Changes In Productivity Associated With Replacement Of Heteropogon Cotortus By Aristida Species And Chrysopogon Fallax In The Savannas Of South East Queensland,
2024
University of Queensland
Changes In Productivity Associated With Replacement Of Heteropogon Cotortus By Aristida Species And Chrysopogon Fallax In The Savannas Of South East Queensland, F P. Wandera, P C. Kerridge, J A. Taylor, H M. Shelton
IGC Proceedings (1977-2023)
Heteropogon contortus-dominated rangelands, which cover 22 million ha, are the most important areas for beef production in northern Australia. Due to overgrazing, this dominant species ,is disappearing and is being replaced by unpalatable species such as Aristida and Chrysopogon in a patchy mosaic pattern. In a large graiing experiment· adjacent to the CSIRO Narayen research station: in south-east Queensland on granite country, patches dominated bf the unpalatable grasses comprised 24-32% of the area. Aristida-dominant and Chrysopogon-dominant patches had lower productivity (1000 and 650 kg/ha, respectively) than areas dominated by Heteropogon contorus (1850 kg/ha). It was estimated that a rangeland …
Dynamics Of Stylosanthes Species In Mixed Pastures In A Marginal Environment,
2024
CSIRO
Dynamics Of Stylosanthes Species In Mixed Pastures In A Marginal Environment, J G. Mcivor, C J. Gardener
IGC Proceedings (1977-2023)
The growth and population dynamics of Stylosanthes hamata cv. Verano and S. scabra cv. Seca were measured in mixed, oversown pastures at Hillgrove (AAR=535 mm) near Charters Towers. Over a 10-year period mean stylo yields ranged from 20 kg/ha to 1800 kg/ha. During the first 3 years Verano outyielded Seca but in the last 7 years Seca had greater yields. Plant density was greater for Verano lhan Seca during the early years but the situation was reversed in later years. The Seca plants lived longer than Verano plants and there was a greater proportion of perennial plants in the Seca …
Distribution And Abundance Of Plant Species In Pastures And Rangelands,
2024
CSIRO
Distribution And Abundance Of Plant Species In Pastures And Rangelands, John G. Mcivor
IGC Proceedings (1977-2023)
The competition-stress-disturbance (CSD) model of Grime (Plant strategies and vegetation processes, New York, John Wiley 1979) is used as the basis for discussing the forces that influence the distribution and abundan.ce. of plant species. Characteristics of plant strategies (competitive, ruderal and stress-tolerator) in both the established and regenerative phases are summarised. Pasture management can be viewed as the manipulation of competition, stress and disturbance. A number of pasture situations ( disturbance-diversity relationships, pasture degradation, weed invasion, management of abandoned farm land, species conservation) are analysed in ecological terms and the consequences for pasture management are outlined. The CSD model can …
Aspects Of Interference Between Nodding Thistle (Carduus Nutans L.) And Pasture Grasses And Legumes,
2024
AgResearch, NZ
Aspects Of Interference Between Nodding Thistle (Carduus Nutans L.) And Pasture Grasses And Legumes, D A. Wardle, K S. Nicholson, A Rahman
IGC Proceedings (1977-2023)
Nodding thistle (Carduus nutans L.) is an important weed species in New Zealand pastures. The available information on interactions between this species and forage grasses and legumes is summarised and discussed. Nodding thistle inhibits pasture productivity, and allclopathy is probably Important at inhibiting pasture at the later stages of its life cycle. Although, nodding thistle is most susceptible to inhibition by forage species early in its life cycle, a minimum pasture cover may be required for seedlings to establish. Nodding thistle therefore acts as a competitor only at the later stages of its development. Grasses arc both stronger at inhibiting …
Effects Of Herbicides And Fertilizers On Ragwort (Senecio Jacobaea L.) In Hill Country Pastures,
2024
AgResearch, NZ
Effects Of Herbicides And Fertilizers On Ragwort (Senecio Jacobaea L.) In Hill Country Pastures, A Rahman, K S. Nicholson, D A. Wardle
IGC Proceedings (1977-2023)
A 3-year study was conducted lo determine the influence of 2 herbicides (2,4-D and glyphosate) and 3 fertilisers (containing N, P or K), in conjunctiun with pasture renovation, on ragwort (Senecio jacobaea L.) populations and pasture productivity in a perennial ryegrass-white clover hill country pasture. Glyphosate-treated plots often contained higher ragwort numbers than 2,4-D treated plots, probably because the glyphosate treatment caused greater discontinuity of pasture. Both N and P fertilisers had a consistently strong beneficial effect on pasture, which resulted in substantial inhibition of ragwort populations. During the end of each of the first 2 years of the …
Regeneration Of Themeda Triandra In Humid South African Rangelands,
2024
University of Fort Hare
Regeneration Of Themeda Triandra In Humid South African Rangelands, K Adams, J E. Danckwerts
IGC Proceedings (1977-2023)
Themeda triandra seeds were planted into undisturbed, burnt and tilled treatments in degenerate humid grassland. More seedlings emerged and survived on tilled soil than on the other two treatments. The plants on the tilled treatments were also larger (had more tillers with greater mass than the other two). The effect of tillage was attributed to removal of competition from undesirable competitors, which seems essential in the reintroduction of T. triandra into humid grasslands of South Africa.
Effects Of The Fire Regime On Grassland And Savanna Rangelands In Southern Africa,
2024
University of Fort Hare
Effects Of The Fire Regime On Grassland And Savanna Rangelands In Southern Africa, Winston S.W Trollope
IGC Proceedings (1977-2023)
Fire is regarded as a natural factor of the environment in southern Africa and the effect of fire on rangeland depends upon the fire regime, i.e., type and intensity of fire and season and frequency of burning, The most common types of fire in grassland and savanna areas are surface fires burning either as head or back fires. Head fires have the least depressive effect on the recovery of the grass sward and cause high« topkill of stems and branches of trees and shrubs than back r1res, Fire intensity has no significant effect on the recovery of the grass sward …
Sward Characteristics Of A Diploid And Tetraploid Cultivar Of Perennial Ryegrass As Measured By Different Sampling Techniques,
2024
Agricultural University
Sward Characteristics Of A Diploid And Tetraploid Cultivar Of Perennial Ryegrass As Measured By Different Sampling Techniques, J H. Neuteboom, E A. Lantinga, H Schlepers, L 'T Mannetje
IGC Proceedings (1977-2023)
In a grazing experiment with monocultures of 2 perennial ryegrass (Lolium perenne L.) cultivars it was found that over a 6-year period the tiller density of the tetraploid Condesa was on average 27% lower than that of the diploid Wendy. The lower tiller density of Condesa went along with a more open sward structure and higher weed proportions after 6 years, Sward structure was suitably characterised by means of absence frequency estimations of rooted perennial ryegrass tillers from concentric sampling quadrats.
Effect Of Localized And Epsidodic Nutrient Supplies And Salinity On Growth Of Selected Grass Species,
2024
Roodeplaat Grassland Institute
Effect Of Localized And Epsidodic Nutrient Supplies And Salinity On Growth Of Selected Grass Species, M M. Wolfson, J Caetano
IGC Proceedings (1977-2023)
The efficient use of non•uniform nutrient supplies may be an important component of plant nutrient relationships in soils, especially where inputs of available nutrients by mineralisation may be slow and unpredictable. The experiments reported here examined the effects of periodic supplies of nutrients as well as localised nutrient supplies on the growth of grass species which are common in cultivated soils and pastures. Most plants cannot produce significant yields when grown under saline conditions owing to the difficulty the plant has adjusting to the osmotic potential of the growth medium and its limited capacity to cope with accumulated c1· and …
Analysis Of A Natural Pasture Of The Karst Region (North-East Italy) Under Chemical Fertilization,
2024
CRSA
Analysis Of A Natural Pasture Of The Karst Region (North-East Italy) Under Chemical Fertilization, G Parente, R Ardiani, F Bozzo, M Onofrii, M Scimone, S Venerus
IGC Proceedings (1977-2023)
To characterise the vegetation changes in a natural pasture, a mineral fertilisation and a 4-year grazing test (1987-1990) were carried out on a typical karstic natural grassland, at that time not grazed by livestock and frequently devastated by fire. Mineral fertiliser and year-long animal grazing have modified the vegetation and seem not to have damaged the agro-ecosystem. An increase of the Arrhenatheretum species and, consequently, higher dry matter production, have been recorded, as well as an extension of the growth period and a greater quantity of grass during the summer. Animal performance has been quite satisfactory as the milk production …
Effect Of Elevation On Vegetation In The Southern Alburz Chain, Iran,
2024
Research Institute of Forest and Rangelands
Effect Of Elevation On Vegetation In The Southern Alburz Chain, Iran, Masoud Mohammad-Aliha
IGC Proceedings (1977-2023)
The effects of elevation on the vegetation composition of the southern rangelands (about 20 000 ha) of the Alburz Chain was studied. The attitudinal zones of the study area were located between 1200 and 3600 m asl. Twenty-three sites were selected alongside the attitudinal gradients (every 200 m change in height was allocated a substation). Twenty-one vegetation types were distinguished and 3 ecological sites (stations) selected. Also some grasses alongside the study area have been considered.
Assessing The Productivity Of Pastures In The Central Highlands Region Of Queensland, Australia,
2024
Queensland Department of Primary Industries
Assessing The Productivity Of Pastures In The Central Highlands Region Of Queensland, Australia, J Willcocks, P Filet
IGC Proceedings (1977-2023)
A sustainable grazing industry requires careful management of pastures. This study measured the growth potential and productivity of different pasture types in the Central Highlands region of Queensland to develop recommendations on stocking rates which are sustainable in the long term. The most productive pasture measured, buffet grass (Cenchrus clliaris) is generally used for fattening prior to sale to the meatworks. The least productive, a mixed native pasture under a eucalypt forest, is generally used for maintaining breeding stock. Forest Mitchell grass (Bothrioclrloa ewartiana) has intermediate levels of productivity and is used for both breeding and …
Seedling Emergence From Buried Seed In Unsown And Oversown Hill Pasture,
2024
AgResearch, NZ
Seedling Emergence From Buried Seed In Unsown And Oversown Hill Pasture, M E. Wedderburn, W J. Pengelly, L A. Greaves
IGC Proceedings (1977-2023)
Seedling recruitment from buried seed was measured in hill country after the resident vegetation was suppressed or killed using herbicide, and either Yatsyn ryegrass, hill ryegrass or a low fertility grass mix was oversown. Unsown plots serves as a control. The total number of seedlings emerging per m2 was similar for all treatments but differences between treatments occurred in the species composition of seedling populations. Ryegrass seedling density in sown plots was 3 times that in unsown plots and white clover seedling numbers were 6 times greater. Other grasses were present in numbers equivalent to sown ryegrass. Subterranean clover and …
Adaptation Of Grassland For Recreational And Amenity Use,
2024
NZ Turf Culture Institute
Adaptation Of Grassland For Recreational And Amenity Use, R J. Gibbs, K W. Mcauliffe, R W. Brougham
IGC Proceedings (1977-2023)
Adaptation of grassland for intensive sport and recreational use introduces constraints not normally experienced under agricultural pasture production. For example, turfgrass is expected to grow in deliberately compacted soils and structureless, inert sands. It is also expected to provide a surface for sports as diverse as golf and horse racing. This paper examines aspects of turfgrass management that differ from agricultural pasture production. These aspects include the ability of turf grass to withstand intensive wear, its ability to produce a dense, low growing and even sward and the specific drainage and playing quality demands of different sports. The key role …
The Product Of Science,
2024
Christian Albrechis Universidt
The Product Of Science, Rolf A.E Mueller
IGC Proceedings (1977-2023)
The relationships between agricultural science, invention, production and consumption are conventionally considered in a hierarchical model with consumption at the basis and science at the pinnacle of the hierarchy. -Two important shortcomings of that model as a basis for organising and manag\ng agricultural research are identified. First, the model does not specify how the direction and intensity of research Is guided in the absence of markets for the outputs from research. Second, the model does not identify the flows of specific information from the consumption and agricultural production sphere to the research sphere where such information is crucial for the …
From Technology Transfer To Resource Management,
2024
De Dellen, The Netherlands
From Technology Transfer To Resource Management, Janice Jiggins
IGC Proceedings (1977-2023)
Six models of technological innovation are examined. The implications for the roles and functions of research and extension, and of agricultural education systems, are analysed. The models are assessed against issues of gender, natural resource management and poverty, with consideration of who pays, and who benefits. The conclusion is drawn that the Transfer of Technology model is not a generalisable model to all circumstances, clients and policy goals. Client-driven systems and participatory approaches which build partnerships among researchers, extensionists, producers and other users of grassland landscapes, can be more effective and efficient.
Combining Agricultural Agent Training In Forages With Graduate Credit,
2024
University of Kentucky
Combining Agricultural Agent Training In Forages With Graduate Credit, Garry Lacefield, Jimmy Henning, M Rasnake, C Forsythe, L Davis
IGC Proceedings (1977-2023)
An intensive agent training programme in alfalfa (Medicago sativa L.) production nnd utilisation was initialed in 1990. The training was organised by slate extension forage specialists to meet the needs of agricultural agents. Previous programmes have offered similar training but did nol resull in graduate credit. This unique approach offered intensive training to agents presented by a multidisciplinary learn of scientists. All requirements for graduate credit were met and the course completion resulted in 3 hours of graduate credit. The course has been rated "superior" by students. When properly organised and implemented, intensive agent training can be offered that …
A Grazing Land Conservation Plan,
2024
USDA-SCS
A Grazing Land Conservation Plan, R G. Hendricks
IGC Proceedings (1977-2023)
In a sample planning scenario, a ranching operation in the USA demonstrates a typical conservation problem on grazing lands. Using SCS conservation planning techniques, problems and objectives are identified, resources are inventoried, data are analysed, solutions formulated and conservation practices implemented to solve the resource problem. With use of the economic analysis routine in Grazing Land Applications (OLA) version 1.1 decision suppott software, return on investment was largest when the client installed a combination of rest-rotation grazing, prescribed burning, and initiated a hunting lease programme.
Range Conservation Planning: The Usda- Soil Conservation Service Method,
2024
USDA-SCS
Range Conservation Planning: The Usda- Soil Conservation Service Method, Rhett H. Johnson
IGC Proceedings (1977-2023)
The USDA-Soil Conservation Service has responsibility for providing one-on-one conservation planning assistance with the private rangeland managers of over 160 million ha in the USA. This assistance is provided on voluntary basis at the request of the private land user through a local conservation district. Through SO years of experience, a successful planning process has evolved, known as the Ten Elements Of Conservation Planning. These elements are: (1) provide information, (2) request assistance, (3) develop resource inventories, (4) recognise problems and opportunities, (5) determine objectives, (6) develop and evaluate alternatives, (7) make decisions, (8) document decisions, (9) implement decisions, and …
Use Of Objective Planning Techniques In The Development Of Large Livestock Farm In New Zealand,
2024
Massey University
Use Of Objective Planning Techniques In The Development Of Large Livestock Farm In New Zealand, K I. Lowe
IGC Proceedings (1977-2023)
Limestone Downs is a sheep and beef cattle property of 3200 ha near Port Waikato, and provides funds for the C Alma Baker Trust for "the furtherance of the science of agriculture". A development programme slatted in 1981 transformed the farm from an extensive "station" into an intensive farming operation, lifting animal performance and financial returns. This followed the adoption of well-proven and relatively inexpensive modifications to management. Similar programmes should have realistic goals, and established decision rules with priorities. These should be supported by an appropriate monitoring programme and the use of objective data in decision making.
