Modelling Productivity and Nitrate Leaching in a Simulated Dairy Farm

Topp, Cairistiona F. E.; McGechan, M.B.

doi:10.1051/agro:2002087

Cited by 10 publications

(5 citation statements)

References 19 publications

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“…From this definition, the amount of silage in surplus or deficit to requirements and the amount of concentrates fed over several years provides a measure of how close the system is to being a workable system (Fitzgerald et al. , 2005), and this approach is comparable to the concept of winter forage requirement used by Topp and McGechan (2003). When performing a simulation for a particular location, input variables, such as stocking rate, N‐fertilizer application rate and pattern, and silage area, are defined in the initial parameterization using data from the National Dairy Blueprint for well and poorly drained soils (O’Donovan, 2000; O’Loughlin et al.…”

Section: Methodsmentioning

confidence: 99%

Simulation of the influence of poor soil drainage on grass‐based dairy production systems in Ireland

Fitzgerald

Brereton

Holden

2008

Grass and Forage Science

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A dairy cow system simulator, Dairy_sim, designed for assessing the interaction of climate and management on dairy cow production, based on rotational grass grazing, was further developed by integrating a soil water model. The soil water model was based on the concept of soil water deficits, and influenced the growth of grass herbage in the simulator when there was an excess of water over field capacity and when water content in the soil was approaching wilting point. The soil water model was tested using baseline meteorological data ) and then the system simulation was parameterized and tested for poorly drained soils using data from a research farm in the west of Ireland. After testing, the effects of regional differences in climate on system management on well-and poorly drained soils were compared. Down-scaled Global Climate Model (GCM) data for the baseline years were used for this purpose. These data resulted in slightly more favourable weather than that recorded. It was found that the simulator was capable of generating results in good agreement with published data for dairy production on poorly drained soils. The regional analysis showed dairy farms on well-drained soils outperformed their equivalents on poorly drained soils and, in general, were able to sustain higher stocking rates by 0AE6-0AE9 cows ha )1 . Dry matter production was around 1AE5-3 t ha )1 greater per annum on well-drained soils compared to poorly drained soils. The simulator, Dairy_sim, also captured a large difference in the requirement for housing and forage between the well and poorly drained soils. The simulation model can now be used to evaluate interactions between soils, systems and weather, and is thus a more useful tool for developing practical advice and for evaluating the impacts of possible climate change.

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Section: Methodsmentioning

confidence: 99%

Simulation of the influence of poor soil drainage on grass‐based dairy production systems in Ireland

Fitzgerald

Brereton

Holden

2008

Grass and Forage Science

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“…Several simulation studies in the Netherlands evaluated N loss from dairy farms using information obtained from De Marke (Hack‐ten Broeke and van der Putten, 1997; Hack‐ten Broeke and de Groot, 1998; Hack‐ten Broeke et al, 1999; Kuipers et al, 1999; ten Berge et al, 2000). Topp and McGechan (2003) extended their Scottish farm model to include N dynamics and then evaluated the impacts of varying fertilizer application rates and stocking densities on nitrate leaching, denitrification losses, and net farm income. Recent work has expanded DAFOSYM to a whole‐farm model with similar emphasis on performance, economic, and environmental issues.…”

Section: Simulation Analysis Of Grassland Farming Systemsmentioning

confidence: 99%

Whole‐Farm Perspectives of Nutrient Flows in Grassland Agriculture

et al. 2005

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who plan row crops and livestock around their grassland hectares are grassland farmers" (Barnes, 1995). Before Grassland agriculture is an important industry for livestock produc-World War II, agriculture in the USA was very diverse tion and land management throughout the world. We review the and integrated, agricultural markets were primarily loprinciples of nutrient cycling in grassland agriculture, discuss examples of grassland farming systems research, and demonstrate the usefulness cal, and nutrients were cycled mainly within farms and of whole-farm simulation for integrating economic and environmental among local farms. With the advent of mechanization, components. Comprehensive studies conducted at the Karkendamm chemical fertilizers, improved seeds, and agrichemicals, experimental farm in northern Germany and the De Marke experifarm size increased, agricultural markets became namental farm in the Netherlands have quantified nutrient flows and tional and international in scope, and nutrient cycles developed innovative strategies to reduce nutrient losses in grassland became more fragmented. Animal agriculture became farming systems. This research has focused on improving the utilizaspecialized and concentrated, relying on off-farm sources tion of manure nutrients on the farm by including grain crops in of feeds and fertilizers, which resulted in nutrient accucropping systems with grassland and by incorporating manure hanmulation on farms. dling techniques that reduce nitrogen losses. Although the information generated in experimental farms is not always directly applicable to Similar changes in farm structure occurred in northother climates and soils, it is being transferred to other regions through western Europe during the 1960s and 1970s (de Wit et computer simulation. A whole-farm model calibrated and verified al., 1987). Farms located in regions with good soils were with the experimental farm data is being used to evaluate and refine converted to crops like winter wheat (Triticum aestivum these strategies for commercial farms in other areas. Simulation of L.), oilseed rape (Brassica napus L.), potato (Solanum farms in northern Europe illustrate that on the sandy soils of this tuberosum L.), and sugarbeet (Beta vulgaris L.), whereas region, maize (Zea mays L.) silage can be used along with grasslands farms on poorer sandy soils specialized in milk producto increase farm profitability while maintaining or reducing nutrient tion with permanent grassland as the main crop. These loss to the environment. Use of cover crops, low emission barns,farms also intensified their use of purchased fertilizers covered manure storages, and direct injection of manure into soil and feed concentrates, and farm-scale nutrient budgets greatly reduces N losses from these farms, but their use creates a net cost to the producer. By integrating experimental farm data with became less balanced because of low conversion rates whole-farm simulation, more sustainable grassland production sys-of nutrients in milk and meat production...

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“…Five synoptic weather stations were selected that were representative of the agro-climatic regions of Ireland described by Holden and Brereton (2004). The winter forage requirement is an important determinant of carrying capacity of a farm (Topp and McGechan, 2003) and, for each location, the simulator was used to identify an optimum system by adjusting management parameters in order to obtain the following objectives: a balance between silage production and feed demand, a minimum number of days of winter housing and to maintain grass availability in the grazing area of the farm, limiting the probability of a need to supplement the grazing herd with silage or concentrates. In each case the simulations were run for 30 years using daily weather data stochastically generated from monthly mean values until optimum systems were reached.…”

Section: Analysis Of Regional Management Variationsmentioning

confidence: 99%

Assessment of regional variation in climate on the management of dairy cow systems in Ireland using a simulation model

Fitzgerald

Brereton

Holden

2005

Grass and Forage Science

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A dairy system simulator, Dairy_sim, was designed to assess the interactions between climate and management in spring-calving milk production systems based on the grazing of grass pastures. The simulator comprises three main components: a grass herbage growth model, an intake and grazing behaviour model, and a nutrient demand model. The simulator was initially parameterized using the Irish National Dairy Blueprint. Sensitivity analysis indicated that the simulator was most sensitive to stocking rate, milk output per cow and nitrogen fertilizer inputs, but less sensitive to other variables. Field data from four grazing systems were used to test the simulator and it was concluded that Dairy_sim was suitable for evaluating the interaction of climate and management for rotational grazing dairy systems based on perennial ryegrass pastures with Friesian cows. The simulator, Dairy_sim, was then used to evaluate the effects of the regional climates of Ireland on system management. The results indicated that, between regions, herbage production at the same input of nitrogen may vary proportionally by 0AE10 and that the length of the grazing season may vary by 0AE25. It was concluded that the simulator could be a useful tool for developing region-specific dairy production blueprints.

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Modelling Productivity and Nitrate Leaching in a Simulated Dairy Farm

Cited by 10 publications

References 19 publications

Simulation of the influence of poor soil drainage on grass‐based dairy production systems in Ireland

Simulation of the influence of poor soil drainage on grass‐based dairy production systems in Ireland

Whole‐Farm Perspectives of Nutrient Flows in Grassland Agriculture

Assessment of regional variation in climate on the management of dairy cow systems in Ireland using a simulation model

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