Increased production and cover in a variable native pasture following intensive grazing management

Native pastures account for approximately half the grazing area of the high-rainfall zone of southern Australia and the appropriate intensity of grazing management to improve pasture production and to sustain native species composition is still debated. This paper describes differences in pasture herbage mass, ground cover and composition for a native pasture managed under three distinct grazing-management intensities (1-, 4- and 20-paddock grazing systems). Grazing-management treatments were implemented for 4 years across a variable landscape and the interaction of grazing management and landscape position (high-, medium- and low-production zones) were examined. Increasing the intensity of grazing management (number of paddocks in the grazing system) resulted in higher standing, green and litter herbage mass and ground cover of pastures, with differences most pronounced in the high-production zone where selective grazing was regulated with grazing management. Landscape position largely influenced pasture composition, with higher pasture production and more productive species (e.g. Microlaena stipoides, Lolium rigidum and legumes) in the high-production zone. Small increases in the DM of native perennial grasses and lower levels of legumes and broad-leaf weeds developed in the 20-paddock system compared with grazing in 1- and 4-paddock systems. Net pasture growth was higher in the 20-paddock than 1-paddock treatment during spring in the last 2 years of the experiment, resulting in 21% (1.6 t DM/ha) more herbage mass accumulated over the year. While productivity and cover were higher under intensive rotational grazing, grazing management had little influence on pasture composition. A stable perennial pasture (>70% perennial grasses) stocking rates that were not degrading and the strong influence of landscape on pasture composition limited management influences. Practically, the results indicated that, at the same stocking rate, increasing the intensity of grazing management can increase the average pasture herbage mass, ground cover and pasture growth by more evenly distributing grazing.

Synthesis of system outcomes for a grazing-management experiment in temperate native pastures

Increasing the intensity of grazing management from continuous grazing or set-stocking to intensive rotational grazing has been proposed as a way of improving the profitability and environmental outcomes for native pasture-based grazing systems in the high-rainfall zone (HRZ) of southern Australia. The present paper synthesised the results and outcomes of eight papers covering different aspects of a grazing-system study investigating the intensity of grazing management at Panuara (33°27ʹS, 148°56ʹE), 25 km south-west of Orange, New South Wales. The systems analysis covered soils and soil water, pastures, animal production, profitability and business risk by using a combination of field experiments and biophysical modelling. The experimental approach, engagement with stakeholders and the potential impact of the research outcomes are discussed; as are the future directions for grazing system research. Increasing the intensity of grazing management from a 1- to a 20-paddock system resulted in a 21% higher pasture growth, 22% higher stocking rate and 20% higher lamb production per hectare. However, modelling demonstrated that seasonal variability had a greater impact on profitability than did the management system, and whole-farm profitability of the 20-paddock system was lower than that of the 1- and 4-paddock systems due to higher infrastructure costs. Pasture stability was associated with a high perennial grass content (>70%), and a stocking rate of 4.2 ewes/ha for continuous grazing or 5.3 ewes/ha for intensive rotational grazing limited the potential for degradation events. Advantages were identified in fencing and managing production zones, with different production potential within a farm, to improve utilisation across the landscape and efficiency of fertiliser use. The farming-system approach successfully integrated field research with pre- and post-experimental modelling, and with strategic input from an advisory group containing farmers, researchers and advisors, to develop a full understanding of the impact, at a system level, of increasing the intensity of grazing management in the HRZ.

Effects of three whole-farmlet management systems on Merino ewe fat scores and reproduction

As part of the Cicerone Project’s whole-farmlet experiment on the Northern Tablelands of New South Wales, Australia, the fat scores and reproductive performance of ewes were measured to assess the effect of different management systems on these important production parameters over time. The three farmlets (each of 53 ha) included one (farmlet B) subjected to ‘typical’ district management consisting of moderate levels of inputs and a target stocking rate of 7.5 dse/ha, with flexible grazing management across eight paddocks. A second farmlet (A) was managed in a similar fashion to farmlet B with respect to number of paddocks and grazing management, but modified by high rates of pasture renovation and higher levels of soil fertility, with a target stocking rate of 15 dse/ha. The third farmlet (C) was managed at the same level of moderate inputs as farmlet B but employed intensive rotational grazing over 37 paddocks and also had a high target stocking rate of 15 dse/ha. The experiment was conducted over 6.5 years from July 2000 to December 2006. In spite of the fact that target levels of stocking rate were chosen at the beginning of the experiment, stocking rate, together with fat scores and reproduction were treated as emergent properties of each farmlet system. Joining took place in April–May and lambing occurred in September–October of each year. Over the first 2 years of the experiment, there were few differences among farmlets in ewe fat scores or reproductive performance. From 2003 onwards, while the percentage of ewes pregnant was similar between farmlets, the average proportion of multiple births (ewes scanned in late July, with twins) was 30%, 16% and 12%, respectively, on farmlets A–C. However, lamb losses were greater on farmlet A, with average lamb mortalities recorded on farmlets A–C of 29%, 10% and 19%, respectively. Over the duration of the experiment, ewes on farmlets A and B were more often above a fat score level of 3, and less often below 2.5, than were ewes from farmlet C. Differences among farmlet ewes in fat score were found to be significant in 7 of the total of 13 assessments over the duration of the experiment. A generalised additive model applied to whole-farmlet data showed that green digestible herbage, legume herbage, stocking rate, the amount of supplement fed and especially the proportion of each farmlet grazed at any one time all influenced fat scores of ewes. While fat scores and conception rates tended to be highest on farmlet A, farmlet B had slightly better reproductive outcomes due to less lambing losses, whereas ewes on farmlet C tended to have somewhat lower fat scores and levels of reproduction. These farmlet-scale findings highlighted the importance for livestock managers to focus not only on grazing management, stocking rate and stock density during lambing, but also on the availability of sufficient green, and especially legume herbage, and the difficulty of overcoming a deficit in quality herbage with supplementation.

Economic risk analysis of different livestock management systems

The Cicerone farmlet experiment, conducted on the Northern Tablelands of New South Wales, Australia, explored aspects of profitability and sustainability under three different whole-farmlet management regimes. The 5-year period over which the treatments were measured occurred over a period of generally below-average rainfall, hence responses to management treatments were limited. A modelling approach was used to estimate profitability over a longer period representing the variable climate of the region. A stochastic discounted cash flow model was developed to estimate economic returns of two of the Cicerone management system treatments scaled up from the farmlet scale (53 ha) to the size of a typical commercial farm in the region (920 ha) over a 20-year period. Several scenarios were used to estimate the commercial-scale returns under different rates of pasture improvement and stocking rates. Over the long-term, Farm A was found to be more profitable but also more risky (in terms of variation around the mean of cumulative discounted cash flow) than the ‘typical’ Farm B management system. If livestock managers choose to adopt a pasture improvement strategy based on renovating pastures and increasing soil fertility, they are more likely to achieve higher net worth with more moderate rates of pasture improvement than those explored on Farm A where a high rate of pasture improvement had been implemented in order to quickly differentiate treatments.

Estimating the balance between pasture feed supply and demand of grazing livestock in a farmlet experiment

Data from the Cicerone farmlet study were used to quantify the balance between pasture feed supply and the demand from grazing livestock, in terms of metabolisable energy (ME), on three differently managed farmlets (each of 53 ha) on the Northern Tablelands of New South Wales, Australia. Farmlet A had a high level of pasture renovation and higher soil fertility than the other two farmlets and employed flexible grazing management over eight paddocks. Farmlet B was designed to represent management ‘typical’ of the region and had the same grazing management and number of paddocks as farmlet A but moderate levels of pasture renovation and soil fertility. The third farmlet (C) had the same level of inputs as farmlet B but practised intensive rotational grazing over 37 paddocks. Regular measurements of the feed supply, namely herbage mass and quality, pasture growth and supplement fed and of feed demand were assembled to provide monthly estimates of the balance between feed supply and animal demand of all classes of livestock run on the experiment over its duration of 6.5 years. The significantly greater stocking rate, liveweight and reproductive rate of sheep reached on the higher input system (farmlet A) meant higher levels of ME were required to satisfy the nutritional demands of these animals. As only limited measurements were taken of animal intake, it was assumed that the supply of ME was derived from pasture growth and supplement fed. Using key livestock management dates and measurements of liveweights, the changes in the energy requirements of each class of animal were calculated and aggregated to provide an estimate of overall livestock energy demand over time. Subtracting the energy demand from the estimated energy supply provided a partial net energy balance. Measurements of the rates of change of green herbage during grazing events were found to be highly dependent on stock density with farmlets A, B and C recording rates of change of up to –50, –30 and –200 green DM/ha.day, respectively. Over a series of generally drier-than-average years, the ME supplied in pasture growth and through supplementation was at times inadequate to meet the energy demands of the livestock, resulting in periods during winter when the partial energy balance became negative. Similar feed deficits were observed for all three farmlets, suggesting that they were over-stocked to a similar extent. In spite of the divergence in the stocking rate supported by each farmlet, the similarity of the ME balances between farmlets suggests that no farmlet was subjected to bias because of decisions relating to feed supply and demand. The analyses presented suggest there is considerable potential for practical paddock and grazing management to be improved if more timely and regular assessments can be made of changes in the feed energy supply using satellite images of normalised difference vegetation indices and feed energy demand using calculations of the ME required by grazing livestock.

Optimising pasture and grazing management decisions on the Cicerone Project farmlets over variable time horizons

This study addresses the problem of balancing the trade-offs between the need for animal production, profit, and the goal of achieving persistence of desirable species within grazing systems. The bioeconomic framework applied in this study takes into account the impact of climate risk and the management of pastures and grazing rules on the botanical composition of the pasture resource, a factor that impacts on livestock production and economic returns over time. The framework establishes the links between inputs, the state of the pasture resource and outputs, to identify optimal pasture development strategies. The analysis is based on the application of a dynamic pasture resource development simulation model within a seasonal stochastic dynamic programming framework. This enables the derivation of optimum decisions within complex grazing enterprises, over both short-term tactical (such as grazing rest) and long-term strategic (such as pasture renovation) time frames and under climatic uncertainty. The simulation model is parameterised using data and systems from the Cicerone Project farmlet experiment. Results indicate that the strategic decision of pasture renovation should only be considered when pastures are in a severely degraded state, whereas the tactical use of grazing rest or low stocking rates should be considered as the most profitable means of maintaining adequate proportions of desirable species within a pasture sward. The optimal stocking rates identified reflected a pattern which may best be described as a seasonal saving and consumption cycle. The optimal tactical and strategic decisions at different pasture states, based on biomass and species composition, varies both between seasons and in response to the imposed soil fertility regime. Implications of these findings at the whole-farm level are discussed in the context of the Cicerone Project farmlets.

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

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.

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

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.

Simulating the impact of fertiliser strategies and prices on the economics of developing and managing the Cicerone Project farmlets under climatic uncertainty

The application of fertilisers to pastures in the high rainfall regions of southern Australia has contributed to large increases in carrying capacity following the widespread adoption of the practice since the late 1940s. Recently, large shifts in the worldwide demand for fertiliser inputs have lead to large rises in the cost of fertiliser inputs. These increasing costs have significant potential ramifications on the future management of soil fertility and its interaction with the persistence and profitability of sown pastures, especially during periods of climatic uncertainty. A dynamic pasture resource development simulation model was used to investigate the implications of fertiliser rates and costs on the efficient management of soil fertility under climatic uncertainty. The framework also allowed the investigation of how the management of soil fertility interacts with the utilisation of pasture resources through different stocking rates. In the application of this method to the Cicerone Project farmlets case study, fertiliser input costs were found to influence the optimal combination of fertiliser inputs and stocking rate. Analyses of the dynamic interaction between fertiliser application and cost, stocking rate and the persistence of desirable species enabled the identification of the most risk-efficient strategies. The implications for grazing industries in the high rainfall regions of southern Australia are discussed.

Whole-farm returns show true profitability of three different livestock management systems

On the New South Wales Northern Tablelands, sheep, wool and beef cattle production account for most agricultural output. The industries have been challenged in recent years by environmental and economic factors and are therefore looking for modified or alternative livestock management systems that are capable of sustaining profitability. The Cicerone Project aimed to address these issues by comparing three different grazing and pasture improvement systems. Some recent livestock industry analyses have been based on gross margins which do not include overhead costs. This is an important limitation; economic analysis needs to report key whole-farm business performance measures since overhead costs can differ significantly between livestock management systems. A representative farm approach was used to compare the profitability of the three different livestock management systems. Commercial-scale whole-farm and cash flow analyses over a 5-year period were used to evaluate profitability. No particular system could be recommended to graziers because the test period was not sufficiently representative of the long-term climate to make an adequate assessment about their long-term profitability. Nevertheless, it is apparent that whole-farm level budgets are essential for comparing the overall profitability of different livestock management systems. It is concluded that analysts, consultants and graziers should use whole-farm and cash flow analyses to gauge profitability of different livestock management systems particularly where sustainability issues are important.

Integrated overview of results from a farmlet experiment which compared the effects of pasture inputs and grazing management on profitability and sustainability

The Cicerone Project conducted a grazed farmlet experiment on the Northern Tablelands of New South Wales, Australia, from July 2000 to December 2006, to address questions raised by local graziers concerning how they might improve the profitability and sustainability of their grazing enterprises. This unreplicated experiment examined three management systems at a whole-farmlet scale. The control farmlet (farmlet B) represented typical management for the region, with flexible rotational grazing and moderate inputs. A second farmlet (farmlet A) also used flexible rotational grazing but had a higher level of pasture renovation and soil fertility, while the third farmlet (farmlet C) had the same moderate inputs as farmlet B but employed intensive rotational grazing. The present paper provides an integrated overview of the results collated from component papers and discusses the inferences that can be drawn from what was a complex, agroecosystem experiment. The measurements recorded both early and late in the experiment were tabulated for each of the farmlets and compared with each other as relative proportions, allowing visual presentation on a common, indexed scale. Because of equivalent starting conditions, there was little difference between farmlets early in the experimental period (2000–01) across a wide array of measured parameters, including herbage mass, potential pasture growth rate, liveweight, wool production per head, stocking rate, gross margin and equity. Although the experiment experienced drier-than-average conditions, marked differences emerged among farmlets over time, due to the effects of treatments. During the latter half of the experimental period (2003–06), farmlet A showed numerous positive and a few negative consequences of the higher rate of pasture renovation and increased soil fertility compared with the other two farmlets. While intensive rotational grazing resulted in superior control of gastrointestinal nematodes and slightly finer wool, this system had few effects on pastures and no positive effects on sheep liveweights, wool production or stocking rate. Whereas farmlet A showed higher gross margins, it had a negative and lower short-term cash position than did farmlets B and C, due largely to the artificially high rate of pasture renovation undertaken on this farmlet during the experiment. Although farmlet B had the highest cash position at the end of the experiment, this came at a cost of the declining quality of its pastures. Modelling of the farmlet systems allowed the results to be considered over the longer timeframes needed to assess sustainability. Thus, returns on investment were compared over realistic amortisation periods and produced outcomes based on long-term climatic expectations which were compared with those that arose under the drier-than-average conditions experienced during the experimental period. The main factors responsible for lifting the productivity of farmlet A were the sowing of temperate species and increased soil fertility, which enhanced the amount of legume and increased pasture quality and potential pasture growth. The factor that affected farmlet C most was the low proportion of the farmlet grazed at any one time, with high stock density imposed during grazing, which decreased feed intake quality. The paper concludes that more profitable and sustainable outcomes are most likely to arise from grazing enterprises that are proactively managed towards optimal outcomes by maintaining sufficient desirable perennial grasses with adequate legume content, enhancing soil fertility and employing flexible rotational grazing.

Comparing the climate experienced during the Cicerone farmlet experiment against the climatic record

Farming systems research conducted under dryland conditions is subject to the vagaries of the climate during the experimental period. Whether such an experiment experiences a representative series of climatic years must be examined in relation to the longer term climatic record. The Cicerone Project’s farmlet experiment was conducted on the Northern Tablelands of New South Wales, Australia, to investigate the profitability and sustainability of three different management systems: one managed under typical, moderate-input conditions (farmlet B); a second which employed a higher level of pasture inputs and soil fertility (farmlet A); and a third which focussed on the use of moderate inputs and intensive rotational grazing (farmlet C). The climate experienced during the 6.5-year experimental period was compared with the 118-year climatic record, using a biophysical simulation model of grazed systems. The model utilised the long-term daily climate data as inputs and provided outputs that allowed comparison of parameters known to affect grazed pastures. Modelled soil-available water, the number of soil moisture stress days (SMSDs) limiting pasture growth, and growth indices over the experimental period (2000–06) were compared with data over the climatic record from 1890 to 2007. SMSDs were defined as when the modelled available soil moisture to a depth of 300 mm was <17% of water-holding capacity. In addition, minimum temperatures and, in particular, the frequency of frosts, were compared with medium-term (1981–2011) temperature records. Wavelet transforms of rainfall and modelled available soil water data were used to separate profile features of these parameters from the noise components of the data. Over the experimental period, both rainfall and available soil water were more commonly significantly below than above the 95% confidence intervals of both parameters. In addition, there was an increased frequency of severe frosting during the dry winters experienced over the 6.5-year period. These dry and cold conditions were likely to have limited the responses to the pasture and grazing management treatments imposed on the three farmlets. In particular, lower than average levels of available soil water were likely to have constrained pasture production, threatened pasture persistence, and reduced the response of the pasture to available soil nutrients and, as a consequence, livestock production and economic outcomes. Ideally, dryland field experimentation should be conducted over a representative range of climatic conditions, including soil moisture conditions both drier and wetter than average. The drier than average conditions, combined with a higher than normal frequency of severe frosts, mean that the results from the Cicerone Project’s farmlet experiment need to be viewed in the context of the climate experienced over this 6.5-year period.

Whole-farm management of soil nutrients drives productive grazing systems: the Cicerone farmlet experiment confirms earlier research

The Cicerone Project included a study of three 53-ha farmlets, each subjected to a different management system. The systems varied first in their input of fertilisers and sown pastures and second in their grazing management. Farmlet A undertook a high level of pasture renovation and had soil fertility targets of 60 mg/kg Colwell phosphorus (P) and 10 mg/kg KCl-40 sulfur (S), while farmlets B and C both had a low rate of pasture renovation and targets of 20 mg/kg P and 6.5 mg/kg S. In addition, both farmlets A and B adopted a flexible rotational grazing regime over the eight paddocks of each farmlet, whereas farmlet C, which had 37 paddocks, adopted intensive rotational grazing. This paper first reviews the literature relating to soil fertility research in the summer-dominant rainfall region of the Northern Tablelands of New South Wales, Australia. It then examines whether the soil fertility targets set for the farmlets were attained and how the consequences of fertiliser management measured in this trial related to earlier research findings. Fertiliser applications, comprising both capital and maintenance rates, were based on soil test results but at times were constrained by the availability of finance. Soil tests over 5 years indicated that only nitrogen (N), P and S varied with time within the farmlets while the other indices of soil fertility remained similar. Phosphorus and S levels increased in response to fertiliser applications whereas N levels responded to increases in legume composition, which was stimulated by the higher P and S levels. Multivariate statistical analyses demonstrated that farmlet productivity was driven by P and S fertility and thus the two farmlets with lower P and S fertility (farmlets B and C) had similar but lower levels of farmlet productivity compared with farmlet A. Significant increases in several measured pasture productivity parameters were observed in response to the higher P and S fertility on farmlet A, especially when climatic conditions were favourable. The results of the Cicerone farmlet experiment confirm the findings of earlier research on the Northern Tablelands, and elsewhere in the high rainfall zone, that has demonstrated that higher soil fertility levels and pasture renovation enhance the productivity of grazing enterprises more than grazing management, without imposing significant risks to the environment.

Selection of experimental treatments, methods used and evolution of management guidelines for comparing and measuring three grazed farmlet systems

The Cicerone Project was a collaborative effort by livestock producers, researchers and extension specialists, which aimed to explore the profitability and sustainability of grazing enterprises on the Northern Tablelands of New South Wales, Australia. A major part of the Project was the creation of a moderate scale, unreplicated farmlet experiment. The process of selecting the farmlet treatments and the design of the experiment involved considerable negotiation over an extended period in order to achieve ‘ownership’ by all those involved. The farmlets were designed to compare a typical farmlet (B) as the control with a second farmlet (A), which received higher levels of pasture renovation and soil fertility, and a third (C), which employed intensive rotational grazing management with short graze and long rest periods. Management guidelines were developed for all soil, pasture, livestock and grazing management decisions on the three farmlets. Whole-farmlet data are presented for the pastures sown, fertiliser applied, supplement fed, the stocking rates attained and the pattern of graze and rest periods over the experimental period from July 2000 to December 2006. Over the first 4 years of the trial, pastures were renovated on 71% of farmlet A while 8% of each of farmlets B and C were renovated. The rates of fertiliser applied to the three farmlets varied according to soil test values and the different target values for soil phosphorus and sulfur. In the first year of the trial (2000–01), the annual average stocking rates on farmlets A, B and C were 9.5, 7.9 and 9.1 dry sheep eqivalents/ha, respectively, whereas by the fifth year (2005), the stocking rates were 11.2, 7.8 and 7.4 dry sheep equivalents/ha, respectively. This paper provides details of the general methods used in the farmlet trial, of relevance to a series of related papers which explore all aspects of the farmlet experiment and its findings. It also reports on the selection and definition of the farmlet treatments and describes how the guidelines evolved over the duration of the trial in response to the practical realities of conducting this complex, agroecosystem experiment.

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

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.

Livestock weights in response to three whole-farmlet management systems

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.

Reflections on the concept, conduct and findings of the producer-led Cicerone Project

The Cicerone Project began as a producer-led partnership that sought, over a period of 8 years, to enhance the profitability and sustainability of livestock enterprises by improving the connection between those producers, research and extension. Following a detailed survey, the research and extension needs of livestock producers were identified and several applied investigations were conducted to meet those needs and delivered through a range of extension activities. This final paper of the Cicerone Special Issue reflects on the entire Project from a wide array of perspectives, including livestock producers, researchers, extension specialists and staff employed by the Project, all of whom are authors of this paper. A notable early successful outcome of the Project was the improved precision of footrot diagnosis, which has been of value to the entire sheep industry, and that flowed from a field investigation of benign and virulent footrot combined with detailed genetic investigations, which led to an improved testing regime. This paper also reflects on the findings of an unreplicated agricultural ecosystem research trial, which measured the impact of pasture renovation, increased soil fertility and grazing management on the profitability and sustainability of three different 53-ha farmlets. Valuable findings from this whole-farmlet trial included the need for a high quality feed supply for increasing stocking rate and animal liveweights; the ability and utility of satellite imagery to detect changes in pasture growth, composition and recent grazing pressure; the value of short grazing and long rest periods for controlling Barber’s pole worms of sheep; the impact of increased stocking rates on whole-farm profitability and risk; methods of optimising decisions relating to pasture renovation, fertiliser applications and grazing management; and an integrated analysis of all key measured components of the farmlet management systems. Collectively, these findings were powerful as they were demonstrated at a scale credible to livestock producers using the ‘compare – measure – learn – adopt’ approach, which was the key philosophy adopted by the Cicerone Project. By comparing and measuring different whole-farm systems, and by ensuring that producers had ownership of the trial process, the Project successfully delivered objective findings that producers trusted and which increased our understanding of important drivers of complex grazing enterprises under variable climatic conditions. Some of these drivers included: the influence of soil phosphorus on botanical composition and subsequent livestock production, the role of pasture renovation and soil fertility on herbage supply, herbage quality and stocking rate, and the improved gastrointestinal nematode control delivered by intensive rotational grazing. The beneficiaries of the Project included the 180 farmer members who participated in some 61 field days and workshops; the research and extension collaborators including four postgraduates who completed their research investigations in conjunction with the Project; and some 500 undergraduate and 300 technical students who benefited from coming to understand the applied field comparisons of the three whole-farmlet systems. Having livestock producers play a significant leadership role led to valuable outcomes achieved with research collaborators; this should encourage the development of other learning partnerships which aim to explore complex farming system issues.

Delivering extension and adult learning outcomes from the Cicerone Project by ‘comparing, measuring, learning and adopting'

The Cicerone Project was a partnership between livestock producers, researchers and extension specialists on the Northern Tablelands of New South Wales, Australia that investigated several complex grazing enterprise issues between 1998 and 2006. It was conducted as a Participatory Action Research project, which first surveyed livestock producers to learn of their problems and then carried out investigations according to the Project’s chosen motto of ‘compare – measure – learn – adopt’. The Project included research into footrot diagnosis and an investigation of whole-farmlet livestock and pasture management systems complemented by a multi-faceted extension and education component, which delivered findings to a wide array of stakeholders across the Northern Tablelands and adjacent regions. This paper describes the extension and education methods and outcomes and reflects on how successful the engagement of livestock producers was through a partnership, which focussed on co-learning by all participants. Several different communication approaches were used including the production of 40 newsletters and the delivery of 61 field days. Collaborators also held two symposia, which presented comprehensive overviews of the research results. In the final year of the Project, a roadshow was held to communicate results to a wider audience in neighbouring districts. The results of the two footrot trials, which were conducted as Participatory Action Research projects, led to rapid and substantial changes in the testing regime for virulent footrot, resulting in large savings for livestock producers through more accurate detection of the disease. Other valued extension and industry outcomes were the ability to compare the biophysical and economic performance of different whole farmlets, an appreciation of the value of the whole-farm system approach, the trustworthiness of the results and the stimulation of livestock producers to think more deeply about their management systems, stocking rate and risk. The Project benefited from the research efforts of four postgraduate students and was of benefit to ~300 high school and technical college students and also some 500 university undergraduate students who undertook learning projects in conjunction with Project members and collaborators. This Special Issue of 24 journal papers represents a substantial delivery of the findings from this complex agroecosystem Project, which broke new ground in terms of securing much closer working relationships between livestock producers, scientists and extension specialists. Ultimately, this volume will allow extension of the results of the Cicerone Project to reach a wider audience than has typically been achieved through other Participatory Action Research projects.