Marginality Principle - Principles of Sustainable Soil Management in Agroecosystems - page 38

offer the potential for mitigation through management of plant and soil systems. The
dynamics of these processes and the linkage to soil management practices have been
recently reviewed by Hatfield et al. (2012).
2.7 SOCIAL VALUES OF SOIL FUNCTIONS: DEFINITIONS
AND MEANINGS OF MARGINALITY
We began this chapter asking how social values and functions of soil influenced
the meanings of marginality and society's willingness and capacities to protect soil
quality. The processes of soil degradation from natural and anthropological sources
have been well documented. Sustainable resource management is one of society's
most complex concerns (Popp et al. 2002). Agriculture is the largest human use of
land on the planet, with almost 38% of productive soils in climates well suited to
farming (Foley 2011). The remainder, deserts, mountains, ice, tundra, cities and sub-
urban places, parks, and other areas, are unsuitable for growing crops, leaving tropi-
cal forests and savannas as primary stores of C and biodiversity (Foley 2011). Forest
clearing, farming of lands with soils and slopes not well suited to cultivation, and
intensified farming of soils in sensitive landscapes present significant threats to long-
term soil productivity and sustainability of ecosystem services. Social pressures to
feed 7 billion people (projected to be 9 billion by 2050) and reduce food insecurity,
predictions of changing and uncertain climate conditions and their impacts on agri-
cultural production, and documented hypoxia zones in gulf and bay waters as the
result of nutrient- and sediment-filled rivers are reminders that soil quality and its
management underlie much of the human-social-biophysical value chain of sys-
tems. To meet world food demand, protecting and enhancing agricultural soils and
their functional capacities is a clear priority. However, society is also increasingly
realizing that there is a difficult and delicate balance among human uses of land for
agriculture and ecosystem regulating functions that are necessary for human and
biophysical wellbeing.
If agricultural landscapes are to be sustained into the future, purposeful land
management decisions and policies are needed to assure that the multifunctional
services of soil are available to meet agricultural productivity and valuable eco-
system services. Public policies and farmer decisions frequently give agricultural
land productivity goals the highest social value, with protection of soil and ecosys-
tem concerns ranking considerably lower. “While productivity-enhancement goals
have largely been met over the last decades, lack of progress on the environmen-
tal side of the agricultural sustainability equation has created increasing levels of
conflict over natural resource degradation” (Morton et al. 2013). In some regions, a
growing number of farmers are uncertain about the connection between their farm
management practices and sustainability of agriculture (Morton et al. 2013). A lon-
gitudinal random-sample panel survey of Iowa farmers revealed in 2002 that almost
29% of farmers were uncertain about whether sustainable farming practices helped
to maintain their natural resource base, compared to 18.8% in 1989 (Morton et al.
2013). This suggests that there is an increasing disconnect between farmer percep-
tions of their current farming practices and how they affect long-term sustainability
of their natural resource base, of which soil is primary.