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Understanding soil fertility in organically farmed systems - OF0164

Description
Maintaining soil fertility (i.e. favourable soil physical conditions, favourable nutrient status and high biological activity/diversity) is crucial to all forms of sustainable agriculture. It could be argued, however, that this is especially pertinent to organically managed systems in which crops rely on soil nutrient supply (rather than additions of water soluble fertilisers). The main objective of the proposed project is therefore to provide a better understanding of the nutrient cycling aspects of soil fertility in organically managed soils, targeting the processes involved and their controlling factors (including the role of biological diversity). This will enable development of advice for the better utilisation of organically (and conventionally) managed soils, in terms of best strategies to encourage efficient nutrient cycling and determining the value (or otherwise) of soil tests for assessing soil nutrient supply. The project is relevant to MAFF’s policy of a greater commitment towards organic farming. The results will provide sound, scientific information on which both to guide policy (organic farming/soil sustainability) and to provide practical information on management practices to the organic farming industry (which may be relevant to conventionally managed farms, too).
Objective
Overall objective:
To provide a better understanding of nutrient cycling in organically managed soils, and define the processes (including the role of biological diversity) involved and their controlling factors.

Detailed objectives:
1. To undertake a comprehensive review of the scientific literature on all aspects of soil fertility in organically managed soils.
2. To select appropriate measurement techniques for detailed nutrient cycling measurement.
3. To identify experimental sites and select the most appropriate for detailed nutrient cycling measurement.
4. In field, pot and laboratory studies, to compare the changes with time in fertility of soils under organic management in terms of
· nutrient pool sizes
· rates of transfer between nutrient pools
· soil biological activity and processes influencing rates of transfer and nutrient availability
· changes in form and function of soil organic matter and the residues returned to the soil
5. In field, pot and laboratory studies, to measure the effects of key fertility building and fertility depleting stages in organic rotations in terms of
· nutrient pool sizes
· rates of transfer between nutrient pools
· soil biological activity and processes influencing rates of transfer and nutrient availability
· changes in form and function of soil organic matter and the residues returned to the soil
6. To assimilate and interpret the results of the review and of the experiments to provide practical advice to both MAFF and the organic farming community in terms of
· factors affecting soil fertility
· sources of nutrient supplies
· measuring and optimising nutrient supply
· providing the basis of field diagnosis of fertility
7. To identify the suitability of existing organic experiments for longer-term studies in this topic area.
8. To publish results from this project, and others, in a special edition of Soil Use and Management in June 2002.
Project Documents
• Final Report : Understanding soil fertility in organically farmed systems   (592k)
Time-Scale and Cost
From: 1999

To: 2002

Cost: £325,851
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER), Henry Doubleday Research Association, ADAS UK Ltd., University of Wales, Bangor
Keywords
Crops              
Farming              
Organic Farming              
Soil              
Fields of Study
Organic Farming