Why is this Important?
Agricultural land is a vital resource for the provision of sustenance to humans and habitat for wildlife. Sustainable management practices are essential for the effective use of working lands, which support ecosystems on a local and global level.
On a global level, agriculture is a large contributor to greenhouse gas emissions. Methane and other gases are released by soil during the crop production process and energy is expended to deliver water. Cattle are a significant source of greenhouse gas emissions through the digestion process and the decomposition of manure.
Agricultural practices effect the environment, and changes in climate and water supply significantly effect farming. Increases in temperature extend growing seasons for crops and breeding season for pests and pollinators, and increase evaporation, contributing to drought conditions.
As one of the nation’s largest agricultural producers, California is in position to be a pioneer of sustainable agriculture practices. Local research on crop rotation, holistic management of pastures, water-efficient farming, and carbon storage in soil help to establish best practices that go beyond greenhouse gas emission reduction.
What is a Sustainable State?
Farmers and ranchers are dedicated to practices that conserve natural resources and reduce greenhouse gas emissions. Government policies reward sustainable agricultural production and discourage other activities that lead to climate change. Agricultural land is protected and supports production of edible crops and healthy soil. Local water sources are efficiently managed and benefit from the reduced use of chemical pesticides, fungicides, and fertilizers. Conservation practices monitor and support habitat for native species.
- For the past three years, the average annual temperature in the central coast region, which includes San Mateo County, has steadily increased.
- Rising temperatures shift snow and rain patterns, causing precipitation to fall as rain. In California, this means less snow in the Sierra snow pack. This snow is the state’s largest water storage system, as snow slowly melts it provides water through the summer months.
- Higher temperatures extend growing seasons, which increases the demand for water to maintain crops.
- In 2016, the USDA allocated $72.3 million in funding, nationwide, to support soil health, nitrogen stewardship, sustainable grazing practices, forest retention, and renewable energy generation on agricultural land.
- In spite of conservation efforts, SPUR reports that 7% of San Mateo County’s farmland and 1% of its pasture is at risk of conversion to other uses.
- Peninsula Open Space Trust (POST) seeks to triple the number of protected farms and farm acreage in the County within 10 years.
- There are at least 206 native species present in the coast habitat. 107 of these species breed in the habitat. The California red-legged frog is classified as a threatened species by the federal government, and the San Francisco Garter Snake is classified as endangered.
- Globally, 16% of vertebrate (birds and bats) and 9% of bee and butterfly species are at risk of extinction.
- California’s current drought began in 2012 and continues through present day in spite of a wet winter.
- Most of the freshwater withdrawals in the state were used for irrigation, approximately 23 billion gallons of water per day.
Indicators and Trends
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Farmland Conservation No clear trend
Climate and Agriculture
Global weather measurements indicate that 2015 was the hottest year on record. As shown in the chart below, the warming trend was present in the Central Coast region (which includes San Mateo County).
Climate is a major factor in agricultural crop production. Plant growth is determined by atmospheric temperature, humidity, moisture, and nutrients (carbon, nitrogen, etc.). Crops are selected for compatibility with the local climate and fluctuations may require a shift in production. Shown below are examples of how climate affects agriculture, drought, and other resources.
- Though a slight temperature increase will result in higher crop output, a change beyond 3 degrees Celsius will decrease production (TIMM, 2015).
- Rising temperatures shift snow and rain patterns, causing precipitation to fall as rain. In California, this means less snow in the Sierra snow pack, the state’s largest water storage system.
- Higher temperatures extend growing seasons, which increases the demand for water to maintain crops. Competition for water resources will heighten demand for energy, while hydropower generation will become less reliable (CalCAN, 2015).
- Heat may damage crops, but its greatest threat is to the well-being of farmworkers.
- Chill time is another climate factor affected by temperature. Minimum hours of chill are needed for apples, cherries, grapes, pears, nuts, avocados, stone fruit, tomatoes, rice, corn, sunflower, and wheat.
- Higher concentrations of atmospheric carbon dioxide stimulate crop growth, as well as weeds, and pests. Warmer weather may cause weeds and pest to migrate north. To combat these threats, growers may increase their use of herbicides and pesticides resulting in air and water pollution.
- Heavy rainfall is another potential side effect of climate change that may damage crops and cause soil erosion.
- Climate change poses threats to pollinators as flowers may bloom at different times of the season out of sync with pollinator’s migration patterns.
8% of California’s greenhouse gas emissions come from agriculture.
Many of the state’s farmers and the organizations that support them are developing techniques to reduce the carbon footprint of farming and enhance resilience to climate change. The California Climate and Agriculture Network and the Natural Resource Conservation Service circulate information about best practices in farming, from water efficiency to soil integrity.
- Irrigation water management plans that improve water efficiency also reduce the amount of energy needed to supply that water, which leads to a reduction in greenhouse gas emissions.
- Healthy soil has an abundance and diversity of microbial life, which not only emits less greenhouse gases, but also stores carbon, preventing absorption into the atmosphere.
- Academic institutions and conservation organizations conduct regional research on soil and guidance for farmers to know exactly which cover crops and nutrients are most beneficial for their soil and climate.
- Crop rotation and diversification, composting, and covers crops are healthy alternatives to excessive tilling and synthetic chemical inputs such as fertilizers, pesticides, and fungicides (Kane, 2015).
- Biochar is an example of transforming excess organic matter to soil amendment with potential benefits for carbon sequestration.
In 2016, the USDA allocated $72.3 million in funding, nationwide, for its new climate smart agriculture strategy. The program will support soil health, nitrogen stewardship, sustainable grazing practices, forest retention, and renewable energy generation on agricultural land.
Cattle and Methane
Over half of California’s methane emissions are from cattle and dairy farms (CalCAN, 2015). To decrease the carbon footprint of cattle products, ranchers and dairy producers are developing a suite of best practices.
Co-digestion of manure and other waste streams is a method to reduce methane emissions, extract reusable water, and create fertilizer. This method is practiced at Straus Family Creamery in Petaluma, CA. Research has shown that dry manure management has the potential to reduce methane emissions and reduce contamination of food and soil compared to wet management practices; however, dry manure management requires more labor.
Local ranches, such as LeftCoast Grass-fed at TomKat Ranch and Markegard Family Grass-fed, implement Holistic Management systems that preserve grassland and contribute to carbon storage. In this system, cattle eat grass and trim the top to stimulate new growth, while fertilizing the land with manure. The cows are then moved to a new swath of grass or pasture to begin the process again. This practice is also beneficial for habitat conservation where riparian areas are maintained; and carbon sequestration is enhanced where perennial grasses exist.
San Mateo County’s agricultural conservation practices are stringent and effective. In October 2007, the county passed the Agricultural Awareness Ordinance, a policy directive to “conserve, protect, and encourage agricultural operations on agricultural land within the county.” In pursuit of this goal, the ordinance established a grievances process to address public concerns regarding agricultural practices.
The County’s General Plan in combination with the Local Coastal Program (LCP) restrict development in rural, coastal areas and on land suitable for agriculture. The Planned Agricultural District (PAD) safeguards against the subdivision of agricultural land and restricts use to farming.
In spite of conservation efforts, SPUR reports that 7% of farmland and 1% of San Mateo County’s pasture is at risk of conversion. The California Department of Land Conservation monitors the conversion of various types of land use. 304 acres of prime, unique, and historic farmland were converted between 2012 and 2014 with the majority transformed to pasture.
The Peninsula Open Space Trust (POST) supports farmland conservation through the purchase of agricultural land and the establishment of conservation easements, which legally restrict the use of land. Farmland may also be protected by an affirmative easement, set by a landowner, prescribing a set of activities allowed on the land. The Williamson Act is an agricultural land conservation tool that offers owners a reduced tax rate for restricting use of their land for a minimum of 10 years. Options to purchase agricultural value (OPVA) is a mechanism that calculates a lower value for agricultural land compared to a market rate inflated by potential commercial development. POST seeks to triple the number of protected farms and farm acreage along the peninsula within 10 years.
Soil received an international spotlight when the Food and Agriculture Organization of the United Nations named 2015 the Year of Soil. Healthy soil is characterized by high levels of soil organic matter (SOM), microorganisms, insects, and other forms of life, which make soil the source of a quarter of the earth’s biodiversity.
SOM is protected by soil structure that is not compromised by over tilling. Cover crops are used to prevent soil erosion in fields between plantings of cash crops. The roots of some cover crops and perennial gases are effective tools for carbon storage.
According to the American Farmland Trust, half of the world’s topsoil has been lost to development and poor soil management over the past 150 years; 1.7 billion tons of topsoil a year in the US alone. Industrial agriculture practices that involve excessive plowing and monoculture farming cause soil erosion, and chemical fertilizers and pesticides pollute soil and reduce the amount of SOM.
Synthetic fertilizers are harmful to watersheds. Farm run-off containing excess nitrogen and phosphorous promotes the growth of algae in waterways and water outlets such as the coast. The algae can become a source of toxic food for fish or its decomposition may deplete oxygen levels in water, effectively suffocating fish and aquatic life.
California’s state government is on the verge of implementing a new Healthy Soils Initiative intended to fund projects that:
- Increase natural soil nutrients (nitrogen and sulfur) for plants and reduce reliance on chemical fertilizers
- Enhance carbon storage in soil and plant roots to reduce the amount of greenhouse gases in the atmosphere
- Absorb water to decease flooding and filter pollutants
- Reduce soil erosion by improving soil structure and SOM
Point Blue Conservation Science in collaboration with TomKat Ranch produced an evaluation of the coastal habitat surrounding Pescadero, CA. The study revealed that there are 206 native species present in the area. 107 of these species breed in the habitat. The California red-legged frog is identified as threatened by the federal government while the San Francisco Garter Snake is classified as endangered.
Nine of these native creatures are on the California Department of Fish and Wildlife Species of Special Concern list.
- Western pond turtle
- Coast horned lizard
- California legless lizard
- Northern harrier
- Olive-sided flycatcher
- Common yellowthroat
- Grasshopper sparrow
- San Francisco dusky-footed woodrat
- American Badger
Three local breeds of bird are on the California Department of Fish and Wildlife Species of Special Concern as well as the US Fish and Wildlife Service Bird of Conservation Concern list.
- Burrowing Owl
- Loggerhead Shrike
- Yellow Warbler
The following species were introduced into the area:
- American Bullfrog*
- Wild Turkey
- Eurasian Collared-Dove
- European Starling
- House Sparrow
- Black Rat
- Wild Pig
*The American Bullfrog is a predator for the California red-legged frog.
The San Mateo County Resource Conservation District implements various projects that support watersheds and the endangered species that inhabit them. Recent projects include the Alpine Creek Fish Passage, a remediation project that will enable Coho salmon and Steelhead trout to access 3 miles of habitat, and the San Gregorio Creek Habitat Enhancement Project, which will provide breeding grounds for these fish.
Pollinators play a vital role in seed and fruit production, as well as biodiversity maintenance and ecosystem health. Though pollination may be performed by the wind and by humans, many plants rely on birds, bees, bats, butterflies, moths, beetles, or other animals to facilitate reproduction. These creatures also play a role in pest management. On a global scale, the ecosystem services provided by pollinators are valued in billions of dollars.
According to the Pollinator Partnership, local almonds, blackberries, cucumbers, and artichokes, among other crops, depend on honeybees and native bees for pollination services. In return, pollinators require wholesome habitats, free of invasive plant and animal species, harmful chemical pesticides and fertilizers, and parasites. View the guidelines on Selecting Plants for Pollinators in the California Coastal Chaparral Forest and Shrub Province to learn how to create a healthy habitat in your environment.
In a recent study, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), found that globally 16% of vertebrate (birds and bats) and 9% of bee and butterfly species are at risk of extinction. Land use practices employed in large-scale agriculture are cited as contributing factors in habitat loss and lifestyle interruption of these creatures, as cover crops and wildflowers are eliminated and pesticides introduce toxins into the pollinator food stream.
In recent years, beekeepers have raised awareness about Colony Collapse Disorder and the resulting 10% decrease in the bee population. The Xerces Society for Invertebrate Conservation reviewed a wealth of research on the effect of neonicotinoids (a specific classification of pesticide) on various types of bees. The findings confirm that these pesticide change behavior in bees as well as “make honey bees more susceptible to parasites and pathogens, including the intestinal parasite Nosema, which has been implicated as one causative factor in Colony Collapse Disorder (CCD)”(Xerces 2012).
- California’s current drought began in 2012 and continues through present day in spite of a wet winter.
- 2013 was the driest year on record.
- In 2010, California pulled $38 billion gallons per day, the highest rate in the nation, accounting for 10% of all freshwater withdrawal.
- Most of the California’s freshwater withdrawals were used for irrigation, approximately 23 billions gallons of water per day.
- The drought has decreased production of crops and grass for livestock.
The Institute for Water Education released calculations for the global water footprint of various crops in 2010. In these calculations, a water footprint is the number of gallons of water used to produce a ton of crops. A portion of the water footprint is present in the crop itself, but much of the water evaporates during the production process. Brussels sprouts, San Mateo County’s biggest food crop, have a water footprint of 285 gallons per ton. 7,485 tons of Brussels sprouts were produced in the county in 2014, an annual water footprint of 2,133,225 gallons.
A water footprint can also be calculated at a regional level. In California, 47% of the state’s cumulative water footprint is consumed by the production of meat and dairy products, while 46% is attributed to other agricultural products (Pacific Institute, 2015).
100 Ponds Project
With funding from the Coastal Conservancy, the San Mateo County Resource Conservation District has initiated an ambitious project to create 100 ponds on agricultural land on the county’s coast side. Farm ponds are used to capture rainwater, irrigation water (run-off), and storm water diverted from streams during wet seasons. The benefits of farm ponds are numerous:
- Freshwater conservation
- Preservation of wetlands and wildlife habitat
- Drought and climate resilience
- Groundwater recharge
- Flood reduction from peak flow capture
- Energy conservation through reduced pumping