CUESA's Sustainable A to Z
From 2004 to 2018, CUESA’s “Sustainable A to Z” exhibit of vibrant eight-by-eight foot photomurals occupied the arcades under the arches in front of the San Francisco Ferry Building. Each letter introduces a concept in sustainable agriculture.
In 2019, the “Sustainable A to Z” exhibit was replaced with a new series, called The Food Change, at the Ferry Building, but the original series is preserved here for posterity.
Animals that graze on pastureland eat a diverse and natural diet. They grow healthier and stronger than animals raised in conventional feedlots. Meat and dairy products from these pasture-fed animals are more nutritious than factory-farmed foods. On small farms, animals such as goats, sheep and cows eat weeds and supply a natural fertilizer. Huge livestock feedlots put out large emissions of methane gas, but grazing animals on rangeland reduces that substantially.
Beneficial bugs such as spiders and ladybugs eat unwanted pests and reduce the need for toxic pesticides. Sustainable farmers encourage beneficial insects on their farms by creating habitats for them. They also release beneficial insects to combat specific pests. Spiders, ladybugs, wasps, lacewings, beetles and dragonflies are some of the hardworking and beautiful bugs that help create a healthy ecosystem on the farm.
Farmers plant cover crops to protect and improve the soil. They plant them between rows of crops or trees and in fields that are not in production. Cover crops control weeds and erosion, keep nutrients in the soil, and provide habitat and food for beneficial insects and microorganisms. Cover crops also absorb standing water, break-up compacted earth, and add nutrients to the soil.
Direct marketing such as farmers markets, community supported agriculture plans (where consumers pre-buy 'shares' in a farm and get a weekly box of produce), and farm stands help smaller farms achieve financial sustainability. Selling directly to consumers allows farmers to get a fair return for their produce. And direct marketing gives consumers access to fresher, healthier, more delicious food straight from the farm.
Mariculture is the farming of fish and shellfish in seawater. Most farmed fish are detrimental to the environment and to wild fish stocks. But shellfish such as oysters, clams and mussels are often farmed ecologically and have few impacts on habitat and do little damage to other sea creatures. In fact, farmed shellfish may even improve water quality by acting as natural filters.
Old-fashioned animal husbandry was "free-range" - animals roamed in outside areas and were provided with appropriate shelter, bedding and food. On today's large-scale agribusiness farms, indoor confinement results in poor physical development, high disease and mortality rates, overuse of antibiotics and inhumane practices. Free-range animals produce eggs, meat and milk that are high-quality, healthy and delicious.
Heirlooms varieties are passed down through generations of gardeners and farmers who harvest and save seeds. Their colors, flavors, shapes and sizes reflect a spectrum of biodiversity that has been threatened by industrial agriculture (today hybrids are bred to be consistent in appearance and easy to ship). Only a fraction of the food plants that were grown commercially a hundred years ago are still around. The genetic richness of heirlooms developed over thousands of years is both a protection against blight and disease and a natural legacy for future generations.
Natural predators including owls, hawks, bats and snakes help control farm pests such as gophers, squirrels, rabbits, and rodents. Sustainable farmers provide habitat for predators by hanging special boxes or perches or by leaving undisturbed wild areas for predators to live in. While protecting their crops with predators, farmers also help support species that have limited access to their natural wild habitat.
Insects such as moths can have devastating effects on crops and many farms use pesticides to control them. Sustainable farmers employ an ingenious alternative called insect pheromone disruption. Insects release sex hormones called pheromones during their mating cycle as location signals. Farmers confuse the insects by hanging pheromone-scented baits in their orchards or fields. When they are unable to find the opposite sex, the insects cannot reproduce. This is just another way ecological farmers avoid using toxins on their fields.
Water is necessary for all plants and animals to grow. But industrial agriculture often makes inefficient use of water resources, including planting crops that need a lot of water in arid regions. Heavy irrigation leads to loss of natural river flows. Pesticide use on many farms leads to toxic pollution in our watershed. These practices destroy wetlands and devastate fish and wildlife populations. Sustainable farmers use water judiciously and prevent toxic run-off.
Small farms and non-toxic farming create wonderful environments for children to live in or visit. Kids growing up in urban environments are often isolated from the earth and its natural cycles. Field trips to farms and school gardens help them reconnect with their food system, and teach them to value agriculture and ecology. On family farms, kids participating in the day-to-day work of the farm may then carry on the family tradition and become the next generation of farmers.
Farm workers are often paid very low wages for long hours spent working in difficult conditions. They may live in sub-standard and unsafe housing. Many farm laborers are Spanish-speaking undocumented workers, and so may have limited opportunities to ensure fair treatment. For our food system to be truly sustainable, all farm workers must earn a living wage, secure decent housing, and ensure safe working conditions.
Mulch is straw, tree bark, old hay, yard trimmings or any other organic matter that farmers spread around plants to prevent weeds from growing and to keep vital nutrients in the soil. Mulch creates a wonderful environment for earthworms, which help create healthy soil. It also protects crops from pests and regulates soil moisture and temperature. In many cases, the mulch itself decomposes into rich soil and becomes a long-term fertilizer.
Crops need soil that is rich in many nutrients, especially nitrogen. Plants such as vetch, bell bean, alfalfa, and clover take nitrogen out of the atmosphere and convert it into a form that plants can use. This is called "nitrogen fixing." The little bumps on the root in this photo are "nitrogen nodules" that are formed with the help of beneficial bacteria. Nitrogen-fixing plants are plowed back into the soil before they use up the nitrogen. The nodules break off, leaving the soil rich in nitrogen for other crops.
Open space is increasingly threatened by urban sprawl. Parks, wilderness areas, ranches and farms all help to create greenbelt around metropolitan areas. Open spaces provide watershed protection and habitat for birds, plants, and wildlife. Farms, ranches, and wild areas are a beautiful and valuable part of our regional landscape.
Pollinators carry pollen from flower to flower, and fertilize trees and plants. Many pollinators such as bees, butterflies, hummingbirds, and bats are threatened by the widespread use of pesticides on conventional farms and the spread of urban development. Non-toxic farming provides habitat for pollinators, ensuring full harvests. And in the case of honeybees, pollinators generate their own sweet harvest: honey!
We all want to eat well and live healthily. We want to breathe clean air, drink clean water, and live in a world that supports life in its many varied and beautiful forms. The farmers market contributes immensely to this quality of life. It provides us with fresh wholesome food, rich in vital nutrients. It also offers a gathering place where people from all walks of life, both urban and rural, come together to form a community. At the same time, sustainable agriculture protects our natural resources for many generations to come.
A watershed is all of the land and water areas that drain toward a particular river, lake, estuary or bay. Drainage systems and underground seepage carry pesticides and agricultural run-off from farms and ranches into our waters, polluting them, changing their chemistry, and ruining habitat for animals and plants. Sustainable farmers and ranchers protect watersheds by limiting or eliminating the use of toxics on their fields, recycling animal waste to keep it out of waterways, and reducing the need for irrigation on their farms.
Healthy soil is the basis for all sustainable agriculture. Soil that has been farmed intensively loses its nutrients and lacks vital beneficial microorganisms. Sustainable farming rebuilds depleted soil and keeps it healthy. There are many ways that farmers build their soil including compost, cover crops, mulch, manure, and the addition of organic nutrients. Soil fertility is the key to growing plants that are productive, resistant to disease, and nutritious to eat.
Sustainable fishing targets specific species while leaving others undisturbed. Harvesting seafood and fish with traps or pots does very little damage to other sea creatures. Other sustainable techniques include hook-and-line fishing, trolling, diving, and using nets that are designed to target specific schools of fish. By contrast, bottom trawling -- also called dragging-- with long nets damages seafloor habitat and kills many sea creatures. Targeted fishing helps preserve our oceans' fish and seafood for generations to come, and helps protect animals such as sea turtles and dolphins.
Sustainable farming strengthens healthy ecosystems. Sustainable farmers understand that everything they do has an impact on the larger environment and the creatures that live in it. They avoid practices that disrupt natural systems and have unforeseen, often disastrous, consequences for life on earth. Sustainable farming, ranching, and fishing protect water, earth, and air, as well as the plants, animals, people, insects, and microorganisms that depend on healthy ecosystems for survival.
In large-scale conventional agriculture, many fruits and vegetables are shipped long distances. They are often picked while still unripe and firm, and then treated with gas to 'ripen' or soften them during transport or distribution. Local small-scale sustainable farmers sell directly to consumers at the farmers market so they can allow fruits and vegetables to ripen on the vine or tree. This means the produce comes to you fresh and delicious, with its nutrients intact, and the best flavor and texture possible.
Farm workers on conventional farms are among those most affected by the use of pesticides, herbicides, and other toxins. Ailments ranging from asthma, to cancer, to birth defects are related to heavy exposure to toxic sprays. Sustainable farming means workers experience a healthy working environment, with the direct benefits of cleaner air, water, and earth.
Sustainable farming requires extra care on the part of the farmer. Sustainable techniques such as hand-weeding and hand-harvesting are often more labor intensive than conventional approaches. All farming is hard work, but sustainable agriculture requires farmers to take the long view, and to take extra care in each decision they make.
All farmers want to produce an abundance of high-quality produce on their land. Despite the prevailing belief that sustainable agriculture cannot produce enough food to feed the world, many studies show that small-scale, diversified, sustainable farms are often more productive per unit of land than large-scale, mono-cropped, conventional farms. Abundant yields are often achieved by inter-planting diverse crops together. This practice helps control pests and weeds, feeds the soil, and uses water efficiently.
Buffer zones protect ecologically sustainable farms from toxic chemicals in neighboring fields. Pesticides, herbicides, and pollen from genetically modified plants can be carried onto fields by the wind. Trees and other foliage planted in buffer zones minimize the risk of contamination and cross-pollination. Perhaps one day these zones will no longer be necessary, when sustainable agriculture is practiced by all farmers on all fields.
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About CUESA
CUESA (Center for Urban Education about Sustainable Agriculture) is dedicated to cultivating a sustainable food system through the operation of farmers markets and educational programs. Learn More »