The Experts below are selected from a list of 100980 Experts worldwide ranked by ideXlab platform
Jorge E Olese - One of the best experts on this subject based on the ideXlab platform.
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nitrogen leaching from conventional versus organic Farming Systems a Systems modelling approach
European Journal of Agronomy, 2000Co-Authors: Irgitte Hanse, Erik Kristense, Ruth Gra, Henning Hoghjense, Svend Erik Simmelsgaard, Jorge E OleseAbstract:Abstract The level of nitrogen leaching from organic compared to conventional Farming was evaluated by using a Systems modelling approach. Two different methods were used for estimating and evaluating nitrate leaching. A simple function was used in which nitrate leaching is dependent on percolation, soil clay content, average nitrogen input and crop sequence. A nitrogen balance model was used to estimate the long-term potential for nitrate leaching. These methods were applied to models of both current conventional Farming Systems in Denmark in 1996 and of well-managed organic Farming Systems. On average, the total estimated nitrogen input to the organic Systems was lower (104–216 kg N ha −1 year −1 ) than to the conventional Farming Systems (146–311 kg N ha −1 year −1 ). The N-balances in the organic fields showed a surplus of nitrogen (net input of nitrogen) in to the root zone of 60–143 kg N ha −1 year −1 . In the conventional Systems the surplus varied from 25 to 155 kg N ha −1 year −1 . The modelled nitrogen leaching from the organic Systems varied from 19 to 30 kg N ha −1 year −1 on loamy soils to 36–65 kg N ha −1 year −1 on sandy soils. The modelled nitrogen leaching from the organic Systems was always lower than from the comparable conventional agricultural Systems due to: (I) the lower total input of nitrogen to the organic Systems; and (II) the composition of the organic crop rotations including extensive use of catch crops. However, the modelling of nitrogen leaching has many uncertainties, principally due to difficulties in predicting the nitrogen leaching from different types of grass fields. Comparison of the results from two methods: (i) modelling of nitrogen leaching; and (ii) N-balances for the root zones, showed that organic arable crop production and dairy/beef Farming on sandy soils are Farming Systems with a clear potential for lower nitrogen leaching than from the selected conventional Systems. It is still uncertain whether the nitrogen leaching is lower or higher from organic arable crop production Systems on loamy soil and organic pig production on loamy and sandy soil than from the same conventional Systems in Denmark. The results point to the need for future research in the following areas: (i) the ability to build up soil organic nitrogen in organic Farming Systems and the consequences for both the level of crop production and nitrogen leaching in the long term; (ii) the effects of catch crops in organic crop rotations; and (iii) a better operational understanding of nitrogen leaching from different types of organically managed grass and grass-clover fields.
C M Yates - One of the best experts on this subject based on the ideXlab platform.
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a comparison of energy use in conventional and integrated arable Farming Systems in the uk
Agriculture Ecosystems & Environment, 2003Co-Authors: Aliso Ailey, W D Asford, N Penlingto, Julia Park, J D H Keatinge, Tahi Rehma, Richard Trante, C M YatesAbstract:Abstract The LINK Integrated Farming Systems (LINK-IFS) Project (1992–1997) was set up to compare conventional and integrated arable Farming Systems (IAFS), concentrating on practical feasibility and economic viability, but also taking into account the level of inputs used and environmental impact. As part of this, an examination into energy use within the two Systems was also undertaken. This paper presents the results from that analysis. The data used is from the six sites within the LINK-IFS Project, spread through the arable production areas of England and from the one site in Scotland, covering the 5 years of the project. The comparison of the energy used is based on the equipment and inputs used to produce 1 kg of each crop within the conventional and integrated rotations, and thereby the overall energy used for each system. The results suggest that, in terms of total energy used, the integrated system appears to be the most efficient. However, in terms of energy efficiency, energy use per kilogram of output, the results are less conclusive.
Irgitte Hanse - One of the best experts on this subject based on the ideXlab platform.
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nitrogen leaching from conventional versus organic Farming Systems a Systems modelling approach
European Journal of Agronomy, 2000Co-Authors: Irgitte Hanse, Erik Kristense, Ruth Gra, Henning Hoghjense, Svend Erik Simmelsgaard, Jorge E OleseAbstract:Abstract The level of nitrogen leaching from organic compared to conventional Farming was evaluated by using a Systems modelling approach. Two different methods were used for estimating and evaluating nitrate leaching. A simple function was used in which nitrate leaching is dependent on percolation, soil clay content, average nitrogen input and crop sequence. A nitrogen balance model was used to estimate the long-term potential for nitrate leaching. These methods were applied to models of both current conventional Farming Systems in Denmark in 1996 and of well-managed organic Farming Systems. On average, the total estimated nitrogen input to the organic Systems was lower (104–216 kg N ha −1 year −1 ) than to the conventional Farming Systems (146–311 kg N ha −1 year −1 ). The N-balances in the organic fields showed a surplus of nitrogen (net input of nitrogen) in to the root zone of 60–143 kg N ha −1 year −1 . In the conventional Systems the surplus varied from 25 to 155 kg N ha −1 year −1 . The modelled nitrogen leaching from the organic Systems varied from 19 to 30 kg N ha −1 year −1 on loamy soils to 36–65 kg N ha −1 year −1 on sandy soils. The modelled nitrogen leaching from the organic Systems was always lower than from the comparable conventional agricultural Systems due to: (I) the lower total input of nitrogen to the organic Systems; and (II) the composition of the organic crop rotations including extensive use of catch crops. However, the modelling of nitrogen leaching has many uncertainties, principally due to difficulties in predicting the nitrogen leaching from different types of grass fields. Comparison of the results from two methods: (i) modelling of nitrogen leaching; and (ii) N-balances for the root zones, showed that organic arable crop production and dairy/beef Farming on sandy soils are Farming Systems with a clear potential for lower nitrogen leaching than from the selected conventional Systems. It is still uncertain whether the nitrogen leaching is lower or higher from organic arable crop production Systems on loamy soil and organic pig production on loamy and sandy soil than from the same conventional Systems in Denmark. The results point to the need for future research in the following areas: (i) the ability to build up soil organic nitrogen in organic Farming Systems and the consequences for both the level of crop production and nitrogen leaching in the long term; (ii) the effects of catch crops in organic crop rotations; and (iii) a better operational understanding of nitrogen leaching from different types of organically managed grass and grass-clover fields.
S D Wratten - One of the best experts on this subject based on the ideXlab platform.
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arable acronyms analysed a review of integrated arable Farming Systems research in western europe
Annals of Applied Biology, 1994Co-Authors: J M Holland, Geoffrey K Frampton, Tamer Cilgi, S D WrattenAbstract:Summary Arable production has come under increasing economic and environmental pressures, especially in the last decade. These have derived from over-production, decreased farm incomes and a concern with the possible environmental effects of intensive pesticide use associated with such intensive cultivation. A number of long-term research programmes on integrated Farming Systems and their sustainability have recently been completed or are currently under way. In the UK, these include the ‘Boxworth’ project, ‘SCARAB’, TALISMAN’, RISC, ‘LINK Integrated Farming Systems’, ‘LIFE’ and the demonstration-only programme ‘LEAF’. These projects are reviewed in terms of their objectives, designs and results to date, and are compared with some parallel programmes in Germany, the Netherlands, Switzerland and France.
Georg Cadisch - One of the best experts on this subject based on the ideXlab platform.
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Nitrogen leaching losses and balances in conventional and organic Farming Systems in Kenya
Nutrient Cycling in Agroecosystems, 2019Co-Authors: Martha W. Musyoka, Noah Adamtey, Anne W. Muriuki, David Bautze, Edward N. Karanja, Monica Mucheru-muna, Komi K. M. Fiaboe, Georg CadischAbstract:Organic Farming has been proposed as a solution to foster agricultural sustainability and mitigate the negative environmental impacts of conventional Farming. This study assessed N losses and soil surface N balances in conventional and organic Farming Systems in a sub-humid and semi-humid (Chuka and Thika) sites in Kenya. Nitrate–N (NO_3^−–N) leached was trapped at 1 m depth using the Self Integrating Accumulator core method and the changes in mineral-N were assessed at different soil depths and different crop growth stages. Both conventional and organic Farming Systems lost substantial amounts of NO_3^−–N at the early growth stages of all the crops. Cumulative NO_3^−–N leached was similar in all the Farming Systems in each cropping season. More NO_3^−–N was leached during potato cropping (22–38 kg N ha^−1) than during maize (0.9–5.7 kg N ha^−1) and vegetable cropping (1.9–2.9 kg N ha^−1). Under maize cultivation, three times more NO_3^−–N was leached at Chuka site than at Thika site. During the potato cropping, between 79 and 83% of the N applied in the low input Systems was leached, compared to 10–20% in the high input Systems. Only Org-High exhibited a positive soil surface N balance (797–1263 kg ha^−1) over a whole rotation period at both sites. We recommend reducing N applications for potato in all Farming Systems and at the early growth stages for all the crops in order to reduce N loss to the environment. We also recommend increasing N application rates in the low input Systems and to developing a model to guide application of organic inputs.
