This slideshow discusses a number of different approaches to sustainable agriculture with a focus on ways to minimize environmental impacts. The influence of Borlaug and Vogt on agriculture are discussed as well.

1. Sustainable Agriculture
and the Future of Food

2. Sustainable Agriculture
Ecology is a central pillar of
sustainable agriculture1,
treating farmed areas first
and foremost as ecosystems
Right: sustainable farming
with mixed crops at
Rancho Cacachilas,
BCS, Mexico 2

3. Sustainable Agriculture
Sustainable agriculture typically stresses treating soil as an
ecosystem and thus keeping it healthy1
 Internal inputs typically rely on natural resources2
 Outside inputs usually cost more and may alter the
farming system3
 Other approaches present it as a compromise between
several sets of social goals: meeting human needs4,
improving environmental quality, using resources
efficiently, ensuring a living wage for farmers
3

4. Sustainable Agriculture
Organic farming:
 For plants: synthetic pesticides, herbicides, fertilizers,
and genetically modified organisms are prohibited
 For animals: antibiotics, hormones, and synthetic feeds
for animals are prohibited
Organic farming generally conserves biodiversity, improves
the structure and organic content of soil, leaches less
nitrate into water bodies, and produces much less pesticide
pollution. 4

5. Sacred Valley NGO, Casa GiraSol (Sunflower House) Organic Farm & Retreat

6. Sustainable Agriculture
In its first years, organic farms typically produce less than
conventional farms1
Production costs tend to be higher with organic agriculture2
Yet, compared to conventional farming, organic farming
creates more fertile soil, higher yields3, better crops (higher
quality protein, better tolerance to stress) [Granstedt &
Kjellenberg 2011], and higher vitamin and mineral content
[Center for Ecological Technology 2011]
6

7. Sustainable Agriculture
“Precision agriculture”1 is another
solution using remote sensing to
help farmers be more judicious with
fertilizer, herbicides, seeds, and
water.
These baby greens (on right) reach
full size by the time they travel to
the far end of the green house. 2
7

8. Sustainable Agriculture
Some 795 million
people (1 in 9) in
the world do not
have enough food
to lead a healthy,
active life.
(FAF, 2019)
8

9. Sustainable Agriculture
To feed every human being, grain production will have to
double without further degrading the environment
Reorienting agricultural systems is a complex task influenced
by many factors1:
• Actual demand for food
• Expansion of agricultural lands
• Opportunities for increased yields
• Availability of water and chemical fertilizers
• Global climate change
9

10. Sustainable Agriculture
In an article that sums up his book, The Wizard and the
Prophet, Mann explores this question:
How can we provide for everyone
without making the planet uninhabitable?
His research led him to see two broad types of response. He
labels their proponents either Wizards or Prophets.

12. William Vogt: The Prophet
Vogt promoted what might be called
apocalyptic environmentalism. His mantra
is “Cut back, before it’s too late!”
Agricultural prophets say: use less land,
waste less water, and stop pouring
chemicals into both.
Sustainable Agriculture

13. Sustainable Agriculture
Vogt introduced a foundational argument of today’s
environmental movement, carrying capacity (every
ecosystem has a limit to what it can produce)
As human populations rise, food demands will exceed the
Earth’s carrying capacity with catastrophic results:
 erosion, desertification, soil exhaustion, species
extinction, and water contamination
 All of this will eventually cause massive famines

14. Sustainable Agriculture
Norman Borlaug: The Wizard
Borlaug is the emblem of techno-
optimism. His mantra is
“Innovation will solve all of our
environmental dilemmas!”
Agricultural wizards say: genetic
modification will create more
productive crops.

15. Sustainable Agriculture
The global population in 2050 will increase 25 percent
People are also projected to be more affluent, meaning that
demand for animal products will multiply (cheese, dairy,
fish, and especially meat)
Growing feed for animals requires much more land, water,
and energy than producing plants for direct human
consumption.
Farmers will have to boost food output by 50 to 100 percent

16. Soil
Agriculturist Justus von
Liebig revolutionized the
nature of farming.
Treating it as a branch of
chemistry and physics,
he saw soil as nothing
more than a foundation
for holding roots.

17. Soil
The Haber-Bosch Process established a way to manufacture the
nitrogenous substances that feed plants (and won Haber and
Bosch Nobel Prizes)
 It is arguably the most consequential technological
innovation of the 20th century
 The process is responsible for almost all synthetic fertilizer,
consuming 1% of the world’s industrial energy
 This investment doubles the amount of food we can grow1

18. Soil
40% of the fertilizer that’s been applied in the past 60 years
was either washed away into rivers or seeped into the air1
Fertilizer in the water
causes eutrophication2
(shown at right)
In the air, nitrous oxide
from fertilizers neutralizes
Earth’s protective ozone
layer

19. Soil
Opposed to von Liebig, the Howards
argued that soil was an intricate living
system that required a wildly complex mix
of nutrients in plant and animal waste.
They called it The Law of Return: “the
faithful return to the soil of all available
vegetable, animal, and human wastes.”
An Agricultural Testament (1943) based on their work in India
and England is a seminal document of the organic movement.

20. The Future of Agriculture: Crops
The Wizards
Evolution produced a work-
around to rubisco’s1
“inefficient” photosynthesis:
C4 photosynthesis.
It produces identical but
faster results (by aiding
rubisco in the process)
Depiction of the activated RuBisCO enzyme (by Ericlin1337)

21. The Future of Agriculture: Crops
C4 Photosynthesis:
 C4 plants need less water and fertilizer than ordinary
plants
 C4 photosynthesis has arisen independently more than 60
times (such as corn, tumbleweed, crabgrass, and
sugarcane)
Global scientists (or “Wizards”) are trying to create a C4
variant of rice

22. The Future of Agriculture: Crops
While “sustainable” farms may yield fewer calories per acre
than industrial farms, Prophets argue we must also consider:
other factors, too:  the costs of watershed
degradation, soil erosion and
compaction, and pesticide and
antibiotic overuse
 harm to rural communities
 the taste and nutritional value
of food

23. The Future of Agriculture: Crops
Others1 have been trying to domesticate a strain of
wheatgrass that would have the benefits of wheat but in a
perennial plant
However, some African and Latin American researchers think
these approaches with cereals are misguided
They argue humans should focus on tubers and fruit trees
because they are generally more productive than cereals

24. The Future of Agriculture: Crops
Cassava, a tuber
that produces
many more
calories per acre
than wheat, is
already
domesticated
and popular

25. The Future of Agriculture: Harvest
In 1930, 21.5% of the U.S. workforce worked in agriculture
After WWII, the U.S. and most other nations consolidated
and mechanized farms to increase harvests and reduce labor
costs
For Wizards, this meant that both the remaining farm
owners and the factory workers would earn more1
By 2000, 1.9% of the U.S. workforce worked in agriculture
and the number of farms fell by roughly 66%

26. The Future of Agriculture: Harvest
To Borlaugians/Wizards,
farming is useful drudgery
that should be eased and
reduced as much as possible
To Vogtians/Prophets,
agriculture maintains
ecological and human
communities that have
cradled life for 10,000 years

27. The Future of Agriculture
If you liked “Can Planet Earth Feed 10 Billion People?”
or just want to continue this discussion,
Read “Are Things Getting Better or Worse”
by Joshua Rothman (2018)