Seasonal Variation Of Taproot Biomass And N Content Of Lucerne Crops Under Contrasting Grazing Frequencies,
2023
Lincoln University, New Zealand
Seasonal Variation Of Taproot Biomass And N Content Of Lucerne Crops Under Contrasting Grazing Frequencies, E. I. Teixeira, D. J. Moot, H. E. Brown, M. Mickelbart
IGC Proceedings (1977-2023)
Taproot nitrogen reserves (TN, kg N/ha) a function of N concentration within taproots (N%) and taproot biomass (TBM) are a major determinant of lucerne (Medicago sativa L.) growth rates after defoliation and in early-spring (Avice et al., 1997b). Several studies have shown that N% changes with seasons (Cunninghan & Volenec, 1998) and defoliation frequencies (Avice et al., 1997a). However the seasonal pattern of TBM deserves further investigation as the dynamics of root reserves is a weak point in lucerne simulation models (Confalonieri & Bechini, 2004). The objective of this experiment was to assess the seasonal variation in …
Herbage Accumulation And Vegetation Structure In Tanzâniagrass (Panicum Maximum, Jacq. Cv Tanzania) Pasture Submitted To Regime Of Intermittent Stocking,
2023
Instituto de Zootecnia, Brazil
Herbage Accumulation And Vegetation Structure In Tanzâniagrass (Panicum Maximum, Jacq. Cv Tanzania) Pasture Submitted To Regime Of Intermittent Stocking, Ana C. Ruggieri, Carlos A. M. Gomide, Estella R. Janusckiewicz, E. D. Contato, R. A. Reis
IGC Proceedings (1977-2023)
Knowledge of pasture structure characteristics such as height, tillering density, leaf area index (LAI) and herbage mass (HM), together with growth rates and forage accumulation, can become important tools to indicate improvements to the production system. This experiment evaluated the structural and productive characteristics and persistence of a Tanzaniagrass pasture.
Dormant-Season Carbon Fluxes In Humid-Temperate Pastures,
2023
U.S. Department of Agriculture
Dormant-Season Carbon Fluxes In Humid-Temperate Pastures, Howard Skinner
IGC Proceedings (1977-2023)
Human induced increases in atmospheric CO2 through the burning of fossil fuels and deforestation are considered to be a primary cause of rising global temperatures. However, carbon sequestration by terrestrial ecosystems has reduced the rate of CO2 accumulation in the atmosphere. Because of their vast size, grazing lands have the potential to sequester significant quantities of carbon, slowing the increase in atmospheric CO2 and reducing the risk of global warming. Although C uptake during the growing season can be substantial, losses following defoliation and drought, and during the winter months can significantly reduce annual sequestration, frequently turning …
Impact Of Climate Change On Potential Distribution And Relative Abundance Of The Migratory Grasshopper (Orthoptera: Acrididae) In The Prairie Ecosystem Of Canada,
2023
Agriculture and Agri-Food Canada, Canada
Impact Of Climate Change On Potential Distribution And Relative Abundance Of The Migratory Grasshopper (Orthoptera: Acrididae) In The Prairie Ecosystem Of Canada, Owen Olfert, R. Weiss
IGC Proceedings (1977-2023)
Climate is the dominant force determining the distribution and abundance of most insect pest species. There has been considerable concern in recent years about climatic warming caused by human activities and the affects of these changes on agriculture in North America. Warming conditions may affect insect populations by altering timing of emergence, increased growth and development rates, shorter generation times and reduced overwintering mortality (McCarthy et al. 2001). Given that the magnitude of predicted temperature change associated with global warming is beyond the historical experience of modern agriculture computer models are one method by which researchers can study the possible …
The Effect Of Legume/Grass Pasture On Soil Organic Carbon,
2023
The Lithuanian Institute of Agriculture, Lithuania
The Effect Of Legume/Grass Pasture On Soil Organic Carbon, Z. Kadziuliene, Alvyra Slepetiene
IGC Proceedings (1977-2023)
Soil organic carbon content is an important integral indicator of soil fertility. The extent at which the soil can sequestrate carbon depends on the nature of agricultural production, land use and soil type (Follet, 2001). More than two thirds of the annual grassland biomass production is allocated to below ground structures and deep humus layers are common in grassland (Körner, 2002). Grasslands differ markedly in species composition, utilisation purpose, fertilisation and this can significantly change their effect on soil organic content (Hassink & Neeteson, 1991). The objective of study was to estimate changes in the soil organic carbon content and …
A Systems Approach To Managing Greenhouse Gases On New Zealand Sheep And Beef Farms,
2023
AgResearch Grasslands, New Zealand
A Systems Approach To Managing Greenhouse Gases On New Zealand Sheep And Beef Farms, M. G. Lambert, H. Clark
IGC Proceedings (1977-2023)
Agriculture contributes more than 50% of New Zealand's greenhouse gas (GHG) emissions, mainly through release of methane (CH4) and nitrous oxide (N2O) from pastoral farms. Decisions on implementation of mitigation strategies will be made by individual farmers, who seek also to maintain financial performance in the face of declining terms of trade for commodities, hence leading to pressure to further intensify production. New Zealand (NZ) sheep & beef farms are typically hill country properties with a mixture of steep and easier topography, and year-round grazing of mainly permanent pastures. Specific GHG mitigation technologies will be difficult …
Methane Emissions Of Dairy Cows In Irish Spring-Calving, Grass Based Production Systems,
2023
University College Dublin, Ireland
Methane Emissions Of Dairy Cows In Irish Spring-Calving, Grass Based Production Systems, Frank O'Mara, D. K. Lovett
IGC Proceedings (1977-2023)
Countries which sign up to the Kyoto Protocol on greenhouse gas emissions are required to return annual inventories of greenhouse gas emissions, including methane emissions from farm livestock. Countries with large agricultural emissions are encouraged to derive specific emission factors (annual production of methane per animal in a specified animal class) for their livestock populations, rather than relying on default emission factors provided by IPCC (1996). In this paper, we describe how an emission rate of methane from enteric fermentation for spring-calving dairy cows in Irish production systems has been derived.
Nitrogen Leaching From A Timothy Sward Following Application Of Anaerobically Digested Cattle Slurry In Japan,
2023
Rakuno Gakuen University, Japan
Nitrogen Leaching From A Timothy Sward Following Application Of Anaerobically Digested Cattle Slurry In Japan, T. Matsunaka, T. Sawamoto, H. Ishmura, K. Takakura, A. Takekawa
IGC Proceedings (1977-2023)
The objective of this study was to quantitatively evaluate nitrogen (N) leaching from a Phleum pratense pasture following application of anaerobically digested cattle slurry by monitoring N uptake by the grass, NH3 volatilisation, N2O emission, and NO3 leaching in a lysimeter trial.
Rainfall And Grazing Impacts On The Population Dynamics Of Bothriochloa Ewartiana In Tropical Australia,
2023
Department of Primary Industries and Fisheries, Australia
Rainfall And Grazing Impacts On The Population Dynamics Of Bothriochloa Ewartiana In Tropical Australia, David M. Orr, Peter J. O'Reagain
IGC Proceedings (1977-2023)
Bothriochloa ewartiana (desert bluegrass) is a palatable, native perennial (C4) grass of considerable importance to the northern Australian grazing industry. However, little is known of the interaction between grazing pressure and the highly variable rainfall found in this area, on its population dynamics. This paper reports interim results (1998-2004) from a long-term study, in which its population dynamics were examined under 3 grazing strategies.
Root And Vigor Response Of Big Bluestem To Summer Grazing Strategies,
2023
University of Nebraska‐Lincoln
Root And Vigor Response Of Big Bluestem To Summer Grazing Strategies, E. M. Mousel, W. H. Schacht, L. E. Moser, C. W. Zanner
IGC Proceedings (1977-2023)
Warm-season grasses e.g., big bluestem (Andropogon gerardii Vitman) are great potential sources of summer forage in eastern Nebraska. Frequent, intensive defoliation can reduce root mass and limit root distribution. Quantifying root structure response to multiple defoliation events in a grazing situation is critical to develop management plans for these types of grasses. This experiment aimed to quantify the cumulative effects of timing and frequency of grazing on root structure and organic reserve estimates in big bluestem pastures.
Effect Of Grazing Management On Herbage Accumulation Of Lucerne-Orchard Grass Sward,
2023
Colegio de Postgraduados, México
Effect Of Grazing Management On Herbage Accumulation Of Lucerne-Orchard Grass Sward, A. Hernández Garay, José L. Zaragoza Ramírez, J. Pérez-Pérez, S. González-Muñoz, J. Herrera-Haro, G. F. Osnaya, Pedro A. Martínez-Hernández, Adrián R. Quero-Carrillo, J. F. Enriquez-Quiroz
IGC Proceedings (1977-2023)
Throughout most of México, lucerne (Medicago sativa) is the primary forage legume used in the dairy industry. Unfortunately, lucerne does not grow in late autumn and winter due to adverse weather. Recent studies with lucerne have suggested that the inclusion of a companion grass will invariably increase the seasonal distribution and total annual yield of swards (Laidlaw & Teuber, 2001). However the management of mixed swards containing lucerne is difficult as a grazing frequency or intensity which suits one species may be detrimental to the other. Changes in balance between grass and legume, especially in grazed swards, have …
Tiller Population Density And Sward Stability Of Brachiaria Brizantha Continuously Stocked By Cattle,
2023
Universidade de São Paulo, Brazil
Tiller Population Density And Sward Stability Of Brachiaria Brizantha Continuously Stocked By Cattle, André F. Sbrissia, S. C. Da Silva, L. K. Molan, D. O. L. Sarmento, F. M. E. Andrade, A. V. Lupinacci, A. C. Gonçalves
IGC Proceedings (1977-2023)
Tiller population density is one the most important parameters of sward structure and its evaluation is normally included in studies of sward dynamics. Moreover, a greater level of understanding is achieved when the survival of successive tiller generations is monitored. (Matthew et al., 2000). This would help to explain seasonal variation in tiller populations based on tiller appearance and death rates. While Brachiaria brizantha c.v. Marandu occupies up to 70 million hectares of cultivated grassland in Brazil, little is known of its ecophysiology. The objective of this work was to calculate survival probability of B. brizantha tillers and …
Managing The Reproductive Development Of Grasses By Grazing Practices,
2023
INRA, France
Managing The Reproductive Development Of Grasses By Grazing Practices, J. P. Theau, L. Chazelas, P. Ansquer, J. Viegas, O. Stefanini, M. L. Petit, P. Cruz, Michael Duru
IGC Proceedings (1977-2023)
Grazing natural grassland communities is necessary for both productive (feeding herbivores) and environmental (maintenance of open landscapes) objectives. Management guidelines should take into account the functional diversity of plant species between and within grassland communities. The management of the heading stage of grasses by grazing is an important tool to maintain acceptable forage quality and to avoid the seeding of low-valued species. The heading stage should be managed even in extensive systems and this needs a good knowledge of the phenological development of dominant species. In this work we illustrate the approach through the study of the development of four …
Grazing Preference, Herbage Production And Quality Of Diploid And Tetraploid Lolium Perenne Cultivars In Southern Chile,
2023
Universidad Austral de Chile, Chile
Grazing Preference, Herbage Production And Quality Of Diploid And Tetraploid Lolium Perenne Cultivars In Southern Chile, Oscar A. Balocchi, Ignacio F. López
IGC Proceedings (1977-2023)
Lolium perenne is the most important plant species used in sown pasture in Southern Chile. Cultivars used are mainly diploid. However, in recent years some tetraploid cultivars have been introduced into the country. The objective of the study was to determine the effect of the ploidy of the cultivars on herbage production, nutritive value, grazing preference and utilisation of the herbage.
The Diet Of Free-Ranging Beef Cattle In A Semi-Arid Savanna Of Eastern Namibia,
2023
Neudamm Agricultural College, Namibia
The Diet Of Free-Ranging Beef Cattle In A Semi-Arid Savanna Of Eastern Namibia, A. Rothauge, A. L. Abate, G. N. Smit
IGC Proceedings (1977-2023)
Beef ranching is the most important agricultural enterprise in arid and semi-arid SW African countries. It earns foreign exchange via beef exports to the EU and very many rural people depend on cattle pastoralism for their livelihood. However there is no published information on what cattle eat in such extensive systems. Therefore, it is difficult to optimize grazing strategies and to prevent degradation of rangeland.
Performance Of Timothy Cultivars In Monoculture Or In Mixtures With Meadow Fescue In Finland,
2023
Experiment Farm of Kesko Agro, FInland
Performance Of Timothy Cultivars In Monoculture Or In Mixtures With Meadow Fescue In Finland, M. Kari, M. Rinne
IGC Proceedings (1977-2023)
Timothy (Phleum pratense) and meadow fescue (Festuca pratensis) are dominating grass species in Nordic countries with severe winters. Dry matter (DM) yield potential, forage quality and winter hardiness are of main interest for commercial cultivars. Further, it is advantageous to take into account the relation between primary growth and regrowth (P/R) DM yield when planning mixtures for different purposes and areas. In the current experiment, three different types of timothy were evaluated: a northern type cv. Jonatan, a southern type cv. Ragnar and an intermediate type cv. Grindstad. In addition, meadow fescue cv. Kasper and mixtures …
Effect Of Dairy Effluent On Turnip Nutritive Characteristics,
2023
Department of Primary Industries, Australia
Effect Of Dairy Effluent On Turnip Nutritive Characteristics, Joe L. Jacobs, G. N. Ward, Frank R. Mckenzie
IGC Proceedings (1977-2023)
In southern Victoria, high summer temperatures and low rainfall lead to low pasture growth and a decline in nutritional value until rainfall commences in autumn. Annual forage crops such as turnips often are used to fill the summer feed gap. Jacobs & Ward (2003) observed that dairy effluent applied at low rates could improve turnip DM yields and crude protein content. Results from the first two years of a 3-year study comparing a range of effluent application rates on turnip leaf and root nutritive characteristics are reported.
Effects Of Grass Suppression On Legume Abundance In A Naturalised Pasture,
2023
INIA, Chile
Effects Of Grass Suppression On Legume Abundance In A Naturalised Pasture, Christian Hepp, I. Valentine, P. D. Kemp
IGC Proceedings (1977-2023)
Low abundance and poor persistence of legumes is a generalised problem in hill country pastures in New Zealand, even at adequate soil phosphorus levels (Woodfield & Caradus, 1996). Likely causes of low legume contents in swards include lack of soil moisture, high temperatures (Barker et al., 1993), frequency and intensity of defoliation (Suckling, 1975; (Lambert et al., 1982) and increased grass competition due to increasing fixed nitrogen in the soil (Lambert et al., 1982). On this later point there is anecdotal evidence that suppression of the grass component with herbicide will boost clover content, colloquially called 'chemical topping'.
Butterfly Pea In Queensland: A Tropical Forage Legume Success Story,
2023
Department of Primary Industries & Fisheries, Australia
Butterfly Pea In Queensland: A Tropical Forage Legume Success Story, Maurice J. Conway
IGC Proceedings (1977-2023)
Butterfly pea (Clitoria ternatea) is a productive and persistent legume adapted to a range of soils and climates in northern (tropical & sub tropical) Australia. Cultivar Milgarra, a composite line of introduced and naturalised accessions, was released in Queensland in 1991. The area planted in Queensland is a measure of its success, reaching <500ha in 1996; 5Kha by 1998; 30Kha by 2000; 50Kha by 2002; and 100Kha by 2004. Butterfly pea is used by cattleman mostly to grow and finish cattle. It is not grown extensively as a ley legume yet. Farmers who crop and have cattle, plant it but usually on cropping soils with limitations e.g. low plant available water capacity, shallow, low N or duplex soils. Farmers without cattle generally choose to use inorganic nitrogen as an N-source for crops.
Estilosantes Campo Grande In Brazil: A Tropical Forage Legume Success Story,
2023
EMBRAPA, Brazil
Estilosantes Campo Grande In Brazil: A Tropical Forage Legume Success Story, Celso D. Fernandes, Bela Grof, S. Chakraborty, Jaqueline R. Verzignassi
IGC Proceedings (1977-2023)
Estilosantes Campo Grande (ECG) is a mixture (80/20 by weight) of Stylosanthes capitata and S. macrocephala, derived through genetic combination of selected accessions by open crossing over 6 generations (Grof et al., 2001). The cultivar is the result of >10 years of research on a collection of >1000 ecotypes of Stylosanthes species collected and maintained by Embrapa. The main use of ECG in Brazil is to improve grass-dominant pastures. It has good persistence with Brachiaria spp., Panicum maximum (Tanzania-1 and Mombaça) and Andropogon gayanus. It has excellent adaptation to low fertility sandy soils and is persistent under …
