Characterisation Of Soil Organic Matter From Pensacola Bahiagrass Pastures Grazed For Four Years At Different Management Intensities,
2022
Universidade Federal Rural de Pernambuco, Brazil
Characterisation Of Soil Organic Matter From Pensacola Bahiagrass Pastures Grazed For Four Years At Different Management Intensities, J. C. B. Dubeux Jr., Lynn E. Sollenberger, N. B. Comerford, Ana C. Ruggieri, K. M. Portier
IGC Proceedings (1977-2023)
Soil fertility and agricultural system sustainability depend upon soil organic matter (SOM), particularly in the tropics, because of highly weathered soils and low fertiliser inputs. Because of the beneficial effects of SOM on chemical, physical, and biological soil properties, Greenland (1994) suggested that SOM is an indicator of agro-ecosystem sustainability. Pasture management may affect SOM by altering the production/decomposition ratio of residues (Johnson, 1995). The objective of this study was to characterise the SOM of Pensacola bahiagrass pastures grazed for four years at a range of management intensities.
Implications For N Transformations In Acidic Soils Of Replacing Annual-Based Legume Pastures With Lucerne-Based Pasture In Dryland Farming Systems Of Southern Australia,
2022
CSIRO Plant Industry, Australia
Implications For N Transformations In Acidic Soils Of Replacing Annual-Based Legume Pastures With Lucerne-Based Pasture In Dryland Farming Systems Of Southern Australia, I. R. P. Fillery
IGC Proceedings (1977-2023)
The supply and demand for nitrogen (N) in annual-based pasture-crop rotations in southern Australia is often poorly synchronised, leading to large losses of inorganic N (Fillery, 2001). Perennial pasture species, particularly lucerne, are being recommended to minimise dryland salinity. The implications for N cycling of using lucerne in place of annual legumes on acidic sandy soils that are widespread have not been widely studied. Lucerne is less tolerant of acidity and could fix less N than annual legumes. Lucerne root residues mineralise at slower rates than annual pasture residues with lower N release to subsequent wheat crops (Bolger et al …
N-Mineralisation And Phosphorous: Important Elements In Decision Support For Grassland Systems,
2022
Agro Business Park, Denmark
N-Mineralisation And Phosphorous: Important Elements In Decision Support For Grassland Systems, A. L. Nielsen, C. C. Hoffmann
IGC Proceedings (1977-2023)
Leaching of N and P from extensively managed grasslands on organic soils varies considerably. In environmentally sensitive areas it is important to diminish leaching by appropriate agricultural management. In Denmark low grazing intensity and management without fertilisation have been given a high priority. The type of soil has not been equally in focus, and it seems that the effect of cutting, compared with grazing, results in a higher removal of nutrients (e.g. Benke et al., 1992) can be used more strategically. The objective of this case study was to combine data from management strategies with data from leaching studies …
Nitrogen Mineralisation In Situ And In Controlled Environment,
2022
The Agricultural Research Institute, Iceland
Nitrogen Mineralisation In Situ And In Controlled Environment, F. Pálmason
IGC Proceedings (1977-2023)
Net mineralisation may be underestimated by in situ soil core methods for at least two reasons: (1) absence of plant N uptake in the soil cores, causing higher immobilisation than in intact soil. Schimel & Bennet (2004) thus concluded that plants compete effectively with microbes, as strongly indicated by cases, where net mineralisation was lower than plant uptake. (2) Gaseous losses of N2O in closed cylinders can lead to underestimation especially during long incubation periods, Abril et al. (2001) and Vor & Brumme (2002).
Effect Of Different Carbon And Nitrogen Inputs On Soil Chemical And Biochemical Properties In Maize-Based Forage Systems In Northern Italy,
2022
Università di Torino, Italy
Effect Of Different Carbon And Nitrogen Inputs On Soil Chemical And Biochemical Properties In Maize-Based Forage Systems In Northern Italy, S. Monaco, D. Hatch, L. Dixon, C. Grignani, D. Sacco, L. Zavattaro
IGC Proceedings (1977-2023)
In agroecosystems, manure application and straw return affect carbon (C) and nitrogen (N) cycling and affect soil organic matter (SOM), nutrient supply and losses to the environment. We examined effects of different organic sources on crop production, N uptake and surplus and SOM in maize systems.
Seasonal Changes In The Ratio Of Microbial Biomass P To Total P In Soils Of Grazed Pastures,
2022
Tokyo University of Agriculture & Technology, Japan
Seasonal Changes In The Ratio Of Microbial Biomass P To Total P In Soils Of Grazed Pastures, M. Kaneko, Y. Kurokawa, H. Tanaka, S. Suzuki
IGC Proceedings (1977-2023)
Phosphorus (P) utilisation efficiency in pasture soils is higher than in arable soils. Because there is a considerable amount of microbial biomass in the root mat layer, which is peculiar to permanent pasture, the microbial biomass P (MBP) contribution may be important in supplying soil P to pasture plants (Chen et al., 2000; He et al., 1997). In the present study, we investigated seasonal changes in MBP and other forms of P relative to total soil P in two pastures in which P uptake was estimated to be different.
Effect Of Soil Chemistry On Microbial Biodiversity And Functionality In Grassland And Tilled Soils,
2022
National University of Ireland, Galway
Effect Of Soil Chemistry On Microbial Biodiversity And Functionality In Grassland And Tilled Soils, C. Carrigg, S. Kavanagh, D. Fay, V. O. Flaherty
IGC Proceedings (1977-2023)
Microorganisms are excellent indicators of soil health, because of their rapid response to environmental change. Traditional microbiology is ineffective for the study of soil, as < 1% of microorganisms are currently culturable (Torsvik et al., 1996). Nucleic acid based methods, however, allow rapid detection of organisms, or particular genes, directly from soil samples. This work investigated, using polymerase chain reaction (PCR)-based approaches, the relationship between key chemical properties and bacterial biodiversity in grassland and tilled soils, with particular emphasis on the abundance and diversity of ammonium oxidisers.
Nitrogen Leaching From Cattle, Sheep And Deer Grazed Pastures In New Zealand,
2022
AgResearch, New Zealand
Nitrogen Leaching From Cattle, Sheep And Deer Grazed Pastures In New Zealand, Keith Betteridge, Sterwart F. Ledgard, Coby J. Hoogendoorn, M. G. Lambert, Z. A. Park, Des A. Costall, P. W. Theobald
IGC Proceedings (1977-2023)
The impacts of intensified grazing in New Zealand are being reflected in declining quality of groundwater, streams and lake water. Manipulation of ratios of grazing animal species may be one way farmers can reduce nitrogen (N) emissions to ground water. The present research quantifies nitrate and ammonium leaching losses from rotationally grazed sheep, cattle and deer pastures in a common environment.
Study Of Dairy Manure N Cycling In Soil-Plant Continuum Using 15N And Other Methods,
2022
USDA, Agricultural Research Service
Study Of Dairy Manure N Cycling In Soil-Plant Continuum Using 15N And Other Methods, J. M. Powell, P. R. Cusick, K. A. Kelling
IGC Proceedings (1977-2023)
Ruminant livestock manure impacts on N cycling in the soil-plant continuum. Most studies of manure N cycling are short-term and rely on indirect methods, i.e. apparent N recovery, fertiliser N equivalents or incorporate 15N into ammonium-N fractions. Direct and perhaps more precise measurements may be achieved by long-term studies using 15N incorporated into all manure N components. This paper summarises results of a 6- year trial to compare indirect and direct measures of manure N uptake by corn for 3 years after application.
Changes In Nutrient Turnover And Supply During The Reversion Of Arable Land To Acid Grassland/Calluna Heathland,
2022
ADAS Gleadthorpe Research Centre, UK
Changes In Nutrient Turnover And Supply During The Reversion Of Arable Land To Acid Grassland/Calluna Heathland, A. Bhogal, B. J. Chambers, R. Pywell, K. Walker
IGC Proceedings (1977-2023)
Lowland heath is of high conservation value because of the specialised and rare assemblages of plants and animals that it supports. Combinations of agricultural and urban development, and lack of appropriate management have resulted in large-scale loss and fragmentation of this habitat throughout the UK. Current UK conservation policies seek to re-create 6,000 ha of this habitat on land previously in agricultural and forestry production. Previous research indicated that high soil pH and fertility, together with a lack of propagules of heathland species, made it difficult to achieve this objective. The aim was to evaluate techniques to establish grass-Calluna …
The Effect Of A Reduction In Phosphate Application On Soil Phosphate Pools,
2022
Wageningen University and Research Centre, The Netherlands
The Effect Of A Reduction In Phosphate Application On Soil Phosphate Pools, C. Van Der Salm, J. Van Middelkoop, P. A. I. Ehlert
IGC Proceedings (1977-2023)
Excessive use of manure and fertilisers in western Europe has led to high phosphorus (P) contents in many agricultural soils leading to environmental P losses by overland flow, subsurface drainage and leaching to groundwater. To stop phosphate build up in the soil and leaching to surface and ground waters, the Dutch government is gradually reducing allowable phosphate application on grassland from 130 kg/ha per year in 2005 to 90 kg/ha per year in 2015. This will lead to a reduction of the phosphate surplus from 40 in 2005 to 0 kg/ha per year. To investigate the impact of reductions in …
How Will Removal Of The Non-Organic Feed Derogation Affect Nutrient Budgets Of Organic Livestock Farms In Wales?,
2022
Institute of Grassland and Environmental Research, UK
How Will Removal Of The Non-Organic Feed Derogation Affect Nutrient Budgets Of Organic Livestock Farms In Wales?, H. Mccalman, S. P. Cuttle
IGC Proceedings (1977-2023)
Agri-environment schemes encourage organic farming in Wales. The National Assembly Government second organic action plan has a target of 10-15% land in organic production by 2010. Although forage based, many organic livestock farmers buy in concentrate feeds, which are important sources of nutrients to the farm. The current derogation allowing organic producers up to 10% approved non-organic feed ends in 2005. Many organic farmers are beginning to make management changes to comply with this. The aims of this study were to construct simple nutrient budgets on different organic livestock farms, investigate any planned system changes, look at impacts on nutrient …
Diet Effects On Dairy Manure Nitrogen Excretion And Cycling,
2022
USDA, Agricultural Research Service
Diet Effects On Dairy Manure Nitrogen Excretion And Cycling, J. M. Powell, T. H. Misselbrook
IGC Proceedings (1977-2023)
The amount and forms of (nitrogen) N excreted by ruminant livestock and post excretion manure N cycling are highly influenced by what is fed. For example, the relative amount of urinary N, faecal endogenous N of microbial and gut origin, and faecal undigested feed N is affected by how much dietary fibre and secondary compounds (e.g., tannins, polyphneolics) are consumed. Each manure N component has a different propensity for loss; for example via ammonia (NH3) volatilisation (Misselbrook et al., 2004), leaching, and cycles differently in the soil-plant continuum (Powell, 2003). We evaluated dairy diet effects on amount and forms …
Effect Of A Grazing Intensity Gradient On Primary Production And Soil Nitrogen Mineralisation In A Humid Grassland Of Western France,
2022
CNRS, France
Effect Of A Grazing Intensity Gradient On Primary Production And Soil Nitrogen Mineralisation In A Humid Grassland Of Western France, N. Rossignol, A. Bonis, J-B. Bouzillé
IGC Proceedings (1977-2023)
Large herbivores have a major influence on the structure and the functions of humid grasslands and especially on primary production. Earlier work on the study site showed that grazing intensity was spatially varied and created a diversity of vegetation patches in the grassland (Loucougaray, 2003). The first objective of this study was to determine whether the variation in grazing intensity led to variation of primary production within the three plant communities located at three topographic levels in the grassland. The second objective was to determine whether a relationship linked primary production variation and net soil nitrogen (N) mineralisation.
The Role Of Grass Tussocks In Maintaining Soil Condition In North East Australia,
2022
USDA-ARS
The Role Of Grass Tussocks In Maintaining Soil Condition In North East Australia, B. K. Northup, J. R. Brown
IGC Proceedings (1977-2023)
Soils of the grazing lands of north eastern Australia are inherently nutrient-poor. Heterogeneously distributed plants are important to the conservation of the limited amounts of nutrients, through storage in plant tissues or in soil sinks close to plants (Ludwig et al., 1997). Loss of perennial vegetation through disturbance reduces conservation of these resources, to the detriment of feedback mechanisms, and ultimately causes loss of soil condition. Large areas of north east Australia have been degraded, or threatened by degradation, through combinations of variability in precipitation and heavy grazing (Gardener et al., 1990). This study examined the inter-related responses …
Within Resting Period Seasonal Soluble Carbohydrate Profiles Of Rotationally Grazed Elephant Grass,
2022
EMBRAPA, Brazil
Within Resting Period Seasonal Soluble Carbohydrate Profiles Of Rotationally Grazed Elephant Grass, L. P. Passos, M. C. Vidigal, I. G. Perry, Fermino Deresz, F. B. De Sousa
IGC Proceedings (1977-2023)
Recent evidence indicates that carbohydrate-rich grazed herbage is effective for improving milk production (Trevaskis et al., 2004). However, the dynamics of water-soluble carbohydrate (WSC) seasonal accumulation as related to forage availability remains unknown, especially during the growth stage of tropical forage grazing systems. The objective of the work was to verify the seasonal WSC profiles of rotationally grazed elephantgrass (Pennisetum purpureum Schum.), by making measurements within each 30-day resting period.
Cool-Season Grass Response To Increasing Nitrogen Fertiliser Rates In Michigan,
2022
Michigan State University
Cool-Season Grass Response To Increasing Nitrogen Fertiliser Rates In Michigan, R. H. Leep, T. S. Dietz, D. H. Min
IGC Proceedings (1977-2023)
Nitrogen (N) fertility recommendations for cool-season grasses in the north central region of the USA have not been species specific. This broad recommendation assumes that all grasses have similar N demands, while seasonal growth patterns and dry matter yield of cool-season grass species vary. Nitrogen fertiliser costs have steadily increased, but recommendations are to be below optimal levels for economic return (Klausner et al., 1998). A more specific N fertiliser recommendation may increase the producers’ net income.
Effects Of Applied Quantity Of Phosphorus Fertiliser On Phosphorus Content In Plant Tissues Of Lucerne (Medicago Sativa) And Seed Yield In North-Western China,
2022
China Agricultural University, China
Effects Of Applied Quantity Of Phosphorus Fertiliser On Phosphorus Content In Plant Tissues Of Lucerne (Medicago Sativa) And Seed Yield In North-Western China, Y. W. Wang, J. G. Han, S. M. Fu, Y. Zhong
IGC Proceedings (1977-2023)
Phosphorus concentration in plant tissue can be a useful index of P deficiency in lucerne, P fertiliser recommendations and monitoring of effectiveness of current P fertiliser practices (Jacobsen & Surber, 1995). The objective of this study was to measure P concentration in different lucerne plant parts and seed yield in relation to P fertiliser application rates in order to improve recommendations for lucerne seed production.
Field Experiments To Help Optimise Nitrogen Fixation By Legumes On Organic Farms,
2022
Institute of Grassland and Environmental Research, UK
Field Experiments To Help Optimise Nitrogen Fixation By Legumes On Organic Farms, A. Joynes, D. J. Hatch, A. Stone, S. Cuttle, G. Goodlass
IGC Proceedings (1977-2023)
During an organic rotation, the aim is to increase the nitrogen (N) content of the soil (and hence build up soil fertility) by recycling crop residues, applying manures/composts and from N fixed by legumes. IGER, with ADAS, Duchy College Cornwall and Abacus Organic Associates are developing improved guidance for organic farmers in the use of fertility-building crops. The main questions are: how to maximise N fixation and how to make the most efficient use of the fixed N? Available soil mineral N, which is generally thought to reduce N fixation, will be increased by manure applications, cutting/mulching and grazing. We …
The Effect Of Forage Legumes On Mineral Nitrogen Content In Soil,
2022
MTT Agrifood Research, Finland
The Effect Of Forage Legumes On Mineral Nitrogen Content In Soil, M. Isolahti, A. Huuskonen, M. Tuori, Oiva Nissinen, R. Nevalainen
IGC Proceedings (1977-2023)
The cultivation of forage legumes is often suggested as a possibility to improve nitrogen (N) utilisation in farming. However, previous studies have indicated examples in which the cultivation of legumes such as white clover has led to accumulation of large amounts of N in soil (Adams & Pattison, 1985). In this study the potential risks of N leaching were estimated by determining amount of mineral N in the soil.
