Unit 1 lecture-1 soil fertility and soil productivity

This is the M.Sc.(Ag.) Course

1. Program: M.Sc. (Ag.) Soil Science & Agricultural
Chemistry 2
nd
Semester, 1
st
Year
SOILS-502: SOIL FERTILITY AND FERTILIZER USE
Dr.LuxmiKant Tripathi
Assistant Professor, SoAg
Unit No. 1
Soil fertility and soil productivity
Lecture No. 1

2. Outlines
•Introduction
•SoilFertility
Factorsaffectingsoilfertility
•SoilProductivity
FactorsaffectingsoilProductivity
•DifferencebetweenSoilfertilityandProductivity
•HistoryofdevelopmentofSoilFertility
•LearningOutcomes
•StudentEffectiveLearningOutcome(SELO)
•References

3. <SELO:8> <ReferenceNo.:1>
•Soilfertilityistheabilityofthesoiltosupplyessentialplantnutrients
duringgrowthperiodoftheplants,withouttoxicconcentrationofany
nutrientsi.e.“thecapacityofsoiltosupplynutrientinavailableform
tocrop”.
•Itisdefinedastheinherentcapacityofasoiltosupplyavailable
nutrientstoplantsinanadequateamountandinsuitableproportionsto
maintaingrowthanddevelopment.Itismeasureofnutrientstatusof
soilwhichdecidesgrowthandyieldofcorp.
Soil Fertility:-

4. <SELO:8> <ReferenceNo.:1>
Factors affecting soil fertility:-
I.Natural factors or Pedogenic factors
a.Parent material.
b.Climate and vegetation
c.Topography and age of soil
II.Edaphic factors or Soil management factors
1.Physical conditions of soil
a.Texture of soil:
b.Structure of soil:
c.Soil water
d.Soil aeration:
2.Root growth and extension
3.Organic matter content of the soil
4.Cropping system:
5.Soil erosion

5. <SELO:8> <ReferenceNo.:1>
•Soilproductivitymeansthecropproducingcapacityofasoilwhichis
measuredintermsofyield(bio-mass).Productivityisaverybroadterm
andfertilityisonlyoneofthefactorsthatdeterminethecropyields.
Soil,climate,pests,disease,geneticpotentialofcropandman's
managementarethemainfactorsgoverninglandproductivity,as
measuredbytheyieldofcrop.Tobeproductive,soilmustcontainall
the13essentialnutrientsrequiredbytheplants.
•Thetotalquantityofnutrientsisnotonlybeingsufficientbutthey
shouldalsobepresentinaneasily“available”formandin“balanced”
proportions.Overandabovefertility,thereareotherfactorsdeciding
productivity.
“All the productive soils are fertile but not all fertile soils are productive”
Soilproductivity:-

6. <SELO:8> <ReferenceNo.:1>
•Thefactorsaffectingsoilproductivityincludeallthosewhichaffectthe
physical,chemicalandbiologicalconditionsofthesoilenvironmentin
whichplantsgrow.Theyincludeallthepracticesthataffectfertility,the
waterandairrelationshipsandtheactivityofthebiologicalagentssuch
asinsects,pests,diseasesandmicroorganisms.
1.Internalfactors:maybecalledasgeneticorhereditaryfactors
whichcannotbemanipulatedsuchassoiltype,textureetc.
2.Externalfactors:mayberegulatedtocertainextent,Theyinclude
e.g.Climaticfactors,EdaphicorSoilfactors,Bioticfactors,
animals:earthworms,smallandlargeanimals,Physiographic
factorsanthropogenicfactorsetc.
Factors affecting soil productivity:-

7. Soil Fertility Soil Productivity:
1.Itisconsideredasanindexof
availablenutrienttoplants.
2.Oneofthefactorsforcrop
production;theothersarewater
supplyetc.
3.Canbeanalysedinlab.
4.Itisthepotentialstatusofthe
soiltoproducecrops.
5.5.Dependsuponphysical
chemicalandbiologicalfactors
ofsoil.
1.Itisabroadertermusedto
indicatecropyields.
2.Itistheinteractionofallthe
factors.
3.Canbeassessedinthefieldunder
particularclimateconditions.
4.Resultantofvariousfactors
influencingsoilmanagement.
Dependsuponlocation,fertility,
physicalconditionsetc.

8. 6.Soilfertilityisthefunctionof
availablenutrientsofsoilfertility=f
(NutrientstatusofSoil).
7.Itisaninherentproperlyofsoil.
8.Thefertilityofacertainsoilissame
inalltheclimates.
9.Allfertilesoilsarenotproductive.
6.Soilproductivityisthefunction
ofsoilfertility,managementand
climate.
SoilProductivity=f(Soilfertility+
Management+Climate)
7.Itisnotaninherentpropertyof
soil.
8.Soilproductivitydiffers
accordingtothevariationsin
climateandlocation.
9.Allproductivesoilsarecertainly
fertile

9. Some Terminology Related to Plant Nutrients:
Plant Nutrition:
Plantnutritionisdefinedasthesupplyandabsorptionofchemical
compoundsrequiredforplantgrowthandmetabolism.Itistheprocessof
absorptionandutilizationofessentialelementsforplantgrowthand
reproduction.
Nutrients:
Nutrientsmaybedefinedasthechemicalcompoundsrequired
byanorganism.
Deficient:
Whenanessentialelementsisatalowconcentrationthatseverely
limitsyieldandproducesmoreorlessdistinctdeficiencysymptoms.
Extremedeficiencieswillleadtodeathoftheplant.

10. <SELO:8> <ReferenceNo.:1>
Insufficient:
•Nutrientcontentsassociatedwithonlygrowthreductionsandnot
accompaniedbyappearanceofdeficiencysymptomsaretermed
insufficient.
Sufficient:
•Rangeofnutrientcontentinplantassociatedwithoptimumcrop
yieldsiscalledsufficient.
Toxic:
•Whentheconcentrationofanutrientelementrisestoohightocause
significantgrowthreductions,itistermedtoxic.Severetoxicitywill
resultindeathofplants.

11. <SELO:8> <ReferenceNo.:1&2>
Excessive:
•Whentheconcentrationofanessentialplantnutrientissufficiently
hightoresultinacorrespondingshortageofanothernutrient.
Bioavailablenutrient:
•Thenutrientavailabletothebiologicalorganismistermedas
bioavailablenutrient.
BeneficialElements:
•Beneficialelementsarethemineralelementswhichstimulateplant
growth,butarenotessentialorwhichareessentialonlyforcertain
plantspeciesorunderspecificcondition.

12. FunctionalNutrient:
•ThistermintroducedbyNicholas(1961)isdefinedasanelementthat
playsaroleinplantmetabolism,whetherornotthatroleisspecificor
indispensable.
TraceElement:
•Traceelementisanelementfoundinlowconcentrations,perhapsless
thanoneppmorstilllessinsoil,plantandwateretc.

13. History of Development of Soil Fertility: -
Theconceptofsoilfertilityanditsmanagementtoimprovecropyieldsis
notnewperhapsitisasoldasthedevelopmentofagriculturebyman.In
ancienttimealso,theyhadknowledgeofapplyingmanuressuchasfarm
yardmanure,greenmanure,nightsoil,bone,woodashes,etc.,tosoilforthe
purposeofincreasingcropyields.
•Xenophan(430-355B.C),aGreekhistorianfirstrecordedthemeritsof
greenmanurecrops.Hewrote“Butthenwhateverweedsareuponthe
ground,beingturnedintotheearth,enrichthesoilasmuchasdung
“meaningincorporatingweedsintosoilsisasgoodasapplyingdung.
•Cato(234-149B.C)wroteapracticalhandbookandrecommended
intensivecultivation,croprotations,andtheuseoflegumesforlivestock
farming.Hewasfirsttoclassify“Land”basedonspecificcrops.

14. Columella(A.D.45)
•emphasizedtheusefulnessofturnipsforsoilimprovements.Healso
advocatedlanddrainageandtheuseofashes,marl(limedeposits),
cloverandalfalfatomakethesoilmoreproductive.
JethroTull(1731)andFrancisHome(1757)
•claimedthatNitre(NitrateSalts),water,air,earth,Epsomsalt(MgSO4),
Saltpetre(Sodium&PotassiumNitrate),Vitriolatedtarter(Potassium
sulfate)andOliveoilincreasedplantgrowth.
•Almostallofthepresentknowledgeaboutthemineralnutritionhas
beenacquiredrelativelyrecentlyduringthelast135yearsorso.These
developmentshappenedinaslowandgradualmanner.

15. Justus Von Liebig (1840),
a German chemist, reported that growing plants obtain elements Ca, K, S
and P from the soil, whereas carbon from CO
2in the air and not from the
soil. He also suggested that plants obtain H & O from air as well as from
water and N from ammonia. He also established certain basic principles
of sound soil management;
•croppedsoilisrestoredtofertilityonlybyaddingtoitallminerals&N
removedbytheplants.
•Heestablishedthetheoryof“LawofMinimum”inrelationtoplant
nutrition.Thelawstatesthattheproductivityofacropisdecidedbymost
limitingfactor.Heisregardedasthe“FatherofAgricultural
Chemistry”

16. FrancisBacon(1591-1624)
suggestedthattheprinciplenourishmentofplantswaswaterand
themainpurposeofthesoilwastokeepplantserectandtoprotect
fromheatandcold.
JanBaptisteVanHelmant(1577–1644)
wasreportedthatwaterwassolenutrientofplants.
RoberBoyle(1627–1691)
anEnglandscientistconfirmedthefindingsofVanHelmantand
provedthatplantsynthesissalts,spiritsandoiletc.fromH
2O.

17. Anthuryoung(1741–1820)
•anEnglishagriculturistconductedpotexperimentusingBarley
asatestcropundersandculturecondition.Headdedcharcoal,
trainoil,poultrydung,spiritsofwine,ostershellsand
numerousothermaterialsandheconducedthatsomeofthe
materialswereproducedhigherplantgrowth.
•Priestly(1800)
establishedtheessentialityofO
2fortheplantgrowth.
•J.B.Boussingault(1802-1882)
Frenchchemistconductedfieldexperimentandmaintained
balancesheet.Hewasfirstscientisttoconductfieldexperiment.
Heisconsideredasfatheroffieldexperiments.

18. <SELO:8> <ReferenceNo.:1>
J.B.LawesandJ.H.Gilbert(1843)
•establishedpermanentmanurialexperimentatRothemsted
AgriculturalexperimentstationatEngland.

19. Year Author Issues
1600 Van Helmont What can be used as food for plant growth
1772 Priestley Plants release oxygen from leaves into the atmosphere
1804 De Saussure Apart from CO2, also water takes part in photosynthesis
1806 Thaer First agricultural academy in Moglin (Germany)
After 1800 Thaer The humus theory for plant nutrition
1834 Boussingault The role of nitrogen in plant nutrition
1841 Liebig Theory of mineral plant nutrition
1842 Sprengel, Liebig Theory of minimum in agricultural chemistry; Liebig's Law of
the Minimum
1842 Lawes Patent: a way to obtain single superphosphate
1848 Lawes First superphosphate factory in Liverpool
1886 Hellriegel and
Wilfarth
Discovery of the phenomenon of nitrogen fixation by
rhizobia
1911 Haber and Bosch Synthesis of ammonia
1970 Borlaug Green Revolution, technological capacity to feed the world
1994 Robert Precision Agriculture
After 2000 Scientists Innovative fertilizers

20. LearningOutcomes
•Thestudentwillbeabletounderstandaboutessentialnutrientsthere
roleinagriculturewithrespecttosoilandcropproduction.

21. Student Effective Learning Outcome (SELO)
8.Abilitytounderstandsubjectrelatedconceptsclearlyalongwith
contemporaryissues.
9.Applicationofconceptsoftopic&it’stechnologicalapplication.

22. References
1.Das(1996)IntroductorySoilScience.KalayaniPublishers.
2.http://ecoursesonline.iasri.res.in/mod/page/view.php?id=7857