Let me start out by saying that P sustainability is simple and complicated at the same time. I will start with a “simple” idea and work through some of the key complexities. There is much more to be said so if you are interested follow some of the links or google it. (At some point this year a book is going to come out about all this, which a co-authored a couple of chapter in, and I will put the link up as well).
Phosphorus, as an essential resource and a pollutant, has been “on the map” for a while (for certain interest and research groups in agriculture and ecology). I would say that in our “modern” time, Dr. Dana Cordell has been a pivotal figure in bringing the current problems with P management to light and has been the impetus for bringing many actors to converge on the idea of sustainable P management.
Her 2009 paper “The story of phosphorus: Global food security and food for thought” (here) was my first real exposure to a whole-system perspective on P management. This article gave me a subject (P) with which I could integrate both my knowledge in ecology and environmental science, and my desire to do solution-oriented research in urban environments.
In her PhD thesis Cordell (2010) defines P sustainability as “all the world’s farmers have access to sufficient phosphorus in the short and long term to grow enough food to feed a growing world population, while ensuring farmer livelihoods and minimising detrimental environmental and social impacts’’
I believe her’s is a nice overarching definition, explicitly putting human well-being at the forefront, and acknowledging the necessity for a “healthy” environment which we ultimately depend on. Still, there is quite a gap between the idea of sustainable P management and the right research questions to facilitate effective management strategies and actual implementation by decision-makers. I think a big part of our knowledge gap stems from the reality that specific P management problems and solutions are complex and depend on what scale (both geographical and temporal) you decide to explore.
In my research I am interested in looking at the regional scale but this implies looking at some cross-scalar issues. Any one location is dependent on some lower scale properties, for example soil type is very important in determining P requirements, and larger scale properties, for example the price of mined-P fertilizer in any location is dependent on global trade and national policies. I could go on about this complexity, but to keep it brief I would say the understanding the context, whether it be biophysical or social in nature, is one of the key areas we need to research in order to make more sustainable P management a reality. Also, I would like to point out increasing P sustainability by increasing efficiency and recycling in the food system does not make P-mining obsolete (for example here). There will always be some losses of P that must be replaced and there are places in the world, notably sub-Saharan Africa, where more P fertilizer is currently needed but don’t have physical or economic access.
I will allow myself one more point: there is no “magic bullet” to sustainable P management. I think it will require us to use many tools in our arsenal to change how we manage food production, food consumption and waste. We also need to think about P at the same time as we think of other important sustainability issues.
Side note: I don’t think we need to get into the issue of peak P to talk about P sustainability. Yes, the numbers have changed since the “initial” Cordell et al. 2009 publication (here and here) and there are numerous papers debating the validity of the idea (here, here), but in my mind (and of others) the issues remain largely the same even without looming peak production (here).