Agroforestry research at Cornell University

In 2002, horticulturists from Cornell University’s College of Agriculture and Life Sciences noticed some hickory trees in an overgrown woodlot behind Cornell Orchards in Ithaca, N.Y. Many mature nut-bearing trees, some with bark circles showing graft-unions, were discovered as plant scientists hacked their way through the choking underbrush. They soon suspected that this might be the land-grant university’s first agroforestry site, the forest that Dr. MacDaniels built.

The MacDaniels Nut Grove was brought back to life after decades of neglect. Dr. Laurence MacDaniels, a Cornell pomologist, developed the 6-acre lot starting in the 1930s as something he called tree crops agriculture. Ken Mudge, currently associate professor of horticulture at Cornell, was one of the those responsible for the recent revival of this nut grove.

The barn at Dilmun Hill Student Farm, built by Cornell University founder Ezra Cornell for his daughter.

In the past five years, Mudge has practiced and researched agroforestry on campus, as well as at the university’s Arnot Forest, an area with over 4,000 acres just southwest of Ithaca in the foothills of the Southern Tier. He leads student experiments to find out which species of trees provide the best logs for raising mushrooms, what small fruits and berries grow best under a forest canopy, and what medicinal plants will work in this system.

He describes forest farming as one aspect of agroforestry. “Forest farming is when you have an established forest and you want to grow nontimber products in that established forest. A two-credit course, practicum in forest farming, gives Cornell students experience in raising three kinds of forest crops: food, ornamental and medicinal.” On about 3 acres, students are growing mushrooms and small fruit, hostas and other ornamental plants, and ginseng and goldenseal for medicinal purposes.

Mushrooms are a big part of agroforestry research at Cornell. At Arnot Forest, Mudge is leading research to compare four tree species—oak, red maple, aspen and beech—as media for growing three fungal species: shiitake, oyster and lion’s mane mushrooms. Another research project will compare six strains of oyster mushrooms, and yet another will compare three locally collected wild isolates of lion’s mane mushrooms, plus a commercial isolate. Every spring, Camp Mushroom, a two-day event at the Arnot Forest, trains volunteers on how to grow mushrooms on logs. They help set up an experiment and take a few mushroom logs home for themselves.

At MacDaniels Nut Grove, Dr.
MacDaniels himself grafted this pignut hickory to shagbark hickory, probably about 70 years ago.

During an autumn tour of the MacDaniels Nut Grove, Mudge demonstrated mushroom logs stacked in a way that aids airflow, a formation called a “rack.” A few dried-out shiitake mushrooms stuck out like ears from 3-foot sections of log called “bolts” used for mushroom production. Bolts are drilled with holes, then the holes are filled with mushroom spawn and sealed with hot wax.

“[It] takes a year before you get any mushrooms, you’ve got to be a little patient,” advised the Cornell forester. “Most of these are shiitake logs. You can buy them [shiitake mushrooms] at Wegman’s, for example, at $7 or $8 a pound. There’s a guy in Ithaca who sells shiitakes at the farmers’ market for $16 a pound.” Near the mushroom logs, a big cattle-watering tank is used for “shocking,” the immersion of logs in cold water for 24 hours, followed by the mushroom fruiting about a week later.

Mudge pointed out a break in the tree canopy created where 10 trees were felled to provide light for a berry patch. “What we’ve done is develop this from a secondary forest back into a forest farm. Some crops, like our ginseng and mushrooms, need as much shade as we can possibly get, but others, like small fruit—these are blackberries—need more light.”

In the 1980s, Mudge met MacDaniels in the legendary professor’s last years. “In about 1923, MacDaniels came into Cornell horticulture,” Mudge said. “He was a pomologist, and apples were his thing, but he was also very much interested in temperate nut trees: hickories, walnuts, filberts and chestnuts. A couple of years after he came to Cornell, this area was completely deforested, bulldozed; he cut some terraces into the side of the hill. There was nothing here. He allowed it to grow back naturally and he also planted some seedlings deliberately.” MacDaniels was a mad grafter in his effort to reproduce exceptional trees and he searched high and low for superior trees, even holding tree contests to get exceptional “scions” (the shoots for grafting onto rootstock) for cloning great nut-bearing trees.

Ornamental hostas grown using pot-in-pot method in Nut Grove.

At the entrance to MacDaniels Nut Grove, there is a red pignut hickory grafted to a shagbark hickory that looks like a joining of two alien species, while another grafting of shagbark to shagbark hickory is clean and almost seamless. At a small fenced plot under the trees, behind a bit of deer fencing, there is a plastic pot with a hosta plant from another bigger plastic pot embedded in the ground. Mudge said, “I’ve never heard of anyone growing ornamentals in the woods, but we figure shade-loving ornamentals like these ferns and hostas, why not try growing them in the woods?”

Further down the hill, three plots with three different amounts of available sunlight all have small fruit plantings, including blueberry, currant, chokeberry, gooseberry and honeyberry (an edible honeysuckle). The grove has five zones. In the most fertile zone, black walnut trees rule. Not all plants can tolerate juglone, a substance that black walnut trees put into soil, so black-cap raspberries were planted there since they appear with walnuts in nature.

At Dilmun Hill, Melissa Madden, organic farm research director at Cornell, and Mudge planned and designed the first stage of an alley cropping agroforestry project at the 13-acre organic farm run by students, which is next door to the nut grove. Maple trees and hybrid-bush hazelnuts were planted in 2008, and these researchers are asking multiple questions with these experiments.

For instance, as maple trees are being raised in rows to supply logs for mushroom growing, sugar maples will be compared with red maples as the “earth” that shiitakes and oyster mushrooms grow in. Root Production Method trees from RPM Ecosystems, the local nursery that invented this process of intensive root growth, will be compared with conventional bare-root plantings of the same kind of tree.

One hundred hazelnut trees were grown in a cover crop of buckwheat and clover, and this past fall little saplings stuck up from the unruly tangle of fallen buckwheat. Another 100 hazelnuts were grown in mulched rows. Randomized testing of tree-guards will explore the effectiveness of this pest protection.

Madden summed up, “Our goal was to put this into an agroforestry alley crop management system that would continue to be useful for annual cropping in the middle rows, demonstrate some polyculture stuff, and provide a continuum to the nut grove.” Students planned the 2009 stage of this project. Wren Albertson-Rogers, a student doing independent study from a permaculture perspective, is designing the rows of annuals and perennials that will be grown in raised beds between tree rows—ornamentals and cut flowers are likely.

Melissa Madden, organic farm research coordinator, at Cornell University’s Dilmun Hill near a developing agroforestry site.

“Wren’s mandate was to really play with plants that provide a self-renewing element to the system,” Madden explained. “So they either mine the soil for micronutrients or they fix nitrogen, or they are really suppressive covers against bindweed. He’s really interested in working with vining plants because one of the mandates he was given by students was, ‘Please make it like a peaceful retreat.’ He’s trying to make covered, shaded places for summer, trying to work with the trellis idea.”

Last fall, about 100 people attended an edible forest garden talk at Dilmun Hill, including community foresters, master gardeners, permaculturists and diversifying farmers from all over central New York state. Madden said, “There’s a real outcry for this kind of information in the community. Having a demonstration site with pretty well-documented and well-thought-out design is a pretty useful thing. Ken and I see it as an excellent outreach opportunity.

How does forest farming get to be part of our food chain? “That’s an excellent question because that’s the foundation of my farm,” Madden said. After spending a year on a Wisconsin farm where hazelnuts were integrated with other nut and fruit trees, Madden and her partner, Garrett Miller, are starting their own agroforestry farm on 69 acres in nearby Seneca County with a mission to avoid monoculture.

She said, “The idea is you can intensify agriculture while you diversify agriculture and make it more ecosystem appropriate. We have an enormous amount of agricultural land dedicated to the production of carbohydrates and protein. Is there a way to do that in a perennial manner?”


New York Forest Mushroom Growers, including information about Camp Mushroom:

Northern Nut Growers Association:

Field and Forest (mushroom growing supplies):

MacDaniels Nut Grove:

Dilmun Hill Student Farm:

The author is a freelance contributor based in Brooktondale, N.Y.