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| Watson, C.A.; Bengtsson, H.; Ebbesvik, M.; Loes, A-K.; Myrbeck, A.; Salomon, E.; Schroder, J.; Stockdale, E.A.. |
| On organic farms, where the importation of materials to build/maintain soil fertility is restricted, it is important that a balance between inputs and outputs of nutrients is achieved to ensure both short-term productivity and long-term sustainability. This paper considers different approaches to nutrient budgeting on organic farms and evaluates the sources of bias in the measurements and/or estimates of the nutrient inputs and outputs. The paper collates 88 nutrient budgets compiled at the farm scale in 9 temperate countries. All the nitrogen (N) budgets showed an N surplus (average 83.2 kg N ha-1 year-1). The efficiency of N use, defined as outputs/inputs, was highest (0.9) and lowest (0.2) in arable and beef systems respectively. The phosphorus (P) and... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover; Soil quality. |
| Ano: 2002 |
URL: http://orgprints.org/8061/2/Watson_orgrpints_8061.pdf |
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| Watson, C.A.; Atkinson, D.; Gosling, P.; Jackson, L.R.; Rayns, F.W.. |
| Complex relationships exist between different components of the organic farm and the quantity and quality of the end products depend on the functioning of the whole system. As such, it is very difficult to isolate soil fertility from production and environmental aspects of the system. Crop rotation is the central tool that integrates the maintenance and development of soil fertility with different aspects of crop and livestock production in organic systems. Nutrient supply to crops depends on the use of legumes to add nitrogen to the system and limited inputs of supplementary nutrients, added in acceptable forms. Manures and crop residues are carefully managed to recycle nutrients around the farm. Management of soil organic matter, primarily through the... |
| Tipo: Journal paper |
Palavras-chave: Production systems; Soil quality. |
| Ano: 2002 |
URL: http://orgprints.org/8060/2/Watson_orgprints_8060.pdf |
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| Baddeley, J. A.; Döring, Thomas F.; Hatch, David; Marshall, Athole; Pearce, Bruce; Roderick, S; Stobart, Ron; Storkey, Jonathan; Watson, C.A.; Wolfe, Martin. |
| There is a pressing need to develop arable cropping systems that are both more efficient in their use of nitrogen (N) and more resilient to an increasingly variable and unpredictable climate. One potential solution is to use species-rich mixtures of grasses and legumes in the fertilitybuilding phase of a ley/arable crop rotation. These mixtures may reduce N losses and increase productivity of the following crop. They may also have other important benefits such as increased in-field biodiversity. In this project, legume and grass species with a range of tolerances to different environmental conditions, and with differing growth characteristics, are being grown individually and as a mixture across the UK, and their performance assessed. |
| Tipo: Conference paper, poster, etc. |
Palavras-chave: Nutrient turnover; Crop husbandry. |
| Ano: 2010 |
URL: http://orgprints.org/19774/1/SACSEPA2010JAB.pdf |
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| Watson, C.A.; Öborn, I.; Eriksen, J.E.; Edwards, A.C.. |
| Changes in agricultural subsidies in Europe and the ready availability of fertilisers have allowed a spatial decoupling of livestock and crop production. This has increased the flow of nutrients that occurs between farms compared to within individual farms. In terms of nutrient cycling mixed farms provide the opportunity to re-integrate aspects of agricultural production. The degree of integration between crop and livestock production is defined by the reliance on the use of home-produced feed compared to imported feed, and is independent of intensity. Farm scale nutrient use efficiency (NUE) is inversely related to stocking density. Management of inputs and/or internal flows offers the scope to improve NUE on mixed farms. Greatest uncertainties in... |
| Tipo: Journal paper |
Palavras-chave: Nutrient turnover. |
| Ano: 2005 |
URL: http://orgprints.org/4571/1/4571.doc |
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