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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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| Loes, A-K.; Bünemann, E.; Cooper, J.; Hörtenhuber, S.; Magid, J.; Oberson, A.; Möller, K.. |
| Organic farming systems need to replace nutrients exported via farm products, especially phosphorus (P) which may otherwise become depleted in soil in the long term. In Europe, EU regulations for organic production are shaping the farming systems with respect to inputs of nutrients. Permitted off-farm P sources include conventional animal manure, composted or anaerobically digested organic residues, rock phosphate, and some animal residues such as meat and bone meal. The recent proposed revision of EU regulations for organic production (2014) puts less emphasis on closing nutrient cycles and instead aims at minimizing off-farm inputs, to reduce the risk of importing contaminants. This development, which has received little attention from the organic sector... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Composting and manuring; Regulation. |
| Ano: 2016 |
URL: http://orgprints.org/32308/1/loes-etal2016-OrgAgri-online-p1-24.pdf |
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