Abby and Nick Johnson are owners of Ox Heights, a 170-acre farm in Molkte Township, Presque Isle County, MI, five miles south of Lake Huron. Thirty acres are row cropped with a rotation of hay, corn, soybeans, and wheat. The forage is fed to our small herd of dairy goats and cattle (n=10). Some of the land is leased for $20 per acre to a local cattle farmer. The tillable land was purchased for $1,200/acre in 2010. 130 acres are dedicated to timber production. The deep well drained soils provide excellent substrate for producing high quality hardwood timber. We specialize in the sustainable production of veneer and high grade sugar maple, red maple, white birch, and yellow birch. Trees are harvested with a chainsaw and skidded by our team of oxen.
Abby and Nick were educated in the College of Agriculture and Natural Resources at Michigan State University. Abby earned her B.S. in Biosystems Engineering during 2009. She is raising our five children ages 9, 8, 6, 5, and 1 and manages chores around the farm. Nick earned his B.S. in Biology and Fisheries Management and works a full-time job as a fish biologist to help support the farm. During the evenings, he serves as an adviser for the Michigan Forestry Assistance Program. We have grown to love this region of Northeast Michigan and chestnuts and want to give something back to the region and chestnut industry. An excellent way to give back is to be a part of research that aspires to develop a sustainable agricultural income for local family farms.
During 2017, 435 Japanese/European grafted chestnut trees were planted in Northeast Michigan where chestnut trees have not traditionally been grown; SARE grant FNC17-1081. Tree survival was 99%, terminal growth was 1-2 ft., and a trace amount of nuts were produced in fall 2018. In future years, the establishing chestnut trees will need fertilizer. Aged manure could be a very good fertilizer for establishing chestnuts because manure is likely to increase soil organic matter, provide macro and micro nutrients, increase moisture availability, and improve winter survival by insulating the ground. But manure has never been tested or evaluated as a soil amendment for establishing chestnuts according to Chestnut Growers of America and the Australian Nutgrower. Therefore, we propose an experiment where aged manure (~7 months) is applied around some trees and inorganic fertilizer recommended by Michigan State University is applied around remaining trees, comparing both tree health and soil outcomes. The project promotes sustainable, diversified agriculture by revealing options for enhancing chestnut orchard establishment and the feasibility of manure application to effectively manage manure and reduce inorganic fertilizer use. A blog, video, field day, and presentation at a nut growers meeting will disseminate results.
- (1) Evaluate the feasibility of using aged manure in lieu of inorganic fertilizer during chestnut orchard establishment by evaluating tree survival, growth, nut production, and soil health.
- (2) Disseminate information regarding the feasibility of using aged manure in lieu of inorganic fertilizer during chestnut orchard establishment results through a blog, conference presentation, field day, and final report to SARE.
Inorganic Fertilizer Application:
Michigan State University (MSU) recommends standardizing fertilizer application at 2-4 oz. of nitrogen per chestnut tree per year for trees between 2-3 years old, and that application occur shortly after bud burst. Consultants from Chestnut Orchards Solutions recommend using Higgins Mix: containing ammonium sulfate (21%) and micro-nutrients and developed by a MSU Forestry professor. Ten ounces of Higgins Mix supplies 2 oz. actual N.
Organic Fertilizer Application:
Goat/cattle manure began aging November 2018 (Figure 1). Based on the manure analysis (Figure 2), an average of 4.3 lbs of nitrogen per ton of manure would be bioavailable during 2019 (converted to 68.8 oz/ton and then 0.0344 oz/lb). Therefore, we applied a target rate of 58 lbs. manure per tree to provide 2 oz. N. According to the FSMA Produce Rule, un-composted manure must be applied and incorporated 120 days before harvest of a crop that contacts the soil, such as chestnuts. Manure was applied April 2019, meeting the 120 day standard because nut harvest occurred in mid October.
Figure 1. Goat and oxen manure started the aging processes November 2018.
Figure 2. Nutrient analysis of aged manure applied to chestnuts during April 2018.
The experimental approach was to apply 10 oz. of Higgins Mix to 1/3 of the trees in each row of our orchard (around drip zone; Figures 3). Another 1/3 of the trees in each row received 58 lbs. aged manure. The remaining 1/3 of trees in each row received 5 oz. Higgins Mix plus 29 lbs. aged manure as a combined treatment. Treatments were systematically assigned to trees with the rows, therefore controlling for variability in soils, topography, wind, and temperature (Figures 4 and 5). General orchard maintenance recommended by MSU was conducted during growing season 2019.
Figure 3. Application of 10 oz of Higgins mix using a cup.
Figure 4. Buckets proved to be efficient distribution devices for aged manure. 12 gallons of manure equaled approximately 58 lbs.
Figure 5. Systematic application of manure only (58 lbs), 50/50 mix (29 lbs manure, 5 oz. Higgins), and Higgins only (10 oz. Higgins) to the rows of trees in the orchard.
Six cultivars of chestnut trees are grown in our orchard, so results for each fertilizer treatment are reported according to each cultivar. Colossal (C) and Bouche de Betizac (BB) are cultivars selected for nut production and are most numerous (sample size of about 50 trees per fertilizer treatment). Labor Day (LD), Marigoule (Mg), Marosol (Ms), and Precoce Migoule (PM) are pollinators and are less numerous (sample size of about 8 trees per fertilizer treatment).
Cost of Fertilizer:
Higgins Mix costs $36 for 50 lbs and because 10 oz of Higgins Mix was needed to apply 2 oz of available nitrogen, the cost of Higgins Mix fertilizer per tree was $0.45 (Table 1). Higgins mix was applied to the orchard at a rate of 1 tree per minute. Assuming a $15 per hour pay rate, labor costs to apply Higgins Mix was $0.25 per tree, meaning the total cost to apply Higgins Mix only was $0.70 per tree. Manure is a waste product from our goat and cattle farming operation, so aged manure was assumed to have zero cost. Aged manure was applied to the orchard at a rate of about 2.4 minutes per tree. Assuming a $15 per hour pay rate, labor costs (and the total cost) to apply aged manure was $0.60 per tree. The 50/50 mix of manure and Higgins Mix cost $1.08 per tree to purchase and apply.
Table 1. Cost for fertilizer and labor to apply fertilizer expressed as a cost per tree.
|Fertilizer Treatment||Cost of Fertilizer per Tree||Cost of Labor per Tree||Total Cost per Tree|
|50% Higgins and 50% Manure||$0.23||$0.85||$1.08|
Weather during 2019 was much cooler and wetter than average. Heat accumulation was about 400 growing degree day (base 50) below normal (Figure 6). About 23 inches of rain fell between April 1st and October 31st, 2019, and is about 4 inches greater than the long term average. Irrigation was only applied once to the orchard during 2019.
Figure 6. Heat accumulation in Northern Michigan during the 2019 growing season. Location of Ox Heights is circled. Data taken from Michigan State University Environweather Network.
Tree growth 2019:
Tree growth during 2019 was high among all cultivars and fertilizer treatments with new terminal growth averaging between 20 (PM) and 30 inches (Ms) (Figure 7). On average, growth of trees given manure treatment was slightly higher than those fertilized with only Higgins Mix (Figure 8). However, the differences were not drastic after one year. Based on previous research with organic fertilizers, growth rates are expected to diverge further among fertilizer treatments during 2020 and future years.
Figure 7. Growth of trees during 2019. First picture is during bud break in late May 2019. Second picture is in middle October 2019. Terminal growth of this individual Marigoule chestnut tree was growth was about 32 inches.
Figure 8. Box and whisker plots of new terminal growth of chestnut trees occurring during 2019. Six different cultivars of chestnuts are being grown (BB = Bouche de Betizac, C = Colossal, LD = Labor Day, Mg = Marigoule, Ms = Marosol, PM = Precoce Migoule) and each cultivar received one of three fertilizer treatments (Higgins = Inorganic; 50/50 = Higgins + Manure; Manure = aged manure).
Educational & Outreach Activities
The project and general orchard maintenance and farm operations were highlighted in 42 blog posts in 2019 at https://oxheights.com/
The project was highlighted in 2 newspaper articles published in the Presque Isle Advance.
A 30 minute presentation about our SARE projects was given at the Annual Meeting of the Midwest Nut Producers Council in March 2019.
A field day in September 2019 in partnership with the Soil Conservation District and NRCS brought 20 people to the farm.
Sunrise Communications highlighted our farm in their 1 hour+ broadcast titled “Let’s Explore Ox Heights”. https://vimeo.com/364787298 The Broadcast likely was viewed by thousands in Northern Michigan.
After year 1, a few lessons are emerging:
(1) Aged manure (including the labor to apply) does not cost more than inorganic fertilizer application; assuming that the cost of manure is $0.00 because it is a byproduct of on the farm animal production. Before this project, we were not sure how long it would take to apply manure around chestnuts trees and it turned out that application with a bucket was efficient and easy to replicate at each tree.
(2) Trees fertilized with aged manure on average grew as much and in many cases more than those fertilized with inorganic fertilizer. Because it can take trees 2 or more years to reflect improvements in soil health/nutrition, we expect differences among treatments may increase in future years as the experiment continues. We may request a no cost extension to continue monitoring growth and survival through years 3 and 4.
(3) Chestnut survival and growth in Northeast Michigan continues to be very high. We continue to expand our orchard and are excited about prospects in chestnut farming.