Sierra Orchards
Organic walnut farm in Winters, CA
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Craig McNamara checking the water pressure of a well that supplies the orchard.
Sierra Orchards is an organic walnut farm in Winters, CA. Sierra Orchards’ walnuts are processed and packaged by Anderson & Son then sent to Trader Joe’s and other organic groceries. In addition to its core walnut-growing operation, the farm leads sustainability projects and sponsors a nonprofit called the Center of Land-Based Learning, an educational program that reaches 2000 students annually. We met with Craig McNamara, the Orchards’ President, owner, and primary operator since he founded the farm in 1980.
acres of farmland
years of operation
Software used
Acuity Agriculture
Soil monitoring
Acuity is an application that shows the temperature and moisture of soil based on readings from sensors around the farm. Each station records soil stats for a different section of the Orchard (with a section name and satellite view). Intuitive devices measure the temperature and moisture level in the soil. Each sensor is connected to the internet, so it can report data in real time. Craig can see the status from the web or a mobile app and can compare the stats for each section of the farm to the allowable depletion and field capacity levels. Sierra Orchards paid an install fee and monthly subscription to use the Acuity platform.
Ceres Imaging
Aerial imagery
Ceras uses aerial photography to water retention and vigor in the trees. The company flys a plane over the orchard, and infrared cameras on the plane detect soil moisture levels, crop health, and more. Craig hires Ceras four times a year to do flyovers and get reports on the health of the trees. The orchard is currently switching to a new irrigation system, and the Ceres reports have been useful for understanding the performance and uniformity of the new system.
Trace Genomics
Measuring soil health
Trace Genomics is a startup helping farmers understand the quality of their soil by testing samples for disease and nutrients. Craig received a report from them on soil quality, which he said has informed some efforts to fight plant disease.
WalnutTek by WeCo
Optical electronic color sorters
Sorting out defective walnuts is crucial to Sierra Orchards’ business; the quality of the walnuts that Sierra Orchards delivers to their processor determines the price they get paid per edible meat yield. Craig uses WeCo’s technology to sort to out discolored nuts automatically during the harvest. WalnutTek automatically identifies and removes after the nuts are hulled based on smart algorithms and machine vision. WalnutTek also provides the moisture meters and door controls that facilitate the nut drying process. When the walnuts are in a drying bin after harvest, an air door responds to internal sensors to achieve a precise 8% moisture level - both over and under-drying reduce the quality (and price!) of the nuts.
What are some of the main problems and challenges that the orchard faces?

Climate: The ultimate uncertainty in farming is, of course, the weather. Responding to weather events like extreme heat or rain are the most urgent problems for McNamara and the operators of Sierra Orchards. For example, a heatwave in the middle of the growing season can result in darker, less desirable walnuts. Heavy rains in the middle of harvest means that tree shakers and other machines can't go out in the fields. "You can’t change the weather, but can prepare for it," McNamara said.

Equipment maintenance: Large scale farming involves a lot of equipment, and machinery upkeep can be a challenge. Sierra Orchards is currently moving to a new irrigation system for the trees, and the team spends much of their day managing the migration to avoid disrupting tree health.

Quality control: Removing defective walnuts and drying walnuts to exactly 8% moisture has a big impact on the farm's revenue because quality and weight determine the price per edible yield. Sierra Orchards invests in technologies and processes to remove defective nuts before sending the harvest to the processor.

How do you discover new software to use?

Word of mouth is the biggest source of discovery for new software. For example, McNamara discovered Ceras through another farmer, who was a close friend. The other farmer mentioned that the technology was valuable for farms in Israel, so McNamara decided to give it a try for Sierra Orchards.

There are still many innovations to come in the agriculture industry. Most work is still done manually, and farmers, processors, and buyers manage much risk and uncertainty. Farmers cope with the essential unpredictability of weather - McNamara explained that a single hot day can cost Sierra Orchards hundreds of thousands of dollars - and a tight harvest timeline. Because of their remote locations, farms have unreliable internet service, meaning it’s difficult to adopt smart devices or internet technologies that rely on data connections. Finally, long feedback loops (most farmers have few harvests every year) and unpredictable demand make it difficult to experiment with new techniques. Despite these obstacles, we identified some areas for possible innovation:

Harvest log: Around the time of harvest, McNamara keeps a complex spreadsheet to track progress. He compares the expenses like hours spent shaking, sweeping, and raking with yield for each section of the farm, records the dates that the harvest is sent for processing, and notes the quality and yield of each crate when he gets quality rubrics back from the processor.

Managing compliance and inspection: The California Certified Organic Farmers (CCOF) requires organic farms like Sierra Orchards to keep a record of their fertilizers, supplements, and any materials used on the trees or nuts. Throughout the year, inspectors visit the Orchards unannounced to audit the paperwork. Although he is a staunch advocate of organic farming, McNamara said that maintaining the CCOF certification is tedious and time consuming because they have to keep so many paper files and invoices on-hand.

Grading sheet platform: “Grade sheets” are quality rubrics that define the price that a grower gets for each crate of walnuts. McNamara explains that, in the fall, he will send his harvest to a walnut processor in another town. There, third-party inspectors weigh and manually evaluate a sample of nuts from each crate using a quality rubric to mark external and internal defects. McNamara gets back a stack of “report cards” and a quarterly check. Today, the process is all done on paper. Although in theory they are certified to be objective evaluators, McNamara said that, in practice, the inspectors have different standards. He keeps a sample bag for each crate that he can use to appeal the inspection, if he feels it is unfairly low.

Electricity management: Sierra Orchards is both a buyer and supplier of PG&E electricity; the property has a small solar farm that sells electricity onto the grid when there is an surplus. McNamara mentioned that the software he uses to manage the electricity and his account with PG&E has usability problems. He said that there’s opportunity to invent a better power management experience.


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Walnut trees from the orchard


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What the walnuts looked like when we visited (in June)!