SCARCITY AND INEFFICIENCY IN FOOD SYSTEMS What is Phosphorus? - - PowerPoint PPT Presentation

SCARCITY AND INEFFICIENCY IN FOOD SYSTEMS

What is Phosphorus?

Etymology: from Ancient Greek meaning

“light bearer”

Origin of the term: phosphorescence

The Evolution of Phosphorus

Why is Phosphorus Important?

• essential for life

○ macronutrient ○ vital role in every plant process involving energy transfer

• Its functions cannot be fulfilled by any other

nutrient

Why is Phosphorus Important?

■ component of phospholipids that make up the cell membrane ■ component of DNA, RNA, and ATP ■ essential for formation of new cells

Phosphorus Soil Cycle

Phosphorus Deficiency

Required for normal growth and development

• Reduction in leaf expansion and surface

area

• Reduced shoot growth
• Dark green leaves

Phosphorus as Fertilizer

• Discovered to be useful fertilizer in the 19th

century

• Phosphorus is mined from phosphate rock

deposits

• 90% of phosphate mined today goes into

fertilizers

○ the rest goes into soft drinks, steel electroplating, toothpaste, detergents, etc.

Historical Global Sources of Phosphorus

The Phosphorus Mineral Fertilizer Cycle

World Phosphate Rock Reserves

The 5 Dimensions of Phosphorus Scarcity

• 1. Physical Scarcity

Scarcity caused by dwindling phosphate rock reserves

• Reserves are estimated to last the next 100-

300 years

• Peak phosphorus is estimated to be reached

around the year 2030

Peak Phosphorus Curve

• 2. Management Scarcity

Improper management of phosphorus, resulting in substantial system inefficiencies that limit the ability of available phosphorus to meet demand Phosphorus losses in every step of production

Eutrophication

• 3. Economic Scarcity

Lack of access to phosphorus, due to constraints in financial capacity or constraints in labor and time capacity to source phosphorus.

• Farmer purchasing power
• Investment lag

Prices of Phosphate Rock

2008 Price Spike

A short-term 800% price increase occurred because of:

• increased agricultural demand
• tight supplies of phosphate rock

This spike led to increased concern about phosphorus resources

• 4. Institutional Scarcity

Scarcity resulting from a lack of appropriate and effective institutional and political structures

• Policies
• Governing bodies
• Feedback Loop

• 5. Geopolitical Scarcity

Access to phosphorus resources is restricted due to political or geopolitical circumstances such as monopolies controlled by governments

• r corporations.

World Phosphate Rock Reserves c

• u

n t r i e s c

• n

t r

• l

9 %

• f

t h e w

• r

l d ’ s r e m a i n i n g p h

• s

p h

• r

u s !

The (Ph)uture of Phosphorus

Phosphorus Security Minimize losses in use Maximize recovery and reuse

Minimizing

• 1. Reduce phosphorus losses in arable land
• Stop overuse of phosphorus fertilizer:

minimise mineral phosphorus use and

• ptimise land use
• Avoid phosphorus losses from cropland soils

○ avoid erosion by improving soil management ○ improve soil quality

Minimizing

• 2. Reduce phosphorus losses in livestock

systems

• Maximize use of phosphorus in manure for

soil fertility in croplands and pastures

• Adjust livestock and human diets
• 3. Reduce phosphorus use
• phosphorus-efficient crops

Maximizing

Recover phosphorus lost in:

• Livestock manures

○ Poultry manure contains ~13kg/ton

• human excreta

○ 3 million tons of phosphorus cycles through human bodies annually

• other organic wastes

○ composts, crop residues, etc.

The “NoMix” Toilet

“We may be able to substitute nuclear power for coal, and plastics for wood, and yeast for meat, and friendliness for isolation—but for phosphorus there is neither substitute nor replacement.”

• Isaac Asimov, 1974

Questions?