Isabelle Kurz

Bio: Isabelle Kurz is an academic researcher. The author has contributed to research in topics: Nutrient management & Nutrient. The author has an hindex of 1, co-authored 1 publications receiving 75 citations.

Agriculture, meteorology and water quality in ireland: a regional evaluation of pressures and pathways of nutrient loss to water

Abstract: The main environmental impact of Irish agriculture on surface and ground water quality is the potential transfer of nutrients to water. Soil water dynamics mediate the transport of nutrients to water, and these dynamics in turn depend on agro-meteorological conditions, which show large variations between regions, seasons and years. In this paper we quantify and map the spatio-temporal variability of agro-meteorological factors that control nutrient pressures and pathways of nutrient loss. Subsequently, we evaluate their impact on the water quality of Irish rivers. For nitrogen, pressure and pathways factors coincide in eastern and southern areas, which is reflected in higher nitrate levels of the rivers in these regions. For phosphorus, pathway factors are most pronounced in north-western parts of the country. In south-eastern parts, high pressure factors result in reduced biological water quality. These regional differences require that farm practices be customised to reflect the local risk of nutrient loss to water. Where pathways for phosphorus loss are present almost year-round * as is the case in most of the north-western part of the country * build-up of pressures should be prevented, or ameliorated where already high. In south-eastern areas, spatio-temporal coincidence of nutrient pressures and pathways should be prevented, which poses challenges to grassland management.

Making the Most of Our Land: Managing Soil Functions from Local to Continental Scale

Abstract: The challenges of achieving both food security and environmental sustainability have resulted in a confluence of demands on land within the European Union (EU): we expect our land to provide food, fibre and fuel, to purify water, to sequester carbon, and provide a home to biodiversity as well as external nutrients in the form of waste from humans and intensive livestock enterprises. All soils can perform all of these five functions, but some soils are better at supplying selective functions. Functional Land Management is a framework for policy-making aimed at meeting these demands by incentivising land use and soil management practices that selectively augment specific soil functions, where required. Here, we explore how the demands for contrasting soil functions, as framed by EU policies, may apply to very different spatial scales, from local to continental scales. At the same time, using Ireland as a national case study, we show that the supply of each soil function is largely determined by local soil and land use conditions, with large variations at both local and regional scales. These discrepancies between the scales at which the demands and supply of soil functions are manifested, have implications for soil and land management: while some soil functions must be managed at local (e.g. farm or field) scale, others may be offset between regions with a view to solely meeting national or continental demands. In order to facilitate the optimisation of the delivery of soil functions at national level, to meet the demands that are framed at continental scale, we identify and categorise 14 policy and market instruments that are available in the EU. The results from this inventory imply that there may be no need for the introduction of new specific instruments to aid the governance of Functional Land Management. We conclude that there may be more merit in adapting existing governance instruments by facilitating differentiation between soils and landscapes.

Evaluation of cover crop and reduced cultivation for reducing nitrate leaching in Ireland.

Abstract: Nitrate (NO3) loss from arable systems to surface and groundwater has attracted considerable attention in recent years in Ireland. Little information exists under Irish conditions, which are wet and temperate, on the eff ects of winter cover crops and diff erent tillage techniques on NO3 leaching. This study investigated the effi cacy of such practices in reducing NO3 leaching from a spring barley (Hordeum vulgare L.) system in the Barrow River valley, southeast Ireland. The study compared the eff ect of two tillage systems (plow-based tillage and noninversion tillage) and two over-winter alternatives (no vegetative cover and a mustard cover crop) on soil solution NO3 concentrations at 90 cm depth over two winter drainage seasons (2003/04 and 2004/05). Soil samples were taken and analyzed for inorganic N. During both years of the study, the use of a mustard cover crop signifi cantly reduced NO3 losses for the plowed and reduced cultivation treatments. Mean soil solution NO3 concentrations were between 38 and 70% lower when a cover crop was used, and total N load lost over the winter was between 18 and 83% lower. Results from this study highlight the importance of drainage volume and winter temperatures on NO3 concentrations in soil solution and overall N load lost. It is suggested that cover crops will be of particular value in reducing NO3 loss in temperate regions with mild winters, where winter N mineralization is important and high winter temperatures favor a long growing season.