Pasture Management for South East Queensland
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Pasture management for South East Queensland compiled by Damien O’Sullivan This publication has been supported by SEQ Catchments through funding from the Australian Government’s Caring for Our Country—Achieving groundcover targets in South East Queensland project. © State of Queensland, 2013. The Queensland Government supports and encourages the dissemination and exchange of its information. The copyright in this publication is licensed under a Creative Commons Attribution 3.0 Australia (CC BY) licence. Under this licence you are free, without having to seek our permission, to use this publication in accordance with the licence terms. You must keep intact the copyright notice and attribute the State of Queensland as the source of the publication. For more information on this licence, visit http://creativecommons.org/licenses/by/3.0/au/ deed.en. This publication has been compiled by Damien O’Sullivan of the Industry and Planning business group, Department of Agriculture, Fisheries and Forestry. The author acknowledges contributions from Ian Crosthwaite, Bill Edwards, Col Paton and Bruce Lord (SEQ Catchments). ii Contents Introduction .......................................................................................................................... 1 Key pasture management skills Pasture basics ..................................................................................................................... 2 Managing pasture condition Grazing systems ................................................................................................................. 8 Grazing to suit your situation Enhancing native pastures ........................................................................................ 11 Using legumes to increase carrying capacity Establishing sown pastures ...................................................................................... 14 Best option for old cultivation land South East Queensland land types ....................................................................... 21 Selecting the best pasture mix Legumes for South East Queensland pastures................................................ 37 Descriptions and planting rates Grasses for South East Queensland pastures .................................................. 49 Descriptions and planting rates Further information ........................................................................................................ 60 Contacts and other information sources Workshops ......................................................................................................................... 62 Species list ......................................................................................................................... 63 iii iv To establish and maintain healthy Introduction and sustainable pastures, graziers need to know: • what plants are in the pasture The beef industry is a major and the condition of the pasture contributor to the wealth of the South • whether there are changes East Queensland region and this occurring in the numbers of valuable industry relies on productive broadleaf weeds, woody weeds pastures. This booklet aims to help or other unfavourable species graziers better understand the • how many stock to carry with development and management of the feed on hand (i.e. when is it pastures suited to the region. time to sell stock or begin to feed Selecting the best mix of grasses supplements?) and legumes for each land type will • how changes in stock or pasture ensure the best financial return on management will affect the investment from improved pastures. pasture composition or condition This booklet is designed to help all • how to maximise income without grazing property managers, from jeopardising pasture health those on small grazing blocks to • how to demonstrate that the properties of 10 000 ha or more. property management strategies are sustainable South East Queensland lies within the southern black speargrass region • how to use a system like of Queenland’s pasture communities. Stocktake to monitor changes in On the surface it may seem simple pasture condition over time. to manage a paddock full of grass but the way graziers manage stock numbers under a variety of climatic conditions can dramatically improve or deteriorate the condition of the ecological system. 1 • legumes—plants with a varying Pasture basics ability to fix nitrogen with the help of bacteria in root nodules (e.g. clovers) • sedges—grass-like plants (e.g. nutgrass) Pastures are complex ecosystems. A wide variety of natural phenomenon • woody weeds—woody plants and management decisions affect with the ability to compete with the composition and productivity of a pasture plants for sunlight, pasture over time. nutrients and moisture (e.g. unwanted regrowth, lantana) Pasture composition • other weeds—any undesirable The composition of pastures varies plant in a pasture that affects considerably. It is important for carrying capacity of the pasture graziers to have a clear idea of what due to its unpalatability, they expect from their pastures competition with more favourable and choose plant species that species or toxicity to livestock have the capacity to fulfil grazing (e.g. creeping lantana and African requirements. lovegrass). There are two very broad plant types Features of a healthy pasture found in most pastures: A healthy pasture has a: • annuals and weak perennials— • high percentage of palatable, plants that live for one or a limited productive, perennial grasses (3P number of growing seasons grasses) • perennials —plants with variable • small number of annual plants life spans, from a year to decades. (e.g. small burrgrass) In the grazing situation the main • small number of weeds (e.g. plants of interest are: verbenas) • grasses—low-growing vegetative • high frequency of desirable forbs plants that can tolerate grazing. (e.g. native legumes such as Stoloniferous grasses like couch glycine) and Rhodes grass spread by seed • variety of other favourable and underground roots called species. stolons. Tussock grasses grow in clumps as distinct individual What affects pasture plants condition and quality? • forbs—non-woody broadleaf Climate, soil type, plant type and plants grazing pressure all interact to determine the quality, productivity and sustainability of pastures. 2 Climate Data in Table 1 shows the perennial Climate, and rainfall in particular, has tussock grasses growing more dry a major effect on pastures. Given the matter per mm of rainfall. wide variation in climatic conditions Soil type within and between years, it is unreasonable to expect pasture bulk Generally, the better the soil, the and quality to remain constant. better the pasture. While we often look at a particular grass as being The nutritive value of a plant varies very good for stock feed, the protein with seasonal conditions and soil level of that grass varies depending fertility. In years of high rainfall, plant on soil fertility. Low soil phosphorus yield is often high but protein content and nitrogen are generally the most is low. The opposite is often the case common nutrient restrictions on in lower rainfall years. Frost, wind, pasture growth. humidity and heat can also affect pasture quantity and quality. Organic matter is an important soil component, providing plant nutrients, The effectiveness of rainfall is binding soil aggregates, improving the major determining factor for infiltration and feeding soil micro and pasture growth. A combination of macro organisms. Low organic matter the following factors will determine levels inhibit plant growth. the amount of effective rainfall and subsequent pasture growth: Once pasture cover drops below • ground cover—pasture 70–80% there is a serious risk of soil condition, plant type and species erosion due to increased run-off. (see Table 1) Much of the fertility in South East • soil type and condition— Queensland soils is carried in the aggregate structure, pore size top 1–3 cm of the profile so it is and amount of organic matter important to manage pastures in a and minerals way that will preserve and improve • rainfall intensity the quality of this soil zone. A • evaporation paddock with pasture composed of • slope annuals and large areas of bare soil • tree cover. loses significant quantities of fertile topsoil every year (see Figure 1). Table 1 – The effect of pasture type on water infiltration and dry matter production Pasture Water infiltration kg dry matter/ % mm rainfall Perennial tussock grasses 76 4 Stoloniferous grasses 55 3 Annual grasses 40 2 Bare ground 25 0 3 6000 Sown pastures 5000 Pastures sown into a prepared 4000 seedbed are the most productive, and the most expensive. Productivity 3000 of these pastures will usually decline 2000 after 5–8 years due to a lack of Soil loss (kg/ha) loss Soil 1000 nitrogen. They can be maintained for longer with fertiliser applications and 0 Perennial Stoloniferious Annual Bare careful renovation. Legumes are an tussock grass plants ground grass essential addition to sown pastures to reduce the effects of run-down. Figure 1 – Soil losses from pastures. Grazing Plant type Stock will select the highest quality diet available to them. Increasing the Each type of plant community has stocking rate reduces each animal’s something different to offer graziers. ability to select and so reduces the The contributions of the three quality of the diet. Forcing stock to eat main pasture types in South East more than leaf (e.g. stem) will reduce Queensland