Digital Commons Network^™

Maximising Slurry Crop Available Nitrogen Utilisation In Grassland Systems, J. R. Williams, E. Sagoo, B. J. Chambers, J. Laws, D. R. Chadwick

IGC Proceedings (1977-2023)

In the UK, approximately 90 million tonnes of animal manure containing ca 450,000 tonnes of nitrogen (N) are recycled to agricultural land each year. The efficient utilisation of manure N can save farmers money and reduce diffuse air (ammonia) and water (nitrate) pollution. For slurries, bandspreading techniques (e.g. trailing shoe and trailing hose) can improve N utilisation by reducing ammonia volatilisation losses compared with conventional broadcast applications. They also provide increased spreading opportunities in spring/summer as slurry is placed in a band on the soil surface limiting herbage contamination, which can reduce the need to apply slurry in the autumn/early …

Phosphorus Transfer To River Water From Grassland Catchments In Ireland, H. Tunney, P. Jordan, G. Kiely, R. Moles, G. Morgan, P. Byrne, W. Menary, K. Daly

IGC Proceedings (1977-2023)

In Ireland it is estimated that at least half of phosphorus (P) loss to water is from agricultural sources and National and European Union policy and legislation aim at reducing phosphorus (P) loss to water in order to reduce eutrophication. In Ireland, the average soil test P (STP) levels increased ten-fold, from less than 1 to over 8 mg Morgan P per l soil over the past 50 years, reflecting increased P inputs in fertiliser and animal feed. One of the main objectives of this three-year research programme, started in 2001, was to investigate P loss to water in grassland …

Supplementation Of Cattle With Rock Phosphate And Urea Treated Straw To Improve Manure Quality And Crop Yields In The Sahel Zone Of Senegal, Maimouna Cissé, M. N’Diaye, C. M. N’Dione

IGC Proceedings (1977-2023)

Mineral deficiencies are a major constraint in improving animal production and crop yield in the Sahel zone (Cissé et al., 1996). Millet (Pennisetum glaucum) and groundnut (Arachis hypogaea,) are two major food and cash crops in this zone. The purpose of this study was to assess effects of supplementing grazing cattle with rock phosphate and nitrogen enriched diets on animal performances, and the effects of the application of their manure on crop yield in a pearl millet-groundnut rotational system located in N Senegal.

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.

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 …

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.

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.

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, 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 …

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.

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, 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.

Study Of Characteristics Of Soil Animals In Halophilous Plant Communities Of Leymus Chinensis Grasslands Of Northeast In China, Xiuqin Yin, Y. Zhang, W. Dong

IGC Proceedings (1977-2023)

We have researched soil animals in 8 types of halophilous plant communities of Leymus chinensis grasslands of Northeast China to characterise soil animal groups and explain the role and function of soil animals in grassland ecosystems (Richard & Roger, 1998) and provide a scientific basis for research to improve alkaline lands in these grasslands.

Grassland Management Practices And The Diversity Of Soil Nematode Communities, R. Cook, P. J. Murray, K. A. Mizen

IGC Proceedings (1977-2023)

Nematodes are numerically abundant in northern temperate grassland soils where, through their feeding on plants, soil microbes and each other as well as being a food resource, they contribute to soil functioning and affect plant soil interrelationships. Permanent plant cover and the consequent abundance of root tissue supply a year-round food supply. There are only limited data on the effects of root-feeding by nematodes on the growth and development of pasture plants but under some circumstances above-ground biomass may be reduced. Herbivory by specific nematode parasites may not only directly affect the host plant but also promote soil microbial activity …

The Addition And Cessation Of Inorganic Fertiliser Amendments In Long-Term Managed Grasslands: Impacts On Above And Below-Ground Communities, C. D. Clegg, P. J. Murray, R. Cook, T. Tallec

IGC Proceedings (1977-2023)

In recent times, land use in the United Kingdom has undergone considerable changes because of social and economic pressures, leading to a fine balance between the demands of highly productive intensive systems and practices which are perceived to be more environmentally acceptable. Plant productivity is governed by the supply of nutrients from the soil, which in turn is dependent on the dynamics of organic matter decomposition driven by soil micro-, meso- and macro fauna. Considerable information is available concerning the impact of inorganic fertiliser additions on communities of macro-fauna and flora, but the effects on specific microbial communities in soils …

Cycling Of N And P In Grass-Alone (Brachiaria) And Mixed Grass/Legume (Brachiaria/ Desmodium Ovalifolium) Grazed Pastures In The Atlantic Forest Region Of Brazil, R. M. Boddey, R. Tarré, R. Macedo, C. De P. Rezende, J. M. Pereira, B. J. R. Alves, S. Urquiaga

IGC Proceedings (1977-2023)

There are estimated to be > 80 M ha of Brachiaria pastures in the tropical regions of Brazil. When continuously grazed with only modest fertiliser inputs (and no N) these pastures can maintain reasonable cattle weight gains (> 200 kg LWG/ha per year). However, without fertiliser and when overgrazed, LWGs fall rapidly to low levels. Recent studies have shown that N and P deficiency are the most important factors limiting productivity. The objective of this study was to study fluxes of N and P in the pasture system in order to understand resilience to poor management and minimum nutrient requirements to …

Integrating Below-Ground Ecology Into Sustainable Grassland Management, R. D. Bardgett

IGC Proceedings (1977-2023)

Key points

1. Grasslands produce soils that sustain an abundant and diverse soil food web, providing tremendous opportunity for below-ground interactions to influence nutrient cycling processes and plant production.

2. Fast developing areas of ecological science offer scope to harness positive outcomes of below-ground ecology for enhancing efficient cycling of nutrients in sustainable grassland systems.

The Influence Of Burning On Soil Microbial Biomass And Activity Along The Boro Route In The Okavango Delta Of Botswana, Tabo Mubyana-John, A. Banda

IGC Proceedings (1977-2023)

The Okavango Delta, a protected area in northeastern Botswana because of its annual flooding pattern, is the main source of water in an otherwise arid environment with a high diversity of plants and animals and forms the main tourist area in the region. However, the area is under threat from range fires. The objective of this study was to assess the influence of fire on soil microbial activity, biomass C, fungal population and diversity, and some soil properties along the Boro route of the Okavango Delta (Botswana).

Chemical Components And Effects On Soil Quality In Temperate Grazed Pasture Systems, M. H. Beare, D. Curtin, S. Thomas, P. M. Fraser, G. S. Francis

IGC Proceedings (1977-2023)

Key points

1. Legume/grass pastures retain feedbacks on N supply that may help to reduce losses of N to the wider environment.

2. Intensive use of N fertilisers tends to increase SOM turnover and increase losses of N to the environment.

3. Increased use of fertilisers has contributed little to soil organic matter storage in grazed pastoral systems.

Physical Constraints In Grassland Ecosystems, I. M. Young, K. Ritz, C. S. Sturrock, R. Heck

IGC Proceedings (1977-2023)

Key points

1. Grassland system management must account adequately for biophysical and biochemical processes.

2. Amenity turf, especially sports turf, provides an excellent case study on how biology and physics interact to impact on the functioning of a grass ecosystem.

3. Microorganisms produce hydrophobic compounds that act to decrease water ingress and alter the function of the soil-grass ecosystem.

Do Pharmaceuticals In The Environment Pose A Risk To Wildlife?, Thomas G. Bean, Elizabeth A. Chadwick, Marta Herrero‐Villar, Rafael Mateo, Vinny Naidoo, Barnett A. Rattner

United States Geological Survey: Staff Publications

The vast majority of knowledge related to the question “To what extent do pharmaceuticals in the environment pose a risk to wildlife?” stems from the Asian vulture crisis (>99% decline of some species of Old World vultures on the Indian subcontinent related to the veterinary use of the nonsteroidal anti‐inflammatory drug [NSAID] diclofenac). The hazard of diclofenac and other NSAIDs (carprofen, flunixin, ketoprofen, nimesulide, phenylbutazone) to vultures and other avian species has since been demonstrated; indeed, only meloxicam and tolfenamic acid have been found to be vulture‐safe. Since diclofenac was approved for veterinary use in Spain and Italy in …

Improved Livelihoods From Grasslands; The Case Of Napier Grass In Smallholder Dairy Farms In Kenya, David Miano Mwangi, D. Romney, S. Staal, I. Baltenweck, S. Mwendia

IGC Proceedings (1977-2023)

In Kenya, smallholder farmers produce about 80% of the marketed milk. The farming systems vary from mixed farms with up to 10 ha of land and < 10 dairy cows (Gitau et al., 1994; Anon., 1985), to intensive smallholder dairy producers in the high human population central Kenya region with 0.9 to 2 ha of land and 3-4 dairy cows (Staal et al., 2001a). Milk production depends heavily on the cultivation of forages, with Pennisetum purpureum (Napier grass) by far the most important. An estimated 350,000 of the 600,000 smallholder farms in Kenya grow and utilize P. purpureum on their farms.

There are …

Role Of Information And Information Providers In Technology Transfer, D. Undersander

IGC Proceedings (1977-2023)

Technology transfer is an essential component of economic change in society. Developers of new technology often fail to realize that there is a science to technology transfer. This lack of appreciation for the skills involved in information dissemination and in activities necessary to affect a change of action in an audience often severely limits the rate and amount of technology transfer that occurs. Significant differences exist between doing a news release or writing a publication and causing audience acceptance of a new technology. The old standards of expecting adoption of a new technology simply because it “will profit farmers” or …

The Contribution Of Participatory Research: On-Farm Research, P. F. Fennessy, N. J. Daniels, S. A. Chadwick, P. A. Speck

IGC Proceedings (1977-2023)

Participatory research in agriculture may range from research and technology development (R&D), carried out on a research station with some involvement of farmers, through to genuine participatory research involving researchers and farmers working together. The latter involves the end-user in actually carrying out aspects of the research and/or in the development and evaluation of technology that is appropriate to commercial enterprises. Researchers often question the validity of the ‘findings of on-farm participatory research’ as they are more comfortable with the ‘controlled’ environment of the research station. However if research is to be applied appropriately on farms, it must go through …

Participatory Research For Smallholder Livestock Systems: Applying Common Sense To Complex Problems, P. M. Horne, Werner Stür

IGC Proceedings (1977-2023)

Key Points:

1. Participatory approaches to research (PAR) bring researchers closer to farmers, the intended users of research outputs.

2. Active, functional participation of farmers in the evaluation and development of new technologies requires researchers to make an important commitment: respecting the knowledge, skills and opinions of farmers while maintaining confidence in their own scientific knowledge.

3. Farmer experimentation is not usually suitable to provide quantitative biophysical data (this can be achieved more effectively in researcher controlled experiments), but to provide qualitative information and improve understanding. This type of information can be collected systematically to enable rigorous analysis.

4. While …

Computer-Based Forage Management Tools: Historical, Current, And Future Applications, David B. Hannaway, C. Daly, D. F. Chapman, B. B. Baker, A. S. Cooper

IGC Proceedings (1977-2023)

Forage management has been an important human activity since the beginning of civilization. By comparison, the personal computer has been available only in the immediate past. The software developed to deal with the complexity of climate, soil, plant, animal, and socioeconomic factors has seen huge changes in a few decades. Mainframe computers facilitated numerical calculations for exploring relationships among dozens of variables. Personal computers opened the door for more individual scientist creativity and routine communication. Web-based communication globalised the option for multidisciplinary teams to tackle problems. Forage-related computer applications abound, allowing farmers, ranchers, and others to more effectively manage the …

Paying For Our Keep: Grasslands Decision Support In More-Developed Countries, Andrew D. Moore

IGC Proceedings (1977-2023)

“Models in grassland science have come to stay, and so they must be made to pay for their keep. To do that, it will be necessary to improve their scientific sophistication and their management relevance...” (Seligman, 1993).

Decision support (DS) tools in grassland agriculture have also come to stay. This review will examine the ways and means by which DS tools are being made to pay for their keep, with a focus upon DS efforts from the last decade and on the lessons that arise for those who develop DS tools for grasslands. A survey of the present state of …

A 14,100 Cal B. P. Rocky Mountain Locust Cache From Winnemucca Lake, Pershing County, Nevada, Evan J. Pellegrini, Eugene M. Hattori, Larry Benson, John Southon, Hojun Song, Derek A. Woller

United States Geological Survey: Staff Publications

The remains of approximately 1000 (MNI) Rocky Mountain locusts (Melanoplus spretus) from an archaeological cache pit in Crypt Cave, Winnemucca (dry) Lake, Nevada, date to between 14,305–14,067 calendar years before present (95.4 % confidence; 12,238 ± 18 ¹⁴C yrs. B.P.). The age of this western Great Basin occupation along the shoreline of Lake Lahontan is consistent with occupation of several other Western North American terminal Pleistocene sites dating prior to 14,000 cal. B.P., including distinctive petroglyphs on the western shore of Winnemucca Lake dating as early as 14,800–13,200 cal. B.P.

Decision Support For Grassland Systems In Developing Countries, P. K. Thornton

IGC Proceedings (1977-2023)

Key points

1. Information flows in complex systems are often themselves highly complex, and decision support approaches based on linear input-output processes may have only limited impact.

2. How decisions are made, and how they can be appropriately supported, is often incompletely understood, in part because of inadequate understanding of the objectives and attitudes of all the decision makers involved.

3. Much of the developing world faces daunting problems in the coming 30 years, and appropriate information could play a critical role in dealing with these.

4. System complexity, household variability, and institutional intricacies have to be embraced rather than …

Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome

LSU Master's Theses

Terrestrial ecosystems along exposed continental shelves during times of relatively low sea level and glaciation are rarely preserved due to the mechanically erosive nature of marine transgression and regression. In this study, I investigate the geochemical and palynological characteristics of two well-preserved sites in the northern Gulf of Mexico (NGOM) to determine the ecologic settings and subsequent mechanisms of preservation in this region. Both sites contain preserved terrigenous sediments of previously exposed coastal margins; the first is located at the Alabama Underwater Forest (~13 km south of Gulf Shores, AL, at ~15 mbsl), and optically stimulated luminescence dates to 72–56 …