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2019

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Articles 181 - 210 of 1656

Full-Text Articles in Earth Sciences

Animal Performance And Productivity Of A New Cultivar Of Brachiaria Brizantha, Valéria P. B. Euclides, Denise B. Montagner, Cacilda B. Valle, Nayana N. Nantes Dec 2019

Animal Performance And Productivity Of A New Cultivar Of Brachiaria Brizantha, Valéria P. B. Euclides, Denise B. Montagner, Cacilda B. Valle, Nayana N. Nantes

IGC Proceedings (1977-2023)

Brazil has the competitive advantage of a very dynamic and cost-effective animal production system on pastures over other countries. The pursuit of more productive forages that will result in higher quality beef at a lower cost is justified. As Brachiaria is the most important forage genus utilised in Brazil, an intense search for new cultivars amongst collected and introduced ecotypes from Africa is underway. Following agronomic evaluation of this material in plots, 8 Brachiaria ecotypes were pre-selected. As part of Embrapa`s process of cultivar development, B. brizantha cv. Xaraés, characterised by high productivity (liveweight gain/area), was released in 2003, followed …


Performance Of Young Nellore Bulls Grazing Marandu Grass Pasture At Different Heights, Ricardo A. Reis, Andre L. S. Valente, Sharadinny M. C. Dos Santos, Fernando H. M. De Souza, Telma T. Berchielli, Ana C. Ruggieri, Sabrina S. Santana, Juliana M. Serra Dec 2019

Performance Of Young Nellore Bulls Grazing Marandu Grass Pasture At Different Heights, Ricardo A. Reis, Andre L. S. Valente, Sharadinny M. C. Dos Santos, Fernando H. M. De Souza, Telma T. Berchielli, Ana C. Ruggieri, Sabrina S. Santana, Juliana M. Serra

IGC Proceedings (1977-2023)

Brazil is one of the largest beef cattle producers in the world with approximately 200 M head. The Industry relies predominantly on warm-season grass pastures, with approximately 90% of animals finished on pastures.

One of the main factors for the intensification of animal production systems based on pasture is appropriate management. Adjustment of stocking rate to maintain optimum forage allowance is essential. Studies on forage allowance have resulted in a better understanding of the response of forage crops and animals to changes in grazing intensity.

The purpose of this study was to evaluate management strategies for beef cattle systems grazed …


Seasonal Expression Of Apospory In Bahiagrass, Esteban F. Rios, Ann R. Blount, Kevin E. Kenworthy, Carlos A. Acuña, Kenneth H. Quesenberry Dec 2019

Seasonal Expression Of Apospory In Bahiagrass, Esteban F. Rios, Ann R. Blount, Kevin E. Kenworthy, Carlos A. Acuña, Kenneth H. Quesenberry

IGC Proceedings (1977-2023)

Flowering plants can reproduce sexually (outcrossing and/or selfing) and/or asexually. Sexual reproduction implies the successful completion of meiosis and double fertilisation for the formation of both the embryo and the endosperm. In contrast, gametophytic apomixis is an asexual mode of reproduction through seeds that involves parthenogenetic embryo development from a cytologically unreduced egg cell (2n). Apospory is the process by which unreduced gametophytes are formed after a series of mitotic divisions of somatic cells (2n) in the ovary. This occurs independently from the sexual meiotic process; and therefore, both sexual and apomictic pathways may coexist simultaneously. Apospory is inherited in …


Morphogenic Responses Of Two Brachiaria Genotypes In Response To Clipping Frequency, Ana Flávia G. Faria, Carlos G. S. Pedreira, Diego N. L. Pequeno, Liliane S. Silva, Damião W. Nguluve, Aliedson S. Ferreira Dec 2019

Morphogenic Responses Of Two Brachiaria Genotypes In Response To Clipping Frequency, Ana Flávia G. Faria, Carlos G. S. Pedreira, Diego N. L. Pequeno, Liliane S. Silva, Damião W. Nguluve, Aliedson S. Ferreira

IGC Proceedings (1977-2023)

Tropical grasslands represent an important resource for the Brazilian cattle industry, which is heavily dependent on grazed pastures. Total pasture area in the country totals 196 M ha (23% of the country’s land area) (FAO 2013). The genus Brachiaria represents around 85% of cultivated pastures in Brazil (Moreira et al. 2009), 40% of which are established with B. brizantha cv. Marandu (Barbosa 2006). Mulato II is a new hybrid brachiaria grass cultivar which has been developed to improve agronomic characteristics, broaden the range of adaptation, and to ensure high forage production and nutritive value. It has also been viewed …


Sward Structural Characteristics Of Perennial Peanut Genotypes As Affected By Harvest Frequency, Aliedson S. Ferreira, Carlos G. S. Pedreira, Carla M. Marassatto Dec 2019

Sward Structural Characteristics Of Perennial Peanut Genotypes As Affected By Harvest Frequency, Aliedson S. Ferreira, Carlos G. S. Pedreira, Carla M. Marassatto

IGC Proceedings (1977-2023)

Despite the high potential of tropical forage species, herbage production, nutritive value and animal productivity in Brazilian livestock production systems are lower than what can be obtained from both a biological and operational point of view (Pedreira and Mello 2000, Da Silva and Sbrissia 2000). Even with these limitations, the livestock industry is often able to sustain high productivity levels (animal product per hectare) by using good animal genetics and supplementation. Reducing production costs, however, will likely depend on the identification and incorporation of a high-quality forage resource, in terms of both improving diet quality of grazing animals and sustaining …


Morphophysiological Adaptations Of Brachiaria Humidicola Cultivars Under Grazing, Rodrigo A. Barbosa, Pedro N. C. Amaral, André F. Sbrissia, Thiago T. Camara Dec 2019

Morphophysiological Adaptations Of Brachiaria Humidicola Cultivars Under Grazing, Rodrigo A. Barbosa, Pedro N. C. Amaral, André F. Sbrissia, Thiago T. Camara

IGC Proceedings (1977-2023)

Pastures of Brachiaria humidicola are broadly used in Brazil, especially in soils with low fertility and poor drain-age (Valle et al. 2010). Currently, 3 cultivars are commercially available: Tully, Llanero and BRS Tupi (available since 2012). Despite the extensive use of this species, research has focused primarily on aspects related to herbage and animal production, while only a few studies aimed at understanding morphological adaptations of the plants when subjected to grazing and contrasting environmental conditions.

Therefore, the aim of this work was to evaluate some morphological traits of 2 B. humidicola cultivars when continuously stocked during 2 seasons …


Land Cover Change Detection In The Urban Catchments Of Dar Es Salaam, Tanzania Using Remote Sensing And Gis Techniques, Philip Mzava, Joel Nobert, Patrick Valimba Dec 2019

Land Cover Change Detection In The Urban Catchments Of Dar Es Salaam, Tanzania Using Remote Sensing And Gis Techniques, Philip Mzava, Joel Nobert, Patrick Valimba

Tanzania Journal of Science

In this study, the Maximum Likelihood (ML) classification, Normalized Difference Vegetation Index (NDVI) and Artificial Neural Network (ANN) methods were applied to three (3) Landsat images collected over time (1979, 1998 and 2014), that contained historical land cover features for the urban catchments of Dar es Salaam. Five major land cover classes were identified, mapped, and the land cover changes investigated. The major land cover changes observed from post-classification comparisons of the classified images are: the forest land losing 17.09% of its area in the period 1979-1998 to other land covers, mainly turning to grassland, and from 1998 to 2014, …


Phytoremediation Potential Of Four Heavy Metals In Soil By Chromolaena Odorata (L.) King & Robinson At The Phytotoxicity Screening Benchmarks, Gloria O. Omoregie, Beckley Ikhajiagbe, Geoffery O. Anoliefo Dec 2019

Phytoremediation Potential Of Four Heavy Metals In Soil By Chromolaena Odorata (L.) King & Robinson At The Phytotoxicity Screening Benchmarks, Gloria O. Omoregie, Beckley Ikhajiagbe, Geoffery O. Anoliefo

Tanzania Journal of Science

The remediative capacity of Chromolaena odorata with respect to heavy metal induced growth-stress was investigated. This was with a view to providing information on the adaptive mechanisms adopted by the test plant during the phytoremediation of selected heavy metals such as copper, manganese, zinc and cadmium. Stems of C. odorata were planted in soils polluted with  Mn, Zn, Cd, and Cu at the ecological screening benchmark (ESB) of 50 mg/kg (Mn and Zn), 4 mg/kg (Cd) and 100 mg/kg (Cu) of metal per kilogram of soil, in varying concentrations of 0 ESB (control), 1 ESB, 3 ESB and 5 ESB. …


Quantitative Assessment Of Resistivity Anisotropy In Evaluation Of Laminated Shaly Sand Hydrocarbon Reservoirs–A Case Study In The Barents Sea, Norway, Ernest S. Mulaya Dec 2019

Quantitative Assessment Of Resistivity Anisotropy In Evaluation Of Laminated Shaly Sand Hydrocarbon Reservoirs–A Case Study In The Barents Sea, Norway, Ernest S. Mulaya

Tanzania Journal of Science

Resistivity anisotropy in shaly sand lamination sequences affects the hydrocarbon evaluation in multiple dimensions of petrophysical logs. Currently, vertical resistivity (Rv) and horizontal resistivity (Rh) from 3D triaxial induction measurements can be applied simultaneously to resolve these petrophysical impacts. In this paper, an extensive analysis is offered with a focus on the hydrocarbon evaluation based on advanced petrophysical logs from a well. A critical analysis is done on the three comparable cases including clean formation as a base case, shaly sand case and laminated shaly sand case towards resolving resistivity anisotropy in a typical shaly sand laminated reservoir. The analysis …


Vegetative Propagation Of Stylosanthes Scabra, Alexandre C. L. De Mello, Adeneide C. Galdino, José C. B. Dubeux Jr., Mércia V. F. Dos Santos, Mário De A. Lira Jr., Felipe M. Saraiva, Mário De A. Lira, Márcio V. Da Cunha Dec 2019

Vegetative Propagation Of Stylosanthes Scabra, Alexandre C. L. De Mello, Adeneide C. Galdino, José C. B. Dubeux Jr., Mércia V. F. Dos Santos, Mário De A. Lira Jr., Felipe M. Saraiva, Mário De A. Lira, Márcio V. Da Cunha

IGC Proceedings (1977-2023)

One way to multiply genetically desirable plants in a more uniform manner is to use vegetative propagation, such as using plant cuttings. This technique multiplies a single plant into several, in an easy low-cost system (Fachinello et al. 2005), so it is useful in plant breeding. This technique may be enhanced through the use of hormonal regulators, with indolebutyric acid (IBA) being most frequently used, because of its stability in hydroalcoholic solution, low sensitivity to biological degradation and good establishment of adventitious roots (Fachinello et al. 1995). In spite of its large-scale use for fruit production, the technique …


Effects Of Two Intake Levels Of Leucaena Leucocephala On Rumen Function Of Sheep, Marcos Barros-Rodríguez, Javier Solorio-Sánchez, Carlos Sandoval-Castro, Athol V. Klieve, Eduardo Briceño-Poot, Luis Ramírez-Avilés, Rafael Rojas-Herrera Dec 2019

Effects Of Two Intake Levels Of Leucaena Leucocephala On Rumen Function Of Sheep, Marcos Barros-Rodríguez, Javier Solorio-Sánchez, Carlos Sandoval-Castro, Athol V. Klieve, Eduardo Briceño-Poot, Luis Ramírez-Avilés, Rafael Rojas-Herrera

IGC Proceedings (1977-2023)

Ruminant production systems based on grass pastures often produce poor animal performance as expressed by growth or reproductive rates. The nutrient imbalance affecting rumen function is due to their low energy and protein intake. The incorporation of leguminous forages such as Leucaena leucocephala, in the diet of ruminants, can stimulate rumen function by providing protein-rich forage (Barros-Rodriguez et al. 2012). This increases the availability of compounds such as ammonia, amino acids and peptides as well as branched short-chain fatty acids, which are produced as a result of degradation of proteins. These substances promote fibre breakdown by acting as ruminal …


Survey Of Pasture Species And Management, Manure Management, Milk Production And Reproduction On Pasture-Based Dairy Farms In Florida And Georgia, Usa, F. Du, K. D. Gay, M. E. Sowerby, Y. C. Newman, C. R. Staples, R. C. Lacy, A. De Vries Dec 2019

Survey Of Pasture Species And Management, Manure Management, Milk Production And Reproduction On Pasture-Based Dairy Farms In Florida And Georgia, Usa, F. Du, K. D. Gay, M. E. Sowerby, Y. C. Newman, C. R. Staples, R. C. Lacy, A. De Vries

IGC Proceedings (1977-2023)

Traditionally, most dairy farms in the south-eastern United States confine cows to barns or on pasture lots year-round and feed stored forages and concentrated feeds (Fontaneli et al. 2005). Often, much of the feed is purchased, however, the cost of purchased feed and fuel has risen rapidly in the last 5 years (NASS 2009). In addition, a significant amount of capital is tied up in buildings, machinery and manure management systems on the farms. For these reasons, many dairy farmers have shown an interest in or started transitioning to pasture-based dairy systems (Ricks and Hardee 2012). The management practices …


Breeding Strategies For Brachiaria Spp. To Improve Productivity–An Ongoing Project, Geovani F. Alves, Ulisses J. De Figueiredo, Antônio D. Pandolfi Filho, Sanzio C. L. Barrios, Cacilda B. Valle Dec 2019

Breeding Strategies For Brachiaria Spp. To Improve Productivity–An Ongoing Project, Geovani F. Alves, Ulisses J. De Figueiredo, Antônio D. Pandolfi Filho, Sanzio C. L. Barrios, Cacilda B. Valle

IGC Proceedings (1977-2023)

Two strategies have been used in the breeding of Brachiaria (syn. Urochloa) to produce new cultivars. The first involves exploring the natural variability existing in nature, which is the selection of ecotypes, mostly apomicts, from the diversity in germplasm banks. This strategy proved efficient originally and the cultivars in use in Brazil were derived in this way, but progress with this strategy is limited in the medium to long term.


Dry Matter Intake By Beef Steers On Piatã Palisadegrass (Brachiaria Brizantha Cv. Brs Piatã) Pasture, Denise B. Montagner, Valéria P. B. Euclides, Teresa C. M. Genro, Nayana N. Nantes Dec 2019

Dry Matter Intake By Beef Steers On Piatã Palisadegrass (Brachiaria Brizantha Cv. Brs Piatã) Pasture, Denise B. Montagner, Valéria P. B. Euclides, Teresa C. M. Genro, Nayana N. Nantes

IGC Proceedings (1977-2023)

Beef production in Brazil is primarily based on tropical pastures and 85% of these pastures are Brachiaria brizantha cv. Marandu. Such a monoculture could prove disastrous if some pest or disease emerged. With the goal of further diversifying pastures and contributing to the sustainability of the pasture production system, B. brizantha cv. BRS Piatã was released by the Brazilian Agricultural Research Corporation (Embrapa). Little is known about the characteristics of this cultivar in relation to grazing management and plant-animal interactions. Dry matter (DM) intake by grazing animals is influenced by the structural characteristics of tropical grasses (Stobbs 1973, 1975), and …


Agronomic Evaluation Of 324 Intraspecific Hybrids Of Brachiaria Decumbens In Brazil, Rogério G. Mateus, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Cacilda B. Valle Dec 2019

Agronomic Evaluation Of 324 Intraspecific Hybrids Of Brachiaria Decumbens In Brazil, Rogério G. Mateus, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Cacilda B. Valle

IGC Proceedings (1977-2023)

Brachiaria decumbens cv. Basilisk is the most planted pasture grass in the tropics owing to its adaptation to poor and acid soils, typical of the tropics, plus good animal performance. This cultivar was responsible for a radical change of scenario in central Brazil in the early 1970s and is the only cultivar available commercially. Efforts to breed this species have been recent, as the successful somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens was accomplished only in 2009 (Simioni and Valle 2009). Subsequently, intraspecific crosses with natural apomictic tetraploid accessions were carried out. Breeding is needed since …


Effect Of Season And Year Of Evaluation In The Selection Of Brachiaria Humidicola Hybrids, Ulisses J. De Figueiredo, José A. R. Nunes, Cacilda B. Valle, Sanzio C. L. Barrios, Geovani F. Alves Dec 2019

Effect Of Season And Year Of Evaluation In The Selection Of Brachiaria Humidicola Hybrids, Ulisses J. De Figueiredo, José A. R. Nunes, Cacilda B. Valle, Sanzio C. L. Barrios, Geovani F. Alves

IGC Proceedings (1977-2023)

Brachiaria humidicola is well adapted to infertile and acid soils with poor drainage or temporary flooding (Keller-Grein et al. 1996). It is widely used in Brazil in wetlands and areas of marginal land characterised by waterlogged soils. During the evaluation stages of the breeding program of this species, genotypes are generally tested using consecutive cuts within different seasons for at least 2 years. The ‘Cerrado’ region, where most animal production takes place in Brazil, has 2 well defined seasons: spring-summer with warm weather and rain; and autumn-winter with cooler, dry weather. Thus, owing to environmental variation, especially related to …


Effects Of Irrigation And Season On Performance Of Grazed Pastures Of Brachiaria Brizantha Cv. Mg5, Rita De C. R. Carvalho, Wellington W. Rocha, Bruno S. Pires, César T. Piza, Luziney D. Silva, Paulo R. V. Leite, Eliel A. Ferreira Dec 2019

Effects Of Irrigation And Season On Performance Of Grazed Pastures Of Brachiaria Brizantha Cv. Mg5, Rita De C. R. Carvalho, Wellington W. Rocha, Bruno S. Pires, César T. Piza, Luziney D. Silva, Paulo R. V. Leite, Eliel A. Ferreira

IGC Proceedings (1977-2023)

In Brazil, livestock production is based primarily on systems with continuously grazed natural or cultivated pastures (FAO 2009). Intensifying animal breeding, handling and knowledge strategies is necessary to obtain improvements in production indices for economically feasible and sustainable grazing systems (Cedeño et al. 2003). Beef cattle breeding on irrigated pasture, like all forms of intensive grazing, requires the use of forage species with high potential for production and quality, and Brachiaria brizantha cv. MG5 is considered a good option. This study aimed to evaluate the effects of irrigation on the performance of B. brizantha cv. MG5 grazed rotationally by …


Development Of Leucaena Mimosine-Degrading Bacteria In The Rumen Of Sheep In Myanmar, Aung Aung, Moe Thida Htun, Lwin Naing Oo, Mar Mar Kyi, Tin Ngwe Dec 2019

Development Of Leucaena Mimosine-Degrading Bacteria In The Rumen Of Sheep In Myanmar, Aung Aung, Moe Thida Htun, Lwin Naing Oo, Mar Mar Kyi, Tin Ngwe

IGC Proceedings (1977-2023)

Myanmar has an agricultural base, and about 70% of people reside in rural areas. They depend for survival on agriculture and small-scale crop production, with ruminant livestock consuming fibrous agricultural residues. For optimal ruminant production, concentrates are needed as supplements to these residues. As concentrates are expensive, researchers are testing alternative protein sources like legumes, including foliage from leguminous trees such as leucaena (Leucaena leucocephala). Leucaena is the most widely used leguminous tree as a ruminant feed because it is rich in protein (~ 22%) and contains easily digestible fibre (23% neutral detergent fibre, 16.6% acid detergent fibre; …


Development, Isolation And Characterisation Of A New Non-Virulent Mimosine-Degrading Klebsiella Pneumoniae Strain From The Rumen Liquor Of German Steers By Using Ibt-Goettinger Bioreactor, Aung Aung, U. Ter Meulen, F. Gessler, H. Böhnel Dec 2019

Development, Isolation And Characterisation Of A New Non-Virulent Mimosine-Degrading Klebsiella Pneumoniae Strain From The Rumen Liquor Of German Steers By Using Ibt-Goettinger Bioreactor, Aung Aung, U. Ter Meulen, F. Gessler, H. Böhnel

IGC Proceedings (1977-2023)

The tropical legume Leucaena leucocephala (leucaena) has many uses, including: a potential source of firewood and timber; for soil erosion control (Dijkman 1950); to provide shade; to enhance soil fertility; and as a nutritious forage for animal feed (Ruskin 1977). It is widely used as forage for cattle in tropical agriculture (Shelton 1998). In Myanmar, leucaena is used as a protein source in urea-molasses multi-nutrient blocks for ruminants (Ni Ni Maw et al. 2004). However, the use of leucaena as ruminant feed is not without problems, because it contains mimosine, a toxic anti-nutritional factor limiting its use as animal …


Brs Paiaguás: A New Brachiaria (Urochloa) Cultivar For Tropical Pastures In Brazil, Cacilda B. Valle, Valéria P. B. Euclides, Denise B. Montagner, José R. Valério, Celso D. Fernandes, Manuel C. M. Macedo, Jaqueline R. Verzignassi, Luis A. Machado Dec 2019

Brs Paiaguás: A New Brachiaria (Urochloa) Cultivar For Tropical Pastures In Brazil, Cacilda B. Valle, Valéria P. B. Euclides, Denise B. Montagner, José R. Valério, Celso D. Fernandes, Manuel C. M. Macedo, Jaqueline R. Verzignassi, Luis A. Machado

IGC Proceedings (1977-2023)

Approximately half the world’s beef is produced in the tropics and subtropics, almost exclusively on pasture. While the world production of beef and veal increased 91% over the past 40 years, the increase in the tropics was 200%. Brazil has today the largest commercial cattle herd in the world (about 190 M head) and is the world's largest exporter of beef. The area of cultivated pasture increased from 30 to 100 Mha between 1970 and 1995 (IBGE 2006). This area has now stabilised or decreased despite the increase in beef production, which reflects the gain in area productivity. Part of …


Performance Of Nelore Cattle On Panicum Maximum Pastures In The Brazilian Cerrado, Giovana A. Maciel, Gustavo J. Braga, Roberto Guimarães Jr., Hélio A. De Araújo, Allan K. B. Ramos, Marcelo A. Carvalho, Lourival Vilela, Liana Jank Dec 2019

Performance Of Nelore Cattle On Panicum Maximum Pastures In The Brazilian Cerrado, Giovana A. Maciel, Gustavo J. Braga, Roberto Guimarães Jr., Hélio A. De Araújo, Allan K. B. Ramos, Marcelo A. Carvalho, Lourival Vilela, Liana Jank

IGC Proceedings (1977-2023)

With the increased demand for meat products, associated with environmental concerns due to global climatic and land use changes, the need to efficiently use pasture and forage resources will increase (Boval and Dixon 2012). Efforts to breed and release new forage cultivars must incorporate these concerns, ensuring that introduced material is of high quality, especially under grazing (Euclides et al. 2008).

In this study, we aimed to evaluate the average daily weight gain and stocking rate of Nelore beef cattle grazing new genotypes of Panicum maximum during the rainy season in the Brazilian Cerrado.


Morphological Divergence Among Progeny Of Macroptilium Lathyroides Accessions From The Semi-Arid Region Of Pernambuco, Brazil, Mércia V. F. Dos Santos, Gabriella P. De Albuquerque, Márcio V. Da Cunha, Mário De A. Lira Jr., José C. B. Dubeux Jr., Marta G. S. Da Silva, Mário De A. Lira, Alexandre C. L. De Mello Dec 2019

Morphological Divergence Among Progeny Of Macroptilium Lathyroides Accessions From The Semi-Arid Region Of Pernambuco, Brazil, Mércia V. F. Dos Santos, Gabriella P. De Albuquerque, Márcio V. Da Cunha, Mário De A. Lira Jr., José C. B. Dubeux Jr., Marta G. S. Da Silva, Mário De A. Lira, Alexandre C. L. De Mello

IGC Proceedings (1977-2023)

Macroptilium is a legume genus with approximately 20 species, usually annual or biennial, herbaceous and distributed mainly in the Americas. It is widely used as a forage resource in grasslands and usually fixes atmospheric N. Martins et al. (2001) indicated that half-sib family selection with progeny testing is the most common plant breeding method used in Brazil. In the scientific literature, however, there are few studies dedicated to Macroptilium spp.

This study evaluated morphological divergence among Macroptilium spp. progeny from accessions collected in 4 counties located in the semi-arid region of Pernambuco State, NE Brazil.


Selecting New Brachiaria Humidicola Hybrids For Western Brazilian Amazon, Giselle M. L. De Assis, Cacilda B. Valle, Carlos M. S. De Andrade, Judson F. Valentim Dec 2019

Selecting New Brachiaria Humidicola Hybrids For Western Brazilian Amazon, Giselle M. L. De Assis, Cacilda B. Valle, Carlos M. S. De Andrade, Judson F. Valentim

IGC Proceedings (1977-2023)

Brachiaria humidicola is a perennial and stoloniferous forage grass, with excellent adaptation to infertile soils and waterlogging. Producers in northern Brazil have become interested in this species, especially after the degradation of large areas of lowly permeable soils sown with B. brizantha cv. Marandu, which is highly intolerant of soil waterlogging (Andrade and Valentim 2006). However, since only 3 cultivars of B. humidicola are registered in Brazil (Mapa 2013), there is a need to develop new cultivars adapted to the range of environmental conditions experienced. Recently, Embrapa Beef Cattle obtained intraspecific hybrids of B. humidicola that need to be evaluated …


Brs Mandobi: A New Forage Peanut Cultivar Propagated By Seeds For The Tropics, Giselle M. L. De Assis, Judson F. Valentim, Carlos M. S. De Andrade Dec 2019

Brs Mandobi: A New Forage Peanut Cultivar Propagated By Seeds For The Tropics, Giselle M. L. De Assis, Judson F. Valentim, Carlos M. S. De Andrade

IGC Proceedings (1977-2023)

Forage peanut (Arachis pintoi) is a forage legume of relatively recent use in beef and dairy cattle feeding. Although it is native exclusively to Brazil, the first cultivar, Amarillo, was released in Australia in 1987. Forage peanut has a great number of favourable attributes for establishing grass-legume mixtures, which guarantee the persistence and high yields of high quality forage in cultivated pastures. Therefore, studies with this species have intensified in many tropical regions of the world (Assis and Valentim 2009). In the state of Acre, western Brazilian Amazon, 137,000 ha are cultivated with forage peanut, cv. Belmonte, benefiting …


A 100-M-Scale Modeling Study Of A Gale Event On The Lee Side Of A Long Narrow Mountain, Halie Xue, Jian Li, Tingting Qian, Hongping Gu Dec 2019

A 100-M-Scale Modeling Study Of A Gale Event On The Lee Side Of A Long Narrow Mountain, Halie Xue, Jian Li, Tingting Qian, Hongping Gu

Plants, Soils, and Climate Faculty Publications

In this study, a gale event that occurred on the lee side of a long narrow mountain was investigated, together with the associated mountain flows, using a realistic-case large-eddy simulation (LES) that is based on the Weather Research and Forecasting Model. The mountain is located on the southeastern Tibetan Plateau, where approximately 58 gales occur annually, mostly in the afternoons during the winter season. Benefitting from realistic topography and high horizontal resolution as fine as 111 m, the LES can replicate features similar to the wind fields observed during the gale period. Investigation of the early morning wind structure over …


Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl Dec 2019

Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl

OES Faculty Publications

Optical instruments can rapidly determine numbers and characteristics of water column particles with high sensitivity. Here we show the usefulness of optically assessed total particle volume below the main pycnocline to estimate carbon export in two systems: the open subarctic North Atlantic and the Ross Sea, Antarctica. Both regions exhibit seasonally high phytoplankton production and efficient export (i.e., a strong biological pump). Total particle volumes in the mesopelagic (200-300 m) were significantly correlated with those in the overlying surface mixed layer (50-60 m), indicating that most particles at depth reflect export from the surface. This connectivity, however, is modulated by …


Evolution And Stratigraphic Architecture Of Tidal Point Bars With And Without Fluvial Input: Influence Of Variable Flow Regimes On Sediment And Facies Distribution, And Lateral Accretion, Pricilla Souza Dec 2019

Evolution And Stratigraphic Architecture Of Tidal Point Bars With And Without Fluvial Input: Influence Of Variable Flow Regimes On Sediment And Facies Distribution, And Lateral Accretion, Pricilla Souza

LSU New Orleans Theses and Dissertations

Tide-influenced point bars represent a significant proportion of shallow-marine deposits, commonly developed along meandering channels in most backbarrier and estuarine systems. However, sedimentological studies to characterize this type of deposit are still emerging. They often present very heterogeneous internal architectures which development is controlled by the complex flow patterns operating in tidal environments. The study of the sedimentological and morphological characteristics of these features provides better understanding of the hydrodynamic processes that shape coastal systems and control their evolution as well as it contributes to better reservoir potential prediction and production strategy optimization, as tidal point bars may represent hydrocarbon …


Green Strategic Planning Approach For International Shipping Activities, Xiaofang Wu, Luoping Zhang, Huan Feng Dec 2019

Green Strategic Planning Approach For International Shipping Activities, Xiaofang Wu, Luoping Zhang, Huan Feng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Sustainability is a long-term and ultimate goal for international shipping, although it is slowly making progress. The shipping perspective that moves away from “port-to-port” operations to “door-to-door” services also requires international shipping to take a long-term and holistic view instead of fragmented efforts. How to achieve the long-term sustainability goal becomes a key issue for door-to-door international shipping. Hence, green strategic planning for door-to-door international shipping was proposed with green development that puts forward the eco-centric point of view as its basic theory for sustainability. This study used a strategic decision-making approach, a so-called multi-dimensional decision-making (MDDM), coupled with the …


Major Lower Paleozoic Horizons Of The Southern Illinois Basin, John B. Hickman Dec 2019

Major Lower Paleozoic Horizons Of The Southern Illinois Basin, John B. Hickman

Report of Investigations--KGS

The geology exposed at the surface in the southern Illinois Basin has been mapped in great detail by countless workers over the past century. With the exception of limited and scattered exposures in incised river valleys, the oldest rocks exposed outside of the Jessamine, Nashville, and Ozark Domes surrounding the Illinois Basin are Mississippian in age. Extensive deposits of Cambrian–Devonian sediments occur in the subsurface above crystalline basement in this region, however. All available data for the region were analyzed to produce a single, comprehensive set of interpretations. The data used in this study include 1:24,000-scale geologic quadrangle maps, oil …


Subglacial Meltwater Supported Aerobic Marine Habitats During Snowball Earth, Maxwell A. Lechte, Malcolm W. Wallace, Ashleig Van Smeerdijk Hooda, Weiqiang Li, Ganqing Jiang, Galen P. Halverson, Dan Asael, Stephanie L. Mccoll, Noah J. Planavsky Dec 2019

Subglacial Meltwater Supported Aerobic Marine Habitats During Snowball Earth, Maxwell A. Lechte, Malcolm W. Wallace, Ashleig Van Smeerdijk Hooda, Weiqiang Li, Ganqing Jiang, Galen P. Halverson, Dan Asael, Stephanie L. Mccoll, Noah J. Planavsky

Geoscience Faculty Research

The Earth’s most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the “Snowball Earth” glaciations, requiring the persistence of oxygenated marine habitats, yet evidence for these environments is lacking. We examine iron formations within globally distributed Cryogenian glacial successions to reconstruct the redox state of the synglacial oceans. Iron isotope ratios and cerium anomalies from a range of glaciomarine environments reveal pervasive anoxia in the ice-covered oceans but increasing oxidation with proximity to the ice shelf grounding line. We propose that …