Now showing 1 - 10 of 19
  • Publication
    Benchmarking Nutrient Use on Irish Farms 2012-2015
    Methods of nutrient accounting are used to quantitatively measure the relationship between nutrient inputs and outputs representing indicators of pressure on the environment. In agriculture these environmental pressures come predominantly from two nutrient inputs, Nitrogen and Phosphorous potentially presenting losses to the atmosphere and the aquatic environment. Various methods of calculating such losses are established in the literature this paper identifies methods of nutrient accounting at farm-level. Through a scored evaluation of six models nutrient balances is identified as the most appropriate tool for monitoring nutrient flow at farm-level. Evaluation is based on two criteria the reliability and availability of data and the usability of indicators for the farmer and the policy maker. Using National Farm Survey data from 2012-2015 this paper presents nutrient balances and nutrient use efficiency indicators on Irish farms and benchmarks economic performance within systems. Findings indicate the most intensive dairy systems have highest levels of nutrient inputs relative to the other farming systems but lower levels of nutrient use efficiency. Nutrient use on-farms present an environmental risk but also an economic cost and so benchmarking farms reflects nutrient use in terms of the economic and environmental impact. Findings show the trends in environmental indicators across all systems and economic performance per unit of product for dairy farms with the best performing dairy farms also having the lowest N surplus per kilogram of milk solids.
  • Publication
    Benchmarking P and N use efficiency in Irish farm systems to motivate practice change
    (The Organizing Committee of the 8th International Phosphorus Workshop, 2016-09-16) ; ;
    Agriculture faces the challenge of achieving sustainable, profitable production while maintaining environmental quality. In Ireland, for example, ambitious national growth targets for agricultural output have been set but, at the same time, Ireland, like other countries, must meet international environmental obligations in terms of water quality and greenhouse gas (GHG) emissions.
  • Publication
    Managing legacy soil phosphorus in grassland soils for agricultural productivity and environmental quality: a review
    Phosphorus (P) is a lithophile element that tends to accumulate in the solid phase at the Earth’s surface and has a low water solubility. As P is a limiting nutrient for plant growth in most terrestrial systems, P in fertilizers has been a major factor underpinning global agricultural production in the 20th and early 21st centuries, including that from grassland. However, P is a costly farm input and it is also a finite mineral resource. Best agronomic practice is to maintain soil P levels at optimum over the medium-to-long term by managing P application and offtake. However, in some cases, soil P levels have been built up in excess of agronomic optimum due to P application driven by organic “waste disposal” or with the intention of building up a “bank” of soil P for future use. This has been associated with P losses to surface waters and impacts on water quality. Legislation, policy and best management practice advice in many countries has attempted to affect these legacy high P soils through a range of measures. In Ireland, for example, the Good Agricultural Practice measures, introduced in 2006 under the Irish Nitrates Action Plan, attempt to impose P deficits on soils with high P. National data shows that P fertilizer use declined by 55% on grassland soils between 2003 and 2008 and would suggest that soils with high soil P levels dropped from 30% in 2007 to 22% in 2011. This paper presents a review of the international literature on legacy excessive P in grassland soils, management practices and policy measures to manage them, and changes in soil P in response to such measures. Consideration is given to both agronomic and environmental concerns. There are a number of factors in grassland production systems, and particularly dairy production systems based on grazed grass, that differ from other agricultural production systems. For example, offtakes are typically lower than in tillage and the recycling of P, either by animal deposition or spreading of manures, gives less control to the farmer. Important questions addressed include: how quickly do grassland soil P levels decline under situations of negative P balance?; what fractions of P control soil P decline?; what grassland management practices are important in determining where and how fast soil P levels decline?; and what scale is appropriate to implement practice change and monitor effects?
  • Publication
    Improving national mapping of critical source areas of phosphorus and nitrogen losses in Irish agricultural catchments to support policy
    Policymakers, farm advisors and water agencies require up-to-date national maps of critical source areas (CSAs) of nitrogen (N) and phosphorus (P) losses from agricultural land to improve catchment management decisions. The DiffuseTools project aimed to achieve this in Ireland by updating the existing Catchment Characterisation Tool and sub-model NCYCLE_IRL, which predicts environmental losses of N and P from the farm via surface runoff, leaching, denitrification and volatilisation. Updates included (i) using improved national maps of farm-scale source loadings as inputs, (ii) sub-field scale modelling of surface transport risk using soil topographic indices derived from 1 m and 5 m NEXTMap digital elevation models (DEMs), (iii) modelling hydrological disconnectivity from microtopography (HSA Index) and reinfiltration (SCIMAP), (iv) improving the national ditch and stream channel network used by the model by DEM extraction, and (v) using SCIMAP to improve predictions of erosion risk. The improved national source loading maps included mean nationally weighted farm-gate N and P imports (fertilizer, feed and livestock) and balance surpluses (kg/ha) calculated for each stocking rate and soil group (land use potential) category within each sector type (dairy, mixed livestock, suckler cattle, non-suckler cattle, sheep and tillage), using annual Teagasc National Farm Survey data (2008-15). Furthermore, updated national maps of soil P and atmospheric N and P deposition inputs were also used within the national source loading maps to improve model performance. National CSA maps for N and P for each pathway were then produced and evaluated using water quality monitoring data and field observations from the Environmental Protection Agency and Teagasc Agricultural Catchments Programme. These maps will be able to support sustainable intensification by informing farm and catchment management decisions such as where to cost effectively target mitigation measures to reduce environmental losses, where to distribute nutrient surpluses (to non-CSAs in nutrient deficit), and improving functional land management.
  • Publication
    Benchmarking farm P and N management to improve agricultural sustainability
    Agriculture faces the challenge of achieving sustainable, profitable production while maintaining environmental quality. Conventional agricultural production is highly dependent on nutrient inputs of P and N in fertilizer and feed and poor use efficiency of these resources is associated with losses to the environment and impacts on water quality, GHG emissions, air quality, acidification and biodiversity. The AgriBenchmark project explored the possibilities for benchmarking of nutrient management performance on Irish farms.
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  • Publication
    A robust method for the evaluation of prison based sex offender treatment programmes
    (Confénce Permanente Européne de la Probation, 2000-01) ; ; ;
    This paper outlines the approach to evaluating the sex offender treatment programme currently running in the Irish prison system. It begins with an introduction to the scope of the problem of sexual offending as reflected by the extent of the prison population in Ireland who have been convicted of a variety of sexual offences. It then outlines two key points that can be gleaned from several decades of general research on evaluating the effectiveness of psychological treatments while indicating how they have been included in our present research. We also describe the variety of data sources that need to be incorporated into an effective evaluation of prison based sex offender treatment programmes. We conclude with an introduction to some preliminary findings from our on-going research. These finding high-light the return in terms of more reliable information when care is taken in developing a robust method for the evaluation of prison-based sex offender treatment programmes.
  • Publication
    A controlled evaluation of a prison based sexual offender intervention programme
    The effectiveness of a prison-based cognitive behavioral program designed to modify psychological risk factors associated with sexual offending was evaluated. The Irish Prison Service Sexual Offender Intervention Programme, is a manualized 10-month Cognitive Behaviour Therapy [CBT] program involving three 2-hour group sessions per week, which are facilitated by a team of clinical psychologists and probation officers. Improvements in 38 consecutive referrals to the program were compared with the status of 38 untreated offenders who were similar in marital status, age when they left school, occupational status prior to imprisonment, offence type, presence of previous convictions, and current sentence length. All research participants completed the same assessment protocol, which evaluated psychological factors associated with sexual offending at times equivalent to pre- and postintervention. Compared with the untreated control group, program participants showed statistically significant improvement on some but not all self-report measures of cognitive distortions, empathy, interpersonal skills, self-regulation, and relapse prevention. Motivation to change among the untreated control group was not associated with change in psychological functioning in the absence of the assistance of the treatment program. Implications for sexual offender intervention delivery are considered.
      1310Scopus© Citations 22
  • Publication
    Source partitioning using N2O isotopomers and soil WFPS to establish dominant N2O production pathways from different pasture sward compositions
    Nitrous oxide (N2O) is a potent greenhouse gas (GHG) emitted from agricultural soils and is influenced by nitrogen (N) fertiliser management and weather and soil conditions. Source partitioning N2O emissions related to management practices and soil conditions could suggest effective mitigation strategies. Multispecies swards can maintain herbage yields at reduced N fertiliser rates compared to grass monocultures and may reduce N losses to the wider environment. A restricted-simplex centroid experiment was used to measure daily N2O fluxes and associated isotopomers from eight experimental plots (7.8 m2) post a urea-N fertiliser application (40 kg N ha−1). Experimental pastures consisted of differing proportions of grass, legume and forage herb represented by perennial ryegrass (Lolium perenne), white clover (Trifolium repens) and ribwort plantain (Plantago lanceolata), respectively. N2O isotopomers were measured using a cavity ring down spectroscopy (CRDS) instrument adapted with a small sample isotope module (SSIM) for the analysis of gas samples ≤20 mL. Site preference (SP = δ15Nα – δ15Nβ) and δ15Nbulk ((δ15Nα + δ15Nβ) / 2) values were used to attribute N2O production to nitrification, denitrification or a mixture of both nitrification and denitrification over a range of soil WFPS (%). Daily N2O fluxes ranged from 8.26 to 86.86 g N2O-N ha−1 d−1. Overall, 34.2% of daily N2O fluxes were attributed to nitrification, 29.0% to denitrification and 36.8% to a mixture of both. A significant diversity effect of white clover and ribwort plantain on predicted SP and δ15Nbulk indicated that the inclusion of ribwort plantain may decrease N2O emission through biological nitrification inhibition under drier soil conditions (31%–75% WFPS). Likewise, a sharp decline in predicted SP indicates that increased white clover content could increase N2O emissions associated with denitrification under elevated soil moisture conditions (43%–77% WFPS). Biological nitrification inhibition from ribwort plantain inclusion in grassland swards and management of N fertiliser source and application timing to match soil moisture conditions could be useful N2O mitigation strategies.
      328Scopus© Citations 15
  • Publication
    Estimated nitrous oxide emissions from nitrogen fertilizer use on multispecies grassland compared to monocultures
    Grassland agriculture faces increasing demands in terms of sustainability; economic, social, and environmental. Soils are critical to sustainable agriculture, in terms of maintaining soil fertility and quality, protecting water quality and mitigating greenhouse gas (GHG) emissions. There is evidence to suggest that greater sward diversity may have benefits in this regard. We report results from SmartGrass; a three year field study at two sites in Ireland investigating grass sward diversity along a gradient from perennial ryegrass (Lolium perenne L.) monoculture to grass-legume mixes to more complex grass-legume-herb mixes of up to nine species. Results reported include estimates of nitrous oxide (N2O) emissions from fertiliser nitrogen (N), soil temperature and moisture conditions, plant-available soil N, changes in soil organic carbon (C) and plant-available phosphorus (P). Estimated direct N2O emissions from N fertiliser (g N2O-N t DM-1 ha-1 yr-1) decreased from 146 for the monoculture at 250 kg fertiliser N ha-1 yr-1 to 35 for the monoculture at 90 kg fertiliser N ha-1 yr-1, to approximately 16 for the grass-legume and grass-legume-herb mixes, also at 90 kg fertiliser N ha-1 yr-1. This was due to a combination of the grass-clover and mixed swards maintaining high DM yields at low fertiliser N input, and the fact that the fertiliser N for these treatments was applied entirely as urea. These results indicate significant potential for more diverse swards to mitigate GHG emissions from fertiliser N use in grassland agriculture.