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Leaf area index

Soil Science

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Physiological And Chemical Characteristics Of Five Cultivars Of Cynodon, C C.C. Gomide, L.R. De A. Rodrigues, T.De J.D. Rodrigues, R A. Reis, D A. Banzatto Feb 2024

Physiological And Chemical Characteristics Of Five Cultivars Of Cynodon, C C.C. Gomide, L.R. De A. Rodrigues, T.De J.D. Rodrigues, R A. Reis, D A. Banzatto

IGC Proceedings (1997-2023)

The experiment was carried out at UNESP, Brazil, to evaluate five Cynodon cultivars: (Cynodon nlemfuensis Vanderyst cv “Tifton 68”, Cynodon spp. cv “Tifton 85”, Cynodon dactylon cv “Florakirk”, Cynodon nlemfuensis Vanderyst var. nlemfuensis cv “Florico” e Cynodon nlemfuensis Vanderyst var. nlemfuensis cv “Florona”). Plants were sampled once a week from 14 to 84 days of growth to study physiological characteristics and at 14-day intervals to study chemical characteristics. The following variables were studied: DM production, leaf/stem ratio, leaf weight/total dry matter ratio, relative growth rate, chlorophyll contents, leaf area, specific leaf area, LAI, and the contents of CP, NDF, …


Canopy Characteristics And Growth Rate Of Bahiagrass Monoculture And Mixtures With Rhizoma Peanut, N. Caram, Lynn E. Sollenberger, Marcelo O. Wallau, C. H. Wilson Jan 2024

Canopy Characteristics And Growth Rate Of Bahiagrass Monoculture And Mixtures With Rhizoma Peanut, N. Caram, Lynn E. Sollenberger, Marcelo O. Wallau, C. H. Wilson

IGC Proceedings (1997-2023)

Understanding relationships among canopy light interception (LI), canopy height and structure, and leaf area index (LAI) informs management decisions and can improve efficiency of forage-livestock systems. In a long-term experiment in Florida, USA, we assessed the LI, LAI and sward height relationships of rhizoma peanut (Arachis glabrata Benth., RP)-bahiagrass (Paspalum notatum Flügge) mixed swards compared with bahiagrass monoculture to determine whether changes in canopy structure affect herbage accumulation (HA) rate due to changes in radiation use. Treatments were arranged in a semi-factorial, split-plot design (r=4). Bahiagrass monoculture and bahiagrass-RP mixtures were whole-plot treatments. Sub-plot treatments were an undefoliated …


Productive Grasslands – The Role Of Adapted Species To Increase Ecosystems Resilience, M. B. Chiavegato, A. F. Mammana, C. Y. Rodriguez Nov 2023

Productive Grasslands – The Role Of Adapted Species To Increase Ecosystems Resilience, M. B. Chiavegato, A. F. Mammana, C. Y. Rodriguez

IGC Proceedings (1997-2023)

Producers are interested in diversifying grazing systems with native warm-season grasses. Climate variations may result in extreme weather events. For instance, recent studies show strong evidence pointing to an increasing frequency of flooding in the central US, due to changes in both seasonal rainfall and temperature across this region. In a constantly changing climate, adapted species play a crucial role in increasing ecosystems resilience and resistance to extreme weather events. Native grasses may be well adapted to the future changes on climatic conditions, with wide ecological amplitude and resistance under different conditions. Use of adapted warm season grasses, associated with …


Effect Of Mineral Nutrition On Red Clover Leaf Area Index, B. Cupina, P. Erić, S. Vasiljević, V. Mihailovic, D. Milic Aug 2023

Effect Of Mineral Nutrition On Red Clover Leaf Area Index, B. Cupina, P. Erić, S. Vasiljević, V. Mihailovic, D. Milic

IGC Proceedings (1997-2023)

The legume red clover (Trifolium pratense) fixes its own nitrogen (N), but requires P and K fertilisation. There are no recent reliable data in the domestic literature, on the amounts of P and K recommended to farmers; present recommendations are often either inadequate or excessive. Red clover mineral nutrition is significantly affected by soil and weather conditions (Taylor & Quesenberry, 1996). The objective of our twoyear study was to enable rational fertiliser application in accordance with soil type and agro ecological conditions.


Growth Characteristics Of Kikuyu Grass With Different Sources And Doses Of Phosphorus, José C. Pinto, Í. P. A. Santos, A. E. Furtini Neto, A. R. Morais, E. E. Mesquita, D. J. G. Faria, I. F. Andrade Aug 2023

Growth Characteristics Of Kikuyu Grass With Different Sources And Doses Of Phosphorus, José C. Pinto, Í. P. A. Santos, A. E. Furtini Neto, A. R. Morais, E. E. Mesquita, D. J. G. Faria, I. F. Andrade

IGC Proceedings (1997-2023)

Growth is defined as the increase in size, volume and mass as a function of time. Growth analysis allows evaluating the final growth of the plant as a whole and the contribution of the different organs in total growth (Benincasa, 1988). The experiment had as objective to evaluate specific leaf area (SLA), leaf area per unit of leaf DM, leaf area ratio (LAR), leaf area per unit of whole plant DM, leaf weight ratio (LWR), leaf weight per unit of plant weight, leaf area index (LAI), leaf area per unit of soil area, leaf/stem ratio (LSR), leaf weight per unit …


Evolution And Ageing Of Brachiaria Brizantha Pasture Component In A Silvopastoral System, M. Rakocevic, F. C. De Oliveira, J. Ribaski, O. J. Lavoranti Aug 2023

Evolution And Ageing Of Brachiaria Brizantha Pasture Component In A Silvopastoral System, M. Rakocevic, F. C. De Oliveira, J. Ribaski, O. J. Lavoranti

IGC Proceedings (1997-2023)

The main causes of the decline of Brachiaria pasture in the tropics are lack of maintenance, fertilisation and excessively high animal stocking rates (Boddey et al., 2004). Brachiaria brizantha has two predominant morphological forms: 1) relatively high stems with grouped tillers at a high position constructed from short leaves (bunch type); 2) low stems with long leaves, which in time evolve into the first type (Kanno et al., 1999). The concept of Brachiaria management involves animals entering to commence grazing when the pasture is 50-60cm high and being removed at 25-30cm, leaving a regrowth period of at least …


Prediction Of Canopy Photosynthesis For Cocksfoot Pastures Grown Under Different Light Regimes, P. L. Peri, D. J. Moot, D. L. Mcneil May 2023

Prediction Of Canopy Photosynthesis For Cocksfoot Pastures Grown Under Different Light Regimes, P. L. Peri, D. J. Moot, D. L. Mcneil

IGC Proceedings (1997-2023)

Plants in field environments can experience frequent fluctuations in irradiance from full sun to shade caused by cloud cover, overstory shading (e.g. silvopastoral systems) and within canopy shading. Research with widely spaced radiata pine (Pinus radiata D. Don) has suggested that due to its shade tolerance cocksfoot (Dactylis glomerata L.) is a suitable grass for silvopastoral systems. However, there is limited explanation of the physiological basis for the responses, and consequently no predictive capacity. This limits the application of results to environments, sites and seasons outside of those in which they were measured. The objectives of this study …


The Duration Of Regrowth Period And The Structural Traits In A Rotationally Grazed Panicum Maximum Sward, Carlos A. M. Gomide, J. A. Gomide Dec 2021

The Duration Of Regrowth Period And The Structural Traits In A Rotationally Grazed Panicum Maximum Sward, Carlos A. M. Gomide, J. A. Gomide

IGC Proceedings (1997-2023)

Panicum maximum 'cv'. Mombaça was rotationally grazed by steers. Three regrowth periods based on the number of expanded leaves per tiller: 2.5; 3.5 and 4.5, were compared. Three groups of seven tester steers, one for each treatment, grazed the replications of each experimental paddocks, the animals being removed from a paddock after 4 to 5 day grazing period when its sward leaf area index (LAI) was 1.5, on the average. Sward height and available biomass increased while tiller population density and leaf-stem ratio decreased with regrowth period. Overall averages observed for LAI and photosyntheticly active radiation interception by the end …


Herbage Allowance And Nitrogen Fertilization Effects On Morphological Characteristics Of Paspalum Notatum Flügge, P. Boggiano, G. E. Maraschin, Carlos Nabinger, J. Riboldi, Mónica Cadenazzi Aug 2021

Herbage Allowance And Nitrogen Fertilization Effects On Morphological Characteristics Of Paspalum Notatum Flügge, P. Boggiano, G. E. Maraschin, Carlos Nabinger, J. Riboldi, Mónica Cadenazzi

IGC Proceedings (1997-2023)

The grazing study was conducted at the Estação Experimental Agronomica – UFRGS, 30o S, on a native pasture, to evaluate the leaf area index and structural morphological traits of bahiagrass (Paspalum notatum Fl.), within the requirements of a Central Composite Rotatable experimental design, providing for equal precision, with two blocks, encompassing two factors at five levels each, namely: Herbage Allowance (HA) = 4.0; 5.5; 9.0; 12.5 and 14.0 kg green dry matter per 100 kg liveweight per day (% LW), in association with Nitrogen (N) fertilization levels of 0; 30; 100; 170 and 200 kg ha-1 as …


Short Term Variations In The Leaf Area Index, Tiller Density And Botanical Composition Of The Grassland In Inner Mongolia As Affected By Light To Very Heavy Grazing Intensities, H. Wan, P. Schönbach, M. Gierus, Anne Schiborra, Y. Bai, Friedhelm Taube Dec 2020

Short Term Variations In The Leaf Area Index, Tiller Density And Botanical Composition Of The Grassland In Inner Mongolia As Affected By Light To Very Heavy Grazing Intensities, H. Wan, P. Schönbach, M. Gierus, Anne Schiborra, Y. Bai, Friedhelm Taube

IGC Proceedings (1997-2023)

No abstract provided.


A Conceptual Model To Explain Increasing Woody Biomass In Arid And Semi‐Arid Regions, Anthony R. Palmer, D. Eamus Nov 2020

A Conceptual Model To Explain Increasing Woody Biomass In Arid And Semi‐Arid Regions, Anthony R. Palmer, D. Eamus

IGC Proceedings (1997-2023)

No abstract provided.


Relationship Between Field Measurements In Three Brachiaria Species With Leaf Area Index And Light Interception By Indirect Methods, Janerson J. Coêlho, Alexandre C. L. De Mello, José C. B. Dubeux Jr., Erick R. Da Silva Santos, Márcio V. Da Cunha, Mércia V. F. Dos Santos, Mario De Andrade Lira Apr 2020

Relationship Between Field Measurements In Three Brachiaria Species With Leaf Area Index And Light Interception By Indirect Methods, Janerson J. Coêlho, Alexandre C. L. De Mello, José C. B. Dubeux Jr., Erick R. Da Silva Santos, Márcio V. Da Cunha, Mércia V. F. Dos Santos, Mario De Andrade Lira

IGC Proceedings (1997-2023)

Brachiaria species play a strategic role in ruminant production systems in Brazil, covering an estimated pasture area of approximately 90 million hectares (Karia et al., 2006), however, these pastures are subject to different degrees of degradation due to inadequate management. In pasture management, field measurements such as canopy height, for example, are used by managers as a tool to establish parameters for the optimal point to cut the forage and for the post-grazing residue, in order to maximize production by harvesting at maximum of herbage mass accumulation, and to avoid problems associated to overgrazing, by setting ideal post-grazing height …


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 Feb 2020

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 (1997-2023)

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.


Canopy Height And Its Relationship With Leaf Area Index And Light Interception Of Tropical Grasses, Janerson José Coêlho, José C. B. Dubeux Jr., Erick Rodrigo Da Silva Santos, João Manoel Carneiro Leão Neto, Márcio V. Da Cunha, Mércia V. F. Dos Santos, Alexandre C. L. De Mello, Mário De A. Lira Feb 2020

Canopy Height And Its Relationship With Leaf Area Index And Light Interception Of Tropical Grasses, Janerson José Coêlho, José C. B. Dubeux Jr., Erick Rodrigo Da Silva Santos, João Manoel Carneiro Leão Neto, Márcio V. Da Cunha, Mércia V. F. Dos Santos, Alexandre C. L. De Mello, Mário De A. Lira

IGC Proceedings (1997-2023)

Photosynthetic tissues, mainly green leaves, are the major component of forage growth and development. The amount of these tissues in a forage plant is influenced directly by the cutting management, which is based on cutting frequency and stubble height. It is usual to recommend as a management practice to cut (or graze) the forage whenever it reaches a given stubble height. Brougham (1956) stated that, when the forage canopy is intercepting 95% of the photosynthetic active radiation, this is the critical leaf area index (LAI), which means the forage is near its maximum growth rate without shading itself. There is …


Structural Characteristics Of Porto Rico Stargrass (Cynodon Nlemfuensis) Pastures Under Different Frequencies And Severities Of Defoliation, Carlos Augusto Brandão De Carvalho, Sergio Trabali Camargo Filho, Domingos Sávio Campos Paciullo, Pablo Giliard Zanella, Elisa Cristina Modesto, Priscila Beligoli Fernandes Dec 2019

Structural Characteristics Of Porto Rico Stargrass (Cynodon Nlemfuensis) Pastures Under Different Frequencies And Severities Of Defoliation, Carlos Augusto Brandão De Carvalho, Sergio Trabali Camargo Filho, Domingos Sávio Campos Paciullo, Pablo Giliard Zanella, Elisa Cristina Modesto, Priscila Beligoli Fernandes

IGC Proceedings (1997-2023)

An understanding of the effects of frequency and severity of defoliation on the sward structure of pastures is essential for identifying pasture management strategies that are more efficient in forage usage in tropical environments (Da Silva and Nascimento Jr 2007; Euclides et al. 2010). Some pasture species have not yet been investigated in this way, e.g. cultivars of Cynodon. The potential of this grass in tropical environments suggests that it should be given priority (Pedreira 2010). This study was designed to evaluate the effects of 2 frequencies (90 and 95% light interception) and severities (20 and 30 cm …


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 (1997-2023)

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 …


Performance Of Some Forages Species (Festuca Arundinacea L., Chloris Gayana Var. Katambora, Lotus Corniculatus L. And Medicago Sativa L.) In Saline Soil, Süleyman Temel, Uğur Şimşek, Bilal Keskin, İbrahim H. Yılmaz Dec 2019

Performance Of Some Forages Species (Festuca Arundinacea L., Chloris Gayana Var. Katambora, Lotus Corniculatus L. And Medicago Sativa L.) In Saline Soil, Süleyman Temel, Uğur Şimşek, Bilal Keskin, İbrahim H. Yılmaz

IGC Proceedings (1997-2023)

Salinity is a soil degradation process which reduces plant diversity and agricultural productivity, decreases fertility and devalues the land in regions with arid and semi-arid climate. This process inhibits water and nutrient intake of plants from soil due to changeable nitrogen percentage and/or the intensity of soluble salt concentration. When the fact that agricultural lands are limited around the world and that the need for nutrition increases incrementally is taken into consideration, it is obvious that available lands should be used more effectively. Hence, it is quite crucial to reclaim saline soil and utilize it more economically (Woods 1996).