Demonstrating recovery of pasture productivity, Mulga Lands - Bollon, South West Queensland

Pasture recovery PDS, Mulga lands

Re-defining the animal unit equivalence (AE) for grazing ruminants and its application for determining forage intake, with particular relevance to the northern Australian grazing industries

The adult equivalent (AE) system describes and quantifies, in commonly recognised units, the grazing pressure imposed on the pasture by foraging ruminants. The AE rank assigned to an animal is determined as the ratio of its (metabolisable) energy (ME) requirements relative to that of a ‘standard animal’, where ME requirements are usually determined using the feeding standards. Previous research has indicated that the Australian feeding standards (NRDR 2007) considerably over-estimated the energy requirements of cattle consuming tropical forages in northern Australia. In the current project, modifications were made to the equations of the feeding standards which improved predictions of ME, and so also forage dry matter (DM) intake by cattle. However, these changes were not tested with cattle in temperate regions, or sheep in any region meaning that two systems, one using modified and the other unmodified equations, were required to accommodate this regional demarcation. Simulations carried out using cattle growth data from northern Australia showed that the estimate of AE score was similar using either system providing they were used systematically. Furthermore, it was found that the forage intake predicted by direct calculation using the modified system could be closely matched by calculating an AE rank using the unmodified system and then multiplying this rank by an intake constant. The optimum intake constant fluctuated with regional variations in animal productivity. This agreement between predictions suggested that, for most circumstances, the existing (unmodified) feeding standards could be used across regional boundaries. Recommendations are made for application of the revised animal unit systems to practical grazing scenarios and forms the basis of revising current EDGE (NutritionEDGE) material

Biodiversity condition assessment for grazing lands

Using the ABCD Framework as a aurrogate for biodiversity condition

A comparison of rehabilitated coal mine soil and unmined soil supporting grazed pastures in south-east Queensland

Land that is disturbed by mining activities is required to undergo suitable rehabilitation. This study compared soils supporting grazed pasture on land that was rehabilitated after coal mining activity with that on unmined land. Pasture biomass, and soil physical and chemical properties important for pasture production and sustainability were intensively monitored on three sites that had completed rehabilitation at different times over the last 10 years, and one unmined control site. A further 18 unmined grazing sites were monitored for benchmarking purposes. Analysis of soil properties of plant available phosphorus and nitrogen, salinity and sodicity in the first year of the study suggested little difference in terms of benefits or constraints to pasture production between the rehabilitated and control sites. Plant-available phosphorus was sufficiently high in the two oldest rehabilitated sites that a fertiliser response would not be expected. Soil depth and the pasture rooting depth at the rehabilitated sites were at the shallow end of the wide range observed across the benchmark and control sites. Higher pasture biomass at the rehabilitated sites compared with the control at the initiation of the trial was attributed more to differences in grazing history than differences in soil attributes

Review of productivity decline in sown grass pastures

Productivity decline in sown grass pastures is widespread in northern Australia and reduces production by approximately 50%, a farm gate cost to industry of > $17B over the next 30 years. Buffel grass is the most widely established sown species (>75% of plantings) and has been estimated to be “dominant” on 5.8 M hectares and “common” on a further 25.9 M hectares of Queensland. Legumes are the most cost effective mitigation option and can reclaim 30-50% of lost production. Commercial use of legumes has achieved mixed results with notable successes but many failures. There is significant opportunity to improve commercial results from legumes using existing technologies, however there is a need for targeted research to improve the reliability of establishment and productivity of legumes. This review recommends the grazing industry invest in targeted R,D&E to assist industry in improving production and sustainability of rundown pastures

Assessing the value of trees in sustainable grazing systems

The retention of trees in strips provides an option for managing non-remnant woody vegetation in native and sown pastures in northern Australia. However, the impact of tree strips on pasture production has not been previously researched in detail in southern Queensland. The influence of existing tree strips on pasture production in southern Queensland was measured at three grazing properties during 2004 and 2005. Soil and pasture attributes were sampled along transects 80 to 300 metres in length positioned perpendicular to tree strips. The tree strips ranged from 15 to 75 metres wide and were 120 to 500 metres apart. The effects of tree strips along the pasture transect were quantified in terms of pasture microclimate (e.g. temperature, humidity and, at one location, wind), pasture growth in grazed and exclosed situations, soil water, soil nutrients and condition, and nutrient availability. An experimental approach using exclosed pasture transects provided a useful ‘bioassay’ potentially integrating beneficial and competitive effects of tree strips on pasture growth as well as other factors (e.g. soil variability). Averaged across two locations and two years, the competitive effects of the tree strip were compensated to some extent by enhanced pasture growth at distances of 1-6 x tree height from the tree strip edge. However, the observed effects on pasture growth along the transect were likely to be due to different causes: pasture microclimate at one site, soil texture and microtopography at a second site and pasture establishment history at a third site. Thus, the trial highlighted the difficulty of attributing effects in real-world situations, given the number of possible causes including the tree strip effects on pasture microclimate and nutrient availability, soil surface disturbance, and systematic variation on soil and water redistribution due to soil micro-topography and felled timber. Despite these many sources of variation, general effects were derived from the field data consistent with other studies on tree strips and wind breaks across Australia. To extrapolate the project results to other locations, tree strip configurations and climates, a new version of the soil waterpasture growth simulation model GRASP was developed allowing simulation of tree and pasture effects and processes for various distances along a pasture transect perpendicular from the tree strip

Review of productivity decline in sown grass pastures

Productivity decline in sown grass pastures is widespread in northern Australia and reduces production by approximately 50%, a farm gate cost to industry of > $17B over the next 30 years. Buffel grass is the most widely established sown species (>75% of plantings) and has been estimated to be “dominant” on 5.8 M hectares and “common” on a further 25.9 M hectares of Queensland. Legumes are the most cost effective mitigation option and can reclaim 30-50% of lost production. Commercial use of legumes has achieved mixed results with notable successes but many failures. There is significant opportunity to improve commercial results from legumes using existing technologies, however there is a need for targeted research to improve the reliability of establishment and productivity of legumes. This review recommends the grazing industry invest in targeted R,D&E to assist industry in improving production and sustainability of rundown pastures

The potential for a rehabilitated coal mine soil to support livestock grazing in south-east Queensland

Land that is disturbed by mining activities is required to be suitably rehabilitated. A trial was initiated to compare the performance of livestock grazing pasture sown on land that was rehabilitated after coal mining activity with that of livestock grazing pasture on unmined land. Pasture biomass, and soil structural, nutritional and hydrological properties important for pasture production and sustainability were intensively monitored on three sites rehabilitated at different stages over the last 10 years, and one unmined Control site. A further 18 unmined grazing sites were monitored for benchmarking purposes. Preliminary results for soil ammonium, nitrate and potentially mineralisable nitrogen suggest little difference in terms of benefits or constraints to pasture production between the rehabilitated and Control sites. Plant-available phosphorus was sufficiently high in the two oldest rehabilitated sites that a fertiliser response would not be expected. Subsoil and rooting depth of the rehabilitated sites was within the range observed across the benchmark sites and shallower than in the Control site. Higher pasture biomass in the rehabilitated sites compared with the Control at the initiation of the trial was attributed more-so to differences in grazing history than differences in soil attributes. Analysis of year one monitoring data is ongoing

Systematic review of methods used in meta-analyses where a primary outcome is an adverse or unintended event

addresses: Peninsula College of Medicine and Dentistry, St Luke's Campus, University of Exeter, Exeter, UK. [email protected]: PMCID: PMC3528446types: Journal Article; Research Support, Non-U.S. Gov't© 2012 Warren et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Adverse consequences of medical interventions are a source of concern, but clinical trials may lack power to detect elevated rates of such events, while observational studies have inherent limitations. Meta-analysis allows the combination of individual studies, which can increase power and provide stronger evidence relating to adverse events. However, meta-analysis of adverse events has associated methodological challenges. The aim of this study was to systematically identify and review the methodology used in meta-analyses where a primary outcome is an adverse or unintended event, following a therapeutic intervention