You keep a few chickens, a beehive and a vegetable patch, and a neighbor mentions you could "get your land classified as agricultural." Or you're looking at rural land and the listing says it's "in an ag preserve." Either way, you want to know: what actually counts as agricultural use in California?
Short answer: it depends on which law is asking. Under the state's agricultural preserve law, agricultural use means using land "for the purpose of producing an agricultural commodity for commercial purposes" (Gov. Code § 51201). Under the urban agriculture law, it is broader — growing crops, raising livestock, bees and poultry, farm stands and agricultural education all count, but timber production does not (Gov. Code § 51040.3). Your city's zoning code may use yet another definition.
Key numbers
| Test | Threshold | Source |
|---|---|---|
| Prime farmland by soil class | Class I or class II | § 51201 |
| Prime farmland by Storie Index | Rating 80 through 100 | § 51201 |
| Prime grazing land | At least one animal unit per acre per year | § 51201 |
| Prime land by crop income | At least $200 per acre per year, in 3 of the previous 5 years | § 51201 |
| "Urban" for the urban agriculture law | Urbanized area of at least 250,000 people | § 51040.3 |
Definition 1: the agricultural preserve law (commercial farming)
California lets counties and cities set up agricultural preserves — areas where landowners can sign contracts that restrict their land to farming, recreation or open space (§ 51201). This is the program most people mean when they say land is "in the Williamson Act" or "under contract."
For this law, the test is commercial:
"'Agricultural use' means use of land, including but not limited to greenhouses, for the purpose of producing an agricultural commodity for commercial purposes." — § 51201
An agricultural commodity means plant and animal products produced in California for commercial purposes, including plants grown for biofuels and industrial hemp grown under state rules (§ 51201). So the backyard chickens that feed your family probably don't make your lot "agricultural" under this law — the word that does the work is commercial.
The same section defines prime agricultural land with the tests in the table above: high-quality soil classes, a high Storie Index (a soil productivity score), enough forage to carry one animal unit per acre, or crops that bring in at least $200 per acre a year (§ 51201).
The Legislature explains why it bothers: keeping farmland in production protects the state's food supply and economy, and discourages "premature and unnecessary conversion of agricultural land to urban uses" (§ 51220). The same findings say housing farmworkers counts among agricultural uses (§ 51220).
One twist: inside a preserve, the law treats recreational and open-space use as if they were agricultural use too. Land in a scenic highway corridor, a wildlife habitat area, a managed wetland or a saltpond can be put in a preserve and restricted the same way (§ 51205).
Definition 2: the urban agriculture law (farming in cities)
A separate law lets counties (and a city and county) create Urban Agriculture Incentive Zones — groups of individual properties designated as urban agriculture preserves for farming (§ 51040.3). It applies in "urban" areas, defined as an urbanized area of at least 250,000 people (§ 51040.3).
Its definition of agricultural use is much wider. It includes:
- cultivating and tilling soil, and growing and harvesting crops or horticultural products;
- raising livestock, bees, fur-bearing animals, dairy animals and poultry;
- agricultural education;
- selling produce at field retail stands or farm stands;
- other practices a farmer performs as part of farming.
It specifically excludes timber production (§ 51040.3). This definition applies only within that urban agriculture chapter — it doesn't change how your zoning code classifies your yard.
What can happen on agricultural land besides farming?
On land under an agricultural preserve contract, other uses must pass three compatibility tests. A use must not (§ 51238.1):
- significantly compromise the land's long-term ability to produce crops;
- significantly displace or impair current or reasonably foreseeable farming — though uses tied directly to the farm, like harvesting, processing or shipping, can still qualify;
- result in significant removal of adjacent contracted land from farming or open space.
On land that isn't prime farmland, a county or city can approve a use that fails the first two tests through a conditional use permit — a discretionary permit with conditions — if it makes findings backed by evidence. Those findings include that the use does not include a residential subdivision (§ 51238.1).
Farmland protected by a state-funded agricultural conservation easement has its own list of uses that are allowed. It includes producing and selling crops and livestock, and building a secondary dwelling unit or farmworker housing within reasonable size and location limits, as long as long-term farming isn't significantly impaired (Pub. Res. Code § 10238).
What about your zoning?
None of these state definitions tells you what your zoning allows. Whether you can keep chickens, run a farm stand or put up a greenhouse on your lot is set by your city or county zoning code, and it varies by city — check your local code. The state laws above matter mainly when land is under a preserve contract, a conservation easement, or in an urban agriculture incentive zone.
Sources
- California Government Code § 51201 — Definitions (agricultural preserves)
- California Government Code § 51040.3 — Definitions (urban agriculture incentive zones)
- California Government Code § 51238.1 — Principles of compatibility
- California Government Code § 51205 — Recreational and open-space land in preserves
- California Government Code § 51220 — Legislative findings
- California Public Resources Code § 10238 — Uses compatible with agricultural conservation easements
