Human Dimensions That Drive Soil Degradation - Principles of Sustainable Soil Management in Agroecosystems - page 181

current theories of decision making might also explain farmer behavior. Early studies
of human decision making emphasized that normative models that assumed rational
decisions about a risk were devoid of emotion and entirely based on maximizing util-
ity. This perspective of decision making calculates risk with economic utility func-
tions that identify all possible options and their probable consequences (Plous 1993).
Normative models are based on the idea that humans are capable of using decision
rules to make consistent, rational choices. Risk, in this sense, is a simple calculation
of the probability of an outcome multiplied by the consequence.
Modern, chemical, and capital intensive agriculture is an excellent example of the
normative model of decision making within an agricultural setting. The production
function, used by the USDA and other private agribusinesses, measures the risks
and benefits of agriculture according to efficiency, replicability, and standardization
(Lyson and Welsh 1995) in order to increase crop yield and maximize profit. Soil
health is not included in this equation. Weeds, in this domain, are a threat to yield
and therefore high risk (Wilson et al. 2008). Management decisions that follow this
normative line of reasoning will be based on the most cost efficient way to control
weeds and improve yields through technology, chemical applications, and mechani-
cal tillage that may damage soil structure.
There are two drawbacks to understanding farmer management decisions using
normative models. Research on organic weed management has shown that ecologi-
cal complexity blurs causation between management choices and weed populations
(Zwickle et al. 2011). A farmer cannot know all the possible outcomes and conse-
quences of weeds and weed management choices for the health of the soil or any
aspect of the agroecosystem. Rational calculations of maximum utility are impos-
sible in this case. Physical attributes of the farm, the farm operation itself, and the
farmer all introduce further limitations to maximizing utility. The farm's limits are
resource based (e.g., available equipment, time, labor, and money) and physical (e.g.,
soil type, geography, and perhaps the most limiting of all: climate and weather pat-
terns), while farmer limitations are cognitively based (e.g., memory, cognitive abil-
ity, and attention span).
The second reason to abandon a normative model for farmer decision making is
that even normative models of risk cannot be free from the influence of value judg-
ments (Slovic 1987). Judging the consequences of a risk, no matter how scientific
or analytically based the assessment may be, involves value-laden judgment (Slovic
1999). In contrast to farms that follow industrial methods and scale up production to
meet market demand in spite of environmental costs, some organic farmers may view
the risks of managing weeds to extend beyond economic values to include the health
of soil, people, animals, and other components of the agroecosystem (Berry 1977;
Lyson 2004). Previous mental model studies found that farmers do indeed combine
financial and lifestyle domains when making decisions (Eckert 2006). Other, noneco-
nomic sources of information in the decision making process are often considered to
be as important as the economic viability of the farm (Eckert and Bell 2005).
7.4.7.4 Heuristics in Decision Making
The theory of bounded rationality explains that humans may intend to be rational
and consistent, but their judgments and decisions are bound by time, resources, and