tiller weight was only affected in the third harvest, showing a linear increment with increasing shade levels. The leaf:stem ratio of signalgrass and forage peanut was not significantly altered by shade. Specific leaf area, leaf area per leaflet and leaf area per tiller increased with shading. Leaf area index (LAI showed linear reduction with shading in the second harvest of forage peanut and signalgrass. Signalgrass and forage peanut have great potential for evaluation and use in silvopastoral systems where the light transmission level is around 50% of photosynthetically active radiation.

  10. Prediction of the Composition of Fresh Pastures by Near Infrared Reflectance or Interactance-Reflectance Spectroscopy Predicción de la composición de pradera fresca mediante espectroscopía de reflectancia o interactancia-reflectancia en el infrarrojo cercano

    Directory of Open Access Journals (Sweden)

    Daniel Alomar

    2009-06-01

    Full Text Available Fast and precise analytical tools can contribute to optimize pasture management decisions. This work was carried out to evaluate the potential of one such technique, near infrared spectroscopy (NIRS, to predict the nutritional value of pastures without previous drying of the samples, comparing two forms of collecting the spectra: reflectance, or interactance-reflectance (fiber optic probe. Samples (n = 107 from different swards were taken across the humid and temperate regions (Los Ríos and Los Lagos of southern Chile. Once their spectra were collected, dry matter (DM and several chemical constituents, such as crude protein (CP, metabolizable energy (ME, neutral (NDF and acid detergent fiber (ADF, soluble carbohydrates (SC, soluble crude protein (SCP and neutral detergent insoluble N (NDFIN, were determined as reference data. Calibrations were developed and the best ranked were selected (by cross-validation according to a lower standard error of cross validation (SE CV and a higher determination coefficient of cross validation (R²CV. Calibrations in the reflectance mode, for DM and CP, reached a high R²CV (0.99 and 0.91, respectively and a SE CV (6.5 and 18.4 g kg-1. Equations for ADF, SCP and ME were ranked next, with R²CV of 0.87, 0.84 and 0.82, respectively, and SE CV of 15.88 g kg-1, 15.45 g kg-1 and 0.34 Mj kg-1. Equations for NDF, SC and NDFIN, with R²CV of 0.78, 0.77 and 0.61, respectively, and SE CV of 35.57, 94.54 and 1.89 g kg-1, respectively, are considered unreliable for prediction purposes. Interactance-reflectance, on the other hand, resulted in poorer equations for all fractions.Disponer de técnicas bromatológicas rápidas y precisas ayudaría a optimizar decisiones en el manejo de praderas. En este trabajo se evaluó el potencial de una de tales técnicas, la espectroscopía de reflectancia en el infrarrojo cercano (NIRS para predecir el valor nutricional de praderas al estado fresco y comparar dos formas de colectar los