This project will provide a feasibility study for improving soil health and crop productivity in poorly-performing urban soils using Stropharia mushrooms. Farmers will gain information about the possible benefits and economic feasibility of using woodchips with and without Stropharia mushrooms to improve soils and crop yields. Farmers will also learn about the commercial viability of two crops that can be readily grown but are rarely sold in Central New York. The market viability study will reduce risk to farmers interested in diversifying their operations with these new crops, either preventing loss from a poor crop choice or increasing income by adding a niche product with demonstrated demand. Because woodchips are an affordable and readily available Organic soil amendment, farmers will learn how to utilize a low-cost soil amendment.
Objective 1. Test efficacy of various woodchip substrates and Stropharia to improve marginal agricultural soils.
Objective 2. Test impacts of Stropharia-inoculated and composted woodchips on yields of lemon cucumbers, cabbage and carrots.
Objective 3. Test marketability of two novel crops: lemon cucumbers and Stropharia mushrooms.
Objective 4. Measure economic viability of various soil amendments used to improve productivity of poorly performing soils.
Agricultural soils everywhere face performance decline from erosion, poor drainage, compaction, and loss of organic matter. Poor soils can take many years to rehabilitate. Compaction is a significant problem, especially for urban farmers attempting to reclaim previously developed land. Remediating compaction and affording soil improvement techniques are critical for all farms seeking to be economically sustainable, and is the emphasis of this project. The goals are threefold: assess the effectiveness of wood chips as soil amendments; measure the benefits of Stropharia rugoso-annulata (wine cap) mushrooms to mitigate soil compaction; and assess marketability of two novel products. The first two goals are accomplished by comparing the effectiveness of five different soil amendments to improve soil microbial activity, available nitrogen, soil nutrition, compaction, and crop yield. Treatments include ramial and mixed hardwood chips inoculated with Stropharia; naturally decomposed ramial and mixed hardwood chips; and an untreated control. Eight repetitions of the treatments are each planted in lemon cucumber and cabbage, then beets. The second goal is accomplished by surveying customers who purchased lemon cucumbers and wine cap mushrooms from the farm. Outreach occurs by three methods: offering factsheets and experimental tours through a county-wide Farm Day, submitting results to local agency newsletters, and hosting workshop and tours for farmers, gardeners and students interesting in improving soils or growing Stropharia mushrooms and/or lemon cucumbers. The desired impact of this work is to bolster regional knowledge of soil amendment techniques using easily attained biomass and market viability of new agricultural products for growers in the Northeast.
Wood chips are a readily available organic matter in urban and rural settings. They are rarely used as a soil amendment due to losses of bioavailable nitrogen when the wood decomposes, and wood chips also are difficult to cultivate with equipment. Ramial mulch describes mulch that is sourced from woody material that is originally no larger than 3” in diameter. The extra nitrogen available through a higher cambium to wood ratio, helps to prevent nitrogen depletion and speed nutrient release of the chips. Brian Caldwell wrote a paper for the University of Vermont summarizing a 15-yr study on the usefulness of woodchips as a soil amendment in Marcellus, NY. The study ended in the 1970’s. Mr. Caldwell compared this research to studies conducted in Quebec, Canada analyzing the use of ramial mulch as a soil amendment. Both studies showed the promise of wood chips as a soil amendment, and he highlights the need to ensure adequate nitrogen to prevent reductions in crop yield. Shrub willow in Canada is made into ramial mulch and sold as a high end landscaping product, but it has not a common material used in the United States.
Stropharia rugoso-annulata is in the white rot family, which is known to break down cellulose and lignin. When the cellulose and lignin in wood chips are first broken down by Stropharia, nitrogen and other nutrients from those woodchips become bioavailable sooner. This could also allow wood chips to be integrated as soil amendments, and not limited to a top-dress application. The combination of Stropharia cultivation in a wood chip amendment may expedite soil building, nutrient availability, and increase crop yields.
In 2014, Eric Fabio of Dr. Smart’s Willow Lab at Cornell University, and Jessi Lyons at Cornell Cooperative Extension of Onondaga County tested the potential of woodchips and Stropharia rugoso-annulata to reduce soil compaction in urban gardens. This pilot study revealed almost 40% increase in soil penetrability due to woodchips grown with Stropharia mushrooms. The study set out to compare ramial mulch sourced from shrub willow wood chips versus readily-available mixed hardwood wood chips, as a growing medium. The study revealed that higher nitrogen substrates supported more flushes of mushrooms, though there was not a significant difference between the willow and the mixed hardwood due to an excessive amount of green leaf litter combined with the hardwood chips. This left a question about the role of nitrogen in supporting the Stropharia growth, and the long-term use of wood chips as a fertilizer. The study did not measure the viability of growing crops in these substrates, or the potential impact of undecomposed wood chips and nitrogen mineralization on future crops.
Stropharia rugoso-annulata has been actively researched at Cornell University in recent years as a viable agro-forestry product. The research has not directly extended into agricultural field production. The benefits of Stropharia mushrooms have been touted for soil moisture retention and increasing symbiotic relationships with plant roots, increasing plant nutrient uptake. Stropharia is an uncommon market crop due to its fragility post-harvest, the inability to predict and control fruiting, and because wildlife and slugs favor the fruit. While Stropharia in itself may not be worth growing as a source of revenue, it can be seen as a “bonus” crop that can provide supplemental income to existing crops.
Eight blocks containing 70′ rows were established to test multiple mulch applications, viability of Stropharia rugoso-annulata on the plots, and impacts to cabbage, lemon cucumbers, and beets.
Mulch treatments were randomized within each block, separately for each crop. Due to a loss of cabbage seedlings in year one, lemon cucumber and cabbage were planted in separate trials. In year two, the beets and cabbage were planted on the same date. Each plot of cabbage consisted of one plant. Lemon cucumber plots consisted of three total plants, and beet plots consisted of four groupings of 3-5 beet were plot. The crops, however, occupied space adjacent to one another in the same rows, so that soil conditions should be similar. In year one, lemon cucumbers and cabbage were tested, and beets and cabbage were tested in year two. Five mulch applications were tested: control; ramial wood chips sourced from shrub willow and inoculated with Stropharia; 2-year old decomposed mixed wood chips; fresh mixed hardwood chips inoculated with Stropharia annuala-rugosa; and fresh wood chips mixed with fresh grass clippings.
Each treatment received one inch of compost application to bare soil prior to mulch treatment and planting. Stropharia rugoso-annulata spawn was applied between the compost and ramial mulch and hardwood mulch applications, respectively and watered in. In year one, lemon cucumber was planted in June and harvested between July 26 and August 24. Cabbage was planted in August, and harvested on December 3. In year two, beets and cabbage were planted in May. Beets were harvested August 3, 2019 and cabbage was harvested August 11, 2019.
Fresh weight and fruit number were recorded for each plot on each harvest date of lemon cucumber. Fresh weight yield and fruit number were summed across all dates within plots in order to analyze total yield and fruit number separately as response variables. For cabbage, only one harvest occurred at the end of the season with one sampling unit (cabbage head) per plant harvested, so only total yield was considered for a response variable. For beets, all plants were harvested on the same day and the total mass of each plot was measured.
For statistical analysis PROC MIXED in SAS was used to perform a one-way analysis of variance (ANOVA) with random blocks. We used this approach because some plants died during the experiment, but we did not attribute this to the mulch treatments. Therefore, we had missing data for some plots and PROC MIXED is the best fit for experiments with missing data. The probably of significance was tested at P = 0.05 and at 0.10 levels. When the ANOVA showed significant main effects of mulch treatment, an all-pairwise comparisons means separation test was used to find significant differences between mulch treatments
Soil samples were taken prior to the treatment, and following the final cabbage harvest in year one.
Plants were maintained with regular watering (at least 1″ of water per week when rainfall wasn’t adequate) and organic pest prevention as necessary. Pest prevention consisted of manual removal of striped cucumber beetles, row covers over cabbage to protect from Swede midge and application of diatomaceous earth around cabbage for slug control. No additional fertilizer was applied beyond the original compost and mulch treatment applications. Lemon cucumber fruits were weighed upon harvest, based on a standard harvest size. Plants were monitored daily for ripeness.
Stropharia mycellium was monitored throughout the growing season, and fruits were weighed when harvested.
1. The first objective was to test efficacy of various wood chip substrates and Stropharia to improve marginal agricultural soils. We tested this by analyzing soil nutrition (pH, Al, Ca, Fe, K, Mg, and Mn, and organic matter) and microbial activity of the soil (NO3, CO2 and SLAN) after the year one growing season. We analyzed effects by treatment, crop and treatment with crop. There was no difference in pH, aluminum, calcium, magnesium or manganese by treatment. We found that iron was significantly less in the control than ramial and mixed hardwood, whereas potassium was significantly less in the control than in the mixed hardwood and hardwood with grass. Organic matter was significantly greater in the ramial treatment than control, and nitrate was higher in the control than in ramial, mixed hardwood and mixed hardwood with grass. There was no significant difference in SLAN or CO2 by treatment.
We also found that pH, calcium, iron, potassium, magnesium and manganese were all significantly lower in the cabbage plots compared to lemon cucumber plots. SLAN and organic matter were also significantly higher in lemon cucumber than cabbage plots.
2. The second objective was to test impacts of Stropharia-inoculated and composted wood chips on yields of lemon cucumbers and cabbage. First, we tested for the effects from different mulch applications on plant productivity, as measured by mass and also number of fruits of the lemon cucumbers.
Year One. For total fruit number produced by lemon cucumber, the ANOVA test did not find significant differences in mulch treatments at the P = 0.05 level, but there was a significant effect at the P = 0.10 level (Table 2). Using the P = 0.10 significance level, the means separate test showed that for total fruit number per plot, Decomposed wood chips had the greatest mean total number of fruits, but they were not statistically greater than ramial mulch, but they were significantly greater than the mixed hardwood and grass treatment.
The cabbage trial did produce a crop, though none of the plants had fully made a head before they were harvested in December. The cabbage was planted in late August due to a loss of seedlings earlier in the season. The plants were then covered with row cover due to a significant presence of Swede midge on other cruciferous crops. The combination of late planting and continual presence of the row cover late in the season likely inhibited growth. The row cover also made it difficult to see damage from slugs. When the row cover was removed in late October, significant slug damage was noted and the plants were treated with diatomaceous earth. Slugs were documented primarily in the hardwood, ramial, and wood chip/grass treatments, likely due to the large air spaces in these mulches providing ideal habitat whereas the decomposed wood chips and control treatments have smaller pore space. We did find a significant effect from mulch treatments, where the control had significantly higher biomass than all other treatments, and hardwood mixed with grass was higher than the ramial.
We again analyzed the second year yield data separately by crop. There were no statistically significant differences among mulch treatments for total yield of beets. For cabbage, there was no significant difference among treatments for harvest number or total yield. There was however a significant difference for individual cabbage weight at the alpha = 0.10 level, with the ramial mulch having significantly greater weight than all but the hardwood chip mulch treatment.
3.The third objective was to test marketability of two novel crops: lemon cucumbers and Stropharia mushrooms. The Stropharia mushrooms successfully colonized the test plots, and mycellia were observed throughout the growing season. The mycellia were not as abundant and deep as we expected, and only two of the 80 test plots had fruit production. The mushrooms that did fruit came over a weekend when they were not observed, and were too mature to properly measure or consume when they were discovered. These mushrooms were discovered in the cabbage plots where row cover was protecting them. The presence of the row cover partially concealed their presence, but also may have created conditions to encourage the very late emergence (early November). Not enough of Stropharia produced fruit to provide any further analysis or results. The Stropharia mycellia did not recolonize the plots in 2019.
Lemon cucumbers were sold at the CNY Regional Market and added to the customer CSA boxes. Customers sought out the cucumbers at the market stand and they sold out within a couple hours of being offered. Market customers who tried this crop would regularly seek them out. Lemon cucumbers were not grown in year two, though customers expressed regret that we did not grow them a second year. Five customers who either visited the farm directly, or the market stand specifically requested that we grow them again. Two community gardens who grew the cucumbers also requested that we grow seedlings for them in future. The demand for these cucumbers far exceeded what we grew. The negative responses from customers related to the “seediness” of the cucumbers, while some customers preferred the more mellow taste and crispy texture.
4.The fourth objective was to measure economic viability of various soil amendments used to improve productivity of poorly performing soils. We assessed this by doing a cost benefit analysis considering the cost of the material, cost of labor spent spreading the material, the potential improvement in sales over time. This analysis is forthcoming.
We found that the application of ramial willow wood chips inoculated with Stropharia can improve crop yields over time, compared to other mulch treatments and a compost-only control. While there was an immediate negative effect on crops in year one, the second year showed a significant increase in crop yields compared to other treatments.
The combination of Stropharia helping to hasten the decomposition of lignin, and the higher nutrient content of ramial mulch compared to other forms of wood chips, helped to increase yields relative to other applications after two years. Whereas the mixed hardwoods were also inoculated with Stropharia, they take longer to decompose and release nitrogen due to the chip size and nitrogen content relative to a ramial mulch. The decomposed wood chips in year one performed better than ramial, but not the control, but the effect did not last into year two. This could be explained by the more available nutrients being depleted in year one, similar to the compost-only treatment. Wood chips mixed with grass were significantly better than ramial in year one, but were significantly worse than all other treatments in year two. This could be explained by the nitrogen in the grass adding a nitrogen boost to crops in year one, but the lack of a decomposer like Stropharia to further decompose the remaining wood chips meant that nutrients were unable to be released from the chips in year two. And control had the highest amount of nitrogen in year one, compared to all other treatments, indicating that all mulch applications are less useful as a nitrogen supplement in the first year of an application. Not surprisingly, the control also had significantly less OM compared to ramial, again indicating a higher C:N and less initially available nitrogen in ramial mulch.
In consideration of use of wood chips for future land use applications, the presence of Stropharia as a primary decomposer is important. And a ramial mulch that naturally has higher nitrogen content than standard wood chips in combination with Stropharia, will have greater yields than other Stropharia inoculated wood chips. When applications of compost are cost prohibitive, and
It was valuable to note that cabbage seems to be a heavier feeder than lemon cucumbers and the production of cabbage itself may have impacted soil characteristics. Cabbage yields increased in the second year in the ramial plots, which may be attributed to the delayed release of nitrates in those treatments due to the initial high lignin content. The higher organic matter present in the lemon cucumber plots also indicates that cabbage was depleting these nutrients more than lemon cucumber. Calcium in the soil was less in the cabbage plots, which may also explain the decrease in pH in those plots. This was an unexpected result worth considering for future soil amendments where pH is very high.
For future uses of mulch treatments for soil amendments where vegetable production will be concurrent, it will be important to consider the specific nutrient requirements of the various vegetables and how they will respond to nutrient availability based on the timing of the mulch application.
Education & Outreach Activities and Participation Summary
We hosted two on-farm field days that were open to the general public. Each of these field days highlighted our research project to visitors going on the tours. In 2018 we had four farmers attend the field day and specifically stopped to learn about the project. We also had 180 visitors from the general public attend the tour and learn about the project. In 2019 we had just one farmer attend the tour, in addition to over 200 members of the public, and six agriculture educators. In 2019 we hosted two educational workshops for refugee farmers. With help from interpreters we were able to highlight the project to 18 new farmers. We also hosted twelve Master Gardener volunteers for a tour to explain the project.
On January 18 2020, we will be sharing flyers and data at the Northeastern Organic Farming Association of NY conference at a tabling event. Additionally, the final fact sheets will be shared with the NY Farm Bureau, Onondaga County Soil and Water Conservation, and Morning AgClips.