We can learn a lot about agriculture in ancient
Egypt from their art.
4-5 million
people during
the New
Kingdom
http://www.artsci.wustl.edu/~anthro/courses/306/Nile%20Delta.jpg
Greek
historian
Herodotus
wrote
“Egypt is
truly a gift
of the Nile”
http://lexicorient.com/e.o/atlas/maps/nile.gif
6 TRILLION CFT
~ 120 million tons
of sediment
accumulate behind
the dam each year
Most of Egypt
This sediment
is desert !
contains
~ 10,000 tons of
High Aswan
Dam
Hoover
Dam
1.2
biologically
available
TRILLION
CFT P and N !
High Aswan Dam
constructed
beginning in 1960
Mediterranean fisheries collapsed after the
construction of the High Aswan Dam
Shrimp harvest along Egyptian Coast
Nixon, 2003. Replacing the Nile: Are Anthropogenic Nutrients Providing the Fertility Once Brought to the
Mediterranean by a Great River? Ambio. Volume 32, Issue 1 (February 2003)
Stercutius
Roman art also reveals a
lot about their agriculture.
In addition to Saturn and Ceres (Roman
god and goddess of Agriculture), the
Romans had a god of manure named
Stercutius who was worshiped by old
women and children.
A number of Roman authors (e.g., Cato, Columella, Pliny the Elder)
wrote detailed textbooks on agriculture that described the use of
animal manures, green manures and crop rotations to improve soil
productivity. These books were considered important sources of
information about agriculture for over a thousand years.
Pliny the Elder (AD 23-79) classified animal
manures with respect to their advantages
and disadvantages of most animal manures
and recommended the use of green
manures. "It is universally agreed by all
writers that there is nothing more beneficial
than to turn up a crop of lupines, before they
have podded, either with the plough or the
fork, or else to cut them and bury them in
heaps at the roots of trees and vines."
The earliest records of soil improvement using green
manures are from the Chou dynasty (~1000 BC) in
China. Later (500 BC), Tsi gave the following advice:
“Green manures are broadcast in the 5th or 6th month,
and plowed under in the 7th or 8th month... Their
fertilizing value is as good as silkworm excrement and
well-rotted farm manure"
“ We desired to learn how it is
possible, after twenty and
perhaps thirty or even forty
centuries, for their soils to be
made to produce sufficiently for
the maintenance of such dense
populations.. “
FH King, 1911
Fertilizing with night soil
Early Chinese Grain Drill
Chinampas Agriculture
in Central America
http://library.thinkquest.org/C006206F/images/images/pint5.jpg
http://www.icarito.cl/vgn/images/portal/FOTO042005/221466640lamina-chinampas.jpg
Building Chinampas
http://kyapa.tripod.com/agengineering/drainage-lowland/veracruzbuildingchinampas.jpg
Chinampas in the Momposina lowland region of Columbia
http://kyapa.tripod.com/agengineering/drainage-lowland/camell-colombia.jpg
In 1240, Roman literature was summarized by Crescentius.
http://www.abbeville.com/Products/InteriorImages/0896599191Interiors.htm
Bernard Palissy (1510-1589)
Far ahead of his time, Palissy
wrote: ”Manure is carried to the
field for the purpose of restoring to
the latter a part of what had been
removed... Proceeding thus you will
restore to the soil the same
substances that have been
removed by previous crops and
which following crops will regain to
their advantage."
Van Helmont’s
pot experiment
169
lbs of
plant
5 lbs
of
plant
For 5 years
only water is
added
200 lbs
of soil
199 lbs,
14oz of soil
Van Helmont also performed
experiments that involved
combusting charcoal and
reported that 62 lbs of
charcoal produced 1 lb of
ash. He wrote that the other
61 lbs consisted of the "spirit
of the wood," which he called
"gas".
Philosophical Transactions Volume 21 (1699 !)
John Woodward discovered
that the growth of spearmint
cuttings was positively
related to the amount of
dissolved solids in water
Last sentence of the article
Jethro Tull invented the grain drill and many
other complementary technologies that
resulted in large increases in grain yields
during the 18th century.
Jethro Tull, 1731
“All sorts of dung and compost
contain some matter, which, when
mixt with the soil, ferments therein;
and by such ferment dissolves,
crumbles, and divides the earth very
much; This is the chief, and almost
only use of dung... This proves, that
its (manure) use is not to nourish, but
to dissolve, i.e., divide the terrestrial
matter, which affords nourishment to
the mouths of vegetable roots.”
Jethro Tull, 1731
Humus theory of plant nutrition
According to the humus theory, plants feed upon
substances which are similar to them in composition.
The organic matter of the soil, or the soil humus, was
regarded as the chief nutrient for plants and the major
source of soil fertility.
The roots of the plants were believed to extract the humus
from the soil and to transform it into plant substance, by
combining it with water.
Plant nutrition was thought to be similar to animal nutrition.
What is humus ?
Soil organic matter was first referred to as
humus by a Swedish scientist named
Wallerius in 1761.
In the early 1800s, French chemist De
Saussure used the term humus to refer
specifically to a dark-colored highly
decomposed fraction of SOM. This is the
standard technical usage today.
Wallerius wrote that "Plants derive no growth from
any mineral earths ... substances that promote plant
growth must be (1) identical or analogous to the
substances in plants, or (2) capable of being
transmuted and combined into a nature that belongs
to plants"
He thought that humus was the "nutritiva" or source
of plant food while all other soil constituents were
the "instrumentalia" that assisted in making this food
available.
Theodore de Saussure was a famous Swiss chemist who rejected
most of the transmutation and "principle of vegetation" concepts
of his predecessors and arrived at many ground breaking
conclusions:
1) soil, not air, is the supplier of N
2) roots are active absorbers of water and salts, not just filters
3) the ash constituents of plants all occur in humus
4) plants do not spontaneously generate potash.
De Saussure, however, was a defender of the humus theory.
Rejection of the humus theory
“ The conclusion should have
been reached long ago that
humus is not such an important
substance as we have been led to
believe, and that the current
doctrine of humus is exceedingly
full of contradictions.”
Carl Sprengel 1838
Liebig did not actually discover the
Justus
von Liebig
Law of
the Minimum
but deserves
credit
forpioneering
popularizing German
the concept
was a
chemist who wrote and lectured
extensively about the mineral
Law of
nutrition of plants.
As the first
the
professor toMinimum
use the laboratory
method of teaching chemistry,
he is regarded as one of the
greatest chemistry educators of
all time.
He was held in such high
esteem that few dared to
question his pronouncements
about mineral nutrition.
Justus von Liebig (1803 -1873)
What is liberated and what is left behind
when plant biomass is burned ?
Liebig believed
that the ash
generated when
a crop is burned
contained the
optimal blend of
nutrients for
fertilizing the
crop
He also promoted a
“check book” approach
to fertilization
Non-metal oxides
(C, N, H and S)
Metal oxides
(K, Ca, Mg, P, Fe…)
Do you
agree
with
Liebig?
Some of Liebig’s theories were not
supported by experimental evidence but
few were willing to publicly question them.
Liebig wrote: ‘Agricultural crops receive quite sufficient
nitrogen from the atmosphere ... ’
Sir John Lawes, a British contemporary of Liebig’s was
bold enough to declare: ‘ There can not be a more
erroneous opinion than this. ’
Sir John Lawes
Sir Henry Gilbert
Rothamsted
Experiment
Station
Lawes and Gilbert founded the first agricultural
experiment station
http://nolimits.nmw.ac.uk/IEN/rotham.jpg
Broadbalk
experiment
• Started in 1843
• Continuous wheat
for more than 160 years
• The oldest agricultural field
experiment in the world.
From : The Gardeners Chronic le
July 1, 1843 page 442
J.B. LAWE'S PATENT MANURES, composed
of Super Phosphate of Lime, Phosphate of
Ammonia, Silicate of Potass, &c., are now
for JB
saleLawes
at his Factory,
Deptford-creek,
London,
opened
one of the first
pricefertilizer
4s. 6d. per
bushel.These
substances
factories
in Europe
andcan
be
had seperately;
the Super
Phosphate
of
needed
to convince
farmers
that they
Lime alone
is recommended
for fixing the
should
use his fertilizers
Ammonia of Dung-heaps, Cesspools, Gas
Liquor, &c. Price 4s. 6d. per bushel
Broadbalk grain yields, selected treatments
Introduction of:
10
fallowing
liming
fungicides
herbicides
Wheat grain yield (t/ha)
9
8
1st wheat in rotation:
FYM+96 kg N
7
Best NPK
6
5
Continuous wheat:
FYM
4
PK+144 kg N
3
2
1
Unmanured, continuous wheat
0
1850
1875
1900
1925
1950
1975
2000
Broadbalk demonstrated the value
of N and P fertilizer and that
manure was not necessary to
produce high crop yields…
The plots receiving both manure and
fertilizer have frequently produced
the highest yields.
The Broadbalk archive
currently contains over
200,000 bottles of hay, grain
and soil
Why do they keep
all these old samples ?
Old samples provide answers
to new questions !
Morrow Plots
- started in 1876 at the U of I
- oldest agronomic experiment in the US
“The farmer should be as familiar with
the names of the ten essential elements
of plant food as he is with the names of
his ten nearest neighbors”
" ... it is not the land itself that
constitutes the farmer's wealth, but it is
in the constituents of the soil, which
serve for the nutrition of plants, that
this wealth truly consists."
Cyril Hopkins (right), head of the U of Illinois Department of Agronomy, and James H.Pettit (left),
assistant in Soil Analysis at the Ag Experiment Station, take a soil sample from the Morrow Plots
Soil Fertility and Permanent Agriculture – Cyril G. Hopkins, 1910
“In recent years, Whitney and Cameron have revived the theory of toxic
excreta from plant roots, in support of a more radical theory announced by
them, to the effect that soils do not wear out or become depleted by cultivation
or cropping.
While this theory is advanced with no adequate foundation and in direct
opposition to practical experience and to so many facts of mathematics,
chemistry, and geology, that it is in itself quite unworthy of further
consideration, the fact is that it has been promoted by Professor Whitney as
Chief of the United States Bureau of Soils, and by Doctor Cameron as the
chief chemist of the same Bureau; and, consequently, it cannot be ignored”
Morrow plots today –
3 of the 10 original plots remain
Long rotations
with fertilization
retained more
OM but
Impact
of nutrients
and rotation
on SOM
all rotations (with and without fertilization) led to loss of OM
http://www.cropsci.uiuc.edu/research/rdc/urbana/morrow.cfm
MLP = Manure, lime and phosphorus added
19th century farmers had limited
opportunities to purchase
nutrients. Some used guano
imported from South America.
Large yield responses were
reported for a wide range of
crops after applications of
guano.
Guano is a concentrated
source of N (~ 12 %) and P2O5
(~ 12 %), with much higher
analyses than most organic
fertilizers.
Guano was mined intensively off the west coast of S. America
during the mid-to late 1800s. During the peak years of guano
mining, Great Britain imported over 150,000 tons annually.
PERU
Mountain of Guano
off the coast of Peru
Fritz Haber – a man with many faces
Laboratory apparatus
designed by Fritz
Haber for producing
NH3 from H2 and N2.
The catalytic process
took place in the large
cylinder on the left.
Founded in 1865, BASF is the world's largest chemical
company, ahead of Dow and DuPont, ~ 100,000 employees,
>80 billion in sales in 2007.
Karl Bosch worked for BASF and designed the technology for
upscaling Haber’s method of NH3 production.
Nitrates and ammonia made up 59 percent of BASF sales in
1919.
Industrial N fixation is very energy intensive
> 700 GDF/ton NH3
Large
improvements
in energy
efficiency
were made
during the 20th
century.
~ 300 GDF/ton NH3
~ 185 GDF/ton NH3
~ 130 gallons of diesel fuel per ton of NH3
GDF = gallon of diesel fuel
Fig. 6.12 in Smil (2001)
What happened 2 years ago ?
Fertilizer application in the US since 1850
Total
N
K2O
P2O5
In 2005, US farmers applied only
75% as much phosphorus as their
crops removed —and just slightly
over 50% as much potassium.
What are the long term consequences ???
http://www.nytimes.com/imagepages/2008/04/30/business/20080430_FERTILIZER_GRAPHIC.html
http://www.earth-policy.org/Updates/2005/Update48_data.htm
Fertilizer prices began spiraling upward in 2007
http://www.agecon.purdue.edu/topfarmer/newsletter/TFCW8_2008.pdf