1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
This paper was prepared as a contribution to the ARNOA conference organized for developing the basic standards for organic rice cultivation and presents highlights of the important soil biodiversity components in organic agriculture, which is a much neglected issue of agricultural ecosystems especially in the tropics. The contents herein emphasize the importance and value of soil biodiversity estimation for opportunities in exploitation for organic certification.
Soil biomass measured as CO
2
evolution rate (or expressed as volume of C) and Simpson diversity index are suggested for determination of ‘organic’ and / or ‘in conversion’ status of an agricultural or forest lands in certification. It is a simple, cost effective and reliable method and will undoubtedly contribute to the needs for easy estimation of organic land certification. These methods would help eliminate sophisticated and costly approaches in organic inspection and certification and ease adopting locally for the benefit of subsistence farmers and groups in the developing countries.
The supportive material has been derived through results of ‘TRI-ORCON’ comparison trial closely monitored for 9-years with tea as well as associated soil surveys conducted for beneficial organisms in Sri Lanka.
This paper is dedicated to subsistence farmers in the Asian region whose genuine efforts have traditionally been devoted for sustainability of the eco system.
Key words:
Biodiversity components, Certification, Cost, Inspection, Organic agriculture, Soil biomass, Soil microbial activity, Sustainability, Tea, Sri Lanka, Tropical soils.
Plate 1 Diminished soil biodiversity in conventional paddy fields due to heavy consumption of agro-chemicals and poor organic matter replacement. (Location:
Horana, Sri Lanka).

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
Organic agriculture discourages any use of synthetic agro-inputs needed for maintaining productivity and fertility of soil and pest management. Instead it promotes maximum use of organic materials such as bio-composts, crop residues, animal excreta, on- and off- farm organic wastes and bio-pesticides, etc. More importantly, it is a comprehensive and appropriate management approach, which integrates several organic recycling processes, indigenous knowledge systems and natural methods. In turn, it enhances and ensures conservation and restoration of natural biodiversity within the system and minimizes environmental pollution. Therefore, organic farming has been identified as one of the best alternatives in view of minimizing the environmental problems encountered in conventional and intensive agricultural systems 14,21 .
Decision III/11 on Conservation and Sustainable Use of Agricultural Biological Diversity
‘encourages the development of technologies and farming practices that not only increase productivity, but also arrest degradation as well as reclaim, rehabilitate, restore and enhance biological diversity and monitor adverse effects on sustainable agricultural biodiversity’ such as
‘ inter alia , organic farming’ 56 .
Moreover, the strong and sustainable health-driven markets worldwide demand for cleaner, purer, safer, fresher and more ‘close to nature’ foods. As a result, organic market in many terms viz.
‘organic’, ‘bio’, ‘all-natural’, ‘additive/preservative-free’, ‘non-GMO’ and ‘free range’ etc. is expanding at a phenomenal rate. The expected market growth of consumption per annum has been aimed at 10%+, 25%+ and 20% for all markets, Europe and USA respectively. The expected market share for organic food will be 5-10% of total food sales by year 2005 50 . Scientists have focused that the Asian region will potentially become one of the largest organic markets in the near future with the gradually improving living standards of the increasing population and awareness on environmental issues 26 .
The organic system is monitored regularly as per basic standards specified by IFOAM (International
Federation for Organic Agriculture Movement) which covers all aspects of production, processing and labeling of organic food ensuring high standards of human and animal welfare and environmental land management. For confirmation, standards for organic production and processing are laid according to European Union Regulation (EEC) No. 2092/91 5 .
Sustainable use of biodiversity is promoted in organic agriculture and environmental conservation processes. The evaluation of biodiversity components has vital importance in this connection.
Population densities of larger sized biota such as birds, butterflies, beetles, bees, earthworms, spiders etc. are traditionally being used as bio indicators in many cases as measure. However, macro-level evaluations posses constraints in terms of variability in the assessments due to lack of expertise, seasonality in agricultural systems etc. 39 Nevertheless, according to the available information, the abundance and species richness of ground beetle have been greater in the organic system compared to the conventional system; six of the 17 species collected were found only in organically-managed plots of Californian agricultural areas 13 . The influx of bird populations in organic farms in Sri Lanka and its importance as bio indicators in natural resource management and integrated pest management are also evident 27 . However, very little information on comparative macro components of biota in organic and conventional agricultural systems is available for reference.
In this context, since farming practices significantly modify soil life, which would change the total number of organisms, the activity and the diversity of species and the aggregate functions of soil biota etc., soil biodiversity components would exhibit clear indications of any changes in the system
1,2,3,4,10,15,18,19,24,37,44,47,49 .

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
Soil is a dynamic, living matrix that is an essential part of the terrestrial ecosystem. It is a critical resource not only to agricultural production and food security but also to the maintenance of most life processes in general. Soils encompass enormous numbers of diverse living organisms assembled in complex and varied communities, which reflect the variability among living organisms in the soil ranging from invisible microbes, bacteria and fungi to the more familiar macro-fauna such as earthworms and termites; plant roots are also considered as soil organisms in view of their symbiotic relationships and interactions with other soil biological components. They interact with the ecosystem, environmental factors, such as temperature, moisture and acidity etc. as well as agricultural management practices. The soil biodiversity complex is well explained by ‘OPQ triangle’ which reflects the living organisms (O), physico-chemical environment (P), and the chemical composition or quality of the organic matter (Q) 53 . Direct and indirect benefits of soil biological components in agricultural systems include economic, environmental and food security benefits:
Soil organisms contribute a wide range of essential services to the sustainable function of all ecosystems; they act as the primary driving agents of nutrient cycling, regulate the dynamics of soil organic matter, soil carbon sequestration and greenhouse gas emission, modify soil physical structure and water regimes, enhance the amount and efficiency of nutrient acquisition by the vegetation and plant health. These services are not only essential to the functioning of natural ecosystems but constitute an important resource for the sustainable management of agricultural systems 20 .
Estimates show that a fertile soil shall contain around 1-6 million bacteria /g and about 1 million fungi /g, earthworms of about 8 million /ha and immense diversity of all the algae, protozoa, nematodes, arthropods and insects 56 .
Under favorable conditions, one tenth of the organic matter in a soil is made up of soil animals.
Thus, a layer of 10 cm of a hectare of soil with 1% organic matter contains roughly 1500 kg of soil fauna. This equals the weight of 3-4 cows 15 .
The importance of soil biodiversity to plant diversity and agricultural productivity has been the subject of anecdotal and empirical investigations for some time, which recently blossomed in many temperate countries. As a result, soil biologists and agriculturalists are challenged to address a major global concern viz
. ‘
How to provide greater food security for all nations on earth in a sustainable way with minimal damage to the environment?’ Some land practices such as gazing (mowing), fire and soil moisture on soil biomass under arid and subtropical conditions have been described 20 .
Experimental evidence from long-term trials with organic farming under temperate conditions is available to show how sustainable is this production system with benefits to the environment.
Research experience under tropical conditions however, is either little or scarce 7,8,12,17,24,25,47,56 . In most cases, comparisons of organic systems with the conventional system are not included, hence the scientific validity is in question.
The total number, diversity, activity of soil biota and their aggregate functions could be expressed as a measure of soil life in a habitat. ‘Soil biomass’ gives a general understanding of soil biodiversity covering all biological components inclusive of both soil organisms and roots of a given locality as a measurement of CO
2
evolution rate. Soil microbial activity on the other hand, expresses the energy capacity in terms of C biomass of soil 3 .
Number of substantial and additional methods are available for assessment of soil biodiversity, but posses some technical or interpretative limitations. These include ATP measurements, chemosystematic-based determinations of taxon-specific cellular constituents (fatty acids, sterols, secondary compounds, proteins etc.), nucleic acid based approaches (whole community nucleic-acid hybridization, community DNA reassociation kinetics, and cloning and sequencing of polymerase

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea chain reaction (PCR)-amplified 16sRNA gene sequences from community DNA samples) and nucleic-acid function-based methods such as hybridization of probes to genes (potential function) or mRNA (expressed function) unique to particular enzymatic activities. Assays of chemical diversity such as enzymatic and chemo systematically important cellular constituents also contribute to identification. The activity of total viable microbial biomass could be assessed by contents of polyphenol, humic acid and phospholipid ester-linked fatty acids (PLFA) in soil. Information on bio indicators (Plate 2) and bioassays with indicator plants could also serve to describe the strength of OPQ triangle 3,9,18,39,49,58 .
Specialist techniques and expensive equipments are needed for detailed measurements of genetic diversity. SIMPSON INDEX, is a simple mathematical method of expressing the species diversity which takes the number of different species and their the total numbers into account 20 . The technology adopted for determination of soil biodiversity will vary with the agronomic values. Soil systems could be described through GIS (Geographic Information Systems) grids using the data on existing soil biota for future monitoring.
Agriculture provides a major share of national income and export earnings in many developing countries, while ensuring food security, income and employment to a large proportion of the population. However, over the last few decades, man has done much to improve agricultural production using artificial inputs, but these have often had detrimental effects on soil organisms and soil fertility. Farmers, governments and scientists are increasingly aware that declining soil fertility is becoming a major concern worldwide with social, food security and environmental implications 4 .
Organic agriculture and processing is based on principle aims specified by IFOAM and the following are equally important in achieving the sustainability with minimal impact on ecological factors with the understanding of the interactions and interconnection of soil organisms with soil fertility 5,41 . These could be extracted as follows:
1.
Interact in a constructive and life-enhancing way with natural systems and cycles.
2.
Encourage to enhance biological cycles within the farming system involving microorganisms, soil flora, fauna, plants and animals.
3.
Maintain to increase long-term fertility of soils.
4.
Promote healthy use and proper care of water, water resources and all the life therein to help conserve soil and water.
5.
To maintain the genetic diversity of the agricultural system and its surroundings, including the protection of plant, livestock and wildlife habitats.
Scientific research has demonstrated that organic agriculture significantly increases the density and species of soil life 1,2,7,11,12,13,14,16,17,19,23,24,25,27,28,30,31,37,38,47,56 . Suitable conditions for soil fauna and flora are encouraged by the practices, avoidance of pesticides, herbicides use etc. that are specific to organic agriculture.
Organic agriculture enhances the value of biological diversity by linking conservation efforts with social and economic benefits. High occurrence of micro-organisms, symbiotants, arthropods and earthworms etc. under organic management is found to be associated with production of microbial carbon, enzymes, high-energy efficiency and erosion control . 5 .
Besides the rich soil biodiversity in the tea ecosystem which is similar to a natural undisturbed forest 55 , the organic tea soils in Sri Lanka possessed the highest incidence index of naturally occurring beneficial organisms as compared to conventionally managed soils 33,34,35 . Significantly greater frequency distribution of soil arthropod populations was evident in organically treated tea soils than that of chemically treated tea soils in India 7 . Studies have demonstrated that free living nematode populations have been (a) consistently superior in organic soils as compared to conventional soils and (b) acting as biological decomposers as well as natural enemies of soil pathogens 30,33,34,35,36,40,48,57 . Bio prospecting and potential exploitation of biodiversity for

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea development process in relation to ecological restoration and organic farming concept have also been discussed 31 .
Plate 2 A rare scene!; Concentration of birds in paddy fields during land preparation which is an indication of abundance of earthworms (inserted photograph) in soil.
(Location: Kurunegala, Sri Lanka).
Among the soils of organic, low-input, and conventional farming systems, phospholipid fatty acid
(PLFA) profiles from the low-input system fell between organic and conventional systems throughout 9 . Determination of base lines for various measurable parameters in the OPQ triangle is therefore possible to harness as potential determinants in organic certification.
Biodiversity is one of the key determinants in organic certification and specifically in the Forest
Garden Product Certification (FGP) system, which considers macro-level biodiversity such as butterfly and bird counts etc. in its evaluations of agricultural lands 6 . However, soil biodiversity posses a reliable estimation with less statistical variability. Residue analyses in soils are some of the conventional methodologies in assuring the organic status but are undoubtedly costly. Therefore, biodiversity measurements could be identified as a considerable component in organic certification with more supportive evidences 3,9,11 . Laboratory analyses or measurements using ‘compost monitors’ or ‘gas sensors’ could be utilized for soil biodiversity determination.
This paper describes the results of soil biodiversity components in the ‘TRI-ORCON’ comparison trial (Organic and Conventional tea cultivation systems) closely monitored for 9 years . The longterm field experimentation with tea (clone DT1) was set up in 1996 followed by a two-year soil rehabilitation period at S. Coombs Estate of the Tea Research Institute of Sri Lanka (TRI). The location lies at a latitude of 6 o 55

N, a longitude of 80 o 40

E, altitude of 1382 m amsl with a mean annual rainfall and air temperature of 2250 mm and 18.4 o C respectively. The three organic farming systems (treatments) as per IFOAM standards with traditional additives (TW: Tea Waste, NOC:
Neem Oil cake and COM: Compost) and a conventional system (CONV: exclusive use of TRI recommended mineral fertilizers and synthetic pesticides) are emulated in replicated trial plots.

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
Data on crop growth, yield and its components, quality of produce, soil parameters, pest, diseases and weed incidence and cost-benefit analyses are being monitored in the trail plots periodically
(Plate 3).
Plate 3 View of ‘TRI-ORCON’ comparison trial set up at the Tea Research
Institute of Sri Lanka.
The results of the ‘TRI-ORCON’ comparison trial confirmed that the organic system of tea cultivation helped improving the soil biodiversity and ecological restoration while maintaining the sustainability of the system. Organic systems sustained with 100% input reduction of synthetic fertilizers and pesticides. However, the mean reduction in yields of organic plots was only 9.7% during the first pruning cycle, which was not statistically significant. The soil fertility levels determined were in par with the required ranges for tea 29 .
Soil microbial biomass increased in the order of CONV < NOC <COM < TW (Figure 1) and remained constant irrespective of season and the cultural practices adopted 29 . This in turn reflects the effect of practices responsible in changing the soil biodiversity levels. Enhanced organic matter levels and altered C:N ratio 46 could have resulted in significantly higher soil biodiversity levels in organic plots 29,37 . The microbial activity measured as CO
2
evolution rate, showed a significant increase in organic tea soils than that of conventionally managed soils (p = 0.05). In the organic systems, efficient and numerous nutrient cycling reactions could be expected. A greater flux of resultant nutrients has rendered the system less dependent on external inputs and more sustainable
54 .

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
0.006
0.005
0.004
0.003
0.002
0.001
0
TW NOC COM CONV ORIGINAL
200
150
100
50
0
TW NOC COM CONV
Figure 1 Improvement of soil biodiversity in the different habitats of the ‘TRI-
ORCON’ comparison trial 9 years after exposure to treatments.
TW: Tea Waste, NOC: Neem Oil cake, COM: Compost and CONV: Exclusive use of TRI recommended mineral fertilizers and synthetic pesticides
Note the significantly greater mean values of CO2 evolution rates in soils of organic treatments (P < 0.05).
Although the soil physical factors such as aggregate stability and bulk density were not determined in the ‘TRI-ORCON’ trial, greater soil stability in organic plots could be expected. Results of the
DOK farming systems in Switzerland revealed significantly and positive correlations between aggregate stability and microbial biomass and between aggregate stability and earthworm biomass
24,25 . ‘TRI-ORCON’ trial exhibited comparatively greater earthworm and microbial (soil) biomass in organic soils.
There was significantly greater population of earthworms in organically treated plots than conventionally treated plots (pr > chisq = < 0.0329). Biomass and abundance of earthworms in the organic plots were several folds higher than in conventional plots, which was evident both in DOK and ‘TRI-ORCON’ trials (Figure 2).

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
M ic r o b ia l A c t iv it y
S o il B io m a s s
In s e c t s
5 0 0
4 0 0
3 0 0
2 0 0
1 0 0
0
Ea r t h w o r m s a t 1 5 - 3 0 c m d e p t h
C o lle m b o la n s
M it e s
M y r ia p o d s
Ea r t h w o r m s a t 0 - 1 5 c m d e p t h
Pa r a s it ic N e m a t o d e s
T W N O C
M y c o r r h iz a
C O M
F r e e L iv in g N e m a t o d e s
C O N V
Figure 2 Detailed soil biodiversity components in the different habitats of the "TRI-
ORCON" comparison trial.
TW: Tea Waste, NOC: Neem Oil cake, COM: Compost and CONV: exclusive use of
TRI recommended mineral fertilizers and synthetic pesticides
Mean values of individual biodiversity components are presented for Insects,
Collembolans, Mites and Myriapods: Mean number (x10
Mean number of spores 100g soil number 100g soil
Mean CO
2
–1
3 ) 100g soil
–1
,Free living and Parasitic nematodes: Mean
, Earthworms: Mean number (x10 1 ) 0.25m
evolution rate (mg) day
–1
,
Mycorrhiza:
–2
, Soil biomass:
–1
, Soil microbial activity: Mean CO
2 evolution rate (mg x 10 5 ) g soil
–1 day -1

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
The epigeic arthropods are important predators and considered sensitive indicators of soil fertility and synthetic inputs. The abundance of micro arthropods (insects, collembolans, myriapods and mites) in
and in
soils were 35, 17, 52 and 11 respectively. A significant (p = 0.05) reduction in the micro arthropod density noted in soils of
and
was attributed to the possible chemical influences in the soil environment 37 . The densities of carabids, staphylinids and spiders in the organic plots have been almost double than that of the conventional plots in the DOK trial 24,25 .
Colonization of the members of Mycorrhizae that ameliorate plant mineral nutrition and contribute to soil aggregate formation did not show significant differences between organically and conventionally maintained soils 46 . However, organic farming systems in the DOK trial noticed
40% greater root colonization by mycorrhizae than in conventional systems 24,25 .
Significantly greater densities of free living nematodes were present in organic soils than that of conventional soils (p=0.05); the ratios of parasitic : free living nematodes in organically and conventionally managed plots were 4.6 and 1.2 respectively. The free living nematode populations have caused natural suppressiveness of parasitic nematode incidence in organic tea soils while serving as organic matter decomposers 34,35,36,57 .
One of the remarkable findings in the ‘TRI-ORCON’ trial was the significant difference of Simpson diversity index between organic and conventional soils (Figure 3). Similarly, DOK trial resulted in significantly different Shannon index H' (soil microbial functional diversity) and qCO2 (metabolic quotient = soil basal respiration/soil microbial biomass). The higher diversity in the organic plots was related to the lower qCO2 observed, indicating greater energy efficiency of the more diverse microbial community 24,25 .
0 .0 0 0 8 2
0 .0 0 0 8
0 .0 0 0 7 8
0 .0 0 0 7 6
0 .0 0 0 7 4
O r g a n ic C o n v e n tio n a l
Figure 3 Simpson diversity index determined for soil biomass in organic and conventional cultivation systems of the ‘TRI-ORCON’ trial.
Organic: mean value of the treatments of TW, NOC and COM
Conventional: treatment CONV
Any healthy ecosystem is characterized by high species diversity. The ‘TRI-ORCON’ trial exhibited a development of diverse composition of weed flora in organic plots as compared to conventional plots (Figure 4). All organic soils consisted of a greater proportion of succulent weed biomass, which was an indication of richness in organic matter. The DOK trial too showed similar results under organic farming system 24,25 .

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
8 0 0
6 0 0
4 0 0
2 0 0
0
T W N O C
B R O A D L E A V E S
C O M
G R A S S E S
C O N V
S E D G E S
Figure 4 Composition of weeds in the different habitats of the ‘TRI-ORCON’ comparison trial.
TW: Tea Waste, NOC: Neem Oil cake, COM: Compost and CONV: exclusive use of
TRI recommended mineral fertilizers and synthetic pesticides.
A few research evidences from associated local findings do substantiate the value of soil biological measurements in determination of organic status. The scatter plot was developed using the mean
CO
2
evolution rates of various organically maintained crop habitats in the different agro-ecological regions in Sri Lanka. Irrespective of the nature of the crop, perennial or short term, the different soil microbial activity levels lied in unique ranges for different crop situations (Figure 5).
Figure 5 Mapping of microbial activity in organic soils of different crops in the different agro-ecological regions in Sri Lanka.
NOTE: 32 observations of mean CO
2 evolution rate of organically maintained soils of coconut, export agricultural crops (EAC), paddy, tea and vegetable have been plotted.

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
However, similar assessments are underway in the conventional system of farming for comparison.
Nevertheless, an initial evaluation with organically and conventionally maintained paddy soils exhibited a clear difference in soil microbial activity (Figure 6). The emission of CH
4 in paddy soils is relatively negligible and therefore, the measure of CO
2
will express the biological activity of the habitat (personal communication, Dr. Sumith Abersiriwardene, Director, Rice Research and
Development Institute of Sri Lanka). Under significantly lower organic matter levels and heavy dressings of agro chemicals (Plates 1 and 2), the expected soil biology is less and any boost could be attributed to correction of the system 38 .
0 . 0 2 5
0 . 0 2
0 . 0 1 5
0 . 0 1
0 . 0 0 5
0
O rg a n ic 1 O rg a n ic 2 C o n ve n t io n a l
Figure 6 Soil microbial activity of organic and conventional paddy lands in Sri
Lanka.
Non-chemical agronomic measures adopted in organic agriculture shall give rise to reclaim, rehabilitate, restore and enhance biological diversity and monitor adverse effects on sustainable agricultural biodiversity. Supportive experimental evidence was extracted from degraded tea soils exposed to several treatments where chemical treatments lowered biological activity in soils while several cultural practices of non-chemical nature elevated health of soil (Figure 7). Soil biology status of crop situation exposed to soil pesticides for 19 years in Briton 19 , tea lands under long-term applications of herbicides in India 7,8,42,433,44 and in vitro analyses with different soil pesticides and soil organic amendments 1,45 revealed similar observations. The potential capacity of soil organic amendments in breaking down and lowering the resident pesticide residues in soil is also demonstrated 11,45 .

1 st
RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea a
4 0 0 a b a b
3 5 0
3 0 0
2 5 0 b c b c
2 0 0 d d
1 5 0
1 0 0
U n t re a t e d F o rm a lin H e rb ic id e N e m a t ic id e F o rk in g
S o i l T r e a tm e n ts
Te a w a s t e C o m p o s t F o re s t
Figure 7 Soil biomass in tea fields as affected by common various cultural practices compared with a natural undisturbed forest system.
(Means with the same letter are not significantly different at p=0.05)
The organic systems studied in the ‘TRI-ORCON’ trial in Sri Lanka featured typical of mature systems showing efficient resource utilization and enhanced floral and faunal diversity (). Similarly, significant correlations between above-ground (unit energy per unit crop yield) and below-ground system efficiency (CO
2
evolution per unit soil microbial biomass) have been demonstrated in the
DOK trial in Switzerland 24,25 . I conclude therefore that the underground measurements determining the system efficiency would be reasonably acceptable judgment and a realistic alternative in organic certification. However, further efforts to develop correlations with below-ground system efficiency and other soil parameters and methodologies to minimize errors and increase acceptance are suggested 22 .
Besides the importance of soil biodiversity in sustainable agriculture, it is evident that the soil biology assessments could be exploited for assuring the organic status of a land. In view of mainstreaming the potentials of soil biology components, the following are suggested for strengthening sustainable exploitation of soil biodiversity components in development process.
1.
Evaluate critical ecosystem services such as organic matter decomposition, nutrient cycling and pest control etc. provided by individual soil biota.
2.
Strengthening the little known influences of functional groups on mid-to long-term gains and sustainable agricultural productivity.
3.
Establish correlations between soil biomass and moisture, levels, pollutant densities, crop situation, agricultural practices and conversion stages in to organic for better understanding of the concept.
4.
Develop appropriate and cost effective bio indicators and field methodologies for monitoring and assessing soil biodiversity.
5.
Assess the effects of soil biodiversity and its functions on efficient land use/management and soil quality for better dissemination of the message to the farmers.
6.
Enhance collaboration among soil biology specialists and agriculturists in promoting best practices of soil biological management.
7.
Expand expertise in sol biology specialists in natural resource management, rural/community development and plant pathology.

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RDA/ARNOA International Conference
“Development of Basic Standard for Organic Rice Cultivation”
12-15 November 2002, RDA and Dankook Univ. Korea
8.
Develop data bases / maps on soil biodiversity components for different crop associations under different agro ecological conditions and crop situations of both organic and conventional systems.
9.
Determine base line biodiversity indices for conventional, organic and in conversion situations of different crops.
Acknowledgements:
The writer sincerely thanks all co-workers and collaborators in connection with the TRI-ORCON trial, especially Professors U. R. Sangakkara and H. N. P. Wijegunasekara, Dr. (Mrs.) Janaki
Mohotti and Abhaya Balasuriya, M/s Wasantha Kulawardhana, Deepthi Molligoda, Sampath
Senavirathna, Madura Tennakoon, Priyanka Premaratne, Avanthi Abeykoon, Kosala Elliyadde,
Amitha Prathapasinghe, Rasanji Wictor Wickrama Arachchi, Nissanka Navaratne and Ratnayake.
The information, practical skills and the need to study the constraints of organic certification aspects supplied by indigenous growers are greatly acknowledged.

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12-15 November 2002, RDA and Dankook Univ. Korea
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