agriculture integrates three main goals--environmental
health, economic profitability, and social and economic
equity. Sustainability rests on the principle that we
must meet the needs of the present without compromising
the ability of future generations to meet their own
needs. Therefore, stewardship of both natural and human
resources is of prime importance. Stewardship of human
resources includes consideration of social responsibilities
such as working and living conditions of laborers, the
needs of rural communities, and consumer health and
safety both in the present and the future. Stewardship
of land and natural resources involves maintaining or
enhancing this vital resource base for the long term.
sustainability needs a systems perspective. The system is envisioned
in its broadest sense, from the individual farm, to the local ecosystem,
and to communities affected by this farming system both locally
and globally. An emphasis on the system allows a larger and more
thorough view of the consequences of farming practices on both human
communities and the environment. A systems approach gives us the
tools to explore the interconnections between farming and other
aspects of our environment.
Making the transition to sustainable agriculture is
a process. For farmers, the transition to sustainable
agriculture normally requires a series of small, realistic
steps in family economics, personal goals etc. Each
small decision to contribute in advancing the entire
system further on the "sustainable agriculture
production practices involve a variety of approaches.
Specific strategies must take into account topography,
soil characteristics, climate, pests, local availability
of inputs and the individual grower's goals. Despite
the site-specific and individual nature of sustainable
agriculture, several general principles can be applied
to help growers select appropriate management practices:
of species and varieties that are well suited to the site and to
conditions on the farm;
of crops (including livestock) and cultural practices to enhance
the biological and economic stability of the farm;
of the soil to enhance and protect soil quality;
and humane use of inputs; and
of farmers' goals and lifestyle choices.
of site, species and variety. Preventive strategies,
adopted early, can reduce inputs and help establish
a sustainable production system. When possible, pest-resistant
crops should be selected which are tolerant of existing
soil or site conditions. When site selection is an option,
factors such as soil type and depth, previous crop history,
and location (e.g. climate, topography) should be taken
into account before planting.
Diversified farms are usually more economically and
ecologically resilient. While monoculture farming has
advantages in terms of efficiency and ease of management,
the loss of the crop in any one year could put a farm
out of business and/or seriously disrupt the stability
of a community dependent on that crop. By growing a
variety of crops, farmers spread economic risk and are
less susceptible to the radical price fluctuations associated
with changes in supply and demand.
managed, diversity can also buffer a farm in a biological
sense. For example, in annual cropping systems, crop
rotation can be used to suppress weeds, pathogens and
insect pests. Also, cover crops can have stabilizing
effects on the agro ecosystem by holding soil and nutrients
in place, conserving soil moisture with mowed or standing
dead mulches, and by increasing the water infiltration
rate and soil water holding capacity. Cover crops in
orchards and vineyards can buffer the system against
pest infestations by increasing beneficial arthropod
populations and can therefore reduce the need for chemical
inputs. Using a variety of cover crops is also important
in order to protect against the failure of a particular
species to grow and to attract and sustain a wide range
of beneficial arthropods.
diversity may be obtained by integrating both crops
and livestock in the same farming operation. This was
the common practice for centuries until the mid-1900s
when technology, government policy and economics compelled
farms to become more specialized. Mixed crop and livestock
operations have several advantages. First, growing row
crops only on more level land and pasture or forages
on steeper slopes will reduce soil erosion. Second,
pasture and forage crops in rotation enhance soil quality
and reduce erosion; livestock manure, in turn, contributes
to soil fertility. Third, livestock can buffer the negative
impacts of low rainfall periods by consuming crop residue
that in "plant only" systems would have been
considered crop failures. Finally, feeding and marketing
are flexible in animal production systems. This can
help cushion farmers against trade and price fluctuations
and, in conjunction with cropping operations, make more
efficient use of farm labor.
management. A common philosophy among sustainable
agriculture practitioners is that a "healthy"
soil is a key component of sustainability; that is,
a healthy soil will produce healthy crop plants that
have optimum vigor and are less susceptible to pests.
While many crops have key pests that attack even the
healthiest of plants, proper soil, water and nutrient
management can help prevent some pest problems brought
on by crop stress or nutrient imbalance. Furthermore,
crop management systems that impair soil quality often
result in greater inputs of water, nutrients, pesticides,
and/or energy for tillage to maintain yields.
sustainable systems, the soil is viewed as a fragile
and living medium that must be protected and nurtured
to ensure its long-term productivity and stability.
Methods to protect and enhance the productivity of the
soil include using cover crops, compost and/or manures,
reducing tillage, avoiding traffic on wet soils, and
maintaining soil cover with plants and/or mulches. Conditions
in most California soils (warm, irrigated, and tilled)
do not favor the buildup of organic matter. Regular
additions of organic matter or the use of cover crops
can increase soil aggregate stability, soil tilth, and
diversity of soil microbial life.
use of inputs. Many inputs and practices used by
conventional farmers are also used in sustainable agriculture.
Sustainable farmers, however, maximize reliance on natural,
renewable, and on-farm inputs. Equally important are
the environmental, social, and economic impacts of a
particular strategy. Converting to sustainable practices
does not mean simple input substitution. Frequently,
it substitutes enhanced management and scientific knowledge
for conventional inputs, especially chemical inputs
that harm the environment on farms and in rural communities.
The goal is to develop efficient, biological systems,
which do not need high levels of material inputs.
frequently ask if synthetic chemicals are appropriate
in a sustainable farming system. Sustainable approaches
are those that are the least toxic and least energy
intensive, and yet maintain productivity and profitability.
Preventive strategies and other alternatives should
be employed before using chemical inputs from any source.
However, there may be situations where the use of synthetic
chemicals would be more "sustainable" than
a strictly nonchemical approach or an approach using
toxic "organic" chemicals. For example, one
grape grower switched from tillage to a few applications
of a broad spectrum contact herbicide in the vine row.
This approach may use less energy and may compact the
soil less than numerous passes with a cultivator or
of farmer goals and lifestyle choices. Management
decisions should reflect not only environmental and
broad social considerations, but also individual goals
and lifestyle choices. For example, adoption of some
technologies or practices that promise profitability
may also require such intensive management that one's
lifestyle actually deteriorates. Management decisions
that promote sustainability, nourish the environment,
the community and the individual.