SAC Research

This project aims to improve the effectiveness of phosphorus use from phosphate rock in organic farming.

The demand for home produced organic food significantly exceeds that which can be supplied. One of the factors limiting crop production of organic crops is the supply and availability of phosphorus. The use of soluble phosphorus fertilisers e.g. triple superphosphate, is prohibited in organic farming, and whilst minimally processed phosphate rock can be used, it has low solubility at the optimum soil pH (~ 6.5) for cropping. Establishing and maintaining the balance between phosphorus supply to sustain production and minimise diffuse losses is of major importance in developing sustainable farming systems and in contributing to better environmental protection.

The efficiency of phosphorus use in rotations could be increased by the targeted inclusion of crops and cultivars with high uptake efficiency. The fermentation of crop residues or green wastes with phosphate rock also has potential to increase phosphorus availability to crops. Neither approach has yet been widely tested in the field and not at all in the UK. For best management practice for phosphorus on organic farms to be formulated, a more detailed understanding of soil-plant phosphorus interactions is required. This project will integrate and test novel approaches to the use of phosphate rock within organic crop rotations.

The project aims to improve the effectiveness of use from phosphate rock in organic farming. This will be achieved through a) developing biotechnological approaches to the solubilisation of phosphate rock using organic waste materials within the organic farming system and using the products to increase short-term phosphorus availability to arable and horticultural crops and b) improved rotation design by inclusion of crops with different abilities to solubilise phosphorus. We will quantify the economic and environmental impact of these approaches through the production chain.

Project Number:  12345

DEFRA
The Bulmer Foundation

Industrial
Tio Ltd
Scottish Organic Producers Association (SOPA)
J & H Bunn Ltd
Abbey Home Farm
The Leen
Organic Recycling Ltd
Organic Farm Foods Ltd
Soil Association

Academic
Dr Christine Watson, Dr Bob Rees, Dr Robin Walker, SAC
Dr Elizabeth Stockdale, Newcastle University
Mr Johnny Johnston, Rothamsted Research
Mr Mark Measures
Dr Tony Edwards