Taking the P

In order to evaluate the most risky limiting factors for food production worldwide, we need to take into consideration the availability of raw ingredients for agriculture and aquaculture. In the previous food security post from Ioannis Zabetakis the value of oils and the need to identify novel lipid sources was discussed. With this post, the issue of phosphorus availability is highlighted.

Bio-essential elements

Phosphorus (P) is one of the bio-essential elements. This term stands for those elements that are indispensably involved in the metabolism of any organism and/or enzymatic activation and they are essential for food production and thus for our survival. These are nitrogen (N), potassium (K) and P. From a food security point of view, the rather unique problem with P, is this: For K and N, their future availability should not be a problem as our atmosphere is a unlimited source of both K. However, P is not abundant and it has a highly dissipative nature because of a series of parameters, like soil erosion, manure and waste water discharges).

Availability of P

To analyse availability, we need to consider the 3 R’s of P:

  1. Reserves (i.e. the share of the total resources that can be economically extracted given the existing technology and the current environmental limitations).
  2. Resources (i.e. where and how much we can find of a given elements subject to various levels of uncertainty).
  3. Research into geopotential (i.e. if new reserves/resources could be identified and used given the modern exploration technologies).

The problem of estimating resources is a rather important one, given that the classification of resources is regarded to be an entirely “subjective task”.

For assessing possible threats (to availability and thus food security), the ratio of resource (R) over consumption (C) is used (R/C ratio). The R/C ratio for P for a given area can though change dramatically if the value of R changes: for Morocco, the R/C ratio for 2008 was reported as 228 and the same ratio was 1923 for 2010! The R/C ratio is just a snapshot of a dynamic system, where novel resources can be identified and this could change a grim situation to a more…optimistic one! We need to bear in mind that neither R nor C remain constant over time.

A football game with shifting goalposts

New resources could be valorised and also consumption may decrease, thanks to novel recycling schemes: the Institute of German Industry (IWD) has made some strong recommendations in 2010 for P recycling (from waste water and sewage sludge). Thus, in order to calculate the P footprint and make reliable predictions, a plethora of parameters need to be addressed (e.g. resources, technological innovation, recycling practices etc).

Further reading

  1. A dynamic view on mineral resources availability: What we may learn from the case of phosphorus?
  2. European Centre for Phosphate Research, CEEP, part of CEFIC