Phosphorus in organic farming systems: Improving supply and use efficiency

Summary

Phosphorus (P) is a key plant nutrient but it needs to be managed it carefully in an organic system, in order to obtain sustainable crop yields and quality without contributing to potential damage to the environment. Minimally processed rock phosphate (PR) can be used, but it has very low solubility at optimum soil acidity for crop growth (pH 6.5). This paper describes a project (PLINK), which is investigating methods of improving P efficiency on organic farms. Approaches include fermentation of crop waste material with PR in order to make P more available to the crop, as well as incorporation of crops or varieties with high P uptake efficiency.