Determining the Effect of Tree Pruning and Nutritional Inputs on a Neglected Chestnut Orchard

Progress report for FNE22-007

Project Type: Farmer
Funds awarded in 2022: $29,975.00
Projected End Date: 02/28/2025
Grant Recipient: Morris Orchard LLC
Region: Northeast
State: Maryland
Project Leader:
Jane Dennison, Ph.D.
Morris Orchard LLC
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Project Information

Project Objectives:

This SARE project will quantify changes in production and soil health as a function of pruning and nutritional inputs over three years. Based on the data, we will estimate the potential increase in income with continued treatment and compare with the expenses. This may provide some information on the viability of restoring mature chestnut trees through pruning and nutrition.

 

  • To determine the effect on yield of pruning a neglected chestnut orchard
  • To determine the effect of nutrient applications on soil health.
  • To gather data on whether pruning and adding nutrition is cost effective for a neglected orchard
Introduction:

Tree crops like chestnuts take considerable investment of time and money to established before producing a yield that can generate income for the farmer. Chestnuts begin producing 7-8 years after planting seedlings and should begin to show profit around year 10. Neglected orchards of chestnuts and other tree crops exist in our region that have the potential to be profitable farming enterprises. Demonstrating that intensive pruning and nutrition increase yields to profitability, accompanied by outreach to orchard owners, will encourage orchard restoration.

Pruning removes dead and diseased wood, increases light and airflow and results in increased productivity. However, pruning large mature trees requires specialized equipment and skilled labor and is a costly endeavor. Farmers seek return on investment for such a large expense.

Good nutrition is also important for orchard trees, increasing their resistance to pests and disease and giving them additional energy for crop production. Ramial wood chips have been shown to increase yield and water retention when applied to agricultural soils. In addition, ramial wood chips feed the fungal components of soil which create symbiotic relationships with tree crops. Ramial wood chips are commonly available from arborists in most areas making them an accessible and affordable soil amendment. Enhancing mineral concentrations available to the trees will also increase their productivity and resistance to disease and pests. Finally, we include in this proposal the application of liquid nutrition such as compost tea but are waiting for preliminary test results before selecting what to apply.

We will estimate the expense and increased production on pruning mature chestnut trees and providing additional nutrition to shed some light on whether it is economically viable to restore a neglected orchardThese restored orchards can produce crops sooner and in larger quantities than newly planted orchards. They can be profitable businesses for farmers and employ workers in farm communities to prune trees and harvest crops. Demonstrating that unmaintained mature orchards can be profitably brought back into production may also protect mature orchards from being destroyed and save important varieties and genetics.

Cooperators

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  • Michael Judd - Technical Advisor
  • Taylor Logsdon

Research

Materials and methods:

Defining the test groups:

A section of the orchard's chestnut trees have been divided into four groups of 14 trees each (the whole orchard was not selected for this study due to the high costs of the arborist.) The groups were selected based on similar tree density and site conditions (see attached orchard schematic). Each group will be marked in the orchard using color coded flags. The groups will be assigned treatments: Group 1: pruning only, Group 2: nutrient application, Group 3: pruning and nutrient application, and Group 4: control, no treatment.

Treating test groups:

Trees in Group 1 and Group 3 will be pruned each winter for three winters. No more than 25% of the tree will be removed each year to ensure the health of the tree. The farmer will consult with the technical advisor and arborist as to the best approach to pruning the trees.

Trees in Group 2 and Group 3 will receive nutrient applications:

  1. Wood chips will be delivered by tree service companies and amassed on site. They will be kept in open piles not to exceed 20 yards each. Once 56 yards of wood chips are collected they will be spread through the orchard at a rate of 2 yards per tree in July 2022 and July 2023. Wood chips will be spread under the canopy of the tree but not on the orchard ground between trees. A tractor front loader sized to deliver the correct amount of wood chips for each tree will be used for spreading.
  2. Minerals: The local chapter of the Bionutrient Food Association is headed by Richard Jeffries who has advised us on mineral application. We will use rock dust from a local quarry but are not including this as a cost on this proposal since we will be getting a bulk supply for use on this orchard and elsewhere.
  3. Liquid compost soil drench: We are taking a preliminary soil sample in November 2021 for laboratory analysis and will consult with the laboratory and Dr. Elaine Ingham’s SoilFoodWeb School (https://www.soilfoodweb.com/) for the best product to apply. Our technical advisor, SilvoCulture, Inc., will pay for this preliminary expense. We will also refer to the Rodale Institute guide on compost teas (https://rodaleinstitute.org/blog/compost-tea-a-how-to-guide/)

Soil Health Analysis:

Based on recommendations from the Bionutrient Food Association, soil health will be measured using Earthfort Lab’s #2 package which tests for total/active bacteria, total/active fungi and protozoa, pH and #7 package which tests for pH, calcium (Ca), % humus, soluble salts, nitrates (NO3), ammonium (NH4), phosphate (HPO4), potassium (K), magnesium (Mg), iron (Fe), manganese (Mn), boron (B), copper (Cu), zinc (Zn), sulfates (SO4), clorides (Cl). A composite sample will be taken from at least 8 locations within each test Group for a total of 4 samples per year to be sent for analysis

Background soil testing will occur in April of 2022 to establish existing soil health conditions of the site. Additional testing in April 2023 and April 2024 will be used to determine the effect of nutrient application on soil health.

Determining Chestnut Yields:

Each October during the grant period chestnuts will be gathered with the help of volunteers from all the tree groups for the duration of the harvest. Volunteers will be recruited through SilvoCulture’s email list. This has been successful for harvesting chestnuts from the orchard in 2020 and 2021.

Gatherers will be assigned rows to walk and methodically collect all fallen chestnuts from each tree in a group. Chestnuts will be collected into 5 gallon buckets marked with the color code for the tree group. Chestnuts will be kept separate per the test Group and sorted based on condition. Nuts will be sorted by the following criteria:

 1) Marketable nuts as a raw product: must be free of disease and blemishes.

 2) Seconds suitable for processing into value added chestnut products such as flour or beer but not suitable for direct sale: May have small blemishes both on shell of nut and interior but must otherwise be in good condition.

 3) Nuts not suitable for direct sale or value added products: Are diseased or damaged to the point that they are unmarketable and not suited for creating value added products.

Nuts will be collected every other day to reduce loss from wildlife and weevils. All nuts will be given a hot bath at 120 degrees Fahrenheit for 20 mins to kill any weevil eggs present. This will be done using our SilvoCulture’s “Chestnut Dunker” which has been used successfully in 2020 and 2021 on chestnuts from the orchard. The dunker consists of a tank of water kept at a steady temperature of 120 degrees by a digital thermometer and propane heater.

The following data will be recorded:

-Yield of chestnuts from each tree group per season

-Cost of materials and labor for work done on each tree group

-Revenue of chestnuts based on price attained through local sales

We will analyze the data looking for statistical differences between nut yield/quality and soil health for the 4 test groups and the effects of yield on pruning and amending with wood chips a neglected chestnut orchard. Revenue from the chestnuts will be quantified through prices obtained from local sales and compared to the cost of work done on the orchard. Local sales will be made through SilvoCulture’s chestnut roast festival and our social network. Value added producers of bread and beer will be identified as buyers for quality chestnuts.

 

Activities Completed in 2022

Defining the test groups: Test groups were marked with different color marking flags to identify which trees belonged to which group. A change in treatment to groups was decided upon to allow for easier spreading of wood chips. Group 1 (Yellow) was pruned and fertilized, Group 2 (Green) was fertilized and not pruned, Group 3 (Blue) was not fertilized and not pruned and Group 4 (Red) was pruned and not fertilized.

First pruning of chestnut trees:

Trees in Test Groups 1 and 3 were pruned in March of 2022. Technical Advisor, Michael Judd met with an arborist on site and determined the best approach to pruning the trees over the three year grant period. The amount pruned from each tree varied depending on the amount of disease and dead wood in each tree. Photos for each of the trees in the grant were taken as a record of the pruning done to them. The second pruning of the trees will occur this February 2023 and will focus on shaping and training the new growth of the trees.

Soil Testing:

Background soil testing was taken for each of the test groups and submitted to EarthFort Lab for analysis. In addition to receiving soil tests results support staff met with EarthFort consultants for a review of the results.

Chestnut Harvest:

Chestnuts were harvested by support staff and volunteers and careful records were kept of yield and quality of chestnuts for each test group. 5 gallon color coded buckets were used to keep nuts from each test group separate.

Soil Amendments:

Throughout the 2022 summer, wood chips were collected on site from local arborists and kept in piles to begin composting. Soil amendments were applied in fall of 2022 after the chestnut harvest. Head of the local chapter of the Bionutrient Food Association- Richard Jeffries, advised Morris Orchard on how to apply compost extract and rock minerals to the test groups . Richard also provided the compost and rock minerals. Compost extract was applied using a backpack sprayer, rock minerals were broadcast by hand and wood chips were spread using a skid steer.

Support staff applied the following rates of amendments to each tree in each test group:

  • 1 gallon of compost extract
  • 1.5 yards of wood chips
  • 1 quart rock minerals

Though an amount of 5 gallons of compost extract per tree was advised, support staff were only able to apply a gallon of compost extract in the allocated time. Morris Orchard is looking into a more efficient was of apply the extract for next season.

Only 1.5 yards of wood chips were applied instead of the planned 2 yards due to being unable to solicit the total amount needed from local arborists.

 

Activities Completed in 2023

Second pruning of chestnut trees:

The second pruning occurred in late winter of 2023. This pruning was lighter than the first and focused on selecting new suckers for continued growth and removing unwanted suckers to increase light and airflow. Some trees experienced wind damaged and lost limbs in 2022 and were pruned to reduce the damage to the tree.

Soil Testing:

The second set of soil tests was taken in the spring of 2023 and sent to EarthFort for soil biology tests. EarthFort discontinued their mineral soil reports 2023 so additional samples were sent to the University of Delaware for mineral analysis.

Chestnut Harvest:

Chestnuts were harvested by support staff and volunteers and careful records were kept of yield of chestnuts for each test group. 5 gallon color coded buckets were used to keep nuts from each test group separate. The task of picking up all nuts regardless of quality, and sorting them by hand to determine percentage of marketable versus unmarketable nuts was found to be too time consuming in 2022. In 2023 we focused on only picking up all the good nuts in the orchard to get accurate data of marketable yields and in order to have enough time to collect all the good nuts in the test plots.

Soil Amendments:

Throughout the 2023 summer, wood chips were collected on site from local arborists and kept in piles to begin composting. Wood chips were spread in the fall of 2023 at a rate of 2 yards per tree.

SilvoCulture consulted with Leslie Lewis of Living Systems Soil regarding the application of compost extract in the orchard test groups. Under Leslie’s guidance, SilvoCulture decided not to use the same compost from 2022 for the orchard. Instead, SilvoCulture staff constructed a biologically active compost following Leslie’s  direction. This compost is still in the composting process and will be used in the spring to create an extract for the test groups. The compost extract will be applied by drilling ½” holes, 4” deep into the soil around the tree roots and pouring the extract into the holes.

 

 

Research results and discussion:

Initial soil tests from 2022 have revealed that the current state of soil health and fertility in the orchard is in poor condition for growing chestnuts.

The following was found:

  • Total and active fungi is very low
  • Total and active bacteria is low
  • Fungi to bacterial ratio is too low in fungi for trees
  • Low organic matter at 4.5%
  • Low in most bio available nutrients

Yield data from the 2022 harvest:

Test Group Total Yield (lbs) lbs marketable % marketable lbs seconds % seconds lbs unmarketable % unmarketable Average Size
1 (Yellow) 44.1 24.3 55% 6.3 14% 13.5 31% medium/large
2 (Green) 172.9 68.5 40% 58.4 34% 46 27% small
3 (Blue) 127 54.7 43% 25 20% 47.3 37% small/medium
4 (Red) 136.4 54.3 40% 39 29% 43.1 31% medium

 

Spring 2023 soil results did not show significant improvements in any of the test groups. The following was found across the test groups:

 

  • Total and active fungi very low
  • Total and active bacteria low
  • Fungi to bacterial ratio too low in fungi for trees
  • Low organic matter ranging 3.1% to 6.4%

 

Yield Data From 2023 Harvest:

 

Group:

Total (lbs)

1 (Yellow)

145.5

2 (Green)

183.5

3 (Blue)

224

4 (Red)

192.5

 

The chestnut trees that were pruned heavily in 2022 did not have a significant yield in 2023. The lightly pruned trees performed well and yielded on average more than the unpruned trees of the other test groups and a considerable increase in yields from 2022 to 2023.

Participation Summary
31 Farmers participating in research

Education & Outreach Activities and Participation Summary

21 Workshop field days

Participation Summary:

39 Farmers participated
1 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

Completed 2022

Fall Harvest 2022 (Workshop/ Field Days):

SilvoCulture staff reached out via Facebook and through our distribution list of 964 people to publicize the harvest event: we received 68 emails from people interested in volunteering, of which 20 showed up. The harvest was held from  9/20 to 10/12/22. Each of the four research quadrants were given a color and buckets marked with that color were used for the harvest and records were kept of the yields. Volunteers also helped with post-harvest activities including dunking the nuts in the hot water heater and sorting the nuts to remove bad ones. The volunteers consisted of people from diverse backgrounds interested in chestnuts for a variety of reasons. Of these, the most common were farmers interested in chestnuts as an agricultural crop and European and Asian immigrants with a fondness of chestnuts from childhood.

Workshop field days: 10

Farmers participating: 8

Completed 2023

Workshop: Pruning to Restore Orchards

The workshop Pruning to Restore Orchards was held on Sunday March 5th from 1-3pm. 

Taylor Logsdon, SilvoCulture’s operations director, gave an introduction to SilvoCulture and the work and research being done through the NorthEast SARE grant. Mathew Jacobsen, a local arborist who has been pruning the orchard, gave a demonstration on pruning and walked through his decision making process for the attendees.Michael Judd, SilvoCulture’s technical director, spoke on the purpose and effect of pruning trees as well as speaking more broadly on chestnuts and tree crops for the mid-Atlantic. Twenty (20) people attended the workshop. Of the attendees, the majority were farmers interested in agroforestry or home gardeners with an interest in tree crops. This included farmers from the BIPOC community. Attendees learned about the principles of tree pruning, the effect of pruning and chestnuts as an agricultural crop.

Workshop: Soil Health 101

On Oct 7th, 2023 SilvoCulture hosted Leslie Lewis of Living Systems Soil at SilvoCulture’s headquarters in Myersville, Maryland for the workshop Soil Health 101. This workshop gave an introduction to the soil food web and principles for creating and maintaining healthy soils. Participants learned about the soil food web, soil biology for home gardens and soil biology for tree crops. SilvoCulture staff gave an introduction to the SARE grant project at the beginning of the workshop. Twelve (12) people attended the workshop. The participants were a mix of farmers and home gardeners including BIPOC farmers. 

Fall Harvest 2023 (Workshop/ Field Days)

SilvoCulture staff used Facebook and our email list to publicize the 2023 harvest and received 40 new emails from people interested in volunteering. 31 people came out and assisted with the chestnut harvest. The harvest was held from 9/22 to 10/16. The same harvest protocol was used as in 2022 except that only good nuts were collected.

Workshop field days: 11

Farmers participating: 31

Introduction to SARE grant social media video:

A first draft of the video was completed in 2023. The video includes footage of pruning, soil testing and harvest as well as an overview of the grant project. SilvoCulture is still in the process of reviewing the draft but anticipate releasing the video in the first quarter of 2024.

 

Learning Outcomes

31 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

In order to collect information regarding learning outcomes, SilvoCulture staff sent a survey email after the Pruning to Restore Orchards workshop. The survey received only two responses. Because of the low response, SilvoCulture staff relied on in-person conversations at the workshops to collect information on learning outcomes. The farmers that attended our workshops and volunteer chestnut harvest days reported a better understanding of the chestnut harvesting process, including:

  • the need to harvest frequently and continuously throughout the harvest period
  • the weevil life cycle and effect on nuts
  • the competition from deer and rodents
  • how to identify a good nut from a bad nut
  • labor and time required to harvest nuts
  • principles of tree pruning
  • principles of soil health
  • chestnuts as an agricultural crop
  • tree crops in the mid-Atlantic

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Heavily pruned chestnut trees vs lightly pruned chestnut trees:

Upon inspecting the chestnut trees to be pruned within the grant the technical advisor and arborist decided that the best approach for some of the trees was to prune them back to the main limbs or trunks to take off all diseased wood. Of the pruned groups- Group 1 had 7 of the 14 trees main limbs removed and Group 4 had 4 of the 14 trees main limbs removed. The resulting new shoots will be thinned this and next winter to create new limbs for the trees. Though this may prove to be the most beneficial for the trees, it does pose a challenge for the yield data of the grant as these heavily pruned trees likely won't begin producing nuts before the completion of the grant. One possible solution to this is to remove the heavily pruned trees from the data set and find the average yield of the lightly pruned trees versus the unpruned trees.

Keeping "unmarketable" nuts data:

As part of the yield data for the grant, bad or "unmarketable" nuts were collected and kept separate from "marketable" nuts and "seconds". This data, though valuable, has made for inefficient harvesting of the nuts and a larger burden of time and labor for the supporting staff. Volunteers in the 2022 season picked all nuts from the ground including the bad nuts and these nuts had to later be sorted through and weighed by SilvoCulture support staff, a process that has turned out to be very time consuming.

Pest pressure:

Large deer and rodent pressure this year meant that many of the nuts that dropped were eaten. Support staff estimate that around half of the nuts were lost this way. Morris Orchard LLC will allow for hunting on the property in 2023 to help deter the deer.

With these considerations in mind, we expect that soil health data may be a better indicator of our efforts over the course of the grant. Chestnut yields may not be a good indicator during the course of the grant.

2023 Update

Heavily pruned chestnut trees vs lightly pruned chestnut trees:

Lightly pruned trees:

Wind damage occurred in 3 trees in the pruned groups in which limbs of the chestnut trees broke and fell to the ground. SilvoCulture staff believe this was due to increased wind flow through the more open canopy that the pruning created. Pruning smaller amounts of the canopy at one time could reduce the likelihood of wind damage.

Heavily pruned trees: 

The heavily pruned trees that put out many new shoots in 2022 were pruned in the winter of 2023. The new shoots were assessed for keeping or pruning and the best were selected to be kept to create the new main branches of the trees. Some of these new branches fruited in the fall of 2023 and produced a limited amount of chestnuts totalling no more than a few pounds. We expect these to produce in larger amounts in 2024.

When accounting for the heavily pruned trees that did not produce in significant quantity in 2024, the pruned trees outproduced the unpruned trees, regardless of soil amendments. 

Average yield of pruned trees vs unpruned trees, if non-producing trees are removed:

 

Group:

Treatment

Total (lbs)

Producing Trees

Average Nut Production per tree (lbs)

1 (Yellow)

Pruned + Fertilized

145.5

7

20.8

2 (Green)

Fertilized

183.5

14

13.1

3 (Blue)

None

224

14

16

4 (Red)

Pruned

192.5

10

19.25

 

Soil Results

The soil tests did not show improvement for the test groups. We believe this is because it takes time for the wood chips to affect the soil biology. We expect to see greater results with the 2024 soil tests. Through our consulting with Living Systems Soil, LLC, we learned that compost we were using for our extract was not biologically active enough to have a large effect on the soil health of the orchard. By applying the biologically active soil made by SilvoCulture staff, in the manner prescribed by Living Systems Soil, LLC we will see what effect a high quality compost extract has on the soil biology.

Pest pressure:

A hunter was invited to hunt in the orchard during the 2023 season. Although there was still a lot of deer pressure, it did seem to be reduced. 

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.