Plant Pathology Commons^™

Isolation Of Root Endophytic Bacteria In Elephant Grass (Pennisetum Purpureum Schum.) Cultivars, José C. B. Dubeux Jr., João Tiago Correia Oliveira, Karina Rodrigues De Miranda, Mario De Andrade Lira Jr., Mércia V. F. Dos Santos, Mario De Andrade Lira, Erinaldo Viana De Freitas

IGC Proceedings (1977-2023)

Elephant grass (Pennisetum purpureum Schum.) is one of the most productive warm-season grasses. Farmers utilize elephant grass in different forms, such as cut-and-carry operations, grazing, conserved forage (silage, hay), and as an energy source (Lira et al. 2010). Nitrogen (N) is an essential element for plant growth and development and it is usually a limiting factor for forage production in the tropics (Boddey et al. 2004). Biological N fixation (BNF) may occur in warm-season grasses by their association with diazotrophic bacteria. These bacteria colonize different niches in the host plant. Endophytic bacteria form colonies inside the plant tissue …

Pernambuco Semiarid Native Rhizobial Populations Nitrogen Fixation Potential With Native Macroptilium, Mércia V. F. Dos Santos, Rerisson Jose Cipriano Dos Santos, Mario De Andrade Lira Jr., Márcio V. Da Cunha, José C. B. Dubeux Jr., Eunice Maria De Souza, Alexandre C. L. De Mello, Vicente Imbrosi Teixeira

IGC Proceedings (1977-2023)

Nitrogen (N) is one of nature´s most abundant elements, accounting for about 78% of the atmospheric gases, but mostly as the inert N₂ form. As such it is not directly available to plants, and is relatively scarce in most agroecosystems. Biological nitrogen fixation (BNF) through diazotrophic bacteria represents ca. 63% of the yearly N input in terrestrial ecosystems (Taiz and Zeiger 2004). Legumes which form effective symbiosis with the diazotrophic group of bacteria commonly known as rhizobia, are a very important source of available N. Tropical forage legumes are usually able to nodulate with a diverse population of rhizobia, …

Microbial Community Response To Various Degrees Of Pasture Soil Disturbance, Pieter A. Swanepoel, Philip R. Botha, Johan Habig

IGC Proceedings (1977-2023)

Commercial dairy farming from planted pasture is commonly practised in the southern Cape region of South Africa. These pastures are established by various methods ranging in degree of disturbance from no-tillage to conventional tillage. Different establishment methods may alter the below-ground ecosystem, and depending on the degree of disturbance, lead to changes in microbial biodiversity and soil health. Disturbance of pasture soil may play an important role in regulating soil microbial community structure. The aim of this study was to investigate changes in soil microbial community-level physiological profiles of kikuyu (Pennisetum clandestinum) pastures reinforced with annual ryegrass ( …

Rehabilitating Degraded Frontage Soils In Tropical North Queensland, Trevor J. Hall

IGC Proceedings (1977-2023)

The extensive tropical grasslands of north Queensland are grazed by beef cattle and provide a significant proportion of the water flowing into the Great Barrier Reef (GBR) lagoon. Soil sediments and nutrients eroding from the grazing lands of the Burdekin and Fitzroy catchments in north-east Queensland contributes to reduced water quality in the GBR lagoon. Degraded and eroded D-condition bare areas and eroding gullies in grazing lands provide a disproportionate amount of soil and nutrient losses from predominately native pasture grasslands used for cattle grazing. Rehabilitating these degraded areas will help improve water quality flowing onto the reef.

Rehabilitation methods …

Relationship Between Soil Chemical And Physical Properties And Vegetation In The Latest Decade Of Alpine Grasslands Of Southern Qinghai, China, Sachiko Idota, Jiahua Yang, Manabu Tobisa, Xiaoqin Li, Guomei Li, Rende Song, Haizhu Li, Nobumi Hasegawa, Masahiro Tasumi, Naoyuki Yamamoto, Aya Nishiwaki, Yasuyuki Ishii

IGC Proceedings (1977-2023)

The Tibetan Plateau is one of the most important ecosystems in the world (Yang et al. 2009), particularly because of the global importance of its climate (Tian et al. 2008; Wang et al. 2008). Grassland ecosystems on the plateau are sensitive to global change, because the plateau is located in marginal land areas where the growth and distribution of plants depend heavily on local climatic conditions (Zhang et al. 1996). The alpine grassland of Qinghai Province in China has been traditionally used for extensive grazing by sheep and yak (Bos grunniens), but is now degraded from …

Vegetation Changes Following Biosolids Applications At An Old Boer Lovegrass Pasture In Northern Sonora, México, Martha R. Martin, Fernando F. Ibarra, Salomón M. Moreno, Alfredo V. Aguilar, Francisco B. Denogean, Fernando M. Ibarra, Felix A. Ayala, Ana D. Martinez

IGC Proceedings (1977-2023)

Short grass prairies (Bouteloua-Aristida) are the main vegetation type in northern Sonora, México, however, factors such as land fragmentation, overgrazing, severe droughts and lack of infrastructure in most ranches poor grazing management has caused land degradation. Boer lovegrass (Eragrostis curvula var. conferta) is an introduced species planted to increase productivity on deteriorated rangelands. Forage production with Boer lovegrass increases two to three fold as compared to native grasses after range seeding but productivity declines as stands become old. Biosolids have been recognized as a useful soil amendment and source of nitrogen, phosphorus, organic matter and other …

Diversity Of Soil Biota In Canadian Grasslands In Relation To Agricultural Cropping Systems, Owen Olfert, N. Melnychuk, R. Weiss

IGC Proceedings (1977-2023)

The Prairie Ecozone of the northern Great Plains of North America is a major contributor to world food production, encompassing the majority of the Canada's productive agricultural cropland, rangeland, and pasture. This has come with some ecological costs. Only small remnants of native short-grass prairie remain and field boundary habitats at best provide only narrow corridors between these remnant natural areas. The desire to maintain the capacity of the soil to sustain biological productivity has positively influenced the study of soil biota that contribute to the quality and health of our prairie soils. Soil meso-fauna (mites, millipedes, collembolans) also are …

Soil Invertebrates Of Lasiurus Sindicus Based Grazing Lands: Impact Of Management And Grazing Intensity, Sharmila Roy, N. R. Panwar, C. B. Pandey

IGC Proceedings (1977-2023)

Arid Western plains of India are dominated by pasture and grazing lands. Lasiurus sindicus (LS) is the dominant na-tive grass species growing on sandy plains and low dunes under the low rainfall extreme desert climate. Palatability and higher crude protein (8-14% in early vegetative growth, 4-6% in 80-120 days of growth) make this grass a highly preferred grazing species. Since drought is frequent (47%) in this part of the country the LS grasslands are under tremendous grazing pressures and classified under poor or very poor condition for livestock. It is imperative to re-store the natural resources on which this grassland …

Investigation Of The Fire Effects On Some Physico-Chemical Characteristics Of Soil (Case Study: Miankaleh Rangeland, Iran), Mohammadreza Tatian, Reza Tamartash, Maedeh Yousefian, Fatemeh Montazeri, Mehdi Jafari

IGC Proceedings (1977-2023)

Fire is one of the ecological factors that can have positive and negative effects on ecosystem processes. Nevertheless, prescribed burning is considered to be an important tool for grassland management, particularly to manipulate the balance between grasses and shrubs (Scheintaub et al. 2009). In Iran, for example, Khodagholi et al. (2001) in the Samirom rangelands of Isfahan Province suggest that fire reduces the shrubs cover and production and leads to the expansion of grasses. Sharifi and Imani (2006) showed that in the semi-steppe of Khalkhal Province shrub cover decreased in contrast to permanent grasses after fire was applied. …

Subsoil Acidity Determines Survival Of Lucerne On A Highly Acidic Soil, Guangdi Li, Mark Conyers, Richard Lowrie, Graeme Poile

IGC Proceedings (1977-2023)

Lucerne (Medicago sativa) is one of most productive perennial species in southern Australia. However, productivity is severely restricted under acid soils (Irwin et al. 2001). Fenton et al. (1996) reported that lucerne performs poorly if soil pH was below 5 and exchangeable aluminium was over 5%. It is estimated that there are 24 m ha of acidic subsoil in southern Australia (Dolling et al. 2001). A long-term liming experiment, 1992 to 2010, aimed to ameliorate subsoil acidity via a vigorous liming program (Li et al. 2001). This paper reports survival of lucerne during the …

Increasing Pasture Production On Drained Saltland, Penny Roberts Craig, Freya Hawker, Amanda L. Bonython, Andrew Craig

IGC Proceedings (1977-2023)

The Upper South East of South Australia has been identified as being at risk of extensive soil degradation, with large areas already affected by dryland salinity and waterlogging. To mitigate this, an extensive network of drains has been installed. In 2009, 19 soil surveys were conducted on land adjacent to a number of deep drains (> 1.0 m) in order to determine soil salinity and pH. The surveys indicated low levels of topsoil salinity (0-10 cm) in the southern part of the region, while 66% of soil sampling sites in the northern zone had salinity levels (ECe) below 4 dS/m. …

Comparing Soil Compaction Under Different Grazing Systems With A Virgin Forest Soil To Determine Optimal Stocking Rates, Wellington W. Rocha, Bruno S. Pires, Moacir S. Dias Junior, Rita De C. R. Carvalho

IGC Proceedings (1977-2023)

The understanding of how soil physical properties respond to differing grazing practices may help explain the main causes of pasture degradation. Soil compaction has been shown to be a main degradation form of soil and the knowledge of techniques to quantify and rectify this are necessary to maintain optimal yields. This research aims to measure the rupture lines of red yellow latossol under differing pasture grazing practices compared to cropping and a natural forest. With this information it is aimed to calculate the correction factor for stocking rates and traffic of tillage tools. The differing soil management practices examined was, …

Establishing Baseline Values For Soil Quality Indicators In The Southern Cape Of South Africa, Pieter A. Swanepoel, Philip R. Botha, Chris C. Du Preez, Hennie A. Snyman

IGC Proceedings (1977-2023)

Commercial dairy farming on pasture is commonly practiced in the southern Cape region of South Africa. In terms of its sustainability, quantification of the impact of dairy-pasture management on soil quality is essential. To comprehend the behaviour of soils in terms of quality, indicators should be assessed to screen the general direction of soil quality within a management system. Development of a soil quality assessment framework necessitates establishment of baseline values for soil quality indicators. The aim of this study was to establish baseline values for soil quality indicators for dairy-pasture soils in the southern Cape. Physical, chemical and biological …

Soil Carbon And Nitrogen Stocks And Their Relationship With Plant And Soil Dynamics Of Degraded And Artificial Restoration Grasslands In An Alpine Region, Yuanyuan Li, Shikui Dong, Yu Wu

IGC Proceedings (1977-2023)

Land disturbances and management approaches can significantly alter grassland soils. Therefore, understanding the carbon and nitrogen storage accompanying plant and soil physical and chemical properties due to anthropogenic disturbance and different management strategies is important. In our study, we investigated carbon and nitrogen storage in artificial grasslands with different durations of restoration and native grasslands with different levels of degradation. We found that total carbon and nitrogen were significantly higher five years after restoration than after seven and nine years, but decreased due to grassland degradation. Furthermore, soil carbon and nitrogen had a close relationship with plant and soil factors, …

Benefits And Uses Of Nematodes In Grassland Soils, Michael J. Wilson

IGC Proceedings (1977-2023)

To most grassland farmers nematodes mean trouble: they are important parasites of both pasture plants and livestock. While there is no doubting the considerable losses caused by nematodes, crop and livestock pests represent a tiny minority of the approximately 26,000 described nematode species. Here I examine the beneficial effects of nematodes within grassland systems and their beneficial uses. Nematodes in grassland soils increase plant available nutrients, move beneficial microbes through the rhizosphere and control insect and mollusc herbivores. We can use nematodes as biological control agents, and also as indicators of soil health/quality. While no single group of organisms can …

Assessment Of Methane Production By Goats Under Intermittent Grazing, Naomi C. Meister, Nailson L. S. Lemos, Fernando O. Alari, Victor C. Silva, William Koury Filho, Ana C. Ruggieri

IGC Proceedings (1977-2023)

There are 875 million goats worldwide (FAO 2012) and the majority are in developing countries where they are typically raised on pasture. Ruminants release gross energy as methane, which is a greenhouse gas. Mthane mitigation strategies require prior knowledge about emission of methane by animals under different management systems. Intake, quality and type of feed are factors that influence methane emissions, therefore the objective of this study was to investigate how grazing intensity, measured by the residual leaf area index (RLAI), influences methane emission by goats under rotational grazing on Tanzania grass pasture.

Effects Of Different Feed Additives On Methane Emissions From Beef Cattle, P. Giraldo, A. Marín, L. A. Giraldo

IGC Proceedings (1977-2023)

The rate of accumulation of methane in the atmosphere from enteric fermentation in cattle has an important impact on the greenhouse effect and contributing to global warming. Additionally, methane emission reduces the energy efficiency of substrate fermention in the rumen. Under-standing the effect of the diet on enteric methane emissions could help to identify strategies to reduce emissions of this greenhouse gas. Therefore, the main objective of the present investigation was to determine the effect of nutritional additives such as monensin, fumaric acid, tannins of Acacia decurrens, and glycerol on methane production and other measures of fermentation characteristics using …

Effect Of Time Of Access To Pasture And The Provision Of A Total Mixed Ration On The Performance And Methane Production Of High Yielding Dairy Cows, Joyce Mufungwe, S. Mark Rutter, Robert G. Wilkinson, Jim A. Huntington, Liam A. Sinclair

IGC Proceedings (1977-2023)

Allowing cows to spend time on pasture may improve their welfare, although high yielding cows are unable to consume sufficient amounts of grass to maintain milk yield and require supplementation (Charlton et al. 2011). The inclusion of grass in the diet of high yielding cows may have benefits as grass contains polyunsaturated fatty acids which can reduce methane production (Martin et al. 2008). Additionally, the soluble carbohydrate content in grass is higher in the afternoon which may increase intake (Trevaskis et al. 2004). The aim of the experiment was to determine the effects of timing of pasture …

Methane Emissions By Lactating Ewes Grazing Italian Ryegrass, Jean V. Savian, Armindo B. Neto, Radael M. T. Schons, Leonardo Barreto Maass, Diego B. De David, Teresa C. M. Genro, Cimélio Bayer, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

Agriculture contributes 13.5% of global emissions of greenhouse gases (GHG) (IPCC 2007), and about 50% of CH4 and 60% N₂O from anthropogenic sources, while livestock contributes an additional 18% of global GHG emissions (FAO, 2006). Among the various sources with a potential negative impact on the environment, methane emissions for which livestock are mainly responsible have been highlighted for the agricultural sector. Studies on means to mitigate these emissions, and understand how integrated crop and livestock production systems may contribute to the reduction of greenhouse gases, are essential for the creation of public policies for environmental preservation.

The …

Radiant Temperature Of Cattle According To Rangeland Environment And Breed, Luciano A. González, Anne-Sophie Clerc, Christopher J. O’Neill

IGC Proceedings (1977-2023)

Heat stress can reduce growth rate and reproduction of beef cattle in tropical regions, which might be accentuated under a scenario of climate change. Adaptation of breeds, acclimatisation of individuals, and shade (natural or artificial) can be used to mitigate heat stress in cattle with body temperature used as an indicator (Finch 1977). In the past few years, infrared temperature (IRT) of the eye and hide have been used as an indicators of core body temperature for disease detection and heat produced (Schaefer et al. 2012; Montanholi et al. 2008). IRT could become an automatic and remote measurement …

The Effectiveness Of Greenhouse Gas Abatement Strategies For The Dairy Industry In South-Western Victoria, Australia, Mao-Heng Kuo, Brendan R. Cullen

IGC Proceedings (1977-2023)

In Australia, the dairy industry generates 8.9 million tonnes of carbon dioxide equivalents (t CO₂e) per year (Christie et al. 2011). Most greenhouse gas (GHG) emissions from the dairy sector are high global warming potential gases such as methane (CH₄) from enteric fermentation and nitrous oxide (N₂O) from cattle urine and nitrogen (N) based fertilizers, contributing to climate change issues. Several GHG abatement options are available to dairy farmers, including increasing diet quality, feeding oils and reducing replacement rates (Eckard et al. 2010), but little assessment of their effectiveness has been carried out …

In Vitro Screening Of Tropical Forages For Low Methane And High Ammonia Generating Potential In The Rumen, Thakshala Seresinhe, A. N. F. Perera

IGC Proceedings (1977-2023)

Goat farming is a livelihood activity which helps ensure food security for small and marginal farmers, landless labourers and rural folk in Sri Lanka. Goats are fed on a diverse range of tree leaves which are their primary food source in rural areas, whereas in peri-urban areas they are fed with other feedstuffs due to limited supply of tree leaves (Seresinhe and Marapana 2011). The poor growth performance of local goats is associated with low digestibility of feeds which may be due to the presence of condensed tannins (CT) present in the feed. Therefore, this study evaluated the suitability of …

Effects Of Fibrolytic Enzymes On In Vitro Ruminal Fermentation And Methane Production From Panicum Maximum (Wild Guinea Grass--Ecotype A) And Rice Straw (Oryza Sativa), Thakshala Seresinhe, R. Mayes, N. E. Odongo

IGC Proceedings (1977-2023)

The wide gap between an animal’s energy requirement and the nutrients available from feeds is a major constraint in animal productivity and should urgently be addressed with novel methods to improve feed utilization and efficiency (Murad and Azzaz 2010). Forages such as Guinea grass (Panicum maximum) and agricultural by products such as rice (Oryza sativa) straw play a vital role as animal feeds in the tropics. However, the total energy requirement of animal cannot be met due to the high fiber content and low digestibility of these feeds. The low digestibility of these feeds not only …

Making Decisions To Identify Forage Shrub Species For Versatile Grazing Systems, Jason Emms, Philip E. Vercoe, Steve J. Hughes, Peter Jessop, Hayley C. Norman, Tanya Kilminster, Andrew Kotze, Zoey Durmic, Nathan Phillips, Dean K. Revell

IGC Proceedings (1977-2023)

Grazing systems in many parts of the world face large challenges, including a declining natural resource base (e.g. soil fertility), marked fluctuations in feed production across seasons and years, climate change (including the contribution of greenhouse gases from livestock), and market demands for sustainable and ethical production systems. The ‘Enrich’ project was established in Australia (Revell et al. 2008; Bennell et al. 2010) within this broad context of emerging challenges to explore the potential of using Australian native perennial shrub species as part of the feedbase for sheep and cattle in southern Australia. The underlying rationale was …

Planet At Risk From Grazing Animals?, Albrecht F. Glatzle

IGC Proceedings (1977-2023)

The famous FAO report “Livestock’s Long Shadow” (Steinfeld et. al. 2006) and hundreds of subsequent publications blamed domestic livestock, in general, and grassland-based production systems in the (sub) tropics, in particular, of causing serious environmental hazards such as climate change, claiming that 18% of anthropogenic greenhouse gas (GHG) emissions are from livestock, more than from the transport sector. Few reviews challenged this claim, and those that did received little attention from the media. Pitseky et al. (2009) revealed the double standard applied by the FAO in this matter. Whereas for livestock products a full life cycle assessment for …

Adaptation Strategies Of Breeders Facing Global Change In Harsh Conditions, Luming Ding, Shikui Dong, Ibrahim Daoud, Enzo Fasioli, Ruijun Long, Véronique Alary, Fernando Coronato, Mona Abdelzaher, Adel Aboul Naga, Alejandro Schweitzer, Thierry Bonaudo, Jean François Tourrand

IGC Proceedings (1977-2023)

Global changes impact breed societies through complex and diverse factors such as global economics, climate change, management and degradation of rangelands, societal demands especially from youth, and new technologies including information and communication technologies. The main objective of this research developed by Livestock farming and local development network (LiFLod, http://liflod.org/) network is to better understand the mental models of local stakeholders for global change and adaptation strategies. Our hypothesis is that in harsh conditions breeders with diverse objectives adopt more or less similar strategies when faced with global change.

Adapting Livestock Production Systems To Climate Change In Nepal: Challenges And Opportunities, D. D. Poudel, R. P. Thakur, T. Duex, G. Blakewood, A. Singh, A. Deramus, B. Chapagain, K. Acharya, S. Adhikari, R. B. Gramling, N. Sharma

IGC Proceedings (1977-2023)

To assess climate change impacts and identify challenges and opportunities for livestock climate change adaption, we conducted a comprehensive study in the Thulokhola watershed of Nuwakot district in Nepal from June 1, 2011 to January 31, 2013. We established nine community livestock groups (CLGs) consisting of 51 members and trained the CLG members in daily livestock record keeping and monitoring surface water quality. Monthly fecal samples from 50 cattle, 50 goats, and 50 buffaloes were collected for the determination of gastrointestinal parasites. Soil and fodder samples were also collected and analyzed. Group discussions, Participatory Rural Appraisals, and full-fledged household survey …

Adaptation To Climate Change In Mixed Crop-Livestock Farming Systems In Developing Countries, Philip K. Thornton, Mario Herrero

IGC Proceedings (1977-2023)

Globally, crop-livestock systems produce over 90% of the world's milk supply and 80% of the meat from ruminants. Mixed crop-livestock systems are particularly important for livelihoods and food security, as they provide most of the staples consumed by poor people. These systems will be under considerable pressure in the coming decades to help satisfy the burgeoning demand for food from rapidly increasing populations, particularly in sub-Saharan Africa and South Asia, where rural poverty and hunger are already concentrated. At the same time, the impacts of climate change will be increasingly heavily felt. Increases in temperatures and changes in the amounts …

Impacts Of Climate Change On Livestock Systems: What We Know And What We Don’T Know, Mark Howden, S. Schroeter, S. Crimp, C. Stokes

IGC Proceedings (1977-2023)

Climate changes and the associated increases in atmospheric carbon dioxide concentration are just two of many possible future drivers of change in grassland systems and whilst there are significant uncertainties around these, they are probably more effectively characterised than many other drivers. The challenge for grasslands systems research is not so much trying to precisely predict future climate in the face of unresolvable uncertainty but rather to work with decision-makers to enhance their decisions for a range of possible climates, build their capacity to make sound risk-based and informed decisions and increase the array of options available for adaptation. There …

Photosynthetic And Growth Response Of Triodia Pungens To Elevated Co2 Concentration, Lisa Xian, Susanne Schmidt, Fernanda Dreccer, Paul Memmott

IGC Proceedings (1977-2023)

Triodia (“spinifex”) is a widely distributed endemic C4 grass genus in Australia. Triodia species form the hummock grasslands which is one of Australia’s dominant vegetation types covering approximately 30% of the continental land mass in the arid zone. Hummock grasslands are commonly used as rangelands and Triodia plays an important role in the ecosystem by providing habitat for arid fauna and maintaining arid lands vegetated.

Currently, Triodia survive extreme temperatures, water deficit and low nutrient availability. Predicted changes for Australia’s arid climate under elevated atmospheric CO₂ (eCO₂) include reduction in rainfall and higher daily average temperatures in …