scholarly journals PASTURE MANAGEMENT AND HILL COUNTRY PRODUCTION

1982 ◽  
pp. 205-214
Author(s):  
D.A. Clark ◽  
M.G. Lambert ◽  
D.F. Chapman
Keyword(s):  
Accumulation Rate ◽  
Leaf Growth ◽  
Grazing Pressure ◽  
Leaf Length ◽  
Animal Production ◽  
Pasture Management ◽  
Hill Country ◽  
Dry Matter Digestibility ◽  
Total Leaf ◽  
Grazing Pressures

Pasture and animal production from farmlets rotationally grazed with sheep(RGS), set stocked with sheep (SSS) and rotationally grazed with cattle (RGC) were compared for 5 years. Herbage accumulation rate, herbage mass, tiller and stolen growth and defoliation and sheep diet selection were measured. RGC increased perennial ryegrass (L&urn perenne L.) and white clover (Trifolium repens L.) content. RGS herbage mass was 1000 kg DM/ ha greater than SSS by January. Despite differences in ewe liveweight and herbage mass profiles, grazing management had no effect on total wool production. In the first two years SSS had higher weaning weight per ha than RGS. Under high grazing pressure sheep selected a diet ranging from 85% dry matter digestibility in December to 56% in June. Total leaf growth was similar for RGS and SSS pastures because greater leaf extension rates for RGS were compensated for by higher tiller numbers in SSS swards. The total leaf length grazed was the same for RGS and SSS pastures because the greater leaf length grazed per tiller for RGS was offset by more frequent grazing of more numerous tillers in SSS. Rotational grazing may allow greater conservation in spring and provide extra feed at very high grazing pressures, but at commercial grazing pressures pasture rationing is unlikely to give greater animal production

PASTURE RESPONSES TO GRAZING MANAGEMENT IN HILL COUNTRY

1984 ◽  
pp. 168-176
Author(s):  
D.F. Chapman ◽  
D.A. Clark
Keyword(s):  
White Clover ◽  
Leaf Growth ◽  
Leaf Length ◽  
Animal Production ◽  
Grazing Management ◽  
Leaf Removal ◽  
Hill Country ◽  
Defoliation Frequency ◽  
Tiller Density ◽  
Leaf Appearance

Components of growth and defoliation of perennial ryagrass and browntop tillers and white clover stolen apices ware measured for 12 months in hill pastures set stocked (SS) or rotationally grazed (RG) with sheep. Leaf appearance intervals of the grasses were unaffected by grazing management. Tiller densities were greater under SS (annual mean 29,700 total tillers/m' cf. 20,100/m* under FIG), compensating for greater leaf extension rates and lamina lengths of individual tillers under RG. White clover leaf appearance intervals were similar under both managements except in summer when RG was superior to SS during 3 grazing rotations. Defoliation of grass tillers was more frequent under SS when rotation lengths exceeded 3 weeks, but more severe (in terms of leaf length removed) under RG throughout the year. These mechanisms, combined with tiller density differences.contributed to the likelihood of equal leaf removal per unit area under both managements. Some advantage to RG in ryegrass leaf growth and total leaf removal was indicated but the differences were small and unlikely to affect animal production. White clover leaf removal was similar under both managements. Grazed swards are dynamic and can change rapidly under different grazing managements; however, at acceptable levels of pasture utilisation, the dominant responSes appear to maintain an equilibrium in leaf growth. Thus the use of other procedures, e.g. fertiliser application and increases in stocking rate, in conjunction with management changes is required to substantially alter pasture and animal production. Keywords: hill country, grazing management, pasture productivity, perennial ryegrass, browntop, white clover, leaf growth, tiller density, defoliation frequency, defoliation severity.

scholarly journals Stocker performance and production in mixed tall fescue–bermudagrass pastures of the Southern Piedmont USA

2012 ◽  
Vol 28 (2) ◽  
pp. 160-172 ◽  
Author(s):  
Alan J. Franzluebbers ◽  
John A. Stuedemann ◽  
Dwight H. Seman
Keyword(s):  
Tall Fescue ◽  
Cynodon Dactylon ◽  
Stocking Density ◽  
Warm Season ◽  
Grazing Pressure ◽  
Pasture Management ◽  
Coastal Bermudagrass ◽  
Forage Utilization ◽  
Environmental Goals ◽  
Grazing Pressures

AbstractStocker performance and production from mixed cool- and warm-season perennial pastures are important determinants of agricultural sustainability that can be influenced by management. We evaluated the factorial combination of three sources of nutrient application (inorganic only, organic+inorganic combination, and organic only) and two forage utilization regimes [low grazing pressure (LGP) and high grazing pressure (HGP)] on steer stocking density and rate, performance and production during 7 years of pasture management {tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] overseeded into existing Coastal bermudagrass [Cynodon dactylon (L.) Pers.] sod} on a Typic Kanhapludult in Georgia, USA. Nutrient source had few major impacts on responses, except for lower animal performance with organic fertilization (broiler litter) than with organic+inorganic and inorganic only fertilization, especially with LGP. Seasonal changes in stocking weight and rate occurred, not only as expected due to environmental conditions and dominant forage species present, but that also counteracted expected differences imposed by grazing pressure; signaling negative feedback of HGP on forage productivity. Steer performance was greatest in spring and summer under both grazing pressures, but was significantly reduced with increasing grazing pressure in the autumn and winter due to low forage availability. Across years, steer gainha−1 (863kgha−1) was not different between grazing pressures, but gainha−1 declined with time under HGP and was stable with time under LGP. Reducing grazing pressure to a moderate level can lead to equivalent steer production as HGP, and would likely contribute to a more sustainable balance among production, socio-economic and environmental goals. These multi-year results will help cattle producers in warm, moist climates design and implement more sustainable grazing systems.

Impact of deferred grazing on profitability of a hill country farm in north-western Waikato

2021 ◽  
Vol 17 ◽  
Author(s):  
Katherine Tozer ◽  
Steve Howarth ◽  
Jon Sherlock ◽  
Ian Tarbotton
Keyword(s):  
Management Practice ◽  
Grazing Pressure ◽  
Management Tool ◽  
Pasture Management ◽  
Target Weight ◽  
Hill Country ◽  
Farm Profitability ◽  
Gross Margins ◽  
The Impact ◽  
North Western

Deferred grazing is a common management practice in which pastures are rested from grazing between mid-spring and the end of summer/early autumn. It has been used to rejuvenate pastures and better manage the spring pasture surplus although its impact on farm profitability is unknown. FARMAX was used to explore the impact of deferred grazing on profitability on a north-western Waikato beef and sheep hill country farm based on experimental data and likely management responses. The Base Scenario modelled farm profitability assuming spring surplus in a typical year. When 15% of the farm was deferred and it was assumed that the increased grazing pressure on the rest of the farm led to greater control of the spring feed surplus and improved pasture quality, there was an increase in ewe performance and the number lambs sold at target weight. Per head and total farm gross margins increased by 8%. Results demonstrate how the use of deferred grazing as a pasture management tool to increase resilience can also enhance livestock performance and profitability at the whole-farm level.

scholarly journals CRITICAL INPUTS INTO GISBORNE HILL COUNTRY

1984 ◽  
pp. 27-37
Author(s):  
M.J. Fitzharris ◽  
D.F. Wright
Keyword(s):  
East Coast ◽  
Farm Management ◽  
Animal Production ◽  
Management Study ◽  
Hill Country ◽  
Farm Production ◽  
The Future ◽  
Farm Profit ◽  
Stocking Rates ◽  
Practical Implications

The results of an analysis of four years data, 1975/76-1978/79, from a farm management study of Gisborne-East Coast hill country farms were presented at the 1980 Grasslands Conference. Analysis of three more years data, 1979/80-1981/82, essentially confirms the association of fencing and fertiliser with high levels of animal production. Recent escalating costs of fertiliser have cast doubts on its profitability. High stocking rates (usually beyond 12 su/ha) and high proportions of cattle (usually up to 50% of su) have emerged as other factors consistently associated with greater productivity and frequently with profitability. It is suggested that manipulation of these factors would be worthy of farmers consideration. The practical implications for the future of these findings are discussed. Keywords: Farm production, farm profit, Gisborne hill country

THE IN VITRO DIGESTIBILITY OF PLANT PARTS OF ORCHARDGRASS CLONES WITH ADVANCING STAGES OF MATURITY

1965 ◽  
Vol 45 (5) ◽  
pp. 503-507 ◽  
Author(s):  
D. N. Mowat ◽  
B. R. Christie ◽  
J. E. Winch
Keyword(s):  
Dry Matter ◽  
In Vitro Digestibility ◽  
Plant Parts ◽  
Dry Matter Digestibility ◽  
Total Leaf ◽  
Early Maturing

The in vitro dry matter digestibility (I.V.D.) of the stem and total leaf fractions of four orchardgrass clones was similar at the preheading stage. Even at 100% head emergence, differences in I.V.D. between stems and living leaves were not great with the early-maturing clones. However, wide differences existed between the values for stems and living leaves in mature plants. Heads were only slightly higher than stems in digestibility.Leaf digestibility was lower for those leaves dead or even partially dead. Nevertheless, in mature plants, dead leaves were higher in I.V.D. than heads or stems. Large differences occurred among clones in stem digestibility. However, the variability among clones in leaf digestibility was small.

The resilience of soil organic carbon stocks under contrasting hill country pasture management practices

2021 ◽  
Vol 17 ◽  
Author(s):  
Alec Mackay ◽  
Ronaldo Eduardo Vibart ◽  
Catherine McKenzie ◽  
Brian Devantier ◽  
Emma Noakes
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Pasture Management ◽  
Single Superphosphate ◽  
Hill Country ◽  
Soil Organic Carbon Stocks ◽  
Environmental Goals ◽  
The Stability ◽  
Soc Stocks

In 2020 we measured the stability of soil organic carbon (SOC) concentrations and stocks under contrasting hill country pasture regimes, by sampling three slope classes and three aspect locations on each of three farmlets of a long-term phosphorus fertiliser and sheep grazing experiment. The farmlets included no annual phosphorus (NF), 125 kg of single superphosphate/ha (LF), or 375 kg superphosphate/ha (HF) that has been applied on an annual basis since 1980. Results from the 2020 sampling event were added to previous results reported from soil samples collected in 2003 and 2014. The SOC concentrations in the topsoil (0-75 mm depth), ranging from 4.23 to 5.99% across all slopes and aspects of the farmlets, fell within the normal range (≥3.5 and <7.0%) required for sustaining production and environmental goals. A trend was shown for greater SOC stocks in the topsoil in the HF farmlet (34.0 Mg/ ha) compared with the other two farmlets (31.6 Mg/ha), but this trend was not evident in the deeper soil layers (75-150, 150-300, 0-300 mm). Under the current conditions, topographical features such as slope and aspect had a more profound influence on SOC stocks than management history.

scholarly journals Effects of leaf length and development stage on the triple oxygen isotope signature of grass leaf water and phytoliths: insights for a proxy of continental atmospheric humidity

2019 ◽  
Vol 16 (23) ◽  
pp. 4613-4625 ◽  
Author(s):  
Anne Alexandre ◽  
Elizabeth Webb ◽  
Amaelle Landais ◽  
Clément Piel ◽  
Sébastien Devidal ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Climate Model ◽  
Isotope Composition ◽  
Leaf Growth ◽  
Development Stage ◽  
Mean Value ◽  
Leaf Length ◽  
Leaf Water ◽  
Grass Species ◽  
Leaf Biomass

Abstract. Continental relative humidity (RH) is a key climate parameter, but there is a lack of quantitative RH proxies suitable for climate model–data comparisons. Recently, a combination of climate chamber and natural transect calibrations have laid the groundwork for examining the robustness of the triple oxygen isotope composition (δ′18O and 17O-excess) of phytoliths, that can preserve in sediments, as a new proxy for past changes in RH. However, it was recommended that besides RH, additional factors that may impact δ′18O and 17O-excess of plant water and phytoliths be examined. Here, the effects of grass leaf length, leaf development stage and day–night alternations are addressed from growth chamber experiments. The triple oxygen isotope compositions of leaf water and phytoliths of the grass species F. arundinacea are analysed. Evolution of the leaf water δ′18O and 17O-excess along the leaf length can be modelled using a string-of-lakes approach to which an unevaporated–evaporated mixing equation must be added. We show that for phytoliths to record this evolution, a kinetic fractionation between leaf water and silica, increasing from the base to the apex, must be assumed. Despite the isotope heterogeneity of leaf water along the leaf length, the bulk leaf phytolith δ′18O and 17O-excess values can be estimated from the Craig and Gordon model and a mean leaf water–phytolith fractionation exponent (λPhyto-LW) of 0.521. In addition to not being leaf length dependent, δ′18O and 17O-excess of grass phytoliths are expected to be impacted only very slightly by the stem vs. leaf biomass ratio. Our experiment additionally shows that because a lot of silica polymerises in grasses when the leaf reaches senescence (58 % of leaf phytoliths in mass), RH prevailing during the start of senescence should be considered in addition to RH prevailing during leaf growth when interpreting the 17O-excess of grass bulk phytoliths. Although under the study conditions 17O-excessPhyto do not vary significantly from constant day to day–night conditions, additional monitoring at low RH conditions should be done before drawing any generalisable conclusions. Overall, this study strengthens the reliability of the 17O-excess of phytoliths to be used as a proxy of RH. If future studies show that the mean value of 0.521 used for the grass leaf water–phytolith fractionation exponent λPhyto-LW is not climate dependent, then grassland leaf water 17O-excess obtained from grassland phytolith 17O-excess would inform on isotope signals of several soil–plant-atmosphere processes.

scholarly journals Morphogenesis and forage accumulation of Urochloa ruziziensis under nitrogen and potassium fertilization management

2019 ◽  
Vol 40 (4) ◽  
pp. 1605
Author(s):  
Karla Rodrigues de Lima ◽  
Carlos Augusto Brandão de Carvalho ◽  
Flavio Henrique Vidal Azevedo ◽  
Fabio Prudêncio de Campos ◽  
Aline Barros da Silva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Accumulation Rate ◽  
Leaf Growth ◽  
Stem Elongation ◽  
Block Design ◽  
Elongation Rate ◽  
Repeated Measurements ◽  
Positive Form ◽  
Potassium Fertilization ◽  
Appearance Rate

The objective of this study was to evaluate the effect of nitrogen and potassium fertilization on the morphogenetic and structural characteristics and production of Urochloa ruziziensis in two summer seasons (summer 1, 2010–2011and summer 2, 2011–2012) and the autumn and spring of 2011. A randomized complete block design with four treatments (0, 120, 240, and 360 kg ha-1 year-1 of N and K2O) and five replications was used, with repeated measurements in each season, in a split plot arrangement. The treatments were allocated to the plots and the seasons of the year to the subplots. The phyllochron (PHY),leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), tiller population density (TPD), tiller appearance rate (TAR), tiller mortality rate (TMR), leaf growth rate (LGR), stem growth rate (SGR), senescence rate (SR), forage accumulation rate (FAR), and leaf accumulation rate (LAR) of Urochloa ruziziensis were evaluated. There was a positive quadratic effect for the PHY and ELR, with maximum values of 4.3 days leaf-1 and 0.43 cm tiller-1 day-1, respectively. While the SER increased linearly (0.0012 cm day-1 kg-1 of N and K2O) during summer 2. The TPD, TAR, and TMR increased linearly (averages of 1.53 tillers m-2, 0.04% and 0.02% per kg of N and K2O, respectively) with nitrogen and potassium fertilization during spring and both summer seasons. The LGR, SGR, and SR also increased linearly with N and K2O application rates during summer 2 (0.2809, 0.0082, and 0.0411 kg DM ha-1 day-1, per kg of N and K2O, respectively), while the FAR and LAR increased in a quadratic positive form (maximum values of 175 and 129 kg dry matter (DM) ha-1, corresponding to 294 and 237 kg ha-1 of N and K2O, respectively) during summer 2. Urochloa ruziziensis is a forage plant with a high DM production capacity during the summer and a high seasonal forage production.

scholarly journals Estimation of total leaf area and D leaf area of pineapple from biometric characteristics

2018 ◽  
Vol 40 (6) ◽  
Author(s):  
Marlúcia Pereira dos Santos ◽  
Victor Martins Maia ◽  
Fernanda Soares Oliveira ◽  
Rodinei Facco Pegoraro ◽  
Silvânio Rodrigues dos Santos ◽  
...  
Keyword(s):  
Leaf Area ◽  
Regression Models ◽  
Carbon Fixation ◽  
Pearson Correlation ◽  
Leaf Length ◽  
Total Leaf Area ◽  
Total Leaf ◽  
Pearson Correlation Analysis ◽  
Biometric Measurements ◽  
Non Destructive

Abstract The estimation of pineapple total leaf area by simple, fast and non-destructive methods allow inferences related to carbon fixation estimative, biotic and abiotic damages and correlating positively with yield. The objective was to estimate D leaf area and total leaf area and of ‘Pérola’ pineapple plants from biometric measurements. For this purpose, 125 slips were selected and standardized by weight for planting in pots. Nine months after planting in a greenhouse, the plants were harvested to evaluate the total leaf area of the plant, D leaf area and D leaf length and width using a portable leaf area meter. Pearson correlation analysis was made and it was observed significative positive and strong correlation among the studied variables. Then, regression models were adjusted. It was observed that the D leaf area of ‘Pérola’ pineapple can be estimated from the length and width of this same leaf and the total leaf area can be estimated from the D leaf area.

A spatially explicit population model of the effect of spatial scale of heterogeneity in grass–clover grazing systems

2013 ◽  
Vol 152 (3) ◽  
pp. 394-407 ◽  
Author(s):  
J. M. SHARP ◽  
G. R. EDWARDS ◽  
M. J. JEGER
Keyword(s):  
Spatial Scales ◽  
Spatial Separation ◽  
Grazing Pressure ◽  
Complete Separation ◽  
Spatially Explicit ◽  
Spatial And Temporal Variability ◽  
N Fixation ◽  
Pasture Management ◽  
Grazed Pasture ◽  
The Impact

SUMMARYThe benefits of using white clover (Trifolium repensL.) as a source of nitrogen (N) and nutritious feed in pasture grazed by ruminant livestock have been widely recognized. However, clover is considered inadequate and unreliable as the main source of N input, since its abundance in pasture is patchy, low (typically <0·20) and shows great year-to-year variation. This is thought to be due to the metabolic costs of N fixation, competition with grass, the preference for clover by grazing animals and patchy dung and urine deposition. One solution suggested by a number of authors is to increase the heterogeneity within the pasture by spatially separating clover from grass. This method of pasture management, in order to sustain higher clover content in both the sward and diet of grazing animals, would remove inter-specific competition and equalize grazing pressure, allowing clover to grow unimpeded in greater abundance than previously observed. An existing spatially explicit grass–clover simulation model, developed to investigate the intrinsic spatial and temporal variability within mixed grass–clover swards, was modified and then used to examine the impact of spatial separation on the content, variability and patchiness of clover in pasture. The results show that spatial separation increases both the content and spatial aggregation of clover and reduces year-to-year variation compared with a mixed pasture that fluctuates around a lower mean. The same model was also used to examine the impact of spatial separation across a range of spatial scales, from narrow strips to complete separation, as a means of managing the concerns over disruption to the N cycle within the pasture. The present study shows the importance of the initial sowing arrangement of plant species in sustaining a high content of clover within a pasture in the short term, to at least 20 years depending on the scale of separation, and demonstrates that the spatial separation of clover from grass within a grazed pasture may overcome some of the limitations associated with the use of clover in conventional grass–clover pastures. Results are discussed in terms of benefits to both herbage dry matter production and animal performance.

Sign in / Sign up

Export Citation Format

Share Document