Welcome to Soil Fertility and Plant Nutrition AGRN 378
Did the ancient Egyptians knowanything about soil fertility?
Ancient Egyptian murals show lots of agricultural practices - tillage, planting,irrigation and harvesting but no fertilization
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
High Aswan Dam constructed beginning in 1960 6 TRILLION CFT 1.2TRILLION CFT High Aswan Dam Hoover Dam
Each year ~ 120 million tons of sediment accumulatesbehind the dam containing ~ 10,000 tons of biologically available P and N !
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 theMediterranean by a Great River? Ambio. Volume 32, Issue 1 (February 2003)
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 MexicoNixon, 2003. Replacing the Nile: Are Anthropogenic Nutrients Providing the Fertility Once Brought to theMediterranean 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 ofanimal manures, green manures and crop rotations to improve soilproductivity. These books were considered important sources ofinformation about agriculture for over a thousand years.
Blue lupinesPliny the Elder (AD 23-79) classified animalmanures with respect to their advantagesand disadvantages of most animal manuresand recommended the use of greenmanures. "It is universally agreed by allwriters that there is nothing more beneficialthan to turn up a crop of lupines, before theyhave podded, either with the plough or thefork, or else to cut them and bury them inheaps at the roots of trees and vines."
The earliest records of soil improvement using greenmanures are from the Chou dynasty (~1000 BC) inChina. 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... Theirfertilizing value is as good as silkworm excrement andwell-rotted farm manure"
China has had more than 50 million people for more than 2000 years and currently has more than 300 million farmers!
“ We desired to learn how it ispossible, after twenty andperhaps thirty or even fortycenturies, for their soils to bemade to produce sufficiently forthe maintenance of such densepopulations.. “ FH King, 1911
Building Chinampas http://kyapa.tripod.com/agengineering/drainage-lowland/veracruzbuildingchinampas.jpg
Chinampas in the Momposina lowland region of Columbiahttp://kyapa.tripod.com/agengineering/drainage-lowland/camell-colombia.jpg
In 1240, Roman agricultural literature was summarized by Crescentius. http://www.abbeville.com/Products/InteriorImages/0896599191Interiors.htm
Bernard Palissy (1510-1589)Ceramicist and hydraulicengineerFar ahead of his time, Palissywrote: ”Manure is carried to thefield for the purpose of restoringto the latter a part of what hadbeen removed... Proceedingthus you will restore to the soilthe same substances that havebeen removed by previouscrops and which following cropswill regain to their advantage."
What is the“principle ofvegetation”? JB van Helmont (1577-1644) Dutch physician and Chemist
What isdo What the“principle of plantsvegetation”? eat? JB van Helmont (1577-1644) Dutch physician and Chemist
Van Helmont’s 169 lbs of plant pot experiment5 lbsofplant only water was added 199 lbs,200 lbs 14oz of soilof soil T=0 T= 5 yrs
Van Helmont also performedexperiments 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
How many of you have heard of the band “Jethro Tull”?
Jethro Tull invented the grain drill and manycomplementary technologies that resulted in large increases in grain yields during the 18th century. Jethro Tull, 1731
George Washington tookgreat 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 Britishbooks about new agricultural practices.Among Washington’s papers are detailed notes taken as he studied Jethro Tull’s Horse Hoeing Husbandry.
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
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 “HumusTheory” developed by Thaer allowed him toestablish a quantitative system of evaluating cropping system sustainability.
The humus theorySimilar to animals, plants must feed upon organic substances that are similar to them in composition. Soil organic matter aka humus, is thechief nutrient for plants and the primary source of soil fertility. Roots absorb humus and transform it into plant substance, by combining it with water.
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 N2) roots are active and selective absorbers of water and salts 3) plants only absorb CO2 and release O2 when exposed to sunlight4) All plant tissues including seeds and roots consume O2 and give off CO2 but did not fully reject the humus theory
Answers to the reading questions should be submitted using WO before the start of Friday’s class
Reading questions1) 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 roots4c) Calculate how much the corn seed’s weight multiplied during a full season of growth.
How is this possible?? grain + cob + 1/100 of an oz stalk + leaves + roots _____ > 1 lb
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
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)
Liebig did not actually introduce the Law of the Minimum but deserves credit for popularizing the concept Law of the MinimumJustus von Liebig (1803 -1873)
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 Liebiggenerated when recommendeda crop is burned a “check book” contained theoptimal blend of approach to nutrients for fertilization fertilizing the crop Metal oxides (K, Ca, Mg, P, Fe…)
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.’
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 : T Gardeners Chronic le he July 1, 1843 page 442 J.B. LA WES 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
Broadbalk demonstrated the value of N and P fertilizer and that manure was not necessary to produce high crop yields howeverthe plots receiving both manure and fertilizer often produced the highest yields
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
The Broadbalk archive currently contains over200,000 bottles of hay, grain and soil Why do they keep all these old samples ?
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 Illinois- oldest agronomic experiment in the US
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
“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 thatconstitutes the farmers wealth, but it isin the constituents of the soil, whichserve for the nutrition of plants, thatthis wealth truly consists."
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 1880sexcreta from plant roots, in support of a more radical theory announced bythem, to the effect that soils do not wear out or become depleted by cultivationor cropping.While this theory is advanced with no adequate foundation and in directopposition to practical experience and to so many facts of mathematics,chemistry, and geology, that it is in itself quite unworthy of furtherconsideration, the fact is that it has been promoted by Professor Whitney asChief of the United States Bureau of Soils, and by Doctor Cameron as thechief chemist of the same Bureau; and, consequently, it cannot be ignored” Legumes can fix their own N *if* they have the appropriate bacteria
Morrow plots today – 3 of the 10 original plots remain
Impact of nutrients and rotation moreSOM Long rotations with fertilization retained on OM butall 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. Americaduring the mid-to late 1800s. During the peak years of guanomining, Great Britain imported over 150,000 tons annually. PERU
Laboratory apparatusdesigned by FritzHaber for producingNH3 from H2 and N2.The catalytic processtook place in the largecylinder on the left.
Founded in 1865, BASF is the worlds largest chemicalcompany, ahead of Dow and DuPont, ~ 100,000 employees,>80 billion in sales in 2007.Karl Bosch worked for BASF and developed the technologyfor upscaling Haber’s method of NH3 production.Nitrates and ammonia made up 59 percent of BASF sales in1919.
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)