Pasture dieback: Past activities and current situation across Queensland (2017).

Over the last 5 years (2012-17), an increasing area of grass pastures, both sown and native, have been dying in patches across multiple districts in eastern Queensland. Symptoms are the same or similar to buffel grass dieback that was first observed in the early 1990’s, that is yellowing and reddening of leaves, stunting and eventual death. Once the pasture has died, the area is typically colonised by a range of broadleaf plants, including weeds, small shrubs, legumes or other (generally undesirable) grasses. Graziers with pastures impacted by this condition have grave concerns about the progressive destruction of pastures, and are looking for answers to ensure the long-term profitability of businesses. The term ‘dieback’ has been used to describe a range of conditions with unrelated causal agents across a broad range of plant types, including trees, shrubs, legumes and grass pastures. While an array of literature has been published about dieback in plant communities, there are relatively few publications specifically outlining dieback in pasture systems utilised by grazing animals (beef and dairy cattle, sheep). A range of pathogens have been identified as causes of dieback in other plants, including fungal root and leaf diseases, and a range of these have been isolated from plant samples affected by pasture dieback in central Queensland. Recent plant testing, and past research including a PhD study, have been unable to determine the causal agent or define the contributing factor(s) of dieback in central Queensland pastures. It is possible that the condition is a complex interaction of multiple contributing factors, for example plant pathogens, insects, soil fertility and moisture stress. Approximately 120 landholders have reported pasture dieback on their properties, and about 35,000ha of pastures are known to be affected, spanning from south-east Queensland, Burnett, central Queensland, Mackay/Whitsunday and North Queensland (as of July 2017). While the entire 35,000ha is not completely affected as generally patches of pasture are affected across this area, the actual area affected is likely to be significantly higher than this due to not all reports being captured by Department of Agriculture and Fisheries staff and other industry organisations. Also, many graziers are unfamiliar with the disease and therefore don’t realise they have pasture dieback, and anecdotal reports indicate some graziers are reluctant to tell authorities they have the disease due to biosecurity concerns, or the potential of land de-valuation by banks. The development and funding of a research project to investigate pasture dieback is a high priority, due to the rapidly expanding area of affected pastures across Queensland being reported and the uncertainty of the cause. There has been relatively little research on pasture dieback in the past compared to the value of the sown grasses being affected. Past research relied on modest budgets, focussed on only a few sites and did not investigate all the possible causal agents. Future research needs to build on past studies where possible, however a coordinated, systematic approach using a multi-disciplinary team is required to provide a better chance of determining what the causal agent(s) are and what the best management practices are likely to be. In total, five priorities for future research, development and extension have been identified. These include: 1. Understanding the extent of the condition, now and into the future; 2. Determining specific details of outbreaks and commonalities across sites; 3 Determining causal factor(s); 4. Determining management solutions; 5. Engaging with industry. Currently, such as proposal that addresses these priorities is under consideration by Meat and Livestock Australia (MLA)

Fertilising for yield and quality in sown grass pastures and forage crops

Sown pasture rundown and declining soil fertility for forage crops are too serious to ignore with losses in beef production of up to 50% across Queensland. The feasibility of using strategic applications of nitrogen (N) fertiliser to address these losses was assessed by analysing a series of scenarios using data drawn from published studies, local fertiliser trials and expert opinion. While N fertilser can dramatically increase productivity (growth, feed quality and beef production gains of over 200% in some scenarios), the estimated economic benefits, derived from paddock level enterprise budgets for a fattening operation, were much more modest. In the best-performing sown grass scenarios, average gross margins were doubled or tripled at the assumed fertiliser response rates, and internal rates of return of up to 11% were achieved. Using fertiliser on forage sorghum or oats was a much less attractive option and, under the paddock level analysis and assumptions used, forages struggled to be profitable even on fertile sites with no fertiliser input. The economics of nitrogen fertilising on grass pasture were sensitive to the assumed response rates in both pasture growth and liveweight gain. Consequently, targeted research is proposed to re-assess the responses used in this analysis, which are largely based on research 25-40 years ago when soils were generally more fertile and pastures less rundown

Feeding forages in the Fitzroy : A guide to profitable beef production in the Fitzroy River catchment

This guide brings together information on: • selection, agronomy and management of suitable forages • example forage yields across the Fitzroy River catchment • expected nutrient content of forages and their relationship to cattle performance • indicative cattle growth rates from a range of high quality forages • approaches to incorporating high quality forages into feed plans to give the best opportunity to achieve the target growth rates and liveweights required to meet market specifications • non-nutritional factors that can affect liveweight gain • example gross margin analysis at key sites across the catchment to provide objective comparisons of various forage options • spreadsheets to allow calculation of forage gross margins with the user’s own input variables • the effect of sown forages on the whole farm profitability • data collected from 24 producer co-operator forage sites across the Fitzroy River catchment during 2011–2014

Productivity and profitability of forage options for beef production in the subtropics of northern Australia

This study measured forage biomass production, diet quality, cattle liveweight gain, and economic performance of six forage types at 21 sites across 12 commercial beef cattle properties in the Fitzroy River catchment of Queensland during 2011–2014 (28 annual datasets in total). The forages were annual forage crops (oats (Avena sativa), sorghum (Sorghum spp.) and lablab (Lablab purpureus)), sown perennial legume-grass pastures (leucaena-grass (Leucaena leucocephala spp. glabrata + perennial, tropical grass (C4) species) and butterfly peagrass (Clitoria ternatea + perennial, C4, grass species)), and perennial, C4, grass pastures. The sown forages resulted in 1.2–2.6 times the annual cattle liveweight gain per ha than perennial grass pastures. Annual cattle liveweight gain per ha, forage establishment and management costs, and cattle price margin (sale price less purchase price, $/kg liveweight) all influenced gross margin, however, none was an overriding factor. The average gross margins ($/ha. annum) calculated using contractor rates, ranked from highest to lowest, were: leucaena-grass pastures, 181; butterfly pea-grass pastures, 140; oats, 102; perennial grass, 96; sorghum, 24; and lablab, 18. It was concluded that the tendency towards greater average gross margins for perennial legume-grass pastures than for annual forage crops or perennial grass pastures was the result of the combined effects of lower average forage costs and high cattle productivity

Adoption, profitability and future of leucaena feeding systems in Australia

Leucaena (Leucaena leucocephala ssp. glabrata) is a highly palatable and productive forage used mainly by beef producers on extensive properties in northern Australia. When sown into native or sown grass pastures, leucaena provides significant production, economic, environmental and social benefits. Adoption of leucaena was slow initially due to a range of technical, agronomic and landscape factors. These have now been largely overcome through extensive research, development, producer experience and other advances, resulting in around 130,000 ha of cultivated leucaena being utilized across northern Australia. A range of aspects will need to be addressed if the adoption of leucaena is to be accelerated into the future. These include environmental concerns, especially potential weediness, and a range of technological needs, including soil nutritional requirements, grazing and toxicity management, opportunities for companion fodder systems and conservation options. Advances in technology and the ongoing need for a high-quality, profitable and sustainable perennial forage will ensure the continued adoption of leucaena across northern Australia for the foreseeable future. © 2019, Centro Internacional de Agricultura Tropical (CIAT)