Agricultural Science Commons^™

Grazing Management Of Lotus In Eastern Australia: A Participatory Approach, M J. Blumenthal, J F. Ayers, Z Hochman

IGC Proceedings (1977-2023)

Both Lotus uliginosus Schkukr and L. corniculatus L. require lenient grazing management for persistent production. However, grazing systems, where Lotus is adapted in eastern Australia are based on intermittent set stocking. Conflict between plant ecophysiology and the adverse influences of traditional grazing systems that limit the adoption of new grazing management technology have been addressed by a participatory (co-learning) research and development process. The approach taken involved the use of a facilitator who ran an initial meeting to involve stakeholders and subsequently established “colearning” groups and “co-learning” experimental sites. These sites are monitored, progress is reviewed, and knowledge is …

Rhizobium Specificity In Leucaena, B F. Mullen, V E. Frank, R A. Date

IGC Proceedings (1977-2023)

Twenty-seven accessions of Leucaena, representing 20 species, were assessed for effective N-fixing symbioses in association with 13 strains of Rhizobium in N-free conditions in a glasshouse. Fifteen accessions formed effective symbioses with most strains of Rhizobium. Only 4 accessions required specific strains. Conversely, 9 of the strains of Rhizobium formed effective symbioses with most accessions of Leucaena. Only one strain was ineffective. Strains CB3060 and CB3126 were effective with 21 and 22 accessions of Leucaena, respectively.

Agronomic Performance Of 118 Leucaena Accessions In The Subtropical Environment Of Southeast Queensland, Australia, B F. Mullen, H M. Shelton

IGC Proceedings (1977-2023)

The DM productivity in contrasting environments of 118 Leucaena accessions was evaluated in sub-tropical Australia over a 2 year period. Harvests were timed to coincide with hot/wet and cool/dry seasons and data were analysed to compare growth in these environments. Eleven accession groups were identified by cluster analysis. Group 1, which contained F1 and F4 interspecific hybrids, were highly productive in all environments. Growth of L. leucocephala accessions was severely checked by psyllids in hot/ wet environments. Four groups comprising 60 accessions were unproductive in all environments. Identification of specific adaptation to cold temperature within groups in psyllid susceptible accessions …

The Effects Of Storage Period On The Germinability Of Rhodes Grass (Chloris Gayana), K C. Kawonga

IGC Proceedings (1977-2023)

An experiment was initiated to investigate the post harvest changes in the seed quality of Rhodes grass (Chloris gayana). The aim of the study was to find out the causes of poor germination of locally produced Rhodes grass seed. Random samples (72) were taken from a seed lot grown at Golden Valley Research Station. Seventy-two random samples were subdivided into groups of twelve and were stored at six locations. Half the samples were stored at room temperature and the other half were stored in the refrigerator for a period of one to six months. The germination test was …

Technology Development Of Pasture Seed Production For Small Scale Farmers In Uganda, P Lusembo, E N. Sabiiti, C Ebong

IGC Proceedings (1977-2023)

Pasture seed production by smallholder farmers in Uganda is hardly developed. The stages of development since the early 1960s are described as initial forage evaluation for adaptability and productivity of various species, seed production trials in relation to plant population, fertilizer requirements and the use of support systems for climbing forage legumes. Annual seed production by smallholder farmers, under an informal seed production system, is reported to have risen from 1,200kg in 1989 to over 35 metric tonnes of forage legume seed in 1995. This was attributed to the availability of appropriate seed production technology and the presence of a …

Flowering Cycle-Related Seed Quality Parameters On 15 New Guineagrass (Panicum Maximum Jacq.) Hybrids, R Usberti, A Usberti Jr, R S. Paterniani

IGC Proceedings (1977-2023)

Fifteen new guineagrass (Panicum maximum Jacq) hybrids, widely variable in flowering cycles, were tested for eleven seed quality parameters: seed viability (tetrazolium)-TZ; normal germination (with and without previous chemical scarification)-TG and NG; presence of viable seeds after the germination tests- RSTG and RSNG; seed dormancy-DTG and DNG; germination rate-TGR and NGR and seed vigor (after accelerated aging test) -AATG and AANG. The genetic materials used presented no significant differences for tetrazolium seed viability. Late- and intermediate-flowering genotypes showed the highest correlations between flowering cycle and seed quality for TG, NG, TGR and NGR (r= 0.468**; 0.731**; 0.422* and 0.683**, …

Effect Of Plant Density On Yield And Yield Components And Seed Chemical Composition Of Some Sunflower Varieties, N A. Noueldin, M E. El-Bially, B A. El-Ahmer, M G. El-Baz

IGC Proceedings (1977-2023)

The objective of this research is to study the effect of varieties (Mayak, Elorida 2000 and sigce 475), hill distance (20, 30 and 40 cm) and ridge width (50, 60 and 70 cm) on productivity of sunflower (Helianthus annus L.). The highest oil % was obtained by sowing sigco 475 at a 40 cm hills distince under 60 cm. ridge width and the highest oil yield feddan-1* as well as seed yield feddan-1 was obtained by sowing Mayak on 20cm hills under a 50cm ridge width.

Seed Banks In A Natural Pasture In Tasmania, Australia: Implications For Species Composition Change, D A. Friend, A S. Cameron, A J. Povey, P L. Dolan

IGC Proceedings (1977-2023)

Seed banks in a natural pasture in Tasmania were examined as part of a study of the effects of grazing on changes in species composition. The dominant native perennial grasses had relatively low seed banks, whereas annual grasses, sedges, rushes and a number of forbs had relatively high seed banks. The results confirm the vulnerability of the native grasses to local extinction in the event of loss of the established plants, e.g. through overgrazing.

Tropical Forage Seed Production In Southeast Asia: Current Status And Prospects, C Phaikaew, L Guodao, A Abdullah, M Tuhulele, E Magboo, B Bouahom, W Stur

IGC Proceedings (1977-2023)

The demand for forage seed in southeast Asia has increased in recent years. More than 1,200 tons of seed were produced in Thailand in 1995 with smaller quantities of seed having been produced in China, Lao PDR, Malaysia, Philippines and Indonesia. Large quantities have been produced of Brachiaria ruziziensis, Stylosanthes hamata, Stylosanthes guianensis and Panicum maximum. There are good prospects to increase forage seed production and to develop trade between countries in the southeast Asian region. There is a need to increase seed production of widely adapted species, and expand production of forages for other purposes such as turf …

Traditional Grassland And Fodder Management Systems In Tanzania And Potential For Improvement, R M. Otsyina, I Essai, D Asenga

IGC Proceedings (1977-2023)

The “Ngitiri” fodder conservation system was developed by the Sukuma agro-pastoralists as a strategy to alleviate acute dry season fodder constraints. This traditional agroforestry system provides the basis and opportunities for development of improved silvipastoral systems. Ngitiri is a major source of dry season fodder supply for livestock and thatch for roofing. The system is widespread in the Sukuma landuse system in central Tanzania. This paper presents the scope and importance of the Ngitiri system, management aspects, constraints, and farmers’ perceptions on improvement. Implications for agroforestry technology development in the Sukuma agropastoral system are also discussed.

Forage Seed Production In Egypt For Domestic Marker And For Export, M A. El-Nahrawy, A Rammah, O Niemelainen

IGC Proceedings (1977-2023)

In Egypt, no major effort is made to provide local and export markets with seeds of correctly identified and pure cultivars of forage crops in spite of the existence of all the essential factors for a successful seed industry. A wide genetic base of indigenous forage crops such as berseem clover and alfalfa, proper irrigation, a harvest and seed maturation period free from rain, sunshine and clear sky all year and highly fertile soils in isolated areas are available. Moreover, uncertified, uncontrolled and unidentified local seeds of berseem clover and alfalfa are highly demanded by foreign markets due to their …

Barley Grass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Barley grass is a common name for Hordeum glaucum and H. leporinum. Barley grass is a major crop weeds species because the seed is readily dispersed, it is renowned for rapidly germinating in autumn, and post-emergent herbicide control options are limited. It can also act as an alternate host for cereal diseases and can develop resistance to herbicides.

The rapid germination of the species after rainfall gives barley grass the potential to act as a green bridge for cereal root rot diseases

Evaluating A Precision Sprayer For Detecting Weeds And Spraying Herbicides In Real Time (Spot Spray) For Weed Management In Corn And Soybean, Adam Eric Leise

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Herbicide sprayers are becoming larger and more efficient in applications in crop fields. A precise and efficient herbicide application is advantageous in effective weed control. New precision sprayers were introduced in hopes of reducing the amount of herbicide applied. Greeneye Technology and John Deere have developed precision sprayers for the detection of weeds in crop fields, which come equipped with a dual tank system that allows for two different herbicides to be separated from tank to tip. The objectives of this study were to evaluate the broadleaf and grass weed control efficacy of spot spray (SS) technology when applied in …

Brome Grass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Brome grass (Bromus spp.) is one of the most competitive grass weeds in wheat. Over the last 10 years, brome grass has increased in importance to a greater extent than any other weed species in Australia.

Recent changes in crop production systems, increased conservation tillage, a lack of available selective herbicides, and a decline in system diversity have seen an increase in the importance of this weed in Western Australia (WA).

Seed is the main source of brome grass infestation and, as few seeds remain dormant, the most important aspect of management is to reduce its seed bank.

Annual Ryegrass And Its Management In Crops, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Annual ryegrass (Lolium rigidum) is one of the most serious and costly weeds of annual winter cropping systems in southern Australia. It is highly competitive and can compete with a crop as early as the 2-leaf stage.

Annual ryegrass is a winter to spring growing weed that can emerge from late autumn to early spring. The number of emergence flushes and the density of plants that emerge are related to initial seedbank levels and the frequency and amount of rainfall.

The Potential Impact Of Endangered Species Legislation On Federal Grazing Lands And The Livestock Industry, G M. Luciuk, B Bristol, T W. Weins, D M. Boyle

IGC Proceedings (1977-2023)

Crown based grazing is an integral part of the management structure of cattle operations, and is very important to the economic fabric of rural communities. Federal crown lands, such as the PFRA operated community pastures are an integral part of the resource conservation efforts in western Canada. These lands represent a significant reservoir of the remaining natural lands which are important for wildlife habitat. Sustainable management of such contiguous blocks of land is essential for the maintenance of biodiversity. Proposed endangered species legislation would require the development of recovery plans on federal lands for endangered, threatened and extirpated species. Rural …

Concepts For Mining Landscape Development In Eastern Germany With Grazing Animals And Agroforestry, S Eichler, F Herzog

IGC Proceedings (1977-2023)

Leipzig South (Saxony) has been heavily transformed by open cast lignite mining. Alternative forms of land use are sought which contribute to an increase of biodiversity and an improvement of soil quality. This could be achieved by the selective introduction of grazing animals and perennials. Specific scenarios for open pits, dumping areas, open pits’ slopes and land reclaimed for agriculture are proposed. Socio-economic drawbacks are outlined.

The Use Of Grasslands To Improve Water Quality In The New York City Watershed, D J. Flaherty, J Drelich Jr

IGC Proceedings (1977-2023)

The purpose of this paper is to demonstrate how grasslands are used in the New York City (NYC) Watershed to improve water quality. A Watershed Agricultural Program was established to voluntarily implement Pollution Prevention Best Management Practices on watershed farms. Grasslands have been used in Whole Farm Plans to reduce nutrients, sediments and other toxic materials reaching New York City’s water supply. Rotational grazing has been used to limit access to streams and stream banks and improve nutrient distribution on pastures. Improved grassland management also helps correct the nutrient balance on the farm and facilitates better nutrient management. Brush removal …

Objective Indicators For Monitoring Drought In Grasslands, D H. White, S M. Howden

IGC Proceedings (1977-2023)

Australia’s National Drought Policy was ratified by the Commonwealth (Federal), State and Territory governments in 1992. However, a sequence of El Niño-based events that started in Queensland in 1991 culminated in much of Australia experiencing abnormally low rainfall throughout 1994 and into 1995. Many farmers experienced substantial loss of income. The Commonwealth government therefore devised measures to determine which areas had been exposed to exceptional drought so that financial assistance could be directed as effectively as possible. In this paper we discuss progress in developing regionally-sensitive indicators and methodologies to aid in future assessments of drought exceptional circumstances.

Are We Ignoring Science In Our Quest For Simplicity In Range Management?, W A. Laycock

IGC Proceedings (1977-2023)

Accurate determination of range condition and trend is essential for proper range management. In the United States, the range condition model currently used is not based on up-to-date ecological knowledge. It assumes a single stable state (climax) and linear pathways. Multiple stable state models more accurately depict community dynamics but have not been widely accepted. U.S. Federal land management agencies are using surrogates, such as qualitative “instant trend” measures and substitution of utilization for measured condition and trend to guide management. Most of these short cuts are not based on science. Attacks on livestock grazing by environmentalists are based on …

Socio-Economic And Climate Change In Mongolia - Effects On Grassland Ecosystems, C Opp

IGC Proceedings (1977-2023)

In Mongolia, in combination with strong changes of the whole society during the past 76 years, from the feudal system to socialism and from the socialist system of planned development to the market economy, there are a lot of changes in the use of natural resources all over the country. In consequence of this a lot of effects on grassland ecosystems, caused by socio-economic and climate driving factors, were observed and studied in different scales: zonal, regional, local.

Integrating Biophysical And Economic Models For Assessing Impacts Of Change On Grazingland Ecosystems, J De Souza Neto, J R. Conner, J W. Stuth, W T. Hamilton, J W. Richardson

IGC Proceedings (1977-2023)

PHYGROW, a hydrologic-based forage simulation model, was parameterized to represent a typical South Texas ranch engaged in the production of cattle and meat goats with an indigenous population of white-tailed deer. Forage production and associated stocking rates for two cattle: goat ratios were simulated for 20 years. Two, ten-year weather scenarios, one representing normal conditions (30% drought years) and one representing dryer weather conditions (50% drought years) were analyzed. Management decision rules were developed for the region to produce estimates of annual animal production and operating cost for the enterprises in each of the four scenarios. These performance and cost …

Linear And Community-Based Processes Of Ethical Decision Making For Grassland Workers, Gary W. Fick

IGC Proceedings (1977-2023)

Grasslands are basic elements in sustainable development, but few grassland workers are familiar with concepts of ethical decision making useful in integrating ecological, economic, and sociological components of sustainability. Most published procedures for ethical decision making are based on linear models for individualized social systems with modern technologies. In the context of sustainable agriculture, nonlinear community-based procedures may be more appropriate. In this paper, a nonlinear model from the Haudenosaunee (Iroquois) Indians is compared to more conventional linear procedures. After identification of a problem, linear models often leave the solution of the ethical dilemma (ranking ethical goals when they conflict) …

Policy Options For Decreasing N And P2o5 Losses From Grassland Based Dairy Farms, P.B M. Berentsen, G.W J. Giesen

IGC Proceedings (1977-2023)

Policy instruments for reducing nutrient losses include extension and education, research, financial incentives such as subsidies and levies, and regulations. The potential of these instruments for reducing nitrogen (N), phosphate (P2O5), and ammonia (NH3) losses is examined for Dutch specialized dairy farms on sandy soils. A linear programming model is used to estimate policy impacts. Results indicate that efficiency improvements through extension, education, and research alone have the potential to decrease total N losses to government target levels in 2005 and to erase 92% of the gap between base and target P2O5 losses, but only 24% of the corresponding NH3 …

Production V Conservation: A Policy Dilemma In The Tree Clearing Debate In Queensland, Australia, J C. Scanlan, E J. Turner

IGC Proceedings (1977-2023)

A process for developing policy for tree clearing that meets the competing goals of conservation and production has been followed. There were two levels at which policy was developed. An overall Statewide policy outlined general targets to meet commitments of the Queensland Government. Local guidelines were developed by a large number of groups containing representatives of government and interested conservation movement and industry representatives. The policy and the local guidelines are an important part of the process used to assess applications for permits to clear woody vegetation.

Forage Production And Performance Of Beef Yearlings Grazing Diploid And Tetraploid Crested Wheatgrass, J D. Bruynooghe, R.D H. Cohen, N W. Holt, P G. Jefferson

IGC Proceedings (1977-2023)

A series of experiments were conducted during 1994 and 1995 at Swift Current, Saskatchewan, Canada to evaluate forage production and animal performance on tetraploid Kirk (Agropyron cristatum (L.) Gaertn.) and diploid Fairway (Agropyron cristatum (L.) Gaertn.) crested wheatgrass pastures under grazing conditions imposed by beef (Bos taurus) yearling steers at four stock density levels (3, 4, 6 and 8 steers ha-1). Total ungrazed forage production for Kirk was greater (<0.05) than Fairway (6302 kg ha-1 vs. 5235 kg ha-1) in 1994 but less (P<0.05) than Fairway in 1995 (3709 kg ha-1 vs. 4633 kg ha-1). Animal performance (average daily gain, animal grazing days and total animal production) did not differ (P>0.05) for steers grazing either Kirk or Fairway pastures. Plant vigour and available energy reserves following one season of grazing were evaluated through etiolated growth with …

Vertical Distribution In Grass Swards: Interactions Between Dry Matter And Nutritional Quality, D R. Buckmaster, R H. Mohtar, S L. Fales

IGC Proceedings (1977-2023)

A field experiment was conducted to study the distribution of mass and quality over plant height throughout the growing season in a pure stand of orchardgrass (Dactylis glomerata L.). When plant density (expressed as kg DM/ha per cm height) is plotted against a height of strata, all treatments show a similar linear shape distribution. ADF and NDF concentrations declined with sward height. Fall treatments had lower ADF and NDF concentrations than summer treatments. Conversely, CP concentrations showed an increase with plant height. Fall treatments showed higher CP than spring and summer treatments. Defoliation management did not affect orchardgrass quality. …

Application Of The Phygrow Forage Production- Runoff Model For Regional Stocking Analysis, J W. Stuth, J R. Conner, W T. Hamilton, D M. Schmitt

IGC Proceedings (1977-2023)

A hydrologic-based forage production model, PHYGROW, was used to simulate forage production and carrying capacity of a subtropical shrubland complex of over 34 species grazed by various ratios of cattle and goats with a population of indigenous white-tailed deer over a 20-yr simulated weather profile. The diet selection algorithm allowed the three animal populations to selectively graze preferred foods based on preferences of plant species, plant parts, and live:dead status by phenological stage. A level of maximum utilization of key species was specified. An incremental analysis of cattle:goat demand ratio was analyzed to determine how different combinations of livestock were …

Using Nested Paddocks To Study Multiple-Paddock Grazing Systems, B E. Anderson, W W. Stroup, W H. Schacht

IGC Proceedings (1977-2023)

There is insufficient information to guide development of multiple paddock grazing systems. Measuring vegetation responses to grazing period/recovery period intervals is prohibitively expensive when using most grazing research designs. Nested paddock designs reduce land area, number of herds, and number of paddocks needed for comparisons. Nested paddocks permit comparisons of animal performance among whole pasture treatments but comparisons are limited for animal performance differences among grazing/recovery period lengths. Nonetheless, nested paddock designs efficiently document vegetation responses to grazing intervals, which may permit predictions of animal performance.

Relationship Between Broadleaf Dock (Rumex Obtusifolius L.) And Seasonal Yield Of Orchardgrass Grazed Pasture, Y Iijima, Y Kurokawa, T Monya, Y Suzuki

IGC Proceedings (1977-2023)

In order to grasp the ecology of R. obtusifolius and the effects of it on seasonal yield of grass in grazing pasture, we investigated seasonal sward characteristics and dry matter yield in grazing pasture. Dry matter yield and coverage of R. obtusifolius predominated those of grass after mid-June and mid-August, respectively. Throughout the year the coverage of R. obtusifolius negatively correlated to the grass yield. After August, the grass yield was negatively related to the yield and the population density of R. obtusifolius. From the facts described above, R. obtusifolius seems to reduce grass yield throughout the year, especially …