Effects of organic amendment on soil quality as assessed by biological indicators

239 Pages·2011·4.59 MB·English

University of Naples Federico II
Faculty of Agriculture

Joint International Ph.D. Italy-Chile in
Environmental Resources Sciences
XXIV Cycle (2008-2011)

Effects of organic amendment on soil quality as
assessed by biological indicators

Ph.D. Dissertation

By Salma Sultana

TUTOR:
Dr Rosaria D‟Ascoli
Prof. Maria A. Rao

COORDINATOR:
Prof. Maria A. Rao

“Who hath created seven universes one above another: Thou seest not,
in the creation of the All-merciful any incongruity, Return thy gaze, seest
thou any rifts. Then Return thy gaze, again and again. Thy gaze, Comes
back to thee dazzled, aweary”

Al-Quran,
(Chapter 67: Verse 3-4)

This, in effect, is the faith of all scientists; the deeper we seek, the
more is our wonder excited, the more is the dazzlement for our gaze

INDEX
Chapter 1 Introduction……………………………………………….... 1
1.1. Soil and its importance……………………………………………... 1
1.2 Agricultural use of soils ……………………………………………. 3
1.2.1 Intensive agricultural management and its impact …………………. 3
1.2.2 Sustainable agricultural management……………………………….. 7
1.3 Soil quality…………………………………………………………... 9
1.3.1 Qualitative approach in defining soil quality………………………... 12
1.3.2 Quantitative approaches in defining soil quality…………………….. 13
1.4 Soil quality indicators ……………………………………………… 14
1.4.1 Soil physical and chemical indicators……………………………….. 15
1.4.2 Soil biological indicators…………………………………………... 18
1.4.3 Soil microbial indices………………………………………………... 22
1.5. Soil organic matter ………………………………………………… 24
1.6. Importance of waste recycling to agricultural land………………. 31
1.6.1. Composted urban waste as an organic amendment…………………. 33
1.6.2. Pulp mill sludge as an organic amendment………………………….. 36
1.7 The role of biodiversity in soil …………………………………….. 39
1.7.1. Soil biodiversity and ecosystem functions ………………………….. 42
1.7.2. Soil biodiversity and agricultural sustainability…………………….. 46
1.7.3. Factors affecting soil biodiversity…………………………………… 48
1.8 Methods to asses microbial diversity in soil………………………. 50
1.8.1 Bacterial community structure by 16s rDNA-PCR-DGGE …………. 54
1.8.2 Soil functional diversity by substrate induced respiration (SIR)…….. 57
1.9. References…………………………………………………………… 61

Chapter 2 Aims……………………………………………………….. 95
Chapter 3 Use of slow-degradable organic amendments to

improve quality of soils under intensive agricultural

management............................................................................................ 97
3.1. Introduction…………………………………………………………. 97
3.2. Materials and methods…………………………………………....... 101
3.2.1 Study area…………………………………………………………...... 101
3.2.2 Physical and chemical properties of the tested 102
amendments…………..........................................................……….
3.2.3 Experimental Design…………………………………………............. 103
3.2.4 Soil amendment and samplings………………………………………. 105
3.2.5 Soil physical and chemical analyses……………............................... 106
3.2.6 Soil Biological analyses………………….…………………………... 107
3.2.7 Soil functional diversity………………………………………………. 108
3.2.8 Microbial indices……………………………………………………… 110
3.2.9 Statistical analyses……………………………………………………. 111
3.3 Result ………………………………………………………………… 112
3.3.1. Effect of organic amendment on soil physical and chemical properties 1 1 2
3.3.2. Effect of organic amendment on soil biological properties and
microbial indices……………………………………………………... 129
3.3.3. Effect of organic amendment on functional diversity of the soil
microbial community………………………………………………….. 143
3.4. Discussions…………………………………………………………… 154
3.5. Conclusions……………………………………………………........... 171
3.6. References……………………………………………………………. 174
Chapter 4 Bacterial community structure and enzymatic activities

in a Chilean volcanic soil as affected by the addition of sludge from

pulp and paper industry ....................................................................... 195

4.1. Introduction…………………………………………………………. 195
4.2. Materials and methodology………………………………………... 196
4.2.1 Study site and experimental design…………………………………... 196
4.2.2 Pulp sludge collection and preparation……………………………... 196
4.2.3 Soil sampling and storage…………………………………………… 197
4.2.4 Soil chemical analyses……………………………………………….. 198
4.2.5 Enzymatic analyses………………………………………………...… 199
4.2.6 Bacterial community structure analysis……………………………... 200
4.2.7 Cluster analysis …………………………………………………….. 202
4.2.8 Statistical analyses ………………………………………………….. 202
4.3. Results ………………………………………………………………. 203
4.4. Discussion…………………………………………………………. 209
4.5. Conclusion………………………………………………………… 214
4.6. References…………………………………………………………. 215

Chapter 5 General conclusion…………………………………………………... 227

Acknowledgment

Chapter 1
Introduction

1.1 Soil and its importance
Relevance of soils as a resource in terrestrial ecosystems has been pointed out on
30 May 1972 by the Committee of Ministers in the Council of Europe that has
written the European Soil Charter, declaring:
1. Soil is one of humanity's most precious assets. It allows plants, animals and
humans to live on the earth's surface
2. Soil is a limited resource which is easily destroyed
3. Industrial society uses land for agriculture as well as for industrial and other
purposes. A regional planning system must be conceived in terms of the properties
of the soil and the needs of today's and tomorrow's society
4. Farmers and foresters must implement methods that preserve the quality of the
soil
5. Soil must be protected against erosion
6. Soil must be protected against contamination
7. Urban development must be planned so that it causes as little harm as possible
to adjoining areas
8. In civil engineering projects, the effects on adjacent land must be assessed
during planning, so that adequate protective measures can be reckoned in the cost
9. An inventory of land resources is indispensable
10. Further research and interdisciplinary collaboration are required to ensure
wise use and conservation of the soil
11. Soil conservation must be taught at all levels and be kept to an ever-increasing
extent in the public eye
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Chapter 1

12. Governments and those in command must purposefully design and administer
soil resources
Soil is linked to everything around us and performs many vital roles in sustaining
life on Earth. Moreover, the European Commission Communication on the
Thematic Strategy have been identified and underlined the key role of soil in
ecosystems as living and powerful element which supports plant and animal life, as
a source of food and raw materials. It is a fundamental part of the biosphere that,
together with vegetation and climate, helps to regulate the circulation and affects
the quality of water (Blum, 2005; EC, 2006).
Additionally, soil has filtering, buffering and transformation capabilities
influencing the water cycle and the gas exchange between terrestrial and
atmospheric systems and protecting the environment against the contamination of
ground water and the food chain (Fig. 1.1).

Fig. 1.1 Filtering, buffering and transformation activities of soil (Blum, 2005).

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