I shared this presentation with my Soil Fertility class the first week of class in Fall 2012

1. Welcome to Soil Fertility
and Plant Nutrition
AGRN 378

3. Did the ancient
Egyptians know
anything about soil
fertility?

4. Ancient Egyptian murals
show lots of agricultural
practices - tillage, planting,
irrigation and harvesting but
no fertilization

5. 4-5 million
people during
the New
Kingdom Why did
Greek
historian
Herodotus
write
Egypt is
truly a gift
of the Nile?
http://www.artsci.wustl.edu/~anthro/courses/306/Nile%20Delta.jpg http://lexicorient.com/e.o/atlas/maps/nile.gif

6. Nile
Most of Egypt
is desert !

7. High Aswan Dam
constructed
beginning in 1960
6 TRILLION CFT
1.2
TRILLION
CFT
High Aswan
Dam
Hoover
Dam

8. Each year ~ 120 million tons of sediment accumulates
behind the dam containing ~ 10,000 tons of biologically
available P and N !

9. Mediterranean fisheries collapsed after the
construction of the High Aswan Dam
Shrimp harvest along Egyptian Coast
So…why are
the fisheries
recovering?
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)

10. So…why are the fisheries recovering?
Shrimp harvest along Egyptian Coast
SEWAGE
from Cairo
Aquatic ecosystems
in the Mediterranean
are nutrient limited
unlike the Gulf of
Mexico
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)

11. 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.

12. 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.

13. Blue lupines
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."

14. 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 planted 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"

15. China has had more than 50 million people for more than 2000
years and currently has more than 300 million farmers!

16. “ 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

17. Fertilizing with night soil

18. Chinampas Agriculture
in Central America
http://library.thinkquest.org/C006206F/images/images/pint5.jpg

19. http://www.icarito.cl/vgn/images/portal/FOTO042005/221466640lamina-chinampas.jpg

20. Building Chinampas
http://kyapa.tripod.com/agengineering/drainage-lowland/veracruzbuildingchinampas.jpg

21. Chinampas in the Momposina lowland region of Columbia
http://kyapa.tripod.com/agengineering/drainage-lowland/camell-colombia.jpg

22. In 1240, Roman agricultural literature was summarized by Crescentius.
http://www.abbeville.com/Products/InteriorImages/0896599191Interiors.htm

23. Bernard Palissy (1510-1589)
Ceramicist and hydraulic
engineer
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."

24. What is the
“principle of
vegetation”?
JB van Helmont (1577-1644)
Dutch physician and Chemist

25. What isdo
What the
“principle of
plants
vegetation”?
eat?
JB van Helmont (1577-1644)
Dutch physician and Chemist

26. Van Helmont’s 169 lbs
of plant
pot experiment
5 lbs
of
plant
only water
was added
199 lbs,
200 lbs 14oz of soil
of soil
T=0 T= 5 yrs

27. 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".

28. 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

29. How many of you have heard of the band “Jethro Tull”?

30. Jethro Tull invented the grain drill and many
complementary technologies that resulted in
large increases in grain yields during the
18th century.
Jethro Tull, 1731

31. George Washington took
great pains to inform himself
about any subject in which
he was interested.
He corresponded with Arthur
Young, Britain’s leading
agriculturalist in the post-
Revolutionary period and
ordered the latest British
books about new agricultural
practices.
Among Washington’s papers
are detailed notes taken as
he studied Jethro Tull’s
Horse Hoeing Husbandry.

32. Tull’s theory of “All sorts of dung and
compost contain some
plant nutrition 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...
The value of dung 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

33. This article starts with a brief review of
theories about plant nutrition and the
importance of humus prior to the mid- 19th
century. It then shows how the “Humus
Theory” developed by Thaer allowed him to
establish a quantitative system of evaluating
cropping system sustainability.

34. The
humus
theory
Similar to animals, plants must feed upon
organic substances that are similar to
them in composition.
Soil organic matter aka humus, is the
chief nutrient for plants and the primary
source of soil fertility.
Roots absorb humus and transform it
into plant substance, by combining it
with water.

35. In the early 1800s, Swiss chemist and plant physiologist
Nicolas-Théodore De Saussure rejected most of the
principle of vegetation concepts of his predecessors
and arrived at many ground breaking conclusions:
1) soil, not air, supplies plants with N
2) roots are active and selective absorbers of water and salts
3) plants only absorb CO2 and release O2 when exposed to
sunlight
4) All plant tissues including seeds and roots consume O2 and
give off CO2
but did not fully reject the humus theory

36. Answers to the reading questions
should be submitted using WO
before the start of Friday’s class

37. Reading questions
1) The article includes an interesting quote from Jethro Tull:
“The chief art of the husbandman is to feed the plants to best advantage; but,
how shall he do that, unless he knows what is their food?”
Identify the contrasting views about plant nutrition contained in the article. Be
sure to mention the proponents of each view.
2) Discuss de Saussure’s relationship with his father. Has anyone in your life
helped to spark or encourage your interest in the Agricultural Sciences?
Explain.
3) De Saussure made many impressive discoveries about plant respiration and
nutrition. Briefly discuss 3 discoveries that you think were particularly
interesting.
4a) Calculate how much a typical corn seed weighs in grams (1 lb = 454 g).
Hint: look up the weight of a bushel of corn and # of seeds in a bushel of corn.
4b) Estimate the total weight of a mature corn plant in grams.
SHOW YOUR WORK!!!!
Assume the following: corn population = 30,000 plants/ac, yield = 200 bu/ac,
weight of grain = weight of stover = weight of roots
4c) Calculate how much the corn seed’s weight multiplied during a full season of
growth.

38. How is this possible??
grain
+
cob
+
1/100 of an oz
stalk
+
leaves
+
roots
_____
> 1 lb

39. 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

40. Justus von Liebig
was a pioneering German
chemist who wrote and lectured
extensively about the mineral
nutrition of plants. As the first
professor to 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)

41. Liebig did not actually introduce the
Law of the Minimum but deserves
credit for popularizing the concept
Law of
the
Minimum
Justus von Liebig (1803 -1873)

42. Non-metal oxides
(C, N, H and S)
What is liberated and what is left behind
when plant biomass is burned ?
Liebig believed
that the ash Liebig
generated when recommended
a crop is burned
a “check book”
contained the
optimal blend of approach to
nutrients for fertilization
fertilizing the
crop
Metal oxides
(K, Ca, Mg, P, Fe…)

43. 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 was bold
enough to declare: ‘There can not be a more
erroneous opinion than this.’

44. 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

45. Broadbalk
experiment
• Started in 1843
• Continuous wheat
for more than 160 years
• The oldest agricultural field
experiment in the world.

46. From : T Gardeners Chronic le
he
July 1, 1843 page 442
J.B. LA WE'S PA TENT MANURES, composed
of Super Phosphate of Lime, Phosphate of
Ammonia, Silicate of Potass, &c., are now
for JB Lawes opened one of the first
sale at his Factory, Deptford-creek, London,
price 4s. 6d. per bushel.These substances can
fertilizer factories in Europe and
be had seperately; the Super Phosphatethey
needed to convince farmers that of
Lime alone is recommended for fixing the
should use his fertilizers
Ammonia of Dung-heaps, Cesspools, Gas
Liquor, &c. Price 4s. 6d. per bushel

47. Broadbalk demonstrated the value
of N and P fertilizer and that
manure was not necessary to
produce high crop yields
however
the plots receiving both manure and
fertilizer often produced the
highest yields

48. Broadbalk grain yields, selected treatments
Introduction of: liming fungicides
10 fallowing herbicides
9
8
Why have the 1st wheat in rotation:
Wheat grain yield (t/ha)
7 FYM+96 kg N Best NPK
6 yields been
5 leveling off? Continuous wheat:
FYM PK+144 kg N
4
3
2
1
Unmanured, continuous wheat
0
1850 1875 1900 1925 1950 1975 2000

49. The Broadbalk archive
currently contains over
200,000 bottles of hay, grain
and soil
Why do they keep
all these old samples ?

50. 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 !

52. Morrow Plots
- started in 1876 at the U of Illinois
- oldest agronomic experiment in the US

53. 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, collect soil samples from the Morrow Plots

54. “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."

55. Soil Fertility and Permanent Agriculture – Cyril G. Hopkins, 1910
Rhizobia bacteria first
“In recent years, Whitney and Cameron have revived the theory of toxic
isolated in mid 1880s
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”
Legumes can fix their own N *if* they have the appropriate bacteria

56. Morrow plots today –
3 of the 10 original plots remain

57. Impact of nutrients and rotation moreSOM
Long rotations with fertilization retained on OM but
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

58. 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.

59. 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

60. Mountain of guano
off the coast of Peru

62. Fritz Haber – a man with many faces

63. 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.

64. 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 developed the technology
for upscaling Haber’s method of NH3 production.
Nitrates and ammonia made up 59 percent of BASF sales in
1919.

65. 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)

66. What happened ~ 7 years ago ?

67. Fertilizer application in the US since 1850
Total
What
happened
during the
80s??
N
Farmers cut way back
on their fertilizer
purchases during the
“Farm Crisis”
K2O
P2O5

68. lbs of
nutrient
applied
per
bushel
produced

69. What are the long term consequences of ratios > 1?
http://www.afa.com.eg/uploads/papers/2011/files/3_fixen_paper.pdf

70. Deficit spending is drawing down
soil test P levels in the Midwest

71. Worldwide Growth In Fertilizer Use
What happened in 1989?
http://www.nytimes.com/imagepages/2008/04/30/business/20080430_FERTILIZER_GRAPHIC.html

72. http://www.earth-policy.org/Updates/2005/Update48_data.htm

76. Fertilizer prices began spiraling upward in 2007
Why??
http://www.agecon.purdue.edu/topfarmer/newsletter/TFCW8_2008.pdf

77. World fertilizer prices collapsed in the fall of 2008
So
Why?? where
are
prices
today?
http://www.growthstockwire.com/images/charts/2009/feb/20090225_chart_a.gif

78. http://farmfutures.com/mdfm/Faress1/author/252/2012/8/WFertR082012.pdf

79. http://farmfutures.com/mdfm/Faress1/author/252/2012/8/WFertR082012.pdf