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 and lemon cucumbers.
Each block was divided in half, each half with five mulch treatment plots. One half of the block contained lemon cucumber, the other half contained cabbage. Five mulch applications were tested: control; ramial wood chips sourced from shrub willow and innoculated with Stropharia; 2-year old decomposed mixed wood chips; fresh mixed hardwood chips innoculated 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. Lemon cucumber was planted in June and harvested in August. Cabbage was planted in August, and harvested in December.
Soil samples were taken prior to the treatment, and following the final cabbage harvest.
Cabbage and lemon cucumbers 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. Entire cabbage plants were harvested to measure biomass.
Stropharia mycellium was monitored throughout the growing season, and fruits were weighed when harvested.
Statistical analysis was a split-plot design, with crop as the whole plot. Mulch treatment as the split-plot factor. We analyzed the data using SAS PROC MIXED. Factors were mulch, crop and block. Mulch and crop were considered fixed effects, and block and the interaction of block and crop were considered random effects. We first analyzed total yield by summing the weight of lemon cucumber across all dates. Since we had multiple fruits per lemon cucumber plant, we also assessed total fruit total per plant. That was analyzed using a one-way ANOVA.
The first objective was to test efficacy of various woodchip substrates and Stropharia to improve marginal agricultural soils. These results are forthcoming, pending soil test results and analysis.
The second objective was to test impacts of Stropharia-inoculated and composted woodchips on yields of lemon cucumbers and cabbage. First, we tested for the effects from different mulch applications on plant productivity. The analysis indicated that lemon cucumber had a marginally significant effect from mulch treatment (p=0.07), where the control and decomposed wood chip treatments had the greatest total fruit number, followed by ramial mulch, hardwood and grass in that order. The cabbage crop was not successful and none of the plants had fully made a head before they were harvested in December. The cabbage was planted in late August and 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 prevented proper 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 woodchip/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. Statistical analysis of the cabbage yields are forthcoming.
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.
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. 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. Further CSA customer survey results are pending.
The fourth objective was to measure economic viability of various soil amendments used to improve productivity of poorly performing soils. These results are pending further soil analysis.