A review of farm-scale nutrient budgets for organic farms as a tool for management of soil fertility
| Autor: | Helena Bengtsson, Eva Salomon, Christine A. Watson, J.J. Schröder, E.A. Stockdale, Anne-Kristin Løes, M. Ebbesvik, Åsa Myrbeck |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: |
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Soil Science PRI Agrosysteemkunde Soil quality Agricultural science Nutrient sales groundwater norway conversion Productivity simple-model Nutrient turnover Nutrient management biological nitrogen-fixation clay cropping systems Pollution Manure Agronomy balance calculations Organic farming Environmental science Agrosystems Soil fertility Arable land Agronomy and Crop Science |
| Zdroj: | Soil Use and Management 18 (2002) Scotland's Rural College Soil Use and Management, 18, 264-273 |
| ISSN: | 0266-0032 |
| Popis: | 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 nine temperate countries. All the nitrogen (N) budgets showed an N surplus (average 83.2 kg N ha(-1) yr(-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 potassium (K) budgets showed both surpluses and deficits (average 3.6 kg P ha(-1) yr(-1), 14.2 kg K ha(-1) yr(-1)) with horticultural systems showing large surpluses resulting from purchased manure. The estimation of N fixation and quantities of nutrients in purchased manures may introduce significant errors in nutrient budgets. Overall, the data illustrate the diversity of management systems in place on organic farms, and suggest that used together with soil analysis, nutrient budgets are a useful tool for improving the long-term sustainability of organic systems. |
| Databáze: | OpenAIRE |
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