- Author: Jeannette E. Warnert
Almond farmers will remember a UCCE demonstration last February when the 50,000-pound Iron Wolf rolled like a tank through an almond orchard in Chowchilla, ripping whole trees into shreds and incorporating the wood into the soil.
Researchers are now considering a less dramatic approach to removing an old orchard and incorporating the wood chips into the soil onsite. Combining a traditional horizontal chipper with a wood chip spreader modified for this purpose can be a viable alternative to the now-mostly banned burning of old orchards or transport of almond tree residue to co-generation facilities that convert biomass to energy.
“It's still cheaper for the farmer if he or she can sell the wood chips for co-generation,” said Brent Holtz, UC Cooperative Extension advisor in San Joaquin County and the research leader. “But co-generation plants are closing and our research is showing that incorporating the biomass into the soil has many benefits.”
When the wood breaks down, it returns nutrients to the soil. Organic matter increases, resulting in carbon sequestration, important for moderating the release of greenhouse gases into the atmosphere that may contribute to climate change.
The chipper and spreader combination pencils out at about $1,000 per acre, while the Iron Wolf costs about $1,500 per acre.
“The Iron Wolf turned out much more expensive and slower than we anticipated,” Holtz said. “It could only grind up and incorporate about two acres of trees per day, while the horizontal chipper can chip 15 acres per day. With the chipper and spreader combination, the chips do have to be disked in, which most growers can easily do.”
The whole orchard recycling project was funded by the Accelerated Innovation Management program of the Almond Board of California.
Whole Orchard Recycling Demonstration
11630 S. Airport Way (near Roth Road), Manteca, Calif.
Thursday, Oct. 13, 2016
10 a.m.
Whole almond orchard recycling and the effect on second generation tree growth, organic matter and soil fertility presentation
Brent Holtz, Ph.D., UC Cooperative Extension advisor
10:30 a.m.
Kuhn & Knight Wood Chip Spreading Demonstration
Randy Fondse, G & F Ag Services, Ripon, Calif.
11 a.m.
Morbark Horizontal Chipper Demonstration
Randy Fondse, G & F Ag Services, Ripon, Calif.

The cost analyses are based on hypothetical farm operations of well-managed orchards, using practices common to each region. Growers, UC ANR Cooperative Extension farm advisors and other agricultural associates provided input and reviewed the methods and findings of the studies. Two studies estimate the costs for establishing and producing almonds grown in the northern San Joaquin Valley and Sacramento Valley using micro-sprinkler irrigation. These are multi-year studies, estimating costs from previous crop (orchard removal) through orchard establishment and the production years.
The study for organic almonds takes into consideration growing conditions in the northern San Joaquin Valley and complying with the National Organic Program. This study is based on an orchard that began the transition period and certification as organic after the second year of establishment. The trees in this study are in production and at full bearing. This organic almond orchard uses a solid-set sprinkler system.
The economic life of the orchards used in this cost analysis is 25 years. The authors describe the assumptions used to identify current costs for the almond crop, material inputs, cash and non-cash overhead. A ranging analysis table shows profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.
- Sample Costs to Establish an Orchard and Produce Almonds in the San Joaquin Valley – North- 2016
- Sample Costs to Establish an Orchard and Produce Almonds in the Sacramento Valley – 2016
- Sample Costs to Produce Organic Almonds in the San Joaquin Valley - North - 2016
Free copies of these studies and other sample cost of production studies for many commodities are available. To download the cost studies, visit the UC Davis Department of Agricultural and Resource Economics website at http://coststudies.ucdavis.edu.
The cost and returns program is funded by the UC Agricultural Issues Center, which is part of UC Division of Agriculture and Natural Resources, and the UC Davis Department of Agricultural and Resource Economics.
For additional information or an explanation of the calculations used in the studies, contact Don Stewart at the Agricultural Issues Center at (530) 752-4651 or destewart@ucdavis.edu, or Christine Gutierrez at (530) 752-1520 or cagut@ucdavis.edu.
- Author: Jeannette E. Warnert
California almonds are on a roll. In the last 20 years, scientific discovery and grower ingenuity have nearly doubled almond per-acre productivity. A good yield in the 1980s was 1,400 pounds per acre. The average yield for 2011 was 2,670 pounds of shelled almonds per acre.
Forty years ago, California farmers produced less than 100 million pounds of almonds on about 200,000 acres of almond orchards. Mechanization, improved irrigation efficiency, advances in insect and disease management, pruning research and fertilization studies have fueled explosive growth in the industry. Farmers in California’s Central Valley now tend 760,000 acres of almond trees, producing about 2 billion pounds of shelled nuts a year. The crop, which represents 100 percent of U.S. almond production and 75 to 80 percent of world production, was valued in 2011 at $3.87 billion, surpassing table, wine and raisin grapes, which were valued at $3.86 billion.
“Even with this record production, we have more demand than we have supply,” said Bob Curtis of the Almond Board. “The driver behind that is nutrition studies that show almonds are a healthy food and snack.”
A tremendous amount of UC research is behind the California almond success story, said Bruce Lampinen, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis, an expert in almond canopy management.
“Higher density plantings of almonds and a trend towards less pruning, and improved water management have led to much higher yields,” Lampinen said.
Many almond growers have replaced flood irrigation with micro-sprinkler or drip irrigation, said Larry Schwankl, UC Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis. These irrigation systems increase the precision of water and fertilizer application. Over the years, UC Cooperative Extension advisors and specialists established demonstrations of micro-sprinkler and drip systems in many parts of the Central Valley and reached out to farmers to show how they could be managed to optimize production.
“Twenty years ago, we simply guessed at the amount of water that the trees needed and we applied it on a calendar basis,” said Joe MacIlvaine, president of Paramount Farming Company in Kern County, one of the state’s largest growers of almonds, pistachios and pomegranates. “Today, we are delivering water and nutrients directly to the root zones when they are needed.”
Two decades ago, a granular form of nitrogen fertilizer was generally applied to almond orchards in the fall to allow winter rain and irrigation to move it into the soil for use by the trees in spring and early summer. Nitrogen use efficiency was believed to be about 40 percent. Now, nitrogen fertilizer is applied through the irrigation system during the growing season, when the tree needs it.
“Today, our nitrogen use efficiency can be as high as 85 percent,” said Blake Sanden, UCCE advisor in Kern County, an irrigation expert. He and Patrick Brown, professor in the Department of Plant Sciences at UC Davis, have conducted nitrogen trials in almonds with Paramount Farming.
“When you increase the conversion of applied nitrogen fertilizer to higher crop yield, there is significantly less potential for nitrogen to leach below the rootzone and contaminate groundwater,” Sanden said. “But each field is unique and requires site-specific management to achieve these high levels of efficiency.”
Another area where UC research has led to significant crop yield growth is in canopy management and tree spacing. Research by Mario Viveros, UCCE advisor emeritus in Kern County, and other scientists showed that a tendency among growers to over prune was taking a toll at harvest time.
“A lot of farmers who are now growing almonds had experience with fresh fruits, where you do need to prune to get light on the fruit for good color. In almonds more canopy generally means more yield,” Lampinen said. “Today, most almond growers only prune when branches are growing in the way of tractors or other equipment.”
UC research also found that orchards planted with traditional wide spacing between the trees weren’t making the most efficient use of sunlight on the farms. Older orchards had 60 to 70 trees per acre. Today, almond orchards are planted at an average density of about 110 trees per acre based on results of UC research.
However, studies have also shown that crowding still more trees into orchards triggers diminishing returns. In almond production, the nuts are shaken from the trees to dry on the ground before they are harvested.
“If the orchard floor becomes too shaded by trees planted too densely, the orchard floor temperature and humidity become optimal for growth of pathogens that could become a food safety problem,” Lampinen said. “You want enough sunlight to hit the orchard floor to reduce potential pathogens, like salmonella.”
MacIlvaine acknowledged the role of UC Cooperative Extension in helping the almond industry achieve the production milestone in 2011.
“The University of California has been a wonderful partner in improving our farming practices,” he said. “The whole system is not only more efficient, but more sustainable at the same time.”
Hear more of MacIlvaine's comments in the video posted below:
- Author: Pamela Kan-Rice
“When I started, there were about 22,000 acres, now there are more than 68,000 acres,” said Krueger, who retired July 1 as UCCE advisor in Glenn and Tehama counties and director for UCCE in Glenn County. Part of that expansion can be attributed to Krueger’s research showing how almonds and walnuts can be produced on marginal soils with high density plantings and drip irrigation.
“Bill Krueger is a great asset to our agricultural community,” said Erick Nielsen, who grows prunes and olives in Orland.
“We have enjoyed working with Bill for many years,” Nielsen said. “He has always been the kind of guy to just jump right in and help. We have appreciated his dedication to agricultural research and his knowledgeable guidance.”
Raised on a farm in Prosser, Wash., Krueger was introduced to farming by his parents, who grew Concord grapes and cherries. He earned his bachelor’s and master’s degrees in horticulture at Washington State University, then worked for a year as foreman at Mt. Adams Orchard Company in White Salmon, Wash., tending cherries, apples and pears.
In 1980, Krueger moved to California to become the UC Cooperative Extension advisor for tree crops in Glenn County.
“I’ve spent my entire career in Glenn County,” remarked Krueger, who specializes in production of almonds, walnuts, prunes and olives.
Seeking opportunities for growers to diversify their crops, Krueger and his fellow UC Cooperative Extension advisor John Edstrom planted a test plot of walnut trees at the Nickels Soil Laboratory in Arbuckle in 1986.
They set up a walnut orchard with 202 trees per acre, much closer than the 60 trees per acre of a traditional orchard. The two varieties that Krueger and Edstrom planted produce a large proportion of walnuts on lateral buds, which allows for hedgerow planting and mechanical pruning. Each year, a giant hedger with eight 38-inch saws buzzed down one side of the tree rows, cropping back branches and encouraging production. In alternate years, they pruned the opposite side of the trees. Rather than being flood irrigated as most walnut orchards, the Nickels orchard was watered and fertilized using drip irrigation.
Crop yields from the dense walnut tree plantings compensated for the marginal soils. The successful demonstration plot led to thousands of acres of walnuts being planted on similar soils.
In 1992, he added responsibility for olives in Tehama County, where the number of acres of olive trees has doubled from 4,000 acres to approximately 8,000 acres. Krueger is internationally respected for his research identifying the most effective method of chemically thinning olives to increase the size of the fruit. Chemical thinning of olives has become a common practice among Sacramento Valley table olive growers.
Over the years, he has collaborated on the development of integrated pest management practices for almonds, walnuts and prunes. In 2004, Krueger was a member of the team that California Department of Pesticide Regulation honored with its IPM innovator award for the Integrated Prune Farming Practices Program.
“Over the years he has assisted us with many different pruning trials in both our olive and prune orchards,” said Nielsen. “The last project he helped us work on was a trial for various degrees of hand pruning versus mechanical pruning in prunes. Bill has a great sense of the current market for the different crops and has always been a front-runner on moving forward with research and development projects.”
Krueger developed pruning strategies to enhance early production of prunes while developing tree structure capable of supporting heavy crop loads. He helped refine mechanical thinning to manage prune crop size, a technique developed earlier by UC researchers, and his efforts to extend this research to growers helped it become a common practice when needed.
His work, in collaboration with others, on reduced pruning of almonds has helped growers save money by reducing pruning costs.
In addition to advising growers, Krueger served a total of 13 years as director for UCCE in Glenn County, from 1996 to 2001, then resuming the helm from 2004 until his retirement.
Krueger has applied for emeritus status with UC so that he can finish up a few projects, but also looks forward to working on his own 10-acre olive orchard south of Orland during his retirement.
On Aug. 17, Krueger will be celebrating his career with friends and colleagues at Mills Orchards in Hamilton City. For details, contact Jody Samons at (530) 865-1155 or jesamons@ucdavis.edu.
- Contact: Pam Kan-Rice, (530) 754-3912, pskanrice@ucdavis.edu
- Contact: Richard De Moura, (530) 752-3589, rdemoura@ucdavis.edu
Each analysis is based upon hypothetical farm operations using practices common in the region. Input and reviews were provided by UC Cooperative Extension farm advisors, UC researchers, growers, farm accountants, pest control advisers, consultants and other agricultural associates.
Each study describes the assumptions used to identify current costs for the individual crops, material inputs, cash and non-cash overhead. A ranging analysis table shows profits over a range of prices and yields. Other tables show the monthly cash costs, the costs and returns per acre, hourly equipment costs, and the whole farm annual equipment, investment and business overhead costs.
The new studies are as follows:
- Sample Costs to Establish an Orchard and Produce Almonds, 2012, Sacramento Valley, by Joseph H. Connell, William H. Krueger, Richard P. Buchner, Franz Niederholzer, Carolyn J. DeBuse, Karen M. Klonsky and Richard L. De Moura.
- Sample Costs to Establish a Walnut Orchard and Produce Walnuts, 2012, Sacramento Valley, by William H. Krueger, Richard P. Buchner, Janine K. Hasey, Joseph H. Connell, Carolyn DeBuse, Karen M. Klonsky and Richard L. De Moura.
- Sample Costs to Establish a Citrus Orchard and Produce Mandarins (Tango), 2011, San Joaquin Valley – South by Neil V. O’Connell, Craig E. Kallsen, Karen M. Klonsky, Richard L. De Moura and Kabir P. Tumber.
- Sample Costs to Establish a Vineyard and Produce Winegrapes (Cabernet Sauvignon), 2012, North Coast Region (Napa) by Monica L. Cooper, Karen M. Klonsky and Richard L. De Moura.
- Sample Costs to Establish a Peppermint Stand and Produce Peppermint Oil, 2011, Intermountain Region, by Rob Wilson, Daniel B. Marcum, Karen M. Klonsky and Richard L. De Moura.
All cost of production studies are available online at http://coststudies.ucdavis.edu, at UC Cooperative Extension offices or by calling (530) 752-3589. For more information about the studies, contact Richard De Moura at rdemoura@ucdavis.edu in the Department of Agricultural and Resource Economics at UC Davis.