Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-27T21:26:56.030Z Has data issue: false hasContentIssue false
  • English
  • Français

Biological indicators of soil quality in organic farming systems

Published online by Cambridge University Press:  19 November 2009

E.A. Stockdale  and
C.A. Watson
E.A. Stockdale*
Affiliation:
School of Agriculture, Food and Rural Development, Agriculture Building, Newcastle University, Newcastle-upon-Tyne NE1 7RU, UK.
C.A. Watson
Affiliation:
SAC, Craibstone Estate, Aberdeen AB21 9YA, UK.
*
*Corresponding author: e.a.stockdale@newcastle.ac.uk
Get access Rights & Permissions [Opens in a new window]

Abstract

The health of the soil, recognized by its active role in the linked processes of decomposition and nutrient supply, is considered as the foundation of agriculture by the organic farming movement. Nutrient management in organically managed soils is fundamentally different from that of conventional agricultural systems. Crop rotations are designed with regard to maintenance of fertility with a focus on nutrient recycling. Where nutrients are added to the system, inputs are in organic and/or non-synthetic fertilizer sources that are mostly slow release in nature. Hence a greater reliance is placed on soil chemical and biological processes to release nutrients in plant-available forms. In this respect, nutrient availability in organically farmed soils is more dependent upon soil processes than is the case in conventional agriculture. The development and use of biological indicators of soil quality may therefore be more important in organic (and other low input) farming systems. The aim of this paper is to evaluate current evidence for the impact of organic farming systems on soil biological quality and consider the identification of appropriate biological indicators for use by organic farmers and their advisors. Organic farming systems are generally associated with increased biological activity and increased below-ground biodiversity. The main impacts on biological fertility do not result from the systems per se but are related to the amount and quality of the soil organic matter pool and disruptions of soil habitat via tillage. Even within the constraints of organic farming practices it is possible for farmers to make changes to management practices which will tend to improve soil biological quality. It is, however, by no means clear that distinct indicators of soil biological quality are needed for organic farming systems. It is important not only to identify the most appropriate indicators but also to ensure that farmers and land managers can understand and relate to them to support on-farm management decisions.

Keywords

microbial biomassorganic matter inputssoil ecosystemtillage
Type
Review Article
Information
Renewable Agriculture and Food Systems , Volume 24 , Issue 4 , December 2009 , pp. 308 - 318
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1Stockdale, E.A., Lampkin, N.H., Hovi, M., Keatinge, R., Lennartsson, E.K.M., Macdonald, D.W., Padel, S., Tattersall, F.H., Wolfe, M.S., and Watson, C.A. 2001. Agronomic and environmental implications of organic farming systems. Advances in Agronomy 70:261–327.CrossRefGoogle Scholar
2Howard, A. 1943. An Agricultural Testament. Oxford University Press, London.Google Scholar
3Balfour, E. 1943. The Living Soil and the Haughley Experiment. Faber and Faber, London.Google Scholar
4Giller, K.E., Beare, M.H., Lavelle, P., Izac, A.M.N., and Swift, M.J. 1997. Agricultural intensification, soil biodiversity and agroecosystem function. Applied Soil Ecology 6:3–16.CrossRefGoogle Scholar
5Watson, C.A., Atkinson, D., Gosling, P., Jackson, L.R., and Rayns, F.W. 2002. Managing soil fertility in organic farming systems. Soil Use and Management 18:239–247.CrossRefGoogle Scholar
6Stockdale, E.A., Shepherd, M.A., Fortune, S., and Cuttle, S.P. 2002. Soil fertility in organic farming systems—fundamentally different? Soil Use and Management 18:301–308.CrossRefGoogle Scholar
7Van Bruggen, A.H.C. 1995. Plant disease severity in high input compared to low input and organic farming systems. Plant Disease 79:976–984.CrossRefGoogle Scholar
8Jackson, L.E. (ed.). 1997. Ecology in Agriculture. Academic Press, San Diego, CA.Google Scholar
9Bengtsson, J., Ahnstrom, J., and Weibull, A.C. 2005. The effects of organic agriculture on biodiversity and abundance: a meta-analysis. Journal of Applied Ecology 42:261–269.CrossRefGoogle Scholar
10Fuller, R.J., Norton, L.R., Feber, R.E., Johnson, P.J., Chamberlain, D.E., Joys, A.C., Matthews, F., Stuart, R.C., Townsend, M.C., Manley, W.J., Wolfe, M.S., Macdonald, D.W., and Firbank, L.G. 2005. Benefits of organic farming to biodiversity vary among taxa. Biology Letters 1:431–434.CrossRefGoogle ScholarPubMed
11Hole, D.G., Perkins, A.J., Wilson, J.D., Alexander, I.H., Grice, F., and Evans, A.D. 2005. Does organic farming benefit biodiversity? Biological Conservation 122:113–130.CrossRefGoogle Scholar
12Benton, T.G., Vickery, J.A., and Wilson, J.D. 2003. Farmland biodiversity. Trends in Ecology and Evolution 18:182–188.CrossRefGoogle Scholar
13Krebs, J.R., Wilson, J.D., Bradbury, R.B., and Siriwardena, G.M. 1999. The second silent spring? Nature 400:611–612.CrossRefGoogle Scholar
14Brussaard, L., Behan-Pelletier, V.M., Bignell, D.E., Brown, V.K., Didden, W.A.M., Folgarait, P.I., Fragoso, C., Freckman, D.W., Gupta, V.V.S.R., Hattori, T., Hawksworth, D., Klopatek, C., Lavelle, P., Malloch, D., Rusek, J., Söderström, B., Tiedje, J.M., and Virginia, R.A. 1997. Biodiversity and ecosystem functioning in soil. Ambio 26:563–570.Google Scholar
15Van der Putten, W.H., De Ruiter, P.C., Bezemer, T.M., Harvey, J.A., Wassen, M., and Wolters, V. 2004. Trophic interactions in a changing world. Basic and Applied Ecology 5:487–494.CrossRefGoogle Scholar
16Wardle, D.A., Nicholoson, K.S., Bonner, K.I., and Yeates, G.W. 1999. Effects of agricultural intensification on soil-associated arthropod population dynamics, community structure, diversity and temporal variability over a seven-year period. Soil Biology and Biochemistry 31:1691–1706.CrossRefGoogle Scholar
17Mulder, C., De Zwart, D., Van Wijnen, H.J., Schouten, A.J., and Breure, A.M. 2003. Observational and simulated evidence of ecological shifts within the soil nematode community of agroecosystems under conventional and organic farming. Functional Ecology 17:516–525.CrossRefGoogle Scholar
18Fitter, A.H., Gilligan, C.A., Hollingworth, K., Kleczkowski, A., Twyman, R.M., Pitchford, J.W., and the members of the NERC Soil Biodiversity Programme 2005. Biodiversity and ecosystem function in soil. Functional Ecology 19:369–377.CrossRefGoogle Scholar
19McCaig, A.E., Glover, L.A., and Prosser, J.I. 1999. Molecular analysis of bacterial community structure and diversity in unimproved and improved upland grass pastures. Applied and Environmental Microbiology 65:1721–1730.CrossRefGoogle ScholarPubMed
20Bardgett, R.D., Whittaker, J.B., and Frankland, J.C. 1993. The diet and food preferences of Onychiurus procampatus (collembola) from upland grassland soils. Biology and Fertility of Soils 16:296–298.CrossRefGoogle Scholar
21Bardgett, R.D., Leemans, D.K., Cook, R., and Hobb, P.J. 1997. Seasonality of the soil biota of grazed and ungrazed hill grasslands. Soil Biology and Biochemistry 29:1285–1294.CrossRefGoogle Scholar
22Parfitt, R.L., Yeates, G.W., Ross, D.J., Mackay, A.D., and Budding, P.J. 2005. Relationships between soil biota, nitrogen and phosphorus availability, and pasture growth under organic and conventional management. Applied Soil Ecology 28:1–13.CrossRefGoogle Scholar
23Hutton, S.A. and Giller, P.S. 2003. The effects of the intensification of agriculture on northern temperate dung beetle communities. Journal of Applied Ecology 40:994–1007.CrossRefGoogle Scholar
24Foissner, W. 1992. Comparative studies on the soil life in ecofarmed and conventionally farmed fields and grasslands of Austria. Agriculture Ecosystems and Environment 40:207–218.CrossRefGoogle Scholar
25Younie, D. and Armstrong, G. 1995. Botanical and invertebrate diversity in organic and intensively fertilised grassland. In Isart, J. and Llerena, J.J. (eds). Proceedings of the First ENOF Workshop—Biodiversity and Land Use. Multitext, Barcelona. p. 34–44.Google Scholar
26Yeates, G.W., Bardgett, R.D., Cook, R., Hobbs, P.J., Bowling, P.J., and Potter, J.F. 1997. Faunal and microbial diversity in three Welsh grassland soils under conventional and organic management regimes. Journal of Applied Ecology 34:453–470.CrossRefGoogle Scholar
27Oehl, F., Sieverding, E., Ineichen, K., Mäder, P., Boller, T., and Wiemken, A. 2003. Impact of land use intensity on the species diversity of arbuscular mycorrhizal fungi in agroecosystems of Central Europe. Applied and Environmental Microbiology 69:2816–2824.CrossRefGoogle ScholarPubMed
28Eason, W.R., Scullion, J., and Scott, E.P. 1999. Soil parameters and plant responses associated with arbuscular mycorrhizas from contrasting grassland management regimes. Agriculture Ecosystems and Environment 73:245–255.CrossRefGoogle Scholar
29Gosling, P., Hodge, A., Goodlass, G., and Bending, G.D. 2006. Arbuscular mycorrhizal fungi and organic farming. Agriculture, Ecosystems and Environment 113:17–35.CrossRefGoogle Scholar
30Haygarth, P.M., Chapman, P.J., Jarvis, S.C., and Smith, R.V. 1998. Phosphorus budgets for two contrasting grassland farming systems in the UK. Soil Use and Management 14:160–167.CrossRefGoogle Scholar
31Reganold, J.P., Palmer, A.S., Lockhart, J.C., and Macgregor, A.N. 1993. Soil quality and financial performance of biodynamic and conventional farms in New Zealand. Science 260:344–349.CrossRefGoogle ScholarPubMed
32Murata, T. and Goh, K.M. 1997. Effects of cropping systems on soil organic matter in a pair of conventional and biodynamic mixed cropping farms in Canterbury, New Zealand. Biology and Fertility of Soils 25:372–381.CrossRefGoogle Scholar
33Filser, J., Mebes, K.H., Winter, K., Lang, A., and Kampichler, C. 2002. Long-term dynamics and interrelationships of soil Collembola and microorganisms in an arable landscape following land use change. Geoderma 105:201–221.CrossRefGoogle Scholar
34Van Diepeningen, A.D., De Vos, O.J., Korthals, G.W., and Van Bruggen, A.H.C. 2006. Effects of organic versus conventional management on chemical and biological parameters in agricultural soils. Applied Soil Ecology 31:120–135.CrossRefGoogle Scholar
35Drinkwater, L.E., Waggoner, P., and Sarrantonio, M. 1998. Legume based cropping systems have reduced carbon and nitrogen losses. Nature 396:262–265.CrossRefGoogle Scholar
36Wander, M.M., Hedrick, D.S., Kaufman, D., Traina, S.J., Stinner, B.R., Kehrmeyer, S.R., and White, D.C. 1995. The functional-significance of the microbial biomass in organic and conventionally managed soils. Plant and Soil 170:87–97.CrossRefGoogle Scholar
37Watson, C.A., Ritz, K., Younie, D., and Franklin, M. 1996. Nitrogen and soil biomass dynamics in ley/arable crop rotations. Aspects of Applied Biology 47:43–50.Google Scholar
38Breland, T.A. and Eltun, R. 1999. Soil microbial biomass and mineralization of carbon and nitrogen in ecological, integrated and conventional forage and arable cropping systems. Biology and Fertility of Soils 30:193–201.CrossRefGoogle Scholar
39Flieβbach, A., Oberholzer, H.-R., Gunst, L., and Mäder, P. 2007. Soil organic matter and biological soil quality indicators after 21 years of organic and conventional farming. Agriculture, Ecosystems and Environment 118:273–284.CrossRefGoogle Scholar
40Bossio, D.A., Scow, K.M., Gunapala, N., and Graham, K.J. 1998. Determinants of soil microbial communities: effects of agricultural management, season, and soil type on phospholipid fatty acid profiles. Microbial Ecology 36:1–12.CrossRefGoogle ScholarPubMed
41Gunapala, N. and Scow, K.M. 1998. Dynamics of soil microbial biomass and activity in conventional and organic farming systems. Soil Biology and Biochemistry 30:805–816.CrossRefGoogle Scholar
42Berkelmans, R., Ferris, H., Tenuta, M., and Van Bruggen, A.H.C. 2003. Effects of long-term crop management on nematode trophic levels other than plant feeders disappear after 1 year of disruptive soil management. Applied Soil Ecology 23:223–235.CrossRefGoogle Scholar
43Shannon, D., Sen, A.M., and Johnson, D.B. 2002. A comparative study of the microbiology of soils managed under organic and conventional regimes. Soil Use and Management 18:274–283.CrossRefGoogle Scholar
44Girvan, M.S., Bullimore, J., Pretty, J.N., Osborn, A.M., and Ball, A.S. 2003. Soil type is the primary determinant of the composition of the total and active bacterial communities in arable soils. Applied and Environmental Microbiology 69:1800–1809.CrossRefGoogle ScholarPubMed
45Cookson, W.R., Osman, M., Marschner, P., Abaye, D.A., Clark, I., Murphy, D.V., Stockdale, E.A., and Watson, C.A. 2007. Controls on soil nitrogen cycling and microbial community composition across land use and incubation temperature. Soil Biology and Biochemistry 39:744–756.CrossRefGoogle Scholar
46Flieβbach, A. and Mäder, P. 1997. Carbon source utilization by microbial communities in soils under organic and conventional farming practice. In Insan, H. and Rangger, A. (eds). Microbial Communities. Functional versus Structural Approaches. Springer Verlag, Berlin. p. 109–120.CrossRefGoogle Scholar
47Hartmann, M., Flieβbach, A., Oberholzer, H.-R., and Widmer, W. 2006. Ranking the magnitude of crop and farming system effects on soil microbial biomass and genetic structure of bacterial communities. FEMS Microbiology Ecology 57:378–388.CrossRefGoogle ScholarPubMed
48Esperschütz, J., Gattinger, A., Mäder, P., Schloter, M., and Flieβbach, A. 2007. Response of soil microbial biomass and community structures to conventional and organic farming systems under identical crop rotations. FEMS Microbiology Ecology 61:26–37.CrossRefGoogle ScholarPubMed
49Jensen, U.B., Elmholt, S., and Labouriau, R. 2000. Distribution of ergosterol in organically and conventionally cultivated agricultural soils. Biological Agriculture and Horticulture 18:113–125.CrossRefGoogle Scholar
50Elmholt, S. and Labouriau, R. 2005. Fungi in Danish soils under organic and conventional farming. Agriculture Ecosystems and Environment 107:65–73.CrossRefGoogle Scholar
51Sattelmacher, B., Reinhard, S., and Pomikalko, A. 1991. Differences in mycorrhizal colonization of rye (Secale cereale L.) grown in conventional or organic (biological-dynamic) farming system. Journal of Agronomy and Crop Science-Zeitschrift fur Acker und Pflanzenbau 167:350–355.CrossRefGoogle Scholar
52Ryan, M.H., Chilvers, G.A., and Dumaresq, D.C. 1994. Colonization of wheat by VA-mycorrhizal fungi was found to be higher on a farm managed in an organic manner than on a conventional neighbor. Plant and Soil 160:33–40.CrossRefGoogle Scholar
53Bending, G.D., Turner, M.K., Rayns, F., Marx, M.C., and Wood, M. 2004. Microbial and biochemical soil quality indicators and their potential for differentiating areas under contrasting agricultural management regimes. Soil Biology and Biochemistry 36:1785–1792.CrossRefGoogle Scholar
54Scullion, J., Eason, W.R., and Scott, E.P. 1998. The effectivity of arbuscular mycorrhizal fungi from high input conventional and organic grassland and grass-arable rotations. Plant and Soil 204:243–254.CrossRefGoogle Scholar
55Franke-Snyder, M., Douds, D.D., Galvez, L., Phillips, J.G., Wagoner, P., Drinkwater, L., and Morton, J.B. 2001. Diversity of communities of arbuscular mycorrhizal (AM) fungi present in conventional versus low-input agricultural sites in eastern Pennsylvania, USA. Applied Soil Ecology 16:35–48.CrossRefGoogle Scholar
56Oehl, F., Sieverding, E., Mäder, P., Dubois, D., Ineichen, K., Boller, T., and Wiemkein, A. 2004. Impact of long-term conventional and organic farming on the diversity of arbuscular mycorrhizal fungi. Oecologia 138:574–583.CrossRefGoogle ScholarPubMed
57Foissner, W. 1997. Protozoa as bioindicators in agroecosystems, with emphasis on farming practices, biocides, and biodiversity. Agriculture Ecosystems and Environment 62:93–103.CrossRefGoogle Scholar
58Bongers, T. and Ferris, H. 1999. Nematode community structure as a bioindicator in environmental monitoring. Trends in Ecology and Evolution 14:224–228.CrossRefGoogle ScholarPubMed
59Neher, D.A. and Olson, R.K. 1999. Nematode communities in soils of four farm cropping management systems. Pedobiologia 43:430–438.CrossRefGoogle Scholar
60Neher, D.A. 1999. Nematode communities in organically and conventionally managed agricultural soils. Journal of Nematology 31:142–154.Google ScholarPubMed
61Brussaard, L. 1994. Soil ecology of conventional and integrated farming systems. Agricultural Ecosystems and Environment 51:ix.CrossRefGoogle Scholar
62Crossley, D.A. Jr, Coleman, D.C., and Hendrix, P.F. 1989. The importance of the fauna in agricultural soils: research approaches and perspectives. Agriculture Ecosystems and Environment 27:47–55.CrossRefGoogle Scholar
63Andren, O., Lindberg, T., Paustian, K., and Rosswall, T. 1990. Ecology of arable land—organism, carbon and nitrogen cycling. Ecological Bulletins 40:1–222.Google Scholar
64De Ruiter, P.C., Moore, J.C., Zwart, K.B., Bouwan, L.A., Hassink, J., Bloem, J., Devos, J.A., Marinissen, J.C.Y., Didden, W.A.M., Lebbink, G., and Brussaard, L. 1993. Simulation of nitrogen mineralization in the belowground food webs of 2 winter-wheat fields. Journal of Applied Ecology 30:95–106.CrossRefGoogle Scholar
65De Ruiter, P.C., Neutel, A.N., and Moore, J.C. 1994. Modelling food webs and nutrient cycling in agroecosystems. Trends in Ecology and Evolution 9:378–383.CrossRefGoogle ScholarPubMed
66Pankhurst, C.E., Doube, B.M., Gupta, V.V.S.R., and Grace, P.R. 1994. Soil Biota—Management in Sustainable Farming Systems. CSIRO, Melbourne.Google Scholar
67Alvarez, T., Frampton, G.K., and Goulson, D. 2001. Epigeic collembola in winter wheat under organic, integrated and conventional farm management regimes. Agriculture Ecosystems and Environment 83:95–110.CrossRefGoogle Scholar
68Mäder, P., Flieβbach, A., Dubois, D., Gunst, L., Fried, P., and Niggli, U. 2002. Soil fertility and biodiversity in organic farming. Science 296:1694–1697.CrossRefGoogle ScholarPubMed
69Doring, T.F. and Kromp, B. 2003. Which carabid species benefit from organic agriculture? A review of comparative studies in winter cereals from Germany and Switzerland. Agriculture Ecosystems and Environment 98:153–161.CrossRefGoogle Scholar
70Watson, C.A., Younie, D., and Armstrong, G. 1999. Designing crop rotations for organic farming: importance of the ley-arable balance. In Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S., and Kopke, U. (eds). Designing and Testing Crop Rotations for Organic Farming. DARCOF Report Number 1, Darcof; Foulum, p. 91–98.Google Scholar
71Higginbotham, S., Leake, A.R., Jordan, V.W., and Ogilvy, S.E. 2000. Environmental and ecological aspects of integrated, organic and conventional farming systems. Aspects of Applied Biology 62:15–20.Google Scholar
72Roschewitz, I., Gabriel, D., Tscharntke, T., and Carsten, T. 2005. The effects of landscape complexity on arable weed species diversity in organic and conventional farming. Journal of Applied Ecology 42:873–882.CrossRefGoogle Scholar
73Clough, Y., Holzschuh, A., Gabriel, D., Purtauf, T., Kleijn, D., Kruess, A., Steffan-Dewenter, I., and Tscharntke, T. 2007. Alpha and beta diversity of arthropods and plants in organically and conventionally managed wheat fields. Journal of Applied Ecology 44:804–812.CrossRefGoogle Scholar
74Kabir, Z. and Koide, R.T. 2000. The effect of dandelion or a cover crop on mycorrhiza inoculum potential, soil aggregation and yield of maize. Agriculture Ecosystems and Environment 78:167–174.CrossRefGoogle Scholar
75Kremer, R.J. and Li, J.M. 2003. Developing weed-suppressive soils through improved soil quality management. Soil and Tillage Research 72:193–202.CrossRefGoogle Scholar
76Hidaka, K. 1997. Community structure and regulatory mechanism of pest populations in rice paddies cultivated under intensive, traditionally organic and lower input farming in Japan. Biological Agriculture and Horticulture 15:35–49.CrossRefGoogle Scholar
77Hossain, M.Z., Choudhury, M.H.K., Hossain, M.F., and Alam, Q.K. 2002. Effects of ecological agriculture on soil properties and arthropod diversity in rice-based cropping systems in floodplain areas in Bangladesh. Biological Agriculture and Horticulture 20:215–227.CrossRefGoogle Scholar
78Mendoza, T.C. 2004. Evaluating the benefits of organic farming in rice agroecosystems in the Philippines. Journal of Sustainable Agriculture 24:93–115.CrossRefGoogle Scholar
79Idowu, O.J., Van Es, H.M., Abawi, G.S., Wolfe, D.W., Ball, J.I., Gugino, B.K., Moebius, B.N., Schindelbeck, R.R., and Bilgili, A.V. 2008. Farmer-oriented assessment of soil quality using field, laboratory and VNIR spectroscopy methods. Plant and Soil 307:243–253.CrossRefGoogle Scholar
80Winding, A., Hund-Rinke, K., and Rutgers, M. 2005. The use of microorganisms in ecological soil classification and assessment concepts. Ecotoxicology and Environmental Safety 62:230–248.CrossRefGoogle ScholarPubMed
81Stockdale, E.A. and Brookes, P.C. 2006. Detection and quantification of the soil microbial biomass—impacts on the management of agricultural soils. Journal of Agricultural Science 144:285–302.CrossRefGoogle Scholar
82Alabouvette, C., Backhouse, D., Steinberg, C., Donovan, N.J., Edel-hermann, V., and Burgess, L.W. 2004. Microbial diversity in soil—effects on crop health. In Schjønning, P., Elmholt, S., and Christensen, B.T. (eds). Managing Soil Quality: Challenges in Modern Agriculture. CABI Publishing, Wallingford. p. 121–138.CrossRefGoogle Scholar
83Brussaard, L., Kuyper, T.W., Didden, W.A.M., de Goede, R.G.M., and Bloem, J. 2004. Biological soil quality from biomass to biodiversity—importance and resilience to management stress and disturbance. In Schjønning, P., Elmholt, S., and Christensen, B.T. (eds). Managing Soil Quality: Challenges in Modern Agriculture. CABI Publishing, Wallingford. p. 139–161.CrossRefGoogle Scholar
84Johnson, M.J., Lee, K.Y., and Scow, K.M. 2003. DNA fingerprinting reveals links among agricultural crops, soil properties, and the composition of soil microbial communities. Geoderma 114:279–303.CrossRefGoogle Scholar
85Srivastava, R., Roseti, D., and Sharma, A.K. 2007. The evaluation of microbial diversity in a vegetable based cropping system under organic farming practice. Applied Soil Ecology 36:116–123.CrossRefGoogle Scholar
86Slattery, J.F., Coventry, D.R., and Slattery, W.J. 2001. Rhizobial ecology as affected by the soil environment. Australian Journal of Experimental Agriculture 41:289–298.CrossRefGoogle Scholar
87Evans, J. 2005. An evaluation of potential Rhizobium inoculant strains used for pulse production in acidic soils of south-east Australia. Australian Journal of Experimental Agriculture 45:257–268.CrossRefGoogle Scholar
88Elliott, E.T. 1997. Rationale for developing bioindicators of soil health. In Schjønning, P., Elmholt, S., and Christensen, B.T. (eds). Managing Soil Quality: Challenges in Modern Agriculture. CABI Publishing, Wallingford. p. 49–78.Google Scholar
89Karlen, D.L., Andrews, S.S., and Doran, J.W. 2001. Soil quality: current concepts and applications. Advances in Agronomy 74:1–40.CrossRefGoogle Scholar
90Xua, M.X., Zhao, Y.G., Liu, G.B., and Argent, R.M. 2006. Soil quality indices and their application in the hilly loess plateau region of China. Australian Journal of Soil Research 44:245–254.CrossRefGoogle Scholar
91Rezaei, S.A., Gilkes, R.J., and Andrews, S.S. 2006. A minimum data set for assessing soil quality in rangelands. Geoderma 136:229–234.CrossRefGoogle Scholar
92Andrews, S.S., Karlen, D.L., and Cambardella, C.A. 2004. The soil management assessment framework: a quantitative soil quality evaluation method. Soil Science Society of America Journal 68:1945–1962.CrossRefGoogle Scholar
93Lal, R. 2001. Managing world soils for food security and environmental quality. Advances in Agronomy 74:155–192.CrossRefGoogle Scholar
94Wallenhamar, A.-C. and Arvidsson, O. 2001. Detection of Plasmodiophora brassicae by PCR in naturally infested soils. European Journal of Plant Pathology 107:313–321.CrossRefGoogle Scholar
95Doran, J.W. and Smith, M.S. 1987. Organic matter management and utilization of soil and fertilizer nutrients. In Soil Science Society of America Special Publication 19. Soil Fertility and Organic Matter as Critical Components of Production Systems. Soil Science Society of America and American Society of Agronomy, Madison, Wisconsin. p. 53–72.Google Scholar
96Beauchamp, E.G. and Hume, D.J. 1997. Agricultural soil manipulation: the use of bacteria, manuring and plowing. In Van Elsas, J.D., Trevors, J.T., and Wellington, E.M.H. (eds). Modern Soil Microbiology. Marcel Dekker, New York. p. 643–664.Google Scholar
97Clapperton, M.J., Chan, K.Y., and Larney, F.J. 2003. Managing the soil habitat for enhanced biological fertility. In Abbott, L.K. and Murphy, D.V. (eds). Soil Biological Fertility—A Key to Sustainable Land Use in Agriculture. Kluwer Academic, Dordrecht, The Netherlands. p. 203–224.Google Scholar