Plant Pathology Commons^™

Does Litter Decomposition Rate Indicate Species Status In The Plant Community Of Alpine Meadow?, Yongchao Zhang, Decao Niu, Tong Han, Dianye Zhang, Hua Fu

IGC Proceedings (1977-2023)

Litter decomposition is the physical and chemical breakdown of dead plant material, which is affected by the litter quality, environmental conditions and the composition of decomposer communities (Parton et al. 2007). Within biomes, environmental conditions set a similar background broadly (Berg et al. 1993; Moore et al., 2001; Raich et al. 2006; Parton et al. 2007) and microbial communities are assumed to be ‘functionally equivalent’ in terms of carbon metabolism (Andrén and Balandreau 1999). Consequently, litter quality has been considered as the predominant control on the rate of decomposition of organic matter in the ecosystem (Cornwell …

Effect Of Slope Aspect On Arbuscular Mycorrhizal Colonization Of Centipedegrass In A Hill Pasture, Manabu Tobisa, Yoshinori Uchida, Yoshinori Ikeda

IGC Proceedings (1977-2023)

Arbuscular mycorrhizal fungi (AMF) form a symbiotic association with more than 80% of terrestrial plants and benefit their hosts principally by increasing uptake of nutrients. This is particularly important for phosphorus uptakes as fungal extraradical mycelium can access relatively immobile phosphate ions through an ability to grow beyond the phosphate depletion zone that rapidly develops around the root (Gosling et al. 2006). This symbiotic association is known to promote growth and improve drought and disease resistance of the host plants (Gosling et al. 2006). Centipedegrass (Eremochloa ophiuroides (Munro) Hack.) is a warm-season perennial that is native to central …

The Characters Of Soil Microbial Biomass And Metabolic Quotient Associated With Shrub Development In The Arid Region, Hongyang Chen, Decao Niu, Shigao Jiang, Li Liu, Caixia Wu, Hua Fu

IGC Proceedings (1977-2023)

Soil microbial biomass (MBC), as the most active of soil organic constituents, controls many important ecological processes in the ecosystem including nutrient cycling and litter decomposition (Jia et al. 2010), and is considered to be the most sensitive biological indicator of soil quality (Sinha et al. 2009). Moreover, soil microbial metabolic quotient (qCO2) reflects the quantity and quality of soil organic matter, soil nutrient availability, microbial substrate utilization efficiency and ecosystem stability (Mao et al. 2010). Shrub is the dominant vegetation of desert ecosystems, contributing to soil nutrient conservation and carbon sequestration. Considerable research related to shrubs in desert …

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 …