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Improving P supply in organic farming systems
Published: Tue, 29 Nov 2005
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Research Note Full Title
Improving P supply in organic farming systems
Organic Action Plans aim to increase the proportion of organic food consumed in the UK so that 70% of it is produced by UK farmers. Phosphorus (P) is a key plant nutrient. Soluble P fertilisers are prohibited under organic rules, and although phosphate rock (PR) can be used, it has low availability at optimum soil acidity for crop growth (pH 6.5). Organic systems that incorporate crops or varieties with high P uptake efficiency into the rotation, is one way to optimise P use within the system. Fermentation of crop residues and crop waste material with PR also has potential to increase the availability of P to the crop plants. These approaches have not been investigated in depth in the field, and never in the UK.
Objectives
This project is sponsored by Defra and SEERAD (May 2007 onwards, Scottish Executive Rural Directorate (SERD)) through the Sustainable Arable LINK Programme. This Defra LINK Project (acronym ‘PLINK’) aims to optimise the use of P on organic farms, although there is scope for the concepts and knowledge gained to be utilised in other farming systems as well. The scientific objectives are:
- Develop the biotechnological solubilisation of P from PR to yield an effective, low-cost P fertilising material
- Quantify the availability of P from PR in arable crop rotations following fermentation or composting with organic vegetable wastes
- Quantify the impact of rotation design and P sources (PR, composted and fermented products) on P offtake in harvestable produce
- Quantify the environmental and economic costs and benefits of new versus traditional approaches to P management in organic farming systems
Approach
Laboratory work will identify the optimum fermentation conditions for mixtures of the PR and crop wastes, with a view to scaling this up to commercial levels. Pot and small scale plot trials will be used to investigate different crops and varieties and their ability to utilise P from the fermented product and PR alone. On-farm rotations will be used to test the ability of a range of ‘P solubilising’ crops and varieties to improve the spacial and temporal efficiency of P use in organic systems. The data collated throughout the project will be used to quantify the economic, environmental and social impact through the production chain.
The project will generate an increased understanding of the interactions between the mineral and biological cycling of P in soils. The project team, in conjunction with fruitful knowledge transfer collaborations with farmers, waste processors and the fertiliser industry have a real opportunity to develop an effective and exploitable biotechnological approach to making P fertilisation more sustainable for all farming systems.
Outcomes
Achievements
Sponsors & Partners
Research Sponsors
Bulmer Foundation
J & H Bunn Ltd
Abbey Home Farm
The Leen
Organic Recycling Ltd
Tio Ltd
Organic Farm Foods Ltd
Research Partners
Mr William Rose, Tio Ltd, Dalcross, Inverness
Partners:
Scottish Agricultural College (SAC)
Mark Measures
Newcastle University
Scottish Organic Producers Association (SOPA)
Soil Association
Sub-contractors:
Dr Tony Edwards
Mr Jonny Johnston, Rothamsted Research