Eastwood Report. Sheep production on buffel grass pasture. The ‘Eastwood’ grazing trial, 1967-1982.

This research project, coded Bkl P50 WR, ran for 15 years (1967-1982) to document the productivity and persistence of buffel grass (Cenchrus ciliaris L.) pasture sown into cleared gidyea shrubland in central-western Queensland. It was initiated when little objective data existed about the potential of such pasture on this newly developed country. Merino sheep were used as the grazing animal at stocking rates between 10 and 1.25 sheep/ha. Data collected concentrated on pasture yield and crown cover, pasture Nitrogen and Phosphorus content, sheep liveweight, wool growth and quality, fleece weight, faecal protein and phosphorus, and intestinal worm burden. Other data was collected on oestrus cycling in young ewes and the effect of differing grazing pressure on their conception rates. Seasonal conditions ranged from very dry to very wet at different stages and there were four distinct research phases which are reported separately. Buffel grass proved highly productive and resilient under the grazing pressures applied and at least as productive as the highly regarded, local Mitchell grass country. However, sheep weight loss was common in winter after the grass was frosted. Optimal sustainable stocking rate was slightly greater than 2.5 Dry Sheep Equivalents (DSEs) /ha. The pasture lacked botanical diversity unless heavily overstocked when ephemeral herbs became common. No unexpected problems arose from the conversion of the gidyea scrub to open grassland. Woody regrowth was ever-present, particularly false sandalwood (Eremophila mitchellii), but did not seriously impinge on productivity in the pasture's first 20 years since clearing. In light of the results, the use of buffel grass pastures in the region for cattle, goats and mixed species grazing is discussed. Potential long-term issues, both environmental and rural industry-related are discussed

Some soil factors constraining buffel grass (Cenchrus ciliaris L.) seedling growth rate across a range of acid red Kandosols in Queensland, Australia

Buffel grass (Cenchrus ciliaris L.) has passionate grazing industry advocates and biodiversity conservation detractors around the world due to its ability to readily establish and spread on certain soil types. A more detailed understanding of what soil factors influence the success of seedling establishment will offer guidance to anyone wishing to either encourage or discourage buffel grass establishment in a particular area. Twenty soils from land types where buffel grass had a varied history of successful establishment and persistence in south western Queensland, Australia were assessed in a pot trial for their influence on early seedling growth rate of buffel grass. Some currently had buffel grass growing there. Aspects of the chemistry of each soil were compared against the rate of seedling growth of buffel grass cv. Biloela that was sown with or without a phosphate coating on the seed. Available soil phosphorus had a major influence on seedling growth in the absence of a phosphate fertiliser coating, but levels of other factors such as exchangeable aluminium and calcium were also critical. Several multiple regression equations with differing soil parameters included proved equally good at predicting buffel seedling growth but they did not greatly improve on the strong correlation with available soil phosphorus. This seemed due to the interchangeability amongst soil pH, cation exchange capacity and degree of clay as controlling factors, over and above available phosphorus. Thus, where available soil phosphorus is marginal for rapid buffel seedling growth, soil pH, exchangeable aluminium and total exchangeable cation levels could have similar importance in determining whether buffel grass colonised or failed to gain a foothold in that area

Bkl P13 WR Buffel Grasses (Cenchrus ciliaris L.) on Different Gidyea Soils - January 1963 to December 1970

This project compared five different buffel grass (Cenchrus ciliaris L.) cultivars on four different gidyea soils in the Blackall district for their growth, nutritive value, palatability to sheep and persistence. The cultivars were American, Biloela, Gayndah, Nunbank and West Australian. Some informal comparisons were also made between these buffels and other pasture grasses commonly sown in nearby brigalow country. The information has been gathered in 2020 from surviving archival files and thus remains incomplete in some aspects. The results presented represent primarily what was known and published by the early 1970s rather than an interpretation in light of knowledge at the time of writing 50 years later. Replicated sowings were done in 30 x 30 link (36m2) plots within a fenced area of about one third of an acre (0.14 ha) into existing West Australian buffel pastures without additional fertilizer after rotary hoeing in late January 1963. The neutral to alkaline soils were characterized in detail for the surface 0-2 (0-5cm) and 2-8 inch (5-20cm) layers. Descriptive recordings were made of the establishment success in every plot and then of the palatability of each species to sheep, the heat and moisture stress tolerance of species and cultivars, and the general vigour of each sown line. Particularly detailed sampling was carried out over several years at one site to document the chemical composition of each buffel cultivar at three growth stages, pre-flowering, peak end-of-summer growth and late winter frosted material

Perennial pastures for marginal farming country in southern Queensland. 1. Grass establishment techniques

Efficient ways to re-establish pastures are needed on land that requires a rotation between pastures and crops. We conducted trials in southern inland Queensland with a range of tropical perennial grasses sown into wheat stubble that was modified in various ways. Differing seedbed preparations involved cultivation or herbicide sprays, with or without fertilizer at sowing. Seed was broadcast and sowing time ranged from spring through to autumn on 3 different soil types. Seed quality and post-sowing rainfall were major determinants of the density of sown grass plants in the first year. Light cultivation sometimes enhanced establishment compared with herbicide spraying of standing stubble, most often on harder-setting soils. A nitrogen + phosphorus mixed fertilizer rarely produced any improvement in sown grass establishment and sometimes increased weed competition. The effects were similar for all types of grass seed from hairy fascicles to large, smooth panicoid seeds and minute Eragrostis seeds. There was a strong inverse relationship between the initial density of sown grass established and the level of weed competition

Perennial pastures for marginal farming country in southern Queensland. 1. Grass establishment techniques

Efficient ways to re-establish pastures are needed on land that requires a rotation between pastures and crops. We conducted trials in southern inland Queensland with a range of tropical perennial grasses sown into wheat stubble that was modified in various ways. Differing seedbed preparations involved cultivation or herbicide sprays, with or without fertilizer at sowing. Seed was broadcast and sowing time ranged from spring through to autumn on 3 different soil types. Seed quality and post-sowing rainfall were major determinants of the density of sown grass plants in the first year. Light cultivation sometimes enhanced establishment compared with herbicide spraying of standing stubble, most often on harder-setting soils. A nitrogen + phosphorus mixed fertilizer rarely produced any improvement in sown grass establishment and sometimes increased weed competition. The effects were similar for all types of grass seed from hairy fascicles to large, smooth panicoid seeds and minute Eragrostis seeds. There was a strong inverse relationship between the initial density of sown grass established and the level of weed competition

Evaluating pasture species for less fertile soils in a subtropical aseasonal low rainfall zone

Grasses, legumes, saltbushes and herbs were evaluated at 6 sites in southern inland Queensland to identify potential pasture and forage plants for use on marginal cropping soils. The region experiences summer heat waves and severe winter frosts. Emphasis was on perennial plants, and native species were included. Seedlings were transplanted into the unfertilized fields in either summer or autumn to suit the growing season of plants, and watered to ensure estab-lishment. Summer-growing grasses were the most successful group, while cool season-growing perennials mostly failed. Summer legumes were disappointing, with Stylosanthes scabra and Indigofera schimperi performing best. Some lines such as I. schimperi and the Eragrostis hybrid cv. Cochise were assessed as potential weeds owing to low animal acceptance. Native Rhynchosia minima grew well at some sites and deserves more study. Cenchrus ciliaris was always easy to establish and produced the highest yields. Persistence of some Digitaria and Bothriochloa species, Eragrostis curvula and Fingerhuthia africana at specific sites was encouraging, but potential weediness needs careful assessment. Standard species were identified to represent the main forage types, such as Austrostipa scabra for cool season-growing grasses, for incorporation into future trials with new genetic materials. The early field testing protocol used should be considered for use elsewhere, if unreliable rainfall poses a high risk of establishment failure from scarce seed

Evaluating pasture species for less fertile soils in a subtropical aseasonal low rainfall zone

Grasses, legumes, saltbushes and herbs were evaluated at 6 sites in southern inland Queensland to identify potential pasture and forage plants for use on marginal cropping soils. The region experiences summer heat waves and severe winter frosts. Emphasis was on perennial plants, and native species were included. Seedlings were transplanted into the unfertilized fields in either summer or autumn to suit the growing season of plants, and watered to ensure estab-lishment. Summer-growing grasses were the most successful group, while cool season-growing perennials mostly failed. Summer legumes were disappointing, with Stylosanthes scabra and Indigofera schimperi performing best. Some lines such as I. schimperi and the Eragrostis hybrid cv. Cochise were assessed as potential weeds owing to low animal acceptance. Native Rhynchosia minima grew well at some sites and deserves more study. Cenchrus ciliaris was always easy to establish and produced the highest yields. Persistence of some Digitaria and Bothriochloa species, Eragrostis curvula and Fingerhuthia africana at specific sites was encouraging, but potential weediness needs careful assessment. Standard species were identified to represent the main forage types, such as Austrostipa scabra for cool season-growing grasses, for incorporation into future trials with new genetic materials. The early field testing protocol used should be considered for use elsewhere, if unreliable rainfall poses a high risk of establishment failure from scarce seed

Impacts of rehabilitating degraded lands on soil health, pastures, runoff, erosion, nutrient and sediment movement. Part II: Literature review of rehabilitation methods to improve water quality flowing from grazing lands onto the Great Barrier Reef.

Over 200 potential references were reviewed with many covering aspects of water quality, grazing lands and their effects on the Great Barrier Reef (GBR), and rehabilitation of degraded landscapes. There was little reported information on the mechanical rehabilitation of bare, D-condition grazing lands in the reef catchments. There is, however, literature on machinery suitable for soil surface disturbance, pasture technology for developing permanent perennial pastures and on grazing management for improving C-condition land. This literature review is complementary to the other two aspects of this project, the field experiments of mechanical disturbance, and the landholder surveys on their rehabilitation experiences. Rehabilitation of degraded grazing lands of the GBR catchments has become a major focus of the Reef Rescue Programme primarily because the large area of land involved has the potential to contribute significant sediments and nutrients to the GBR lagoon. Poor water quality from grazing lands has the capacity to do serious damage to the reef ecosystems. Any reduction in sediment runoff from eroding land implies a worthwhile improvement in water quality entering the GBR lagoon. A limitation with this idea is that it assumes almost no net losses as the turbid water moves downstream and minimal ability of the marine and reef ecosystems to recover from short-term stresses. Recent published research indicates that neither assumption is correct. It also does not recognise the dynamic nature of natural ecosystems in the semi-arid tropics where there is perpetual shifting of species dominance and mixes in response to the perturbations in the surrounding environment, particularly grazing pressures, climatic extremes and high seasonal variability. High levels of sediment, pesticides, nutrients, or fresh water does kill or weaken some reef species, however, other species benefit, either directly by better using the incurring resources or by expanding into the ecological gap left by the damaged suite of species. For example, the increase in algae due to extra sediment and nutrients at the expense of hard corals is well known, but if the perturbation is short-lived (like a flood plume) or not widespread, then recolonisation by the displaced species can occur, provided no ongoing trauma occurs. However there is good evidence to suggest that the amount of sediment and nutrients reaching the ocean from agricultural and urban land is well above the 18th century levels, and thus could be damaging the reef ecosystems and the fishing and tourism industries that depend on them being in good health. There is also data to show that the quality of pastures on grazing lands is often poorer than 150 years ago and that areas of land may be denuded more than is desirable, particularly by grazing in drought periods. Thus it is beneficial to all if better pasture quality and cover on grazing lands is encouraged and achieved. The main questions are what should the pasture quality target be and how can this be achieved at a realistic social and economic cost. Because the relationship between runoff and sediment load against ground cover is strongly non-linear, logic says that the greatest benefit will accrue from revegetating the barest areas, such as D-condition land. This eroded land is often found close to major watercourses so that the payoff is greater for the investment made in improvements because there is little scope for deposition of entrained sediment between those eroding areas and the nearby fast-flowing channel water. Published studies, plus this project’s research, have shown that the regeneration of healthy, perennial pastures on D-condition land is possible on many soil types provided several pre-conditions and favourable seasonal co-incidences are met. These include: grazing animals, including macropods, have to be excluded completely for some time; significant disturbance of the soil surface is needed for all soils that do not have a natural loose surface; and, good growing season rainfall has to be received shortly after the surface disturbance and pasture seed has been sown. If good rains are not received soon after rehabilitation, resowing of pasture seed may be needed along with re-cultivation to loosen and roughen the soil surface. There is a broad range of appropriate cultivation implements available for rehabilitation work, but the options for perennial grasses and legumes to sow are limited, as is the availability of adapted native species seed

Perennial pastures for marginal farming country in southern Queensland. 2. Potential new grass cultivar evaluation

Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species) against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production. Accessions sown at a site were determined by prior experience with them on a range of soils. High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp. Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana. The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species. While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises. Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities

Perennial pastures for marginal farming country in southern Queensland. 2. Potential new grass cultivar evaluation

Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species) against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production. Accessions sown at a site were determined by prior experience with them on a range of soils. High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp. Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana. The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species. While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises. Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities