A TAXONOMICAL ECOLOGICAL INVESTIGATION OF THE SOIL MESOFAUNA IN THE RHIZOSPHERE OF CITRUS TREES AT ZE-

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A TAXONOMICAL ECOLOGICAL INVESTIGATION OF THE SOIL MESOFAUNA IN THE RHIZOSPHERE OF CITRUS TREES AT ZE-

BEDIELA ESTATES

by

P. G. OLIVIER

(Institute for Zoological Research, Department of Zoolo- gy, Potchefstroom University for C.H.E., Potchefstroom)

THE SIS

PRESENTED FOR THE DEGREE OF

DOCTOR SCIENTIAE

IN THE POTCHEFSTROOM UNIVERSITY FOR C.H.E.

PROMOTER: PROF. P.A.J. RYKE, DSc. (U.S.), DSc. (P.U.)

JANUARY 1968

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A TAXONOMICAL - ECOLOGICAL INVESTIGATION OF THE SOIL MESOFAUNA IN THE RHIZOSPHERE OF CITRUS TREES AT ZE-

BEDIELA ESTATES

by

P.G. OLIVIER

(Institute for Zoological Research, Department of Zoology, Potchefstroom University for C.H.E., Potchefstroom)

1 INTRODUCTION .. ¹

2 SAMPLING AREA 6

3 SAMPLING PLOTS 8

3.1 SAMPLING SITES ⁹

3.2 SAM PLI NG DATES ⁹

4 THE SOIL 10

4.1 PARENT MATERIAL AND GEOLOGY ₁₀

4.2 SOIL TYPES ¹¹

4.3 SOIL TEXTURE AND SOIL PROFILE AT S

At~

P LIN G SIT E ¹²

4.4 SOIL ANALYSIS . ¹²

4.41 Phosphorus 13

4.42 Potassium 13

4.43 Calcium 14

4.44 Magnesium 14

4.45 Sodium 15

4.46 Organic material 20

4.47 Soil resistance 20

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4.48 4.5 4.6 4.7 4.8 4.81

4.82 4.821 4.83 4.831

4.8311 4.8312 4.8313 4.84

5 5.1 5.12 5.13 5.2 5.21 5.211 5.22 5.221 5.222 5.3 5.4 6 6.1

Soil pH 21

RAINFALL 22

SOIL MOISTURE 25

TEMPERATURE 33

CULTIVATION PRACTICES. 34

Irrigation 34

Pest control 34

Chemical applications on the experimental plots 34 Nutritional practices (in general) 35 Nutritional applications on the experimental

plots

^'0

36 Nitrogen treatments 36

Potassium treatments 36

Boron treatment 37

Weed control 37

METHODS SAMPLING The sampler

Sampling procedures EXTRACTION

The heat extraction battery system Funnel extraction procedures

Grease film extraction Preliminary experiments The grease film extraction SORTING AND IDENTIFICATION BIOMASS ESTIMATION

ANALYSIS OF THE MESOFAUNA . GENERAL

38 38 38 39 40

41

42

43

45

46

49

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6.2 6.21 6.22 6.23 6.3 6.31 6.32 6.33 6.34 6.4

7 7 .1 7.11 7 . 111 7.112 7.113 7.114 7 . 115

8 THE MESOFAUNA Acari

Collembola

"Other Arthropoda" . ANALYSIS OF THE ACARI Trombidiformes .

Mesostigmata Oribatei Acaridiae

ANALYSIS OF THE IIOTHER ARTHROPODA" •

SEASONAL FLUCTUARIONS OF THE MESOFAUNA ..

SEASONAL FLUCTUATIONS OF THE DIFFERENT PLOTS The mesofauna ..

Trombidiformes • Mesostigmata

Oribatei Acaridiae

"Other I\rthropoda

^ll ^•

VERTICAL DISTRIBUTION

8.1 SEASONAL RECORDING OF THE MESOFAUNAL VERTICAL

8.11 8.12 8.13 8.14 8.15 8.16

DISTRIBUTION IN PLOTS A - E Plot A .

Plot B • Plot C . Plot D . Plot E •

General vertical distribution pattern

50 51 56 56 57 57 64 66 70 70 76 78 78 87 98 101 108 108 126

126

129

132

135

137

140

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8.2 STRATIGRAPHY OF ECOLOGICALLY IMPORTANT FAMILIES AND

SPECIES 142

9 COMPARISON OF THE CITRUS SOIL FAUNA WITH THE CITRUS 9.1

9.11 9.111 9.112

9.113 9.114 10 10.1 10.2

TREE FAUNA . 152

THE FAUNA · 152

The Acari . 157

Trombidiformes • 157

Mesostigmata . 158

Oribatei • 159

Acaridiae . 159

THE INFLUENCE OF CITRICULTURAL PRACTICES ON THE

COMPOSITION OF THE SOIL MESOFAUNA . . 161 THE INFLUENCE OF CITRUS TREES ON THE COMPOSITION

OF THE SOIL MESOFAUNA . . 161

THE INFLUENCE OF REPLANTING CITRUS TREES ON THE

COMPOSITION OF THE SOIL MESOFAUNA . . 167 10.3 THE INFLUENCE OF PESTICIDES ON THE COMPOSITION OF

A TAXONOMICAL ECOLOGICAL INVESTIGATION OF THE SOIL MESOFAUNA IN THE RHIZOSPHERE OF CITRUS TREES AT ZE-

A TAXONOMICAL ECOLOGICAL INVESTIGATION OF THE SOIL MESOFAUNA IN THE RHIZOSPHERE OF CITRUS TREES AT ZE-

BEDIELA ESTATES

by

P. G. OLIVIER

(Institute for Zoological Research, Department of Zoolo- gy, Potchefstroom University for C.H.E., Potchefstroom)

THE SIS

PRESENTED FOR THE DEGREE OF

DOCTOR SCIENTIAE

IN THE POTCHEFSTROOM UNIVERSITY FOR C.H.E.

PROMOTER: PROF. P.A.J. RYKE, DSc. (U.S.), DSc. (P.U.)

JANUARY 1968

A TAXONOMICAL - ECOLOGICAL INVESTIGATION OF THE SOIL MESOFAUNA IN THE RHIZOSPHERE OF CITRUS TREES AT ZE-

BEDIELA ESTATES

by

P.G. OLIVIER

(Institute for Zoological Research, Department of Zoology, Potchefstroom University for C.H.E., Potchefstroom)

CONTENTS

1 INTRODUCTION .. 1

2 SAMPLING AREA 6

3 SAMPLING PLOTS 8

3.1 SAMPLING SITES 9

3.2 SAM PLI NG DATES 9

4 THE SOIL 10

4.1 PARENT MATERIAL AND GEOLOGY 10

4.2 SOIL TYPES 11

4.3 SOIL TEXTURE AND SOIL PROFILE AT S

P LIN G SIT E 12

4.4 SOIL ANALYSIS . 12

4.41 Phosphorus 13

4.42 Potassium 13

4.43 Calcium 14

4.44 Magnesium 14

4.45 Sodium 15

4.46 Organic material 20

4.47 Soil resistance 20

4.48 4.5 4.6 4.7 4.8 4.81

4.82 4.821 4.83 4.831

4.8311 4.8312 4.8313 4.84

5

5.1 5.12 5.13 5.2 5.21 5.211 5.22 5.221 5.222 5.3 5.4 6 6.1

Soil pH 21

RAINFALL 22

SOIL MOISTURE 25

TEMPERATURE 33

CULTIVATION PRACTICES. 34

Irrigation 34

Pest control 34

Chemical applications on the experimental plots 34 Nutritional practices (in general) 35 Nutritional applications on the experimental

plots

36

Nitrogen treatments 36

Potassium treatments 36

Boron treatment 37

Weed control 37

METHODS SAMPLING The sampler

Sampling procedures EXTRACTION

The heat extraction battery system Funnel extraction procedures

Grease film extraction Preliminary experiments The grease film extraction SORTING AND IDENTIFICATION BIOMASS ESTIMATION

ANALYSIS OF THE MESOFAUNA . GENERAL

38 38 38 39 40

41

42

43

43

45

45

46

49

49

6.2 6.21 6.22 6.23 6.3 6.31 6.32 6.33 6.34 6.4

7 7 .1 7.11 7 . 111 7.112 7.113 7.114 7 . 115

8

THE MESOFAUNA Acari

Collembola

"Other Arthropoda" . ANALYSIS OF THE ACARI Trombidiformes .

Mesostigmata Oribatei Acaridiae

ANALYSIS OF THE IIOTHER ARTHROPODA" •

SEASONAL FLUCTUARIONS OF THE MESOFAUNA ..

SEASONAL FLUCTUATIONS OF THE DIFFERENT PLOTS The mesofauna ..

1 INTRODUCTION .. ¹

3.1 SAMPLING SITES ⁹

3.2 SAM PLI NG DATES ⁹

4.1 PARENT MATERIAL AND GEOLOGY ₁₀

4.2 SOIL TYPES ¹¹

P LIN G SIT E ¹²

4.4 SOIL ANALYSIS . ¹²