Karl Behrendt

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.

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.

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.

Methodology for assessing optimal rates of pasture improvement in the high rainfall temperate pasture zone

Pasture improvement is a well-established technology for increasing production in extensive livestock grazing industries by changing pasture composition and increasing soil fertility. The Cicerone Project farmlets located at Chiswick Research Station, near Armidale in New South Wales, are providing valuable information at a credible scale on the response to 3 different management systems varying in levels of inputs and grazing management. The purpose of this paper is to outline a methodology for assessing farmlet performance in such studies. The assessment focuses on the stochastic efficiency of the different treatments. The impact of pasture persistence, climatic risk, and stochastic commodity prices on optimal rates of farm development are explored by using preliminary data from the Cicerone farmlets to calibrate the GrassGro model. The farmlets modelled represent 2 technology packages. One is a moderate-input package and the other is a high-input package. Preliminary analysis indicates that direct comparison of the 2 farmlets may produce the wrong assessment, because 1 farmlet is operating at a suboptimal level of efficiency in a stochastic sense. This means that direct comparisons of technologies based on the field data may be biased as the technologies should be evaluated at the risk-efficient frontier. The concept of a risk efficient frontier is explained and applied to aid in identifying the trade-offs between profit and risk, and identify differences in the efficiency of the 2 farmlets.

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.

Assessing the profitability of native pasture grazing systems: A stochastic whole-farm modelling approach

Grazing enterprises on the Central Tablelands of New South Wales employ a range of different strategies to manage temperate native grassland pastures common in the high rainfall zone of southern Australia. This paper uses a stochastic whole-farm simulation modelling approach to assess the impact of grazing system and stocking rate (SR) on the long-term profitability of a representative case-study enterprise. In particular, the impact of infrastructure costs, debt and downside risk, on whole-farm performance are examined over a 10-year planning horizon. In total, 12 different strategies were modelled under both price and climate risk, with a matrix of three paddock systems (1-paddock, 4-paddock and 20-paddock rotations) and four stocking rates (SR of 3, 4.2, 5.3 and 7 ewes/ha). Profitability was primarily driven by SR. In general, higher SR increased total farm output and annual profits under favourable conditions, although they were also associated with higher costs and greater downside risk in poor seasons, which in turn was magnified by the compounding effect of accumulating debt over time. When SR increased above 4.2 ewes/ha, it had a negative impact on lamb sale weights, resulting in lower prices due to lambs not meeting the ≥40-kg liveweight specification. Although this was offset by increased whole-farm production volumes at 5.3 ewes/ha, declines in profitability occurred at 7 ewes/ha as a result of significant increases in supplement feeding costs, and lambs not meeting sale weight specifications. The analytical scale of the analysis also had an impact on the relative profitability between alternative treatments. When assessed using a partial measure of economic analysis (gross margin per ha), there was little difference between paddock system treatments at the same SR. When the cost of additional fencing and water infrastructure were accounted for at the whole-farm analytical scale, the 20 paddock system was markedly less profitable than the 1- and 4-paddock rotations. This highlights the need for assessing production systems at an appropriate analytical and temporal scale to better understand the relationship between the key drivers of long-term profitability and risk. Overall there were relatively small differences in whole-farm performance between the four best performing strategies in this study. Given the trade-offs between profitability, downside risk, ground cover and feedbase sustainability, the lower risk 1- and 4-paddock systems with a SR of 4.2 ewes/ha are proposed as being optimal.

Price risk exposure of Australian Merinos – is it in the bloodline?

Sheep producers and their advisors utilise Australian Merino bloodline trial data to guide future sheep breeding objectives and ram selection. To adequately assess the economic outcomes from different bloodlines in the decision making process, there is a need to consider the impact of wool and sheep meat price risk. Using a steady-state wether flock model that accounts for the lifetime productivity of 268 reported Merino bloodlines and stochastic dependency in weekly wool and sheep meat prices from 28 June 2005 to 10 November 2011, gross incomes per dry sheep equivalent (GI/DSE) were calculated for a weekly time step. The analysis found that across all bloodlines and market price scenarios, GI/DSE ranged between AU

Analysis of agribusiness value chains servicing small-holder dairy farming communities in Punjab, Pakistan: three case studies

13.92 and AU

Seed contamination in sheep: new investigations into an old problem

67.83, with an overall mean of AU

Identifying management strategies to improve sustainability and household income for herders on the desert steppe in Inner Mongolia, China

32.60. The individual means of bloodlines across the time series ranged from AU