Changes in botanical composition on three farmlets subjected to different pasture and grazing management strategies

2013 ◽  
Vol 53 (8) ◽  
pp. 670 ◽  
Author(s):  
L. M. Shakhane ◽  
J. M. Scott ◽  
R. Murison ◽  
C. Mulcahy ◽  
G. N. Hinch ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Initial Conditions ◽  
Management Strategies ◽  
The Other ◽  
Grazing Management ◽  
Curvilinear Relationship ◽  
Botanical Composition ◽  
Rotational Grazing ◽  
Tall Grass ◽  
Soil P

As part of the Cicerone Project’s farmlet experiment, conducted on the Northern Tablelands of New South Wales, Australia, between July 2000 and December 2006, this study assessed the effects of varying soil fertility, pasture species and grazing management on the botanical composition of three 53-ha farmlets subjected to different management strategies. Starting with the same initial conditions, the farmlets were managed to reach different target levels of soil phosphorus (P) and sulfur (S); Farmlet A aimed at 60 mg/kg of Colwell P and 10 mg/kg S (KCl40) whereas Farmlets B and C both aimed at 20 and 6.5 mg/kg of P and S, respectively. Pastures were renovated on six out of eight paddocks on Farmlet A, but only one paddock of each of Farmlets B (typical management) and C (intensive rotational grazing) was renovated. Flexible rotational grazing was employed on Farmlets A and B (each of eight paddocks) while Farmlet C used intensive rotational grazing over its 17 major paddocks, which were further subdivided into 37 subpaddocks. This paper focuses on the botanical composition dynamics observed across all three farmlets and the explanatory variables associated with those changes. Eight assessments of botanical composition were carried out at approximately annual intervals across each of the 37 major paddocks distributed across the farmlets and the results for each of 49 species were aggregated into seven functional groups for analysis. The strongest correlation found was a negative curvilinear relationship between sown perennial grasses (SPG) and warm-season grasses (WSG). The most significant factors affecting the functional group changes were soil P, sowing phase, paddock and date. These factors led to significant increases in SPG and correspondingly lower levels of WSG on Farmlet A compared with Farmlet B. Farmlets B and C experienced similar, declining levels of SPG, and increasing levels of WSG suggesting that intensive rotational grazing did not lead to substantial changes in botanical composition, compared with flexible rotational grazing, in spite of the fact that intensive rotational grazing had much longer grazing rests and shorter graze periods than the other two farmlets. Soil P levels were also significantly associated with levels of cool-season annual grasses, legumes and herbs, especially on Farmlet A. In general, the largest differences in botanical composition were between Farmlet A and the other two farmlets; these differences were most closely associated with those plants categorised as sown, introduced, C3 pasture species. The levels of legume were generally low on all farmlets, due largely to the dry seasons experienced over most of the trial. Efforts to increase the legume composition on all farmlets were more successful on Farmlet A than on the other two farmlets due, presumably, to higher soil fertility on Farmlet A. Farmlet C, with its long rest periods and short graze periods, had a small proportion of legumes, due to the competitive effects of the accumulated tall grass herbage between grazings. The ‘typical’ management of Farmlet B also resulted in low levels of legume as well as increased ‘patchiness’ of the pastures and increased numbers of thistles.

scholarly journals Livestock weights in response to three whole-farmlet management systems

2013 ◽  
Vol 53 (8) ◽  
pp. 727 ◽  
Author(s):  
G. N. Hinch ◽  
J. Hoad ◽  
M. Lollback ◽  
S. Hatcher ◽  
R. Marchant ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Management Strategies ◽  
Experimental Period ◽  
Supplementary Feeding ◽  
Grazing Management ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Average Value ◽  
Management Regime ◽  
Similar Range

This paper reports changes in livestock weights recorded in a whole-farmlet experiment, which aimed to examine the profitability and sustainability of three different pasture and grazing management strategies. The assessment of liveweights was considered a key component of measuring the integrated effects of the farmlet-scale treatments. The three farmlets comprised a typical management regime, which employed flexible rotational grazing over eight paddocks with moderate soil fertility (farmlet B), a system based on the same grazing management and paddock number but with higher levels of sown pasture and soil fertility (farmlet A) and a farmlet with moderate soil fertility and intensive rotational grazing over 37 paddocks (farmlet C). Early in the experimental period, there were no significant differences between farmlets in the liveweight of any class of livestock. However, from the second year onwards, as the pasture renovation, soil fertility and grazing management treatments took effect, differences in liveweight between farmlets became more apparent and significant. The stocking rate, which was treated as an emergent property of each farmlet, reached a maximum annual average value after 5 years of 12.6, 8.5 and 7.7 dry sheep equivalents (dse)/ha on farmlets A, B and C representing 84, 113 and 51% of their respective target stocking rates which were 15, 7.5 and 15 dse/ha. The liveweights of ewes, both before joining and during pregnancy, varied with year and farmlet with those on farmlets A and B tending to be significantly heavier than those on farmlet C. From 2003 to 2006, liveweights were significantly (P < 0.001) affected by a wide array of factors and their interactions including: date, ewe age, green digestible herbage, legume herbage mass, proportion of farmlet grazed, stocking rate and level of supplementary feeding. The weights of lambs/weaners/hoggets, both pre- and post-weaning, were at times also higher on farmlets A and B compared with those on farmlet C and were affected by a similar range of factors to those which affected ewe weights. Similar relative differences also applied to the liveweights of the other livestock run on the farmlets, namely wethers and non-reproductive cattle. The results suggest that stocking rate was able to be increased towards the higher target of farmlet A due to the higher level of pasture renovation and soil fertility on that farmlet, which led to high liveweights per head as well as the higher stocking rate. However, as the stocking rate increased on farmlet A, the differences between farmlets in liveweight per head diminished and the need for supplementary feeding increased. In contrast, the intensive rotational grazing practised on farmlet C did not allow the farmlet to increase its stocking rate towards its higher target. It appears that the higher proportion of each of farmlets A and B grazed at any one time allowed all classes of livestock to reach higher liveweights per head than on farmlet C, due presumably to the greater proportion of those two farmlets grazed at any one time.

scholarly journals The effects of pasture inputs and intensive rotational grazing on superfine wool production, quality and income

2013 ◽  
Vol 53 (8) ◽  
pp. 750 ◽  
Author(s):  
D. Cottle ◽  
C. A. Gaden ◽  
J. Hoad ◽  
D. Lance ◽  
J. Smith ◽  
...  
Keyword(s):  
Soil Fertility ◽  
Management Strategies ◽  
Fibre Diameter ◽  
Production Quality ◽  
Grazing Management ◽  
Rotational Grazing ◽  
Wool Production ◽  
Staple Strength ◽  
Fleece Weight ◽  
Staple Length

A farmlet experiment was conducted between July 2000 and December 2006 as part of the Cicerone Project, which sought to enhance the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A self-replacing Merino enterprise was grazed as the dominant livestock enterprise, together with ~20% of the carrying capacity as cattle, on each of three farmlet treatments: higher levels of soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet A), moderate soil fertility and pasture renovation with flexible rotational grazing over eight paddocks (farmlet B) and moderate soil fertility and pasture renovation with intensive rotational grazing over 37 paddocks (farmlet C). Prior to commencement of the trial, the three 53-ha farmlets were allocated equivalent areas of land based on soil type, slope and recent fertiliser history. This paper describes the effects of the three pasture and grazing management strategies on the production, quality and value of the wool produced per head, per ha and per farmlet. Up until 2001 there were no differences in wool production between farmlets. Thereafter, significant differences between farmlets emerged in greasy fleece weight per head and price received per kg of fleece wool. For example, the clean fleece value averaged over the 2003–05 shearings for all hoggets, ewes and wethers was 1531, 1584 and 1713 cents/kg for farmlets A, B and C, respectively. There were small but significant differences, which varied between sheep class and year, between the farmlets in average fibre diameter and staple length but less so with staple strength. In general, while the differences between farmlets in staple strength varied over time, farmlets A and B tended to have wool with longer staple length and broader fibre diameter than farmlet C and this affected wool value per kg. Differences in wool income per ha between farmlets grew in later years as the farmlet treatments took effect. In spite of farmlet A having a slightly lower wool value per kg, after taking into account its greater fleece weight per head and its higher stocking rate, the total wool income per ha was higher than on either farmlets B or C. The average gross wool income per ha from 2003 to 2005 was $303, $215 and $180 for farmlets A, B and C, respectively. The highest amount of greasy wool produced was in 2004 when 38.2, 26.5 and 21.5 kg/ha was harvested from farmlets A, B and C, respectively. The fibre diameter profiles of 2-year-old ewes showed similar profiles for farmlets A and B but a significantly finer fibre diameter profile for farmlet C ewes due to intensive rotational grazing. However, sheep on all three farmlets produced wool with high staple strength. Multivariate analyses revealed that greasy fleece weight, staple length and staple strength were significantly positively correlated with the proportion of the farm grazed at any one time, and with soil phosphorus, legume herbage and green digestible herbage thus highlighting the significant influence of pasture and soil inputs and of grazing management on wool production and quality.

Effects of grazing management on botanical composition of native grass-based pastures in temperate south-east Australia

2000 ◽  
Vol 40 (2) ◽  
pp. 225 ◽  
Author(s):  
D. L. Garden ◽  
G. M. Lodge ◽  
D. A. Friend ◽  
P. M. Dowling ◽  
B. A. Orchard
Keyword(s):  
Management Strategies ◽  
Grazing Pressure ◽  
Grazing Management ◽  
Botanical Composition ◽  
Holcus Lanatus ◽  
Themeda Triandra ◽  
Continuous Grazing ◽  
Wide Range ◽  
Drought Conditions ◽  
Native Pastures

Grazing management strategies to alter botanical composition of native pastures were investigated at 4 locations in the high rainfall zone of south-east Australia, including Tasmania. These studies were conducted as part of the Temperate Pasture Sustainability Key Program, which evaluated the effects of grazing management on a wide range of pasture types between 1993 and 1996. Pastures in this study were based on Aristida ramosa/Bothriochloa macra, Microlaena stipoides–Austrodanthonia spp. or Themeda triandra–Austrodanthonia spp. Seasonal rests, increased grazing pressure in spring, mob stocking and cutting for hay were compared to continuous grazing at all sites. In addition, specific local treatments were tested at individual sites. Changes in composition resulting from the treatments were minimal at most sites. This may have been due to a combination of the inherent stability of the pastures, the relatively short duration of the experiments, and the drought conditions experienced, which minimised differences between treatments. Some strategies to alter composition of natural pastures are suggested. In the Aristida–Bothriochloa pasture there was a general decrease in Aristida and an increase in Bothriochloa, which was largely unaffected by the type of grazing management applied. The combination of drought conditions and increasing grazing pressure was sufficient to alter composition without specific management strategies being necessary. In the Themeda–Austrodanthonia pasture, resting in spring, 12-month rests or cutting for hay (which involved a spring rest) allowed Themeda to increase in the pasture. The Microlaena–Austrodanthonia pastures were very stable, especially where annual grass content was low. However, certain treatments allowed Microlaena to increase, a result which is regarded as being favourable. The major effects in these latter pastures were on undesirable species. Vulpia spp. were reduced by resting in autumn and increased spring grazing pressure, while Holcus lanatus was increased dramatically by resting in spring and was also increased by resting in autumn or winter, but only when conditions were suitable for growth of this species. In many cases, treatment differences were only expressed following recovery from drought, showing that timing of grazing management to achieve change is critical.

scholarly journals Statistical methodologies for drawing causal inference from an unreplicated farmlet experiment conducted by the Cicerone Project

2013 ◽  
Vol 53 (8) ◽  
pp. 643 ◽  
Author(s):  
R. Murison ◽  
J. M. Scott
Keyword(s):  
Longitudinal Data ◽  
Statistical Model ◽  
Field Experiment ◽  
Causal Inference ◽  
Statistical Inference ◽  
Treatment Effects ◽  
Management Strategies ◽  
Grazing Management ◽  
Botanical Composition ◽  
Longitudinal Profiles

The present paper explains the statistical inference that can be drawn from an unreplicated field experiment that investigated three different pasture and grazing management strategies. The experiment was intended to assess these three strategies as whole farmlet systems where scale of the experiment precluded replication. The experiment was planned so that farmlets were allocated to matched paddocks on the basis of background variables that were measured across each paddock before the start of the experiment. These conditioning variables were used in the statistical model so that farmlet effects could be discerned from the longitudinal profiles of the responses. The purpose is to explain the principles by which longitudinal data collected from the experiment were interpreted. Two datasets, including (1) botanical composition and (2) hogget liveweights, are used in the present paper as examples. Inferences from the experiment are guarded because we acknowledge that the use of conditioning variables and matched paddocks does not provide the same power as replication. We, nevertheless, conclude that the differences observed are more likely to have been due to treatment effects than to random variation or bias.

scholarly journals STUBBLE MANAGEMENT OF HAY AFTERMATH

1984 ◽  
pp. 225-229
Author(s):  
D.R. Stevens ◽  
M.L. Smetham
Keyword(s):  
White Clover ◽  
Management Strategies ◽  
The Other ◽  
Silt Loam ◽  
Botanical Composition ◽  
Main Determinant ◽  
Herbage Yield ◽  
Dead Material ◽  
Clover Pasture ◽  
Lincoln College

Possible management strategies for areas of stubble left after hay had been harvested from a ryegrass/white clover pasture were studied in a trial on an irrigated Wakanui silt loam at Lincoln College, Canterbury. Following a hay crop cut in late December, the stubble was either trimmed to 2 cm (920 kg DM/ha) or left intact at 8-12 cm (2200 kg DM/ha) and spelled for either four or eight weeks. Subsequent regrowth herbage yield, botanical composition and digestibility were measured. The highest live herbage mass of 5380 kg DM/ha resulted from leaving the stubble intact and cutting the regrowth at four weekly intervals. The other treatments gave herbage masses from 4120 kg DM/ha to 4350 kg DM/ha but did not significantly differ from one another. However while 1220 and 1650 kg DM/ha of dead material was present in the "stubble intact" treatments, only 470 and 880 kg DM/ha occurred where the stubble was trimmed to 2 cm. The amount of dead material was the main determinant of overall digestibility, as the digestibility of the green herbage was similar (79-80%) for all treatments. As a result of differing amounts of dead material therefore, the herbage mass from trimmed stubble was from 4 to 10% higher in digestibility than that from the stubble left intact treatment. Clover proportion was high throughout the treatments, ranging from 50% in the long spelled treatment to 70% in the short spelled treatment. The results of this trial suggest that hay stubble should be left intact but regrowth should be closely defoliated after four weeks to maximise production and return the sward to a leafy state as quickly as possible.

scholarly journals A biophysical dairy farm model to evaluate rotational grazing management strategies

Agronomie ◽  
2003 ◽  
Vol 23 (2) ◽  
pp. 105-122 ◽  
Author(s):  
Marie-Jos�e Cros ◽  
Michel Duru ◽  
Fr�d�rick Garcia ◽  
Roger Martin-Clouaire
Keyword(s):  
Management Strategies ◽  
Dairy Farm ◽  
Grazing Management ◽  
Rotational Grazing ◽  
Farm Model

EVALUATION DES CRITÈRES DE DIFFÉRENCIATION POUR LA CLASSIFICATION DE 92 MATÉRIAUX TOURBEUX DU QUÉBEC ET DE L’ONTARIO

1980 ◽  
Vol 60 (3) ◽  
pp. 479-486 ◽  
Author(s):  
M. LÉVESQUE ◽  
H. DINEL ◽  
R. MARCOUX
Keyword(s):  
The Other ◽  
Curvilinear Relationship ◽  
Organic Soils ◽  
Botanical Composition ◽  
Efficient Utilization ◽  
Close Relationship

In order to evaluate the differentiation criteria for classification of organic soils, 92 peat-like materials have been characterized according to criteria generally used by the Canadian Pedological Commission (C.P.C.). The botanical composition and the Ca:Mg ratio have been added to these criteria. A close relationship was found (r = −0.865**) between the pyrophosphate indices obtained by the method adopted by C.P.C. and those measured using the Kaila method. The distribution of peat-like materials which are classified as fibric, mesic and humic was different depending on whether the differentiation criterion used was rubbed fibre or pyrophosphate index. A classification using the first criterion gives a dominant mesic population, while the second criterion favored the fibric group. The curvilinear relationship obtained between the content of rubbed fibres and the pyrophosphate index shows that the degree of decomposition measured by these criteria was proportional only for materials which are fundamentally fibric or humic. The mesic group is more or less well-defined by the two criteria. The botanical composition proved to be the most discriminatory differentiation element. Also, a previous grouping of the materials according to this criterion would ensure a more orderly and efficient utilization of the other characterization criteria, and would provide a better-defined differentiation of the mesic materials.

scholarly journals Effect of grazing management strategies on the yield and nutritional value of Marandu grass in the semiarid of Brazil

2021 ◽  
Vol 42 (4) ◽  
pp. 2503-2522
Author(s):  
Maria Catiane Silva Veloso Araújo ◽  
◽  
Eleuza Clarete Junqueira de Sales ◽  
Flávio Pinto Monção ◽  
Vicente Ribeiro Rocha Júnior ◽  
...  
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Accumulation Rate ◽  
Structural Characteristics ◽  
Block Design ◽  
Management Strategies ◽  
Grazing Management ◽  
Rotational Grazing ◽  
Pasture Management ◽  
Sward Height

The objective of this study was to evaluate the effects of two grazing management strategies on structural, productive and nutritional parameters of Marandu grass (Urochloa brizantha cv. Marandu). A completely randomized block design with two pasture management strategies and eight replications (blocks) was used. The grazing management strategies were: (1) low intensity rotational grazing (LI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 24 cm, i.e., a defoliation intensity of 50%; (2) High intensity rotational grazing (HI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 10 cm (±70% defoliation intensity). Pastures were sampled before and after grazing for estimation of forage mass, forage accumulation rate, structural characteristics, nutritional value and dry matter intake.The LI strategy resulted in higher dry matter production than HI before (18.33%) and after grazing (49.06%), increasing pre-grazing forage density by 13.21% (P < 0.05). The production of potentially digestible dry matter was highest (P < 0.05) in LI strategy (21.3% before and 39.6% after grazing, respectively). Higher post-grazing green forage mass (45%) increased the residual crude protein in LI. The LI management strategy increased forage mass production and can be used in Marandu grass pastures.

GRAZING SYSTEMS FOR EWES AND LAMBS

1962 ◽  
Vol 42 (2) ◽  
pp. 139-144 ◽  
Author(s):  
F. W. Calder ◽  
J. W. G. Nicholson ◽  
H. M. Cunningham
Keyword(s):  
Experimental Period ◽  
The Other ◽  
Grazing Management ◽  
Management Systems ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Creep Feeding ◽  
Free Range ◽  
Internal Parasites ◽  
Grazing Systems

Two experiments were conducted to compare forward creep grazing of lambs with other grazing management systems for ewes and lambs. In the first experiment, forward creep grazing with and without creep feeding of concentrates was compared with rotational grazing, using 7 ewes with single lambs per plot of [Formula: see text] acres. The first lambs reached market weight by the 57th day of the experiment, at which time the average lamb gains were higher on the creep grazed-creep fed groups, but there was no difference in the gains on the other two systems. The experiment was continued for 35 days and during this period the lamb gains on the creep grazed plots were higher than on the rotationally grazed areas. This later period coincided with a period of reduced herbage growth due to below normal precipitation. The average daily gains for the entire experimental period were.45,.51 and.57 pounds for rotational, creep, and creep fed-creep grazed systems respectively.In the second experiment, forward creep grazing was compared with rotational grazing and free range grazing, using a higher stocking rate of 8 ewes and 10 lambs per plot. The average daily gains for the experiment were.38,.40 and.34 pounds for rotational, creep grazed, and free range systems respectively. The differences between grazing systems were not statistically significant at P = 0.05. Both the ewe and lamb gains were lower on the free-range system than on the other systems. The ewe gains were higher on the rotationally grazed areas than the forward creep grazed areas in both experiments. This indicates that forward creep grazing of lambs can be advantageous under conditions where herbage is abundant.Evidence obtained from helminth ova counts on fecal samples, and examination of representative digestive tracts of the lambs marketed, indicated that the forward creep grazing of lambs reduced but did not prevent a build-up of internal parasites.

scholarly journals Pasture herbage mass, quality and growth in response to three whole-farmlet management systems

2013 ◽  
Vol 53 (8) ◽  
pp. 685 ◽  
Author(s):  
L. M. Shakhane ◽  
C. Mulcahy ◽  
J. M. Scott ◽  
G. N. Hinch ◽  
G. E. Donald ◽  
...  
Keyword(s):  
Growth Rate ◽  
Soil Fertility ◽  
Vegetation Index ◽  
Seasonal Pattern ◽  
Ground Cover ◽  
The Other ◽  
Grazing Management ◽  
Management Systems ◽  
Explanatory Factors ◽  
Normalised Difference Vegetation Index

The effects of different whole-farm management systems were explored in a farmlet trial on the Northern Tablelands of New South Wales, Australia, between July 2000 and December 2006. The three systems examined were first, a moderate input farmlet with flexible grazing on eight paddocks considered ‘typical’ of the region (farmlet B), a second, also with flexible grazing on eight paddocks but with a high level of pasture renovation and increased soil fertility (farmlet A) and a third with the same moderate level of inputs as farmlet B but which practised intensive rotational grazing on 37 paddocks (farmlet C). The changes in herbage mass, herbage quality and pasture growth followed a seasonal pattern typical of the Northern Tablelands with generally higher levels recorded over spring–summer and lower levels in autumn–winter but with substantial differences between years due to the variable climate experienced. Over the first 18 months of the trial there were no significant differences between farmlets in total herbage mass. Although the climate was generally drier than average, the differences between farmlets in pasture herbage mass and quality became more evident over the duration of the experiment. After the farmlet treatments started to take effect, the levels of total and dead herbage mass became significantly lower on farmlet A compared with farmlets B and C. In contrast, the levels of green herbage were similar for all farmlets. Throughout most of the study period, pastures on farmlet A with its higher levels of pasture renovation and soil fertility, had significantly higher DM digestibility for both green and dead herbage components compared with pastures on either of the moderate input systems (B and C). Thus, when green herbage mass and quality were combined, farmlet A tended to have higher levels of green digestible herbage than either of the other farmlets, which had similar levels, suggesting that pasture renovation and soil fertility had more effect on the supply of quality pasture than did grazing management. This difference was observed in spite of the higher stocking rate supported by farmlet A after treatments took effect. Levels of legume herbage mass, while generally low due to the dry conditions, were significantly higher on farmlet A compared with the other two farmlets. While ground cover on farmlet A was found to be less than the other farmlets, this was largely associated with the higher level of pasture renovation. Generally, all three farmlets had ground cover levels well above 70% for the duration of the experiment, thus being above levels considered critical for prevention of erosion. A multivariate analysis showed that the main explanatory factors significantly linked (P < 0.01) with the supply of high quality herbage were, in decreasing order of importance, those related to season and weather, pasture renovation, grazing management and soil fertility. Measurements of net pasture growth conducted using a limited number of grazing exclosure cages on three paddocks per farmlet revealed clear seasonal trends but no significant (P > 0.05) differences between farmlets. However, post hoc estimates of potential pasture growth rate using remotely sensed MODIS satellite images of normalised difference vegetation index captured weekly from each farmlet revealed a significant (P < 0.001) relationship with the seasonal pattern observed in the measurements of pasture growth rate.

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