Possible scarcity of micronutrients in the food system (Alterra project)

Wim Chardon and Oene Oenema

17-10-2013

Motive for project

Platform published an –alarming- report in summer 2012

Main conclusions: Zn and Se shortage in many soils, and small reserves on a global scale newspaper articles

Workshop Micronutrients in Agriculture

22 November 2011

Ministry of Economic affairs, Agriculture, and Innovation

Platform Agriculture, Innovation & Society Role: to advise Ministry of Agriculture etc.

Headlines Dutch newspapers, summer 2012

Essential nutrient zinc is probably gone within 21 years Shortage of zinc and selenium large global risk [Availability of] essential raw materials not obvious Large risk of zinc shortage [We have to] anticipate on zinc shortage

Motive for project

Aims of Alterra project (2012) for Ministry of Economic affairs, Agriculture, and Innovation :

Make clear if there is now, or if there will be in the future, a scarcity of micronutrients

What the consequences will be for agriculture and food security

Workshop Micronutrients in Agriculture

November 2011

Platform Agriculture, Innovation & Society Role: advise Ministry of Agriculture etc.

Research questions of the project

Possibility of global or regional scarcity of micronutrients in our food system. Possibilities to prevent losses of these micronutrients to

the environment and/or accumulation in the soil. Potential consequences of scarcity and possibilities to

reduce the causes of scarcity.

Macro- versus micronutrients

Macronutrients: N, P, K, Ca, Mg, and S (nitrogen, phosphorus, potassium, calcium,

magnesium, sulfur)

Micronutrients : relatively small need with plant, human or animal Handbook mentions 20 elements:

Al, As, B, Cl, Co, Cr, Cu, F, Fe, I, Mn, Mo, Na, Ni, Pb, Se, Si, Sn, V, Zn

1991, 750 pp.

Not all 20 elements included in this study

1st selection – high content in earth's crust or sea no risk of global scarcity : 7 skipped: Al, Cl, Fe, I, Mn, Na, Si

2nd selection – plant need not really shown / only few crops: 7 skipped: As, Cr, F, Ni, Pb, Sn, V

Selected for study: (20-7-7=6) B, Co, Cu, Mo, Se en Zn boron, cobalt, copper, molybdenum, selenium and zinc

Differences between elements

World-soil

Plant

Crit. Raw Mat. EU

Export Restricted

Element

mg/kg mg/kg

B 10 40

Co 8 0.2 CRM

Cu 20 10 China

Mo 2 0.5 China

Se 0.2 0.02

Zn 50 50

Price development, indication of scarcity?

Only for molybdenum and selenium a real increase of the price is found in recent years, when compared with 1991

0

1

2

3

1990 1995 2000 2005 2010 2015

Pri

ce c

omp

. w

ith

19

91

(=

1)

Year

Price development 1991-2011, infl.corr. 3%/jr

B

Co

Cu

Zn

0

2

4

6

8

10

1990 1995 2000 2005 2010 2015

Pri

ce c

omp

. w

ith

19

91

(=

1)

Year

Price development 1991-2011, infl.corr. 3%/jr

Mo

Se

Reserves, production and scarcity

Element Reserves Kton

ProductionKton / year

R/P USGS year

R/P Platform

year

Zn 250000 12400 20 21

Reserves = “the amount of an element that can be produced with current techniques and at the current price”

Essential nutrient zinc is probably gone within 21 years

Reserves, production and scarcity

Element Price Reserves Production R/P

Zn 1 250,000 12,400 20

Reserves = “the amount that can be exploited with current techniques and at the current price”

Example: when market price of element increases, also lower grade ores can be exploited reserves increase, so R/P increases, scarcity decreases

Element Price Reserves Production R/P

Zn 2 600,000 11,500 52

Reserves, production and prices of micronutrients

Element Reserves Production R/P

USGS R/P

Platform R/P

Cohen

Price 2007-2011

USD/kg

Year 2011 2011 2011 2010 2006

B 65220 1340 49 60

4

Co 7500 98 77

56

Cu 690000 16100 43 39 61 7

Mo 10000 250 40 42 45

Se 93 2 47 39 84

Zn 250000 12400 20 21 46 2

Variation in R/P

Zn lowest price

Did the increase in price of Zn lead to increase in R/P, so decrease in scarcity?

Temporal price increase of Zn led in 2006/07 probably to higher estimation for R/P by Cohen (2007)

0

1

2

3

1990 1995 2000 2005 2010 2015

Pri

ce U

SD

/kg

Year

Price development zinc 1991-2011

R/P ratio - “equilibrium values” of elements

R/P ratios of Cu, Pb and Zn are at equilibrium while production continues .... Source: Wellmer (2008) Zeitschrift Deutschen Ges. Geowiss. 159:575-590

R/P

ratio

R/P ratio - “equilibrium values” of elements

“... money is not spent now on discovering potential deposits which cannot or will not be brought into production within the foreseeable future (+ 25 years).....” “Between reserves and consumption there exists a kind of equilibrium. This equilibrium R/C number is specific for each commodity: for crude oil it is about 45 ..... For zinc it is between 20 and 25, but so far crippling shortages have never occurred” Source of both: Wellmer (2008) Zeitschrift Deutschen Ges. Geowiss. 159:575-590

Thus: the period (years) calculated as R/P is NOT the time after which global reserves will be depleted, but only reflects the size of the stock kept by producing companies.

Use of micronutrients in agriculture and recycling within industry

Element % Agriculture % Recycling

B 12 0

Co < 1 24

Cu < 1 32

Mo < 1 30

Se 11 0

Zn < 1 27

Boron and selenium: significant % use within food system, but no recycling ...., other elements: agriculture use not relevant

Copper and zinc in animal manure

• Copper and zinc are used as feed additives in pig production, which leads to relatively high Cu and Zn concentrations in pig manure.

• Balance calculations for Dutch soils show that there is a net accumulation of Cu and Zn.

• On longer term this could lead to leaching and environmental problems.

• Reducing levels in feed would be more sustainable.

Alternatives for use of micronutrients within industry

Element Alternatives ?

B yes

Co no

Cu yes

Mo yes

Se yes

Zn yes

Cobalt: few alternatives for (industrial) use

Micronutrients in sewage sludge

Micronutrients we consume end up in sewage sludge. In many countries sewage sludge is burnt, because agricultural use is not allowed.

Ash of sludge ends up in landfills, including the phosphorus that is present in the sludge.

Research is done on recycling of P in sludge, not of micronutrients.

Agricultural use of sewage sludge would be good for recycling of both P and micronutrients.

Conclusions and points for discussion

Via animal manure a non-sustainable accumulation of copper and zinc takes place in Dutch agricultural soils. This should be reduced by lowering Cu/Zn levels in feed.

The price development of zinc does not give an indication for scarcity in the near future; because of the low price of zinc the R/P-ratio is possibly not a good indicator.

The period (years) calculated as R/P is NOT the time after which global reserves will be depleted, but only reflects the size of the stock kept by producing companies.

The price development of selenium and boron indicates that scarcity may develop, there is hardly any recycling of both.

Agricultural use of sewage sludge would be good for recycling of both P and micronutrients.

References

This presentation is based on the report: Chardon, W.J., and O. Oenema. 2013. Exploration of possible scarcity of micro nutrients in the food system (in Dutch: Verkenning

mogelijke schaarste aan micronutriënten in het voedselsysteem.) Report 2413, Alterra Wageningen. http://edepot.wur.nl/257460

See also the report (in Dutch) by the Platform Agriculture, Innovation & Society : Udo de Haes, H.A., R.L. Voortman, T. Bastein, D.W. Bussink, C.W. Rougoor, and W.J. van der Weijden. 2012. Schaarste van

micronutriënten in bodem, voedsel en minerale voorraden. Urgentie en opties voor beleid. Advies aan Minister EL&I, Platform

Landbouw, Innovatie & Samenleving, juni 2012. http://www.stuurgroepta.nl/rapporten/Micro-nutrienten-compleet-web.pdf

A paper on (mis)interpretation of R/P values: Wellmer, F.-W. 2008. Reserves and resources of the geosphere, terms so often misunderstood. Is the life index of reserves of natural

resources a guide to the future? Zeitschrift Deutschen Ges. Geowiss. Stuttgart 159:575-590.

Other papers cited: Cohen, D. 1991. Earth's natural wealth: an audit. New Scientist magazine, 23 May 2007, p. 34-41

http://www.science.org.au/nova/newscientist/027ns_005.htm

USGS MCS, United States Geological Survey, Mineral Commodity Summaries, available for different elements and years via http://minerals.usgs.gov/minerals/pubs/commodity/

Thanks for your attention !