JOURNAL OFTHESCIENTIFIC AGRICULTURAL SOCIETY OFFINLAND Maataloustieteellinen Aikakauskirja
Voi. 3SS-362, 1983
Effect of liming
onphosphorus
in twosoils of different organic
matter contentII
Changes
inthe availability of phosphorus
toturnip
rape
(Brassica campestris
)HELINÄ HARTIKAINEN
Department
of
Agricultural Chemistry, Universityof
Helsinki, 00710 Hel-sinki71
Abstract. The effectof calcitic limestonetreatmentson theavailabilityofP toturniprapewasstudied
withtwoacid mineral soils ofpH4.8(CaCl2) ina potexperimentduringtwogrowingseasons.The soil reactions ofaconnected incubationtestservedto interpretthe results obtained inthepotexperiment.
The experimental soils represented soil types of dissimilar responses to liming in regard to P availability. Inthemuddyfine sand(3 %of org. C), initiallypoor in easily solubleP, limingenhanced plant growthas wellasPuptakeinthe secondyear.However, in spiteofintensifiedP removal,the final
contentofwater-solubleP inthe limed soilswasnotlower thaninthe unlimedones.Thiswasassumedto
demonstrate anaugmented availability ofP.
Alsointhe fine sandsoil(6.4%oforg.C),rich inwater-solubleP, liming slightly improved growthof
the second harvestinthepotsnottreatedwithP,but it did notaffectPremoval.Inthe pots amended with P, onthe contrary,liming hadnoeffectonthe drymatteryields,but it tendedtodepressPwithdrawal.
Nevertheless, all the limed soils contained finally less water-solubleP than the unlimed ones, which suggests adiminishedavailability.
The results of thepotexperiment demonstrate thatarelatively low soilpH doesnotnecessarilylimit growthofturniprape, provided nonutrientdeficiencyor metaltoxicityoccurs.
Introduction
The role and importance ofpH control in plant production have been
largely discussed and contested during the last few decades. Liming is conventionally used toreduce soilacidityand toimprove growth conditions
as well as the availability ofsomenutrients, e.g. phosphorus. The profitable effect on Puptake is attributed to manyfactors, e.g. an intensifiedminerali- zation of organicP compounds(SALONEN 1946,DORPH-PETERSEN 1953)or
an increased solubility of secondary inorganic phosphate compounds (GHANI and ALEEM 1942). Since the introduction of the concept of ligand
exchange, the action oflime is rather attributed to the competition between hydroxyl and phosphate ions for sorption sites.
InFinland, incubation experimentshave shown theapplication ofbaseto cause someredistribution ofnative P between various fractionsassumed to
represent different P compounds (KAILA 1961 and 1965, HARTIKAINEN 1981).These reactions are consideredresponsible forthe increased solubility of P in water (HARTIKAINEN 1981), but there is no evidence of the relationship between them and the availability ofP toplants.
In an incubation experiment with two soil samples carried out by
HARTIKAINEN (1983), liming tended toenhance the solubility ofP inoneof the samples and to depress it in the other. The detrimental effect was
observed in the soil rich in organic matterand seemed to be associated with the simultaneous reactions of soil Al. Thepurpose ofthe present study was to investigate the relevancy of the incubation test data by comparing them with the results of a connected potexperiment.
Materials and methods
The potexperimentwascarriedoutin 1980and 1981withtwomineral soilsamplesthe characteristics
of which arereportedinapreviouspaper (HARTIKAINEN 1983).Mitscherlichpotswerefilled with4.5kg
of moistsoil correspondingto3.9kg of air-dried muddy fine sand and3.6kg of air-dried finesand. The soilsweretreated with0,6, 12or24 gofCaC03andplant nutrientswereaddedasfollows: 1000mgNas NH4NO,,200mgMgasMgCl2■6 H2O, 10mg BasH3B03, 15mg CuasOuSO4•5H2O,10mgMnas
MnS04 ■ H2O, 10mg Zn asZnS04 • 7 H2O, smgMo as NaMo04 ■ H2O. Half of thepots were amended with400mgofP,addedasK2HP04,correspondingto 104mg and114mg perkgof themuddy finesandand fine sandsoil,respectively. The controlpotsreceived acorrespondingquantity ofK(1000 mg) as KCI. Liming as well as Mg and P treatments were performed only in thebeginning of the experiment,buttheothernutrients wereaddedalso inthesecond springbefore sowing.
After nutrient treatmentand liming,20 seedsofturniprape (Brassica campestrisv. oleiferaf.annua) were sownperpot. Theexperiment was carriedoutwithfour replicates. Ithas been describedin more detailbyJOKINEN (1982).
Plant analyses. The plantmaterial, first driedat60°Candthereafter heatedat 105°Cfortwohours,
was ground and digested with the acid mixture of HCIO„: H2S04: HNOj inthe ratio of 1: 2.5: 10 (scharrer and MUNK 1956). TheP content in the filtered extract was determined by an ammonium
vanadate method(JACKSON 1958). 4
Soil analyses. Aftercultivation,the contentof solublesaltsinsoilsolutionwasestimatedby measuring the electricalconductivityof the clear supernatantsolution from awater-soilsuspension. SoilpH was
measuredin 0.01 MCaCl2solution.Water-solublePwasextractedbyaslightlymodifiedvanderpaauw (1971) and SISSINGH (1971) method and various Pforms by amodified CHANG and JACKSON(1957) fractionationmethod.
Results
a) Dry matteryields
The drymatter yields in grams perkg of air-dried soil are givenin Table 1.The dataofboth soils and years are tested separately. Withoutliming and
Limeadded Year 1980 Year 1981 Total
g/pot - Papplied - Papplied - Papplied
Muddyfinesand
0 5.3* 9.2b' 1.3* 4.4b 6.6* 13.6'
6 6.1* 10.0' 3.4b 6.5' 9.5b 16.5d
12 6.0* 11.3' 3.4b 6.7' 9.4b 18.0d
24 6.5‘b 10.9' 3.8b 6.4' 10.3b 17.3d
fine sand
0 8.4“b 10.1*b 5.7* 7.8cd 14.1* l?^
6 8.3*b 10.7*b 7.2bc 8.7d 15.5*b 19.4d
12 9.6*b 11.0b 6.4b 8.3“* 16.0,bc 19.3'd
24 B.l* 10.6‘b 6.4b 8.9d 14.5* 19.5d
Pfertilization,the totalyield ofthefinesand soil samplewas abouttwicethat ofthe muddy fine sand sample.
The experimental soils differed in their responses to P treatment and liming. Inthefirst year, Paddition improved thegrowth of turniprape in the muddy fine sand, but not in the fine sand soil of higher initial content of water-soluble P. A positiveresidual effect ofP fertilization appeared inboth soils, though, more markedly in the muddy finesand sample.
The influence of CaCOj treatment on the dry matter yields could be verified only in the second year. In all the soils not receiving P, liming promoted plant growth but remained ineffective in the fine sand soils amended withK2HP04and had no influenceon thetotal shoot yields ofthis sample.
The P content was lower in the shoots harvested from the muddy fine sand soil than in those harvested from thefinesand soil: withoutP addition, itranged in the first yield 3.76-4.01°/00and 4.04-4.68 °/00, and in the second
one 1.91-2.69°/00and 2.61-3.46°/00, respectively. It wasinteresting tonotice
thatin thefinesand soil the highest dosages oflime tendedto diminish theP
Table2. AmountsofP(mg/kgofsoil) taken up by yields.
Lime added Year 1980 Year 1981 Total
g/pot - P added - P added - Padded
Muddyfinesand
0 19.4* 41.7b 3.4* 16.1° 22.8* 57.8*
6 24.7* 42.3b 8.4b 20.2C 33.lb 62.5'd
12 22.5* 52.0b 6.5“k 19.1c 29.0*b 71.1d
24 24.3* 48.lb 9.5b 16.0C 33.8b 64.1'd
Fine sand
0 38.5*b SO.O1* 20.1*b 33.1' 58.6* 83.1'
6 37.6‘b 53.5' 23.0bc 32.3d' 60.7*b 85.8'
12 39.7*b 50.4bc 17.4* 29.1de 57.0* 79.5'
24 33.0* 45.5*b' 16.7* 27.4'd 49.7* 72.9bc
Table 1. Dry matteryields (g/kgofsoil).
content. In the second yearthis depressive effectwas reflected in the uptake of native P (Table2) despite theslight improvement in thedry matteryields.
However, partly because of a great variation between the replicates, the differences of the treatments oftenremained statisticallyinsignificant. In the muddy fine sand soil, on the contrary,liming enhancedremoval ofnative P along with increased dry matter harvests.
In most cases P fertilization raised P percentages only in the second harvests. As could be expected on the basis ofdry matteryields, in the first
year theP addition increased the Pquantities taken up from the muddy fine sand sample,but did not affect equally significantlythose removed from the fine sand soil. Nevertheless, the positive residual effect on the P uptake appeared distinctlyalso in the finesand sample. The percentages ofadded P recovered in the shoots harvested were as follows:
CaCO, g Muddy
fine
sand Fine sand0 34 21
6 28 22
12 41 20
24 29 20
The data suggest quite marked amounts of applied P to have been immobilized by root material orretained by various soil components. This surplus was greater in the fine sand soil in which liming did not affect the supply ofadded P toturniprape. On the otherhand, in the muddyfine sand samplethe medium dosage ofCaCOj(12 g/pot) seemed most favourably to promote utilization of this P source.
b) Soil analyses
For further informationabout the effect of liming, the soil samples were
analyzed for inorganic P. In addition, some other indicativeanalyses were
performed. In thepot experiment, CaCOj neutralized the soil acidityto the
same rate as in the incubation test described earlier (HARTIKAINEN 1983),
but cultivation tended further to raise pH by 0-0.2 and 0.2-0.4 pH units in the muddy fine sand and fine sand, respectively. This was probably due to a
marked decrease in salt concentration of the soil solution, indicated by a
lowered electrical conductivity (about31-91 %). The decreaseseemed to be
more considerable in the limed soils.
The lime-induced reduction in soil acidity hardly increased the final P intensity,as determined bywater extraction. The results reported in Table 3 show the water-soluble P in the fine sand soil to have been even lowered.
This isunexpected, because in this soil theP uptake by the turnip rape was
not enhanced: it rather tended to be reduced as liming was intensified.
Further, as stated above, the salt concentration in the soil solution decreased simultaneously, whichinmostsoils is known toenhance theextractability of soilP into water. On the other hand, in the muddy finesand soil, liming did
not decrease the finalwater-soluble P, even if theuptake of this nutrientwas
significantly augmented.
Table 3. Water-solubleP(mg/kg) insoils after cultivation.
Limeadded Muddy fine sand Fine sand
g/pot - Papplied - P applied
0 5.9' 11.7C 27.5‘ 38.18
6 5.T 11.4bc 24.lb 35.6f
12 5.6' 10.5b 23.lb 32.8'
24 5.9' 12.lc 20.5' 29.6d
Changes in native P during the cultivation were investigated by the CHANG and JACKSON fractionation method, comparing the differences between a given fraction in the cultivated and uncultivated samples (Table 4).
The differences between theP fractions in the samples treated and those not treated with K2HP04 were assumed to represent the accumulation of residual applied P. It can be concluded from the datain Tables 2and 4 that
the quantitiesremoved by shoot harvests are generally lower than the total depletion in thefractions.This is partly attributable tothe immobilization of P in theroot material.
Table 4. Changescaused by cultivation in nativeP fractions (a) and recovery of residual added P in variousforms(b) as mg/kg.
Lime added P extracted sequentially by
g/pot NH,CI NH,F NaOH H2S04 £
Muddyfinesand
0 a 0 -9-5-9 -23
b 1 24»» 29»» 5 59
6 a -1»»» -19» -22»» 0 -42
b 1»»» 24»»» 21»» 2 48
12 a -2»»» -19» -32»» -A -57
b 0 15» 22» 5 42
24 a -1»»» -15» -33»» 10 -39
b 2»»» 26»»» 13» 2 43
Finesand
0 a -1» -37»»» -5 -11» -54
b 1» 33»» 29» 14 77
6 a -3»» _53»»» _7 _1 -64
b 2» 53»»» 21» -8 68
12 a -4»»» -41»*» -16»» -6 -67
b 3»»» 51»»» 30»»» 7 91
24 a -3»»» _29»»» -36»»» 4 -64
b 3»»» 49»» 30»»» -1 81
The results in Table 4 imply that intensified liming decreased native NaOH-P more and NH4F-P less in the muddy fine sand than in the fine sand. It isnoteworthy that in all the limed finesand soils the total depletion
was of about the same magnitude, which iscontradictory to what could be expected on the basis of the finalwater-soluble P.
Therecovery ofapplied P in the shoots and soil P fractionsamounted to 71_90 %and 82-99 %in the muddyfinesand andfinesand soil,respectively.
As expected, greater amounts of residual added P were extracted from the finesand soil in generalthanfrom themuddy finesand. Table4showsliming
to increase the enrichment of applied P in the former soil sample and to decreaseitin the latter. These results seemed tobe attributed to anenhanced accumulation in the NH4F solublefraction inthe finesand and to areduced accumulation in the NaOH soluble one in the muddy fine sand. In the unlimed fine sand soils, also H2S04-P seemed somewhat toincrease.
Discussion
Phosphorus seemed tobea growth-limitingfactorinthemuddy finesand soil. In the fine sand soil,on the contrary, theP reserves accumulated during the intensive sugar beet cultivation were nearly sufficient to satisfy the requirements of the first turniprape harvest. The positive residual effect of applied P also in this sample suggests, however, P uptake later to have reduced theP supplying power.
In spite of increased harvests and P uptake, the final intensity ofnativeP in the limed muddy fine sand soils was not lower thanin the unlimed ones,
whichsuggests limingtohave rendered native soilPbetter available toturnip rape. This isin accordance with theincrease inthe water-extractableP in the coexistent incubation test (HARTIKAINEN 1983). The result gives, in turn, reason to infer that in the P deficient muddy fine sand the improved availability of soil P reserves was responsible for the more abundant shoot yields in the limed pots. The retarded effect of liming is due to the slow solubility of CaC03. It can be ascribed also to the fact that a raised pH affects the P solubility the more favourably the poorer the soil is in this nutrient (HARTIKAINEN 1981). The conditions prevailing in the second growth period better complied with this qualification.
In the muddy fine sand pots amended with P, the CaC03 treatment
seemed toameliorate growth conditions other thanP supply. However, the medium limedosage appeared somewhat toadvance the total withdrawal of
applied P. The remaining water-soluble P being a little lower in this treat- mentisin agreementwith theeffective Putilization by plants. Evidently, the moderate liming was sufficient to promote P uptake but not too heavy to cause some disbalance between the different nutrients.
On the other hand, in the fine sand soils not treated with P, liming improvedplant growth without affecting P removal. In the soils amended withP, the highest dosageof CaC03 even markedly reduced the P uptake.
Nevertheless,the final water-soluble P was significantly reduced in all the
limed treatments,indicatinga diminished availability. The indicative incuba- tion test(HARTIKAINEN 1983)showed a similar decrease in theP solubility inthe limed soils. These results lead toconclude that also inthefine sand soil
not treated with P liming improved other factors than P supplying power.
Nowadays, Al toxicity is considered an important factor contributing to
the infertility of acid soils (e.g. EVANS and KAMPRATH 1970). The lime- induced drop in the exchangeable Al found in the connected incubation experiment (HARTIKAINEN 1983) may have some profitable effect on the growth of turnip rape. Theimproved growth appeared, however, only inthe second growth period, even though plenty of exchangeable Al was neutral- ized already during the first season. The retarded effect suggests that the impoverishment in P status owingtoplant uptake reinforced theinfluence of Al stress. Further, the incubation test showed the application of basic K2HP04to have lowered the level of exchangeable Al inboth experimental soils. Hence, the P treatment may have substituted or masked the influence of liming on the growth of turnip rape.
Thefractionation analysis data agreed withthose of plant analysesand the incubation test(HARTIKAINEN 1983).In themuddy fine sand, limingtended
to increase the exhaustion ofnative P, especially NaOH-P, and to decrease the accumulationof applied P. In thefine sand,on thecontrary, itpromoted the enrichment of added P, but less in the H2S04 fraction than in the incubation experiment.
According to general knowledge, liming augments P uptake from soil.
However, a soil type ofdissimilarresponse, e.g. the fine sand in thepresent study, is not necessarily very exceptional. As concluded in earlier studies
(HARTIKAINEN 1981and 1983),the changes in P solubilityduetoincreasing pH are anetresult ofprocesses enhancing desorption and ofthosepromoting sorption. Yet, it is possiblethat underfieldconditions thedifferencebetween the experimental soils would not have been as distinct. For instance, in the field trials of JAAKKOLA et ai. (1977), it was difficult to determine with certaintytheeffect of limingonPfertilization requirement. Thebasaldressing of fertilizersraises the utilization degreeand may partly impairthe efficiency of lime. On the other hand, the results of the present study and the experience obtained in the sugar beet cultivation on the line sand block (see HARTIKAINEN 1983) demonstrate that a relative low soil pH does not
necessarily limit the growth of even pretentious plant species, provided no nutrient deficiency or metal toxicity occurs.
References
CHANG, S. C.&JACKSON, M,L. 1957.Fractionation ofphosphorus. Soil Sci. 84; 133-144.
DORPH-PETERSEN,K. 1953. Kalkningens virkning päsurejordersfosfattilstand. Tidssk.f.Planteavl.
50; 653-675.
EVANS, C.E. &KAMPRATH, E. J. 1970.Lime response asrelated topercentA 1saturation, solution
Al,andorganicmatter content. SoilSei. Soc. Amer. Proc. 34: 893-896.
GHANI,M.O.& ALEEM, S.A. 1942.Effectoflimingon the transformation ofphosphorus inacid
soils. Indian], Agric. Sei. 12;873-882.
HARTIKAINEN, H. 1981.Effect of decreasingacidityonthe extractability ofinorganicsoil phospho-
rus. J.Scient.Agric. Soc.Finl. 53: 16-26.
1983.Effect of limingonphosphorusintwosoils ofdifferentorganicmatter content. I Changesof native and applied phosphorusinincubationexperiment.J.Scient.Agric.Soc.Finl. 55: 345-354.
JAAKKOLA,A., HAKKOLA, H., KÖYLIJÄRVI,J. & SIMOJOKI,P. 1977.Effect of liming on phosphorusfertilizer requirement incereals andley. Ann. Agric.Fenn. 16: 207-219.
JACKSON, M. L. 1958.Soil chemicalanalysis. 498 p.London.
JOKINEN,R. 1982.Theefficiencyof dolomiticlimestone,basicslag andpeatashaslimingagents,andas calciumandmagnesium sourcesforturniprape. J.Scient.Agric. soc. Finl. 54: 371-383.
KAILA, A. 1961.Effectofincubation and limingonthe phosphorus fractionsin soil.].Scient.Agric.Soc.
Finl. 33: 185-193.
1965.Somephosphorus testvalues andfractions of inorganic phosphorusin soils.J.Scient.Agric.
Soc.Finl. 37; 175-185.
PAAUW, F. vander, 1971. Aneffectivewaterextractionmethod for the determination ofplant-available soilphosphorus. Plant and Soil 34: 467-481.
SALONEN,M. 1946.Kalkituksen vaikutuksistamaaperän orgaaniseen ja helppoliukoiseenfosforiin. J.
Scient.Agric. Soc. Eini. 18; 1-10.
SCHARRER,K.&MUNK, H. 1956.ZurMethodik dernassen Veraschunginderagrikulturchemischen Analyse. Agrochimica 1:44-55.
SISSINGH,H. A. 1971. Analyticaltechnique ofPw method,used for theassesment of the phosphate
status of arablesoilsin theNetherlands.Plant and Soil34:483-486.
Ms receivedMay6, 1983
SELOSTUS
Kalkituksen vaikutus fosforiin kahdessa erityyppisessä hietamaassa
II Muutokset fosforin käyttökelpoisuudessa rypsille (Brassica cam-
pestris)
Helinä Hartikainen
Helsingin yliopiston maanviljelyskemian laitos, 00710Helsinki71
Kaksi kasvukautta kestäneessä astiakokeessa selvitettiin kalsiittikalkin vaikutusta fosforin käyttökelpoisuuteen kahdessa happamassamaanäytteessä(pH caci24.8). Rypsillä tehdyn kas- vatuskokeen tuloksia vertailtiin vastaavanlaisessa muhituskokeessa saatuihin.
Kalkitus vaikutti eri tavalla koemaiden fosforin käyttökelpoisuuteen, mutta vastatoisena kasvukautena. Vähän helppoliukoista fosforia sisältäneessä liejuisessa hiedassa kalkitus edisti rypsin kasvua sekä fosforin ottoa. Huolimatta tehostuneesta fosforin otosta kalkitut maat
sisälsivät kokeen lopussa yhtä paljon vesiliukoistafosforiakuin kalkitsemattomatmaat,minkä katsottiin osoittavan,ettäkalkitus paransi fosforin käyttökelpoisuutta.
Runsaasti vesiliukoista fosforia sisältäneessä karkeassa hiedassa kalkitus nosti jonkin
verran satoja, mutta ei niiden ottamia fosforin määriä koejäsenissä, joita ei lannoitettu fosforilla. Sitä vastoin fosforilla lannoitetuissa koejäsenissä kalkitus ei vaikuttanut kuiva- ainesatoihin, muttapyrki alentamaan fosforin hyväksikäyttöä. Koska kaikki kalkitut maat
sisälsivät kuitenkin kokeen lopussa vähemmän vesiliukoista fosforia kuin kalkitsemattomat, tulos viittaa alentuneeseen fosforin käyttökelpoisuuteen.
Muhituskokeen tuloksia, jotka olivat samansuuntaisia kasvatuskokeessa saatujen kanssa, käytettiin hyväksi kalkituksen vaikutusmekanismin tulkinnassa.
