Soil Stresses, Quality and Care Proceedings from NJF Seminar 310 Ås, April 10-12 2000
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Soil Stresses, Quality and Care Proceedings from NJF seminar 310 Ås, April 10-12 2000 Susanne Elmholt, Bo Stenberg, Arne Grønlund & Visa Nuutinen Department of Crop Physiology and Soil Science P. O. Box 50 DK-8830 Tjele DIAS report Plant Production no. 38 • December 2000 Publisher: Danish Institute of Agricultural Sciences Tel. +45 89 99 19 00 Research Centre Foulum Fax +45 89 99 19 19 P.O. Box 50 DK-8830 Tjele Sale by copies: up to 50 pages 50,- DKK (incl. VAT) up to 100 pages 75,- DKK more than100 pages 100,- DKK Subscription: Depending on the number of reports sent but equivalent to 75% of the price of sale by copies. Photos: Reidun Aspmo & Per Schjønning NJF-seminar Soil Stresses, Quality and Care Different people understand differently the word soil. The soil can be looked upon as a body of nature and a part of the landscape. To many people soil is the substrate for plant growth and a prerequisite for food production and wealth. A third and perhaps growingly important view is soil as the physical ground for housings, roads and industry. Soil is important to the whole society, not only for the agricultural sector. Soil has important ecological functions as it interacts with the dead bedrock, the atmosphere, the water, and the living organisms. Important functions are: Biomass producer and transformer Geomembrane, filter and buffer Habitat for living organisms Raw material and building ground Cultural heritage Even if these important roles of soil are probably widely known, the world's soil resources are degraded at an alarming rate. This is well documented by for instance the World Resources Institute (http://www.nhq.nrcs.usda.gov/WSR/). We need to care for our prime agricultural soils, soils which provide the green in urban areas, as well as soil resources in natural landscapes. Soil and agricultural scientists have detailed knowledge of specific functions and processes in soil. Seminar topics in NJF’s Section 1 (Soils and fertilisers) in the recent years show that soil biology and ecology have been added to the previous production-related research such as tillage and fertilisation. We are now prepared to study the whole soil and we have to show that our knowledge concerns the society and not only the farmers and gardeners. We believe that the concept of soil quality will help us to improve our communication about soils and soil use. Politicians, authorities, and farmers need a soil quality classification that makes the choices between different soil uses and managements based on soil science. Such classifications have been used in agriculture for many years. However, it is necessary to develop them and relate the classification systems and parameters used to present-day problems and technology. It is also important to use in communication modern language, as less and less people have hands-on experience with soils in an agricultural context. This seminar intended to elucidate and discuss the present knowledge and research that can help us assess the quality of soils and to identify key properties which may be used as indicators of soil health. The seminar showed that we possess the knowledge, and that we have a good base for the further work with the soil quality concept and its practical use. On behalf of the Nordic Association of Agricultural Scientists I will thank the organising committee for a well planned and conducted seminar. Svein Skøien, Chairman, NJF Section Soil and Fertilisers Contents The land quality concept as a means to improve communications about soils. .........................1 J. Bouma The soil quality concept: A tool for evaluating sustainability..................................................15 Douglas L. Karlen and Susan S. Andrews Factors influencing resilience and resistance in Norwegian silt loam soils .............................27 Tore E. Sveistrup and Trond K. Haraldsen Soil quality with chromatography ............................................................................................35 Solveig Buvarp Nyborg Multi-level assessment of soil quality – linking redutionist and holistic methodologies........43 Per Schjønning, Lars J. Munkholm, Kasia Debosz and Susanne Elmholt Biotic and abiotic binding and bonding mechanisms in soils with long-term differences in management..............................................................................................................................53 Susanne Elmholt, Kasia Debosz, Lars J. Munkholm and Per Schjønning Multivariate techniques for presentation, interpretation and evaluation of soil quality data ...63 Mats Johansson and Bo Stenberg Denitrification, a soil quality indicator.....................................................................................73 Mikael Pell, Kalle Svensson and Ewa Bringmark Changes in redox potential and Fe mobilization due to waterlogging in cultivated and non- cultivated soils at Alta, Northern Norway................................................................................81 Christian Uhlig, Gunter Wriedt, Thomas Baumgartl and Rainer Horn Effects of crop rotation with perennial crops on macroporosity of a clay soil.........................89 Laura Alakukku Indication of soil degradation in strawberry fields: disappearance of earthworms..................99 Sanna Kukkonen and Susanna Vesalo Soil biological, chemical and physical properties in fields under different management systems....................................................................................................................................109 Ansa Palojärvi, Laura Alakukku, Esko Martikainen, Marina Niemi, Pekka Vanhala, Kirsten Jörgensen and Martti Esala Effects of management practice on soil organic matter content.............................................115 Tor-Gunnar Vågen Organic wastes and soil quality..............................................................................................123 Søren O. Petersen, Kasia Debosz and Frank Laturnus Levels of structural and functional complexity in soil OM turnover as revealed by physical fractionations ..........................................................................................................................133 Bent T. Christensen Management of biodiversity in arable soil by field inoculation - an example using deep burrowing earthworms............................................................................................................151 Visa Nuutinen and Jyrki Pitkänen Land use changes and degradation of forest and soil in watersheds of Nepal – A review.....159 B.K. Sitaula, K.D. Awasthi, N.R. Chapagain, G. S. Paudel, R.P. Neupane, P.L. Sankhayan, B.R.Singh and O. Hofstad Soil Stresses, Quality and Care: Concluding remarks from discussions in working groups and plenary sessions of NJF-Seminar no. 310 ..............................................................................171 Susanne Elmholt, Bo Stenberg, Arne Grønlund and Visa Nuutinen The land quality concept as a means to improve communications about soils J. Bouma Member Scientific Council for Government Policy, the Hague and Professor of Soils, Lab. Soil Science and Geology, Wageningen University, the NETHERLANDS E-mail: [email protected] Summary Soil expertise is not communicated effectively enough to the public at large, nor to planners and politicians. Use of the land quality (LQ) concept and emphasis on soil behavior as a function of management are expected to be helpful in improving communications. Existing definitions of “soil quality” and “sustainable land management” are analyzed to derive a procedure for defining LQ indicators of sustainable land management. Land- rather than soil qualities are considered to reflect the impact of the climate and the landscape on soil behavior. Land quality is different for different types of land use and attention is arbitrarily confined here to agriculture. Simulation modeling of crop growth and solute fluxes is used to define land quality (LQ) as the ratio between yield and potential (or water-limited) yield (x 100), which defines a “yield gap LQ”. For soils with nutrient mining, a nutrient-depletion LQ is defined. The actual agro-ecological condition and its potential, both expressed by LQ ‘s for a given piece of land, is considered here as independent input into broader land-use discussions which tend to be dominated by socio-economic and political considerations. Agro-ecological considerations should not be held hostage to actual socio-economic and political considerations, which may change in the near future while LQ’s have a much more permanent character. The proposed yield-gap LQ reflects yields and risks of production as simulations are made for many years, and soil and water quality associated with the production process is taken into account. Yields and pollution risks are expressed for Dutch conditions in terms of the probability that groundwater is polluted with nitrates. The proposed procedure requires the selection of acceptable production and pollution risks, before a LQ value can be obtained. Existing definitions implicitly emphasize the field and farm level. However, LQ is also important at the regional and higher level, which, so far, has received little attention. Then, again, an agro-ecological approach is suggested when defining LQ’s as input into the planning process, emphasizing not only an independent assessment of the potential for agricultural production, but of nature conservation as well. Keywords: agro-ecosystems, nitrate pollution, risk assessment, potential crop yields Introduction