PHOSPHORUS FERTILISERS FROM BY-PRODUCTS AND WASTES

摘要

This paper addresses the question 'Can fertilisers from processed byproducts and wastes become a competitive alternative for conventional mineral phosphorus fertilisers?' In answering this question, we take a global perspective. Firstly, we briefly summarise the global phosphorus (P) stocks and flows. We then describe the main by-products and wastes available in the world that may be used as P fertiliser. Next, we discuss the possible processes and treatments used before by-products and wastes are used as fertilisers, and consider the P availability of these fertilisers to crops. We argue that fertilisers from (processed) byproducts and wastes may become a competitive alternative for ordinary mineral P fertilisers only regionally. We proceed by addressing the question 'How to use ordinary P fertilisers from rock phosphate and P fertilisers from by-products and wastes in an optimal way, from the viewpoints of food security, resources use efficiency, equity, environmental sustainability and feasibility?'