The Proposed Elimination of Prime Farmland at Cal Poly, San Luis Obispo

The US loses nearly a square mile of farmland every day (Conservation Fund 2025). Sometimes these losses occur when farming families have little to no choice. But in the case of Cal Poly, the proposal to eliminate productive agricultural land and lease it to a developer for a hotel and retail space is a choice that has left me dumbfounded, yet again. This is the second time the administration has made such a proposal. The first time in 2015 was supposed to be the last.

Family Farms

Drive up Hwy 101 towards the Bay Area and you’ll pass through some of the most fertile and productive agricultural lands in the world. Yes, the world. The agricultural output of this stretch of land dwarfs the entire output of most US states and of entire nations. It should be a treasured resource. But it is under threat. Along that 101 drive you can see massive structures being built on prime agricultural land. In the Salinas Valley, there’s an Amazon distribution warehouse, and another proposed for Gilroy. Giving up farmland must be difficult for families and businesses. I can only speculate that some reduction is necessary, oftentimes there’s no one else in the family to farm the land, kids move away, retirements, deaths; sometimes it’s a business decision. Land that has been in families for generations, now being paved over is a painful sight for all involved in agriculture, big and small. Once you build on it, you never get it back.

The Proposal

The loss of agricultural land could be happening here right on my home campus of Cal Poly, San Luis Obispo, but for very different reasons. The university’s administration is proposing to build on what is designated as Prime or Class 1 farmland; thereby, eliminating a rare resource used to teach students how to become responsible and innovative leaders in all aspects of agriculture in California and beyond. The heart of our learn-by-doing approach…gone.

Cal Poly’s Master Plan 2035 is intended to guide land development on campus through 2035. By the time it and the environmental impact report were finalized in 2020, new builds on campus were to be concentrated in the campus core and avoid negatively impacting other natural resources. Specifically, 250 acres of Prime farmland that were explicitly excluded from further development.

Apricot trees on at the campus farm at Cal Poly, San Luis Obispo. — Apricot trees planted by students, staff and faculty in 2022.

Cal Poly President Jeff Armstrong’s current vision does not honor the Master Plan 2035. Instead, he wants to lease this land to an off-campus developer to build a hotel, restaurants, senior living space, mixed use residential areas, a theater, etc. Basically, this is a way to create more revenue for the university. A direct quote from the proposal states “The site’s current role as a living classroom - home to lemon groves and active fields - is not just history, but an opportunity to create a bustling neighborhood, interwoven with industry partnerships and activation.” They literally are saying our living classrooms are history. They want to replace student learn-by-doing spaces with a “bustling neighborhood”. They want to pave over the fields Cal Poly’s reputation was founded on.

Cal Poly Agricultural Lands

Cal Poly, San Luis Obispo, has 280 acres of Prime farmland. About 200 of which is rangeland for grazing livestock. There are approximately 83 acres of agricultural and horticultural fields and over an acre of greenhouse spaces. These lands are right on campus and easily accessible for students and staff from the campus core and classrooms.

Modified map from Cal Poly Working Lands Mapping Project Documentation showing Cal Poly’s 280 acres of prime agricultural lands, with key crops and activities adjacent to the campus core and easy access for students.

What is so special about this land? The map below shows the Highland Avenue entrance to the west side of campus off of Hwy 1/Santa Rosa St. Entering campus, you pass by 54 acres of Prime farmland that includes a 10-acre lemon orchard, row crop fields, and a new deciduous orchard that has fruit and nut varieties suitable for coastal climates. The administration’s proposal puts buildings and parking lots on these lands.

Building on Prime Farmland

The area (outlined with a white dotted line above and in red below) is designated as Prime farmland. The map below is from Cal Poly’s Master Plan 2035. The legend is clear, P stands for Prime or Class 1 farmland. Other nearby fields are designated as Farmland of Statewide Importance, or Unique Farmland, or Farmland of Local Potential. Armstrong and the Cal Poly administration are well aware of these designations, but do not appreciate how critical a resource these lands are locally and statewide.

A map from Cal Poly’s Master Plan 2035. The added red dotted line outlines the Prime farmland that the Cal Poly administration is proposing to lease for urban development.

When I heard about this proposal, I had to speak up. I have a vested interest in the success of the Plant Sciences department and not just because I worked there for nearly 30 years. I’ve participated in and observed the learning that happens in our fields and orchards. Companies hire Cal Poly graduates because of the experiences they gain working in these living laboratories. And as a human who likes to eat, I have a personal interest in keeping all Prime farmland in production and not paved over with asphalt.

Soil Designations

Note: If you want to skip the details (not recommended), scroll down to the What Can You Do section below.

The terms soil, topsoil, arable land, and prime agricultural land are not just nouns. Prime or Class 1 farmland are not just a catchy descriptions. They are actual classifications of a non-renewable resource. They are specific definitions used to categorize land that in turn helps us determine how best to care for it.

I use the deductive method - moving from general to specific - as an organizing framework in my teaching. So here we go...

Earth

We’re on Earth. Its outer shell is the crust made up of rock ranging from 3 to 44 miles in thickness. The crust is thin. It represents less than one percent of the planet's radius.

Soil

The outermost layer of the crust is mostly covered with soil - the superficial unconsolidated and usually weathered outermost part of the crust or lithosphere of a planet.

On Earth specifically, soil is the surface layer where plants can grow. Soil averages 5 to 10 inches deep; in some places it can be 20 to 40 inches deep. This means soil is 0.0004% to 0.0001% of the crust’s overall thickness. All terrestrial life on this planet depends on a whisper thin skin of soil 10 inches thick.

Topsoil

Topsoil is a term that puts an anthropocentric spin on soil beyond simply just being. Topsoil is the surface soil including the organic layer in which plants have most of their roots and which is turned over in plowing.

As a term, topsoil changes the focus. Soil goes from a benign end product of planetary weathering that provides a resource in which plants grow on their own to a resource where we conduct food growing activities for our benefit.

Arable Land, a Non-Renewable Resource

Not all soil is suitable for growing plants, and not all topsoil is suitable for growing food, hence the next term: arable. Arable land is fit for and used for growing crops.

Needless to say, there’s not a lot of soil available for growing food and we often hear about the constant loss of arable land. The US loses nearly a square mile of farmland every day (Conservation Fund 2025). Another source puts it this way: Since the 1996 Farm Bill changed what growers decide to grow (seminal change in US farm policy), land in US farms has declined by 74.7 million acres or -8%. By far, pastureland declined the most, accounting for 88% of the total decline. The other two major farmland categories have also declined: woodlands by -6% and cropland by -2%. (Farm Doc Daily 2024). Another perspective: in the 5 year period between 2017 and 2022, the US lost, or farming ceased, on 20.1 million acres, an area equal to the size of Maine (American Farm Bureau Federation 2024). This isn’t just a US problem. Globally, the world has lost one-third (33%) of farmable (=arable) land since 1975 (Science Alert 2015).

It takes 1,000 years of natural processes to make 1 inch of topsoil (Scientific American 2014). So yes, arable land qualifies as a non-renewable resource.

Prime, Class 1 Farmland

The lemon orchard, Cal Poly, San Luis Obispo. — The lemon orchard has taught thousands of students about citrus production and pest management methods. Cal Poly, San Luis Obispo, 2026.

Not all arable lands are equal. Some are better than others.

In the U.S., agricultural lands are classified based on their use such as farming or ranching or even timber production. Specific regulations vary by state. In California, agricultural lands are classified based on a grading system of 1, 2, 3a, 3b, 4 and 5. Grades 1 and 2 receive the most planning protections and 3a land is considered as “best and most versatile” (BMV) land and also has planning protections.

The best of the best is Class 1 or Prime farmland and has the strongest state and local agency planning protections. Meaning, building on such soil – a rare, non-renewable and widely beneficial resource – is guarded against and in some cases prohibited. There are restrictions in place to protect these resources, such as:

Under CEQA, converting Prime farmland to non-agricultural uses triggers rigorous environmental review, and local agencies are intensely discouraged or legally challenged if they approve projects that destroy Prime farmland without major overriding public benefits and mandatory mitigation.

At Cal Poly, the Prime farmland designation is amplified by the fact that these fields are our laboratories for hands-on, learn-by-doing teaching, just as a chemistry lab, engineering lab, design studio, or theater are. All are cornerstones of a polytechnic university and Cal Poly’s learn-by-doing motto.

Would Cal Poly’s administration walk into a chemistry lab and say, hey, let’s turn this into a Starbuck’s for the town folk? No, that would be ridiculous and obviously antithetical to Cal Poly’s mission.

Also, teaching labs at California State Universities are officially categorized and designated by the state and the California State University system as “formal instructional and capacity space”. The state tracks physical facilities using formal space standards originally tied to the Coordinating Council for Higher Education, separating academic space into specific designations like lecture rooms, faculty offices, and teaching laboratories. Further, teaching laboratories are bound by specific state-level utilization formulas (measuring weekly student contact hours and station occupancy) to justify capital outlay and state funding.

Let’s Measure Some Student Contact Hours, Shall We?

Students, staff and faculty walk from the campus core and within 10 minutes they are working and learning and experimenting in the fields that grow many of California’s most important crops. I walked my students out there nearly every week for every class I taught for 29 years. Four different courses, some multiple times per year, averaging 40 to 50 students per course. That’s 6,670 students and ~70,000 weekly student contact hours of instruction in our agricultural fields over the course of my career. That’s just one professor providing learning experiences not available at any other four-year university campus in California. The diversity of crops and breadth of learning is unmatched across the US. And There are more than a dozen faculty that constantly use those fields for teaching. This equates to hundreds of thousands of accumulated student hours of unique learning and honing valuable skills.

Those skills are crucial to student success. They research, and experiment and make mistakes during the process, which is where the most important learning takes place. They gain experience that puts them head and shoulders above graduates from other campuses. That is a defensible definition of student success.

Round 2

This is not the first time we've had to protect our farmland. President Armstrong made a similar proposal in 2015, and the response was swift. Students mobilized, fought back and won. The university administration agreed not to build on the agricultural lands and to find other ways to satisfy the university’s need for buildings in the future. There is an existing signed document - the Master Plan 2035, but Armstrong is ignoring that agreement.

Cal Poly’s mission is to teach, not to make money off of leases and eliminate one of our most precious resources, a resource that is under duress all over California. We should be the example of how to conserve such a resource, not the example of how to forsake it.

What can you do? ‍ ‍

It’s time to organize and put a stop to this, again. The faculty definitely have a dog in this fight, but the administration doesn’t listen to our protests because they believe they have a better understanding of student needs. We were successful last time because students, alumni, the community, concerned leaders in agriculture, The Farm Bureau, the planning commission and others rallied together as one voice and said no to Armstrong. We need that same level of outside organization and support again. It’s going to take a few folks willing to get together, make some calls, set up an organizational structure and develop a plan. Who will be a champion for Cal Poly and for agriculture? Are you ready?

We have to protect California’s farmland and stop the loss of Class 1 Prime acreage essential for training the next generation of food producers. Period. Tell Armstrong and the Cal Poly administration NO! Tell them to keep their hands off our teaching lands. Tell them to honor their previous promise not to build on a precious natural resource.

Steps you can take:

Spread the word amongst your network to get this message out to as many people as possible
Write your representatives: Rep. Salud Carbajal; Sen. John Laird; Supervisor Bruce Gibson; and Supervisor Heather Moreno. Tell them about this situation and that it needs to be stopped.
Write to Jeff Armstrong (jarmstro@calpoly.edu) and Brian Horgan (bhorgan@calpoly.edu) the Dean of the College of Agriculture, Food and Environmental Sciences. Tell them to honor their previous commitment. Tell them you want rare agricultural soils preserved in perpetuity. And tell them agricultural learn-by-doing requires large fields in active crop production to ensure competency for future generations of highly qualified food producers in this state.
And lastly, if you’re willing to step up and take a leadership role, email me at info@californiainsectscience.com. The time is now.

‍Sources‍ ‍

Conservation Fund - 4 Surprising Statistics Reveal What’s Really Happening to America’s Lands‍ ‍

FarmdocDaily -Loss of US Farmland in the 21st Century: The National Perspective from the Census of Agriculture‍ ‍

‍Farm Bureau Intel - Over 140,000 Farms Lost in 5 Years‍

Science Alert - The World Has Lost a Third of Its Farmable Land in The Last 40 Years‍ ‍

Scientific American - Only 60 Years of Farming Left If Soil Degradation Continues‍ ‍