Applied Soil Ecology 15 2000 61–73
Fostering soil stewardship through soil quality assessment
Michelle M. Wander
a ,∗
, Laurie E. Drinkwater
b ,
1
a
Department of Natural Resources Environmental Sciences, University of Illinois at Urbana-Champaign,
1102 S. Goodwin Ave., Urbana, IL 61801, USA
b
Rodale Institute, 611 Siegfriedale Rd., Kutztown, PA 19530, USA
Abstract
Soil quality is not a purchased technology; instead, it is a concept that can be used in making land management decisions. Researchers have generally agreed upon the soil properties that determine soils’ capacity to function and have emphasized that
soil quality must be understood in context. Soil quality research has included the following: 1 soil management research, where the effects of management on soil properties and dependent processes are assessed; 2 measurement development for
soil quality assessment to be carried out by the farmers themselves, by advisors, or consultants and 3 systems assessments, that consider the physical and cultural contexts that impact soil quality decision-making. Because stewards of the land ultimately
determine whether soil quality is improved, maintained, or diminished, many research projects in the US have included the active participation of farmers in efforts to develop the soil quality concept. More effort has been spent on soil management and
on the development and testing of farmer oriented measurements than on system assessments. There is growing consensus that the development of soil quality assessments to be used by farmers to solve problems within individual fields will be
challenging. Organic matter and organic matter-dependent properties are the most promising indicators for use in a soil quality assessment where the information will be used in management decisions. Unfortunately, the successful development
of on-farm measures may not be sufficient to guarantee that soil quality is maintained because there is a mismatch in the temporal and physical scales over which soil quality and farm security are achieved. Educational materials that highlight
soil contributions to farm, landscape and global functioning coupled with dialoguing between practitioners, scientists, and policy-makers can communicate the importance of soil quality to sustainability. Successful soil quality efforts will relate
soil properties to soil function in a way that fosters stewardship among individuals and builds public support for polices that promote soil management to ensure agriculture, industry, and the natural environment are sustained. Strategies and priorities
are expected to vary according to audience, land-use constraints and the intended scale of application. © 2000 Elsevier Science B.V. All rights reserved.
Keywords: Soil quality; Minimum data set; On-farm research; Participatory; Indicators; Sustainability; Systems research
1. Introduction
The concept of soil quality has grown out of con- cern about the sustainability of agriculture Parr et al.,
∗
Corresponding author. Tel.: +1-217-333-9471; fax: +1-217-0244-3219.
E-mail addresses: mwanderuiuc.edu M.M. Wander,
ldrinkrodaleinst.org L.E. Drinkwater
1
Tel.: +1-610-683-1437; fax: +1-610-683-8548.
1992; Warkentin, 1995; Doran and Zeiss, this issue. A distinguishing characteristic of soil quality research
is the use of multidisciplinary approaches to assess- ment. This reflects a major paradigm shift in the field
of soil science. Soil quality research has been fueled by the National Research Council’s NRC Board on
Agriculture recommendation that we ‘conserve and enhance soil quality as a fundamental first step toward
environmental improvement’ NRC, 1993. The NRC further advised that the concept of soil quality be the
0929-139300 – see front matter © 2000 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 9 - 1 3 9 3 0 0 0 0 0 7 2 - X
62 M.M. Wander, L.E. Drinkwater Applied Soil Ecology 15 2000 61–73
principle that guides agricultural policies and prac- tices. Scientists, who find the black and white terms of
laws and regulations incompatible with nature’s com- plexity Moran, 1994, have responded to the NRC
call by directing research toward farmer-friendly soil quality assessment strategies.
Soil degradation is a widespread problem having negative consequences on both agricultural productiv-
ity and natural ecosystems. The vast majority of agri- cultural lands in the US already have depleted levels
of soil organic matter SOM McGill et al., 1981; Campbell and Zentner, 1993; Lee and Phillips, 1993.
Furthermore, nutrient losses through leaching and soil erosion are substantial Carpenter et al., 1998 and soil
loss through erosion often exceeds sustainable rates Pimentel et al., 1995. Soil degradation in intensive
cropping systems may result from 1 carbon additions that are insufficient to maintain SOM; 2 the return
of only high carbon, senescent organic residues to the soil; 3 nutrient inputs that exceed harvested exports
Carpenter et al., 1998; 4 excessive tillage or tillage at times that exposes soil to wind and water erosion
and 5 rotations that include long fallow periods and temporal monocultures.
In the US, soil quality research was initially dom- inated by efforts to define terms and develop assess-
ment strategies e.g. Larson and Pierce, 1991; Doran and Parkin, 1994; Seybold et al., 1997. Many defini-
tions of soil quality or health emphasized the concept of soil fitness to perform functions Larson and Pierce,
1991; Warkentin, 1995; Karlen et al., 1997. A widely accepted definition of soil quality is “the ability of
soil to function within ecosystem boundaries to sup- port healthy plants and animals, maintain or enhance
air and water quality, and support human health and habitation” Karlen et al., 1997. These functions are
impacted by multiple soil attributes. Accordingly, soil scientists also identified a generally agreed upon min-
imum data set MDS; Table 1 of soil parameters that could be used to quantify soil quality Bouma, 1989;
Larson and Pierce, 1991; Arshad and Coen, 1992; Do- ran and Parkin, 1994. The selection of MDS parame-
ters has been based upon a wealth of soil management research that relates soil attributes to soil function and
ideally relates management practices to soil attributes. Soil quality functions proposed by Larson and Pierce
1991, 1994 and Karlen and Stott 1994 are exam- ples of theoretical frameworks that combine physical,
Table 1 Soil quality minimum data set
a
Biological Chemical
Physical Microbial biomass
pH Texture
Potentially mineralizable N
EC Bulk density
Soil respiration N, P, K
Depth of rooting Organic matter
Infiltration Water holding capacity
a
Doran and Parkin 1994; Larson and Pierce 1994.
chemical and biological measures to assess soil condi- tion. Even though the soil quality concept is relatively
well established and increasingly accepted, it remains difficult to see how the complex and site-specific na-
ture of soils will be translated into measurable param- eters that might reflect the state of a soil. Furthermore,
it has been unclear exactly how the concept of soil quality will be translated into practices, agricultural
policy or regulatory statutes. In this paper we review soil quality research conducted on-farm. Our conclu-
sions were based upon our review of the literature and phone interviews with investigators participating in
ongoing projects. Our objective is to trace the chrono- logical evolution of soil quality research. We divide
soil quality efforts into three categories: 1 soil man- agement research, where the effects of management on
soil properties and dependent processes are assessed; 2 measurement development, where soil quality as-
sessment would be carried out by farmers, advisors, or consultants and 3 systems assessments, where the
effects of different physical and organizational scales on soil quality and soil dependent phenomena are con-
sidered. The assumptions, objectives and accomplish- ments associated with various phases of soil quality
research are discussed. Finally, we highlight continu- ing needs of, and promising strategies for, soil quality
research. Soil organic matter management is used as an example to demonstrate how research efforts might
overcome barriers of scale and sector to serve the in- terests of a society dependent upon the soil resource.
2. Chronology of soil quality
