An evaluation of fungal bioassay procedures for assessment of soil phosphate status : thesis presented at Massey University College of Manawatu in part fulfilment of the requirements for the degree of Master of Agricultural Science

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Copyright is owned by the Author of the thesis. Permission is given for

a copy to be downloaded by an individual for the purpose of research and

private study only. The thesis may not be reproduced elsewhere without

the pennission of the Author.

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AN EVALUATION OF

FUNGAL BIOASSAY PROCEDURES FOR ASSESSMEf\TT OF SOIL PHOSPHATE STATUS,

Thesis

presented. at Massey University College of Manawatu in part fulfilment of the :requfre- me-,1ts for the ee of Master of icul tura1

Sc ence~

by

JIJ. M. D • Man

t

^{,j ika}

63 -

- Lifl"IA!<Y

MASSEY UNIVE!L ' .• ·:·:, r;,;;;;AwAm PALMER$'i0.",J

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I I I

III IV

V

VI

VTI

'l1ABLE OF

coN~

¹

E1rrs

⁰

1

3

DET :__;Rf:IlI'i.AJ'IOF 01<' AVATLABLE SOIL PHOSI)H_ATE BY

3

1. The Aspergillus ou1ture...

3

2. I?es¹J_lts achieved by the ap:o1ication of the pro-

3.

Advant2,ges and shortcomings of the A. nige:r:_

O'i'H}:ITH :B7TJWGUS SP}'TICTES USJID FOR ::⁰nIL PHOSPHORUS DE~C-~1(IvIIl,Jl4.TTOlf ~ ~ • ,. " • ,. ^(t^1'~ ^• ^l¾^$ ^• * ,, • • ,, ~ " • " ¢ ~ ^" ^{• • •}⁹^{• •}

1. Soil sam:oling and preparatton of sarrrples.

2. TVTforohtologioal Assays .••••...•••.•••

3.

Pot exnertment .•••.••••.•••••••..•••••.

4.

Chemioa1 Analyses for Soil Phosphate .•

FESULTS ••..•.••••••..••••••••••

1.

2.

3.

4.

Microbiological Assays.

Pot experiment .•.•...•••

Chem-Leal Analyses of Soi1 PhoFrnha te .•

Relationships and comparisons between methods.

DISCUSSIOrJ OF RE:iTJLTS •.••

1. Funga1 bioassay.

2. Pot experiment •.

3.

Chemical analyses of soil phos1)hate.

...

ACKNO 1.;LEDGE?i!ENTS APPIB:llTDICES

17

2~

25 27

30 30 30

35 48 53 53 66 87 91

102 102 104 106 108 111

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LIST OF TABLFS.

PAGE

L Description of Soils ••••••••••.••••••••••.••••••..•...•••

~8

2. pH and. Water B:olding Ca0acities of soils •••.•••••••.•..••

3.

Weights of soils arcl diluents per pot .••••.••••••••....••

39

Ll. • Amount of "irater retajned hy unc.ilnted soils in each pot •• Ll.O

5.

Grouping of soils accord:i:ng to water holding cam,c:i t~r (H.TLC.) of the diluted soi1s . . . .

6.

Mycelja1 dry weights of A. niger with so:i.l as the sour~e

of phos ::9ha te ^IJ ^*~ ^it^, ^,,, ^*^(!\^,,^.,^{• • • ,,}~ ^1J^(!,- ^{, .}^• ^{, ,}• • " o $ . . . ., "' * ., • ,, • ,. ➔ ^" ~ ^" ^"'^'II, ^"'^{* • ,,}

56 7.

Myce1ial dry ,mights of P. lilliacum with soil as the

S011),7'06 of phosphate.",,.",, '!J . . . . " " ' , , - , ' I ' # ; , , . e ~ e " . Iii 41 * ~. '!J 8"" "",. e

*.. 58

8.

Mycelial dry weights of C. geniculata with soil as the

s orirc e of phos !)hate. e • • • • ,, • • o • ,ff • e ., * • ,, . . . & • ,,. • • • " ilJ ,, ll' • " 60

9.

Mycelial dry weight of Fusarium sp. with soil as the

source of phosphate.~,,.,,._ <I'!,,,,, 4 " -& ,, • • • ,;, • r:, o.,.,,,,,,,. "',,,, o ¢."' (;},,,"',,..

62

10.

11.

12.

13.

16.

18.

19.

20.

Ranking of soils by the different fungi according to the

"9hosphate statllS of the soils •• ,, •. o . . . ,, . . . @,,,,~., ••• ,. • .,.$

rrihe amounts of "available" soil :ohosuhate as estimated by A. niper, P. lilliacum, and C. geniculata . . . '" .. .

Dry

weights of MiJ.let top growth .•

.. . . . . . . . . . . . . . . . . . . . .

Dry weights of Millet root.

. . . . . . . . . . .

_'

. .. . . . . . . . . . . . . .

Dry weights of Mi11et total yj.elds.

. ... . . . . . . . . .. . . . . . .

Rankin~ of soils bv Mil1et to~, root and total yields accordjng to the phosphate status of the soils ..•••••.•••

Dry treights of r_rurnj_p total :rields ^*^1$^(J^{• •}o.",, ~,, 4",, ^$ ^• ^,.

#.

⁴

*.

^'°'

}?ankins of soils by 'l¹urnip tota1 yie:1.ds acco:r'di.ng io the 1)hosphate status of the s:::itls ••••.• , •..••.•.••.•... ,., .••

Dry weights of Lucerne top ?J.'O"·Tth.

. . . . . . . . .. . . . . . . . . . .

Dry weights of Lucerne root.

. . . . .

_'

. . . . . . . . . . .

'

. . . . . . . . . . .

:Dry weights ^o·F' Iu'.3erne total yield.s .•

. . . . . . . .

'

.

^,

.

'

. . . . . . .

64

67

70

72

75

79

80

8?

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TABLE

21.

22.

23.

LIST OF 'T'ABLES.

(Continued)

Ranking of soils by Lucerne to:9, root, and total y:i.elcts a,ocordin~-; t':l the pbosph2,te stat,,1_s o:1:' the soj ls., ... , ..•

Forms of sojl :9bos~hate and rank-irg of so~ls ..•....•.••

Comb ,f't~.ons of forms of soil phosphe.te arid of

25.

Ordinary Correlation Coefficients between plnrt ytelds and othe^1: methoa.s em2Jloyed for d8term:'riati on of soil

PAGE

86 88

90

:ph o ^Rr,ha t e s t 2, t,J s • • . • . • , • • • • , • • . . • • • • , • • • • • . • • . • • . . . • , , , o ⁰

26.

Rank Correlat,011 Coeff:Lcients (Spearman¹

s)

for plant

yields a5ainst other methods emplr:iyed for assessing

11available¹¹ soj J rihos:r,hate ••.•.••.•... , •••.•... , •... ,..

93 27.

Overall total and average ^IIordinary" correlati.on

coeffjcients for ~olant yield method against fungal

assays a1•d cheri.ical extraction methods, ••• , ••••••• , . . . .

94

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PLATE

I II I I I

IV

V

VI VII VIII

LIST OF PLATES AND FIGURES.

T;'iechal'.'.ic::i,1 Shredder and_ barid ²i eve for soil preparation •••.

Part 0f the lab. and some of the equi T)ment ¹_1sed_., ...••.•..•

Type of f'leta1 not used and the seed1incs after thi:n:nine: .•.•

rrbe seedlings befoi·e beinc: thinned out •.••••••••..••..•.•••

Placement of pots and insta1latjon of tens~ometer ••••.•.•••

Installation of tens, 0111eters a1:1ong mat11re t1irni:r> rllants., .•

a-,-,01-rth differences for A. Y'!ig8r for a raYlge of phos:9hate

PAGE

30a 30a

35a

41a

44a

c ⁰¹¹⁰en tr at i 01:,s {, ,, ^$ ^.,^{• •}^#,, • • • 4 • * • ~ ,,,, , • ,r f> ti- ffe • • ,,, • Iii' ., . . . ,. • ., • • ,,, • • • IP • • • " It

54

IX Lucerne, turnip and millet plants at

3

weeks after

X

XI

germina t j_ or1. ^{s "}~ • e • " • 'lf f/!} ,~ /$ '? & ... e " " ,, " • & " " * 1' " • f> 4 ~ ^ti ^" a ,,. " • " "' 1/J " .,. t! "' ,,. " " "

9 6

Turni]J, lucerne and millet plants at 6 weeks after

germination 'grmm ovi Soils 1 a11d

16 ...•• , •.•.••.•...• ,

Tnrni:p, lucernP, and millet plants at 6 week:s after

f_!'errninatj on gTOWn on Soi_ls

19

and

20... . ....•.•....•.••• 97

XII Millet plants at

61

weeks after germination grow:1 o:n Soi ls

XIII

XIV

xv

XVI

XVII XVIII

witb djff8rent :9hosnhate levels,. ... ., . . . ., •. . , , .

97

Ti1rni:o :9lants at

7

ueeks after germination grmm on soi1s

with different 1Jhosi;,hcd:e J eveJs ••.•.•••. , . . .

98

Lucerne 1)] r1-rts at 6f~·re0lrs after germi112.tioYJ ,:rovm 0,1 sci_ls

·witb di:fere--1t Phosph2.te levels ..••••...••.•..•••••••.••••

99 99

1)evelo:;:irieYlt of turnip 1troot1t grou11 on Soils 13 ana. 16 ••••••• 100

XIX Ramifi.catjon of root it: a variety of potted soils ••••••••••• 101 XX Brass boxes used_ in the detex·minatio"Y! of water ho1ding

Capacity of SO i 1 S ^1//J⁹ ^{,, •} * <Ill ~ ^"'^e-^e^1'^{,, •} ^• ^• ^'1^• ~ ,. ,. " ,, ,, ~ ^" ^• ^• ^,.,^" ., "' • ,,, ,, t> ~ ^f'^,.~ ^,,~ ^,.^,,

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FIGTJRE

1.

2.

3.

LIST OF PLATES AND FIGURES.

(Continued)

Maximum and Minimum Daily ese$••

Grov;tft C1J.rve for .lle niger ... 4 * * - ' • • · · · · € i g / f $ 0 - ' 1 1 ' ¢ f l & O t ! ' ~

Growth curve for P. lilliacum •••••••.••

Growth curve for C. geniculata .•.••••••••

PAGE

45/46

54/55

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1

I. HFI1RODUCTION.

Microbiological assays, especially with A. niger, have been used rather widely to assess phosphate status of soils. The merits as well as shortcomings of these :orocedures have been a_iscussed in the literatuxe by various investigators. The speed, cheapness, and simplic with which microbiological assays may be car:ried. ou.t hav8 been used as arguments in favour of their use. It was this type of argument, considered in relation to the fact that good correlations have been reported by a number of workers between results obtained. by A. niger and_ by field tests, which suggested to the writer that microbiological assay might have special merit in those developing covntries where a rapid assessment of soil potential is required in the interests of food produc ⁰cion but where limited finance is available for full-scale soil investigations.

The work reported here was u..nd.ertaken to investigate further the value of the A. niger procedure as a means of evaluating soil phosphate status and to examine the possibihty that other fungi iY1cluding some not previously employed for this purpose might be even more suitable.

The present invest was confined to a range of Zealand sotls, As field response data were not available for these soils a pot experiment incorporating a number of crops was conducted to provide

data with which the results of microbiological assay could. be correlated..

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Chemical testing of soils has found much w:i.der application than microbiological assay and there is a possibility that such methods might provide superior evaluation of soil phosphate status, which could out1reigh the advantages of cheapness Emd. simplictty claimed for the biological -cechni(}.ues. As an extension of the present study it was therefore considered worthwhile to determine whether Truog•s procedure (1930)

fo:,:, determining available soil :phosphate ( the method employed. by the . .

New Zea1and De:9artrnent of Agri.cul ture) possessed any marked. advantage over the bjologjcal assays. It was further considered of interest to determine whether any OY1e form of soi1 phosphate or combinatj ons of forms a.etermined by selectjve extracting agents would show bettffc correlatio¹^-i id.th plant growth than shown by bjologj_oal assay.