Progress 07/01/22 to 11/30/23

Outputs
Target Audience:In this research, a wide array of entities and individuals have played a part. Listed below is a chronological sequence of the people that have been involved in the project and those that are expected to directly see the results and reports. Additional people are expected to be involved as the project continues into commercialization (Phase II). DEVELOPMENTAL WORK Several industrial hemp growers & producers are supplying feedstocks for the work, and looking ahead, they are anticipating growing hemp for commercial development. A fiber processing equipment manufacturer has evaluated and quoted on large scale equipment for processing at much higher volumes than in the pilot plant. A fiber analysis lab has implemented their dairy feed analysis techniques to evaluate the makeup of the industrial hemp fibers. PROCESSING WORK The entire production staff at PittMoss, LLC participated in trial processing and formulation of test blends for the growth trials at the University of Arkansas and at Dr. Bethke's research greenhouse. The QC and Lab Staff at PittMoss, LLC learned techniques for evaluation and measurement of physical and chemical properties of raw materials and formulated blends. A research assistant and master's degree student from the Ohio State University assisted in some evaluations and traveled to the University of Arkansas to observe the growth trials there. This soil science master's degree candidate has since joined the staff at PittMoss as an assistant soil scientist. PERFORMANCE & EVALUATION WORK Researchers at the University of Arkansas, including Dr. Ryan Dickson, a doctoral graduate student assistant, and a number of undergraduate and graduate students evaluated blends for physical properties and chemical properties and also grew and evaluated plant growth as a part of their learning while being trained in horticultural research and plant and soil science. The plan for evaluations at North Carolina State University on physical property measurements could not be completed because they ceased performing contracted lab work. The physical properties work, along with growth trials, was then conducted by Horticulture Consultant Charles L. Bethke with assistance from his associates who learned more about properties of horticultural substrates and how to measure the most significant properties. Three different substrate & soil analysis labs performed evaluations and analyzed input materials and final blends. REPORTS AND PRESENTATIONS PittMoss, LLC administration and staff have prepared internal reports covering segments of the project. Additionally, segments of the project were presented to the West Michigan Sustainability Forum and the OEFFA Cultivating Care 2024 Conference. A presentation on cost of substrates has been accepted and some of the findings on using industrial hemp will be included at the Ohio Cultivate'24 conference for greenhouse growers and educators in July of 2024. Discussions on using hemp in landscape and growing substrates are planned for the Illinois Landscape Association March 7th, 2024, workshop on growing substrates. Articles are being written for submission and publication in horticulture trade magazines. The public will soon be able to view information on this work in the technical information section on the PittMoss website. Research at the University of Arkansas has been completed and Dr. Dickson is preparing academic journal articles for peer review and eventual publication in horticultural journals. In addition, he references the work with hemp to students and research colleagues demonstrating advances in replacing sphagnum peat and producing more environmentally compatible growing substrates. Changes/Problems:The work progress schedule was delayed by two primary events: The COVID-19 pandemic and health issues experienced by Dr. Bethke. The COVID-19 pandemic caused global supply chain problems and significant delays in processing equipment upgrades at the PittMoss plant. Various health problems resulted in Dr. Bethke requiring three separate hospitalizations related to knee infections, a knee joint replacement, and a subsequent second infection that partially incapacitated him for the initial period of the originally scheduled granting period. Despite the delays, the grant work proceeded systematically and mostly as originally planned with only minor adjustments. Fortunately, nine-months of extensions to the grant period have allowed the work to be performed completely and effectively. The work yielded noteworthy progress toward understanding the properties of hemp as they relate to the production of sustainable substrates. Failure to have the upgraded equipment running in time for the first grant-related growth trials required a switch to hand blending of the substrate formulations for the University of Arkansas's and Dr. Bethke's first grow trials. This delay turned out to be beneficial for Dr. Ryan Dickson and staff at the University of Arkansas, providing more effective scheduling of their research greenhouse and better coordination a midst other projects and staffing. As a result, the longer-term crop originally planned for this study was changed from chrysanthemums to a dwarf fruiting tomato. There was also a similar case for the work by Dr. Bethke at his operation: dwarf sunflowers replaced the chrysanthemums. In keeping up with timing of the study, the hemp used for the trials had to be processed by an outside vendor. It turned out to be too coarse and should have had a slightly finer texture. The coarser hemp particles in the test blends required a change at the University of Arkansas from the planned subirrigation methods to surface irrigation. That was due to the reduced hydraulic conductivity within most of the trial blends. That was not an issue for the work at Dr. Bethke's facility since his plan always included surface irrigation, however it did raise the challenge to better process the hemp to achieve finer textures of the particles and more effective water movement within the blends. Another problem discovered in those first growth trials was high boron levels in the specific batch of PittMoss paper aggregate used for the trial blends. The minor level of toxicity was discovered soon after the trials began. High boron content severely damaged three of the ten trial blends (those containing hemp and PittMoss at rates of 100, 66, and 33 percent) putting those blends outside of the normal boron tolerances. By comparison, the trials of hemp in combination with coconut coir and sphagnum peat functioned normally. Additionally, some surprising discoveries within these first growth trials included observations that the biological activity in blends incorporating this whole stalk hemp was remarkably high. As a result, the soluble (available) nitrogen was consumed faster than it was supplied via fertigation. That very rapid nitrogen consumption resulted from high microbial demand given the elevated levels of labile carbon made available in the shredded hemp particle. This effectively taught us that we needed to further evaluate the nitrogen dynamics in blends containing whole stalk hemp and particularly those with high bast fiber content. Additional studies were undertaken to determine the quantity and rate of the observed nitrogen drawdown. Further learning in the first grow trials was a higher pH level. It became apparent that the batch of hemp supply that was used contained high soluble potassium, resulting in a high pH in the blends containing higher levels of hemp. That observation raised the question of variability in sources of industrial hemp and apparently was related to the soil where the resource was grown. Together, the high potassium and the higher pH of the hemp created some nutrient imbalances in blends with high ratios of hemp. These observations demonstrated that careful sourcing and monitoring of feedstocks will be necessary in commercialization to precisely balance nutrition in blends containing field grown industrial hemp. Another important change from the planned work occurred when the NCSU lab ceased performing analyses on physical properties. The physical property work was then transferred to Dr. Bethke's lab and modified Porometer measurements delivered the air-water-solids percentages and wet and dry bulk densities on processed hemp and trial blends. What opportunities for training and professional development has the project provided?The project has provided a number of opportunities for personal and professional development within the PittMoss company and at the University of Arkansas. Employees at PittMoss, LLC have learned about the growing and processing of industrial hemp and have developed some expertise in processing the raw fibers. Some of the employees have been exposed for the first time to the concept of sustainable substrate production using industrial hemp. Managers and equipment operators have observed and developed information to be used in processing protocols. Management personnel at the company have learned about the hemp market. A summer employee who is a master's degree student from The Ohio State University visited to observe the research being done at the University of Arkansas and communicate with the researchers. This employee subsequently helped prepare and edit the interim report for this project to the USDA. A research consultant who works closely with PittMoss, LLC, Dr. Charles L. Bethke, has learned about the properties and characteristics of industrial hemp and how it can be manipulated through processing and the introduction of additives to become an excellent growing substrate component. Graduate and undergraduate students and the research professor at the University of Arkansas (Dr. Ryan Dickson) had the opportunity to participate in the development of sustainable growing substrates. They learned more about controlled plant growth studies through the practice of plant growth monitoring, data collection and analysis, and production of a final report. Dr. Dickson expanded his knowledge of industrial hemp as a sustainable growing media component and plans to submit articles to academic, trade, and professional publications. How have the results been disseminated to communities of interest?During developmental work, interactions with the hemp-producing community and researchers at several universities included informal discussions of the concepts around using industrial hemp for greenhouse growing and other agricultural substrates. Machinery manufacturers were interested in our project and provided helpful suggestions on equipment. Several labs provided suggestions on the best testing procedures to get useful results. Staff at the PittMoss plant were made aware of the goals and provided unlimited suggestions and observations. Visitors to the production facility were curious about the work with hemp. Work on measurements of properties and growth performance created environments for discrimination of the purpose and functional aspects of hemp in growing substrates. This was especially true at the University of Arkansas. Soil science and horticultural students saw firsthand how a farm raised material could be used as a growing substrate thus creating greater awareness of more sustainable ways of growing plants. Dr. Dickson has discussed the use of hemp with his circle of growing substrate researchers at universities around the country and plans to include some of the information in presentations, publications, and journal articles. Some researchers at NCSU produced transplants while trialing early versions of hemp propagation mixes. They have presented their observations in a session at a research meeting discussing producing transplants for an agronomic crop. Plans are in place to expand information on hemp on the PittMoss website, in trade journal articles, informational product flyers, and presenting information on webinars. Discussions and trials have begun to move toward commercialization of a full array of hemp containing substrates. Among those already exposed include greenhouse growers, poultry farmers, mushroom growers, and worm producers. Interest is high and trial results are very encouraging. It is anticipated that, with some promotions, entrance into the various markets will be rapid. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? IMPACT: This work demonstrates that industrial hemp can have a very significant impact on the standard horticulture growing media formulations and sources of the base materials. Through appropriate processing and nutritional balancing, hemp can reduce and even fully replace sphagnum peat in an array of growing media blends while reducing fertilizer and water requirements. With work toward commercialization, the implementation of hemp presents opportunities for changing the current practice of importing sphagnum peat from Canada and Northeastern Europe to using regionally and locally produced hemp fiber as the base for growing substrates. The accomplishments from this work were mostly executed as laid out in the original plan. General descriptions of the findings are segmented into the following activity groups. 1 - IDENTIFYING AND ACQUIRING INDUSTRIAL HEMP SUPPLIES: Increased understanding of the hemp industry and the channels for acquiring raw materials was established. Online learning, visits to industrial hemp growers, and attendance at research field days at Penn State University and Cornell University provided a solid base of understanding. Raw materials, including whole-stalk and processed bast and hurd fibers continue to be purchased from select growers as we commercialize the products. Sourcing feedstock will require evaluations of mineral content in the feedstock from different producers. 2 - PROCESSING TEST RUNS: Evaluations were made as to how whole-stalk hemp and hurd fiber feedstocks fared in the processing system. The objective was to make particles suitable for finished growing mixes. Other key findings included developing methods to avoid clogging of the system and reducing the dust production. In full-scale commercial production systems, more elaborate dust abatement measures will be necessary. 3 - CHEMICAL AND PHYSICAL PROPERTY EVALUATIONS: Developing particle sizes and forms most suitable for use in growing substrates was a major objective of the project. Evaluations of the processed hemp fibers were performed at the Ambridge, PA lab and at several horticultural substrates labs. Soluble salt and pH levels, along with wettability, moisture content, and particle size distributions were determined for the various hemp materials and blends. The physical property evaluations were performed at Dr. Bethke's research facility because the NCSU lab discontinued their public testing services. The modified porometer tests measured aeration, water holding (at saturation), percent space occupied by solids, and wet and dry bulk densities. These measurements helped to determine the influences that different hemp materials, as well as different particle sizes and forms, had on the properties of the blends. That information will be essential during commercialization. Determinations of the chemical makeup of the hemp fibers were performed by Dairy Land Labs in Wisconsin. Differences in the percentages of sugars, starches, cellulose, and lignin within the whole-stalk hemp and hurd fibers were observed. Detailed chemical evaluations, including the soluble and total nutritional contents of hemp fibers and trial blends were made by three outside labs. Of special interest were the forms of nitrogen and the levels of major and minor nutrients present and their relative plant availability. Findings that require special consideration are the very high levels of potassium, high pH levels, and the low nitrogen content. These findings resulted in an expansion of the project to include evaluating methods to lower pH and to supply sufficient nitrogen. In commercial production it will be necessary to address the variability and source dependent mineral levels. 4 - PHYSICAL PROPERTY MANIPULATIONS: Due to manufacturing upgrade problems the first trial blends were formulated using the best pre-processed, whole-stalk ground hemp provided by a supplier. Results from those trials performed at the University of Arkansas's and Dr. Bethke's greenhouses demonstrated that the particle sizes were too large. Subsequent processing alterations have yielded materials with a wider array of possible outcomes. As a result we were able to easily mill hemp materials that possessed the most desirable ratio of air and water holding with a range of only 10-14% solids. 5 - NUTRITIONAL LAB ANALYSES: Testing by three different labs defined the nutritional balance of hemp raw materials and the produced blends. The evaluations included both saturated media analysis (SME), that reports the water-soluble nutrients, and the total mineral content (TOT) to quantify the amount of the nutrients present in soluble and insoluble forms. Multiple determinations of pH and soluble salts (EC) were made by the University of Arkansas and by Dr. Bethke. The pH and EC levels in the test blends varied with the hemp contents in the trial blends. The PittMoss component in four of the blends showed high pH levels and very low nitrate-nitrogen levels. From these lab tests and subsequent first growth trials, it became apparent that the pH, potassium, and very low nitrogen levels had to be addressed for commercialization. CROP GROWTH TRIALS: The first trials at the University of Arkansas and at Dr. Bethke's facility, using an array of 10 test blends and three control formulations, demonstrated effective growth in the substrates composed of hemp in combination with sphagnum peat, coconut coir, and the PittMoss paper-based materials. Key findings of the first trial included the discovery that those hemp particles were too coarse to support effective hydraulic conductivity thus making surface irrigation the preferred water delivery method in the higher hemp containing substrates. Additionally, when incorporated at higher rates, the soluble salts and pH levels tended to be higher than desired. Overall, crops grew best in blends that contained 33% or less of this coarser version of hemp particles These first trials provided solid information used for subsequent investigations with improved hemp particle sizes and development of better nutrient balances in blend formulations. 7 - EVALUATION OF THE IMPACT OF CROPPING: Observations in production showed that the bast fibers decayed more rapidly, while the hurd fibers are very resilient and maintain their shape and size over at least 18 months of cropping. Chemically, the high nutrient buffering provided by the hemp resulted in little shifts in pH and good absorption of applied nutrients, providing greater nutrient efficiencies, and greater plant mass. 8 - ANALYZING LEACHATES: Water applications and leachate volumes were compared for hemp hurds incorporated at rates from 0 to 40 % in combination with a PittMoss blend (Plentiful) at 100 to 60%. The frequency of water applications and the quantity of leachates were not significantly altered by altering the rate of hemp. Due to budget limitations the concentrations of nutrients in the leachates were not lab analyzed as planned but pH and soluble salt tests showed high levels of absorption of nutrients with little change in pH. 9 - ANALYSIS OF DATA AND COMPILATION OF FINDINGS: Findings from manipulation of the hemp fibers showed how various processing influenced blend properties. Compiling findings from subsequent processing iterations, formulating new blends, and then testing the impact of the new blend on the properties served to guide development of substrates throughout this project. Viable substrates for use in growing blends were made. "Proof of Concept" for using hemp as a growing substrate component was made by crop growth and data analyses at each step along the way. 10 - FINAL REPORTS AND PRESENTATIONS: Educational efforts and the transfer of information are already being developed based on findings to date.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Cullinan, M., C. L. Bethke. 2023. Becoming Circular with PittMoss. Presented at the Western Michigan Sustainability Forum.
• Type: Other Status: Other Year Published: 2023 Citation: Bethke, C. L., M. Cullinan. 2023. Evaluating the use of hemp in paper-based growing substrates. Provided as a handout at the Western Michigan Sustainability Forum and at the OEFFA 2024 Cultivating Care conference.
• Type: Journal Articles Status: Other Year Published: 2025 Citation: Articles regarding this work are being developed by Dr. Ryan Dickson and his team at the University of Arkansas. They are anticipated for publication within the next couple of years.

Progress 07/01/22 to 06/30/23

Outputs
Target Audience:During the research to date, a wide array of entities and individuals have been a part of this project. Listed below is a chronological sequence of the people that have been involved in the project and those that are expected to directly see the results and reports. DEVELOPMENTAL WORK Several industrial hemp growers & producers have supplied feedstocks for the work. A fiber processing equipment manufacturer has evaluated and quoted on large scale equipment for processing at much higher volumes than in the pilot plant. A fiber analysis lab has implemented their dairy feed analysis techniques to evaluate the makeup of the industrial hemp fibers. PROCESSING WORK At PittMoss LLC: Nearly the entire production staff participated in trial processing and formulation of test blends for the growth trials at the University of Arkansas. The QC and Lab Staff at PittMoss LLC: Learned techniques for evaluation and measurement of raw materials and formulated blends. A research assistant and master's degree student from the Ohio State University in summer work assisted in some evaluations and traveled to the University of Arkansas to observe the growth trials there. Three different substrate & soil analysis labs performed evaluations and analyzed input materials and final blends. PERFORMANCE & EVALUATION WORK Researchers at the University of Arkansas, including Dr. Ryan Dickson, a graduate student assistant, and a number of undergraduate and graduate students evaluated blends in growth trials and physical property measurements. The plan for evaluations at North Carolina State University on physical property measurements could not be completed because they ceased performing contracted lab work. The physical properties work, along with growth trials, was then conducted by Horticulture Consultant Charles L. Bethke with assistance from his associates. REPORTS AND PRESENTATIONS SBIR Staff have been involved in supervision and report evaluations. PittMoss LLC administration and staff have prepared internal reports covering segments of the project and a summary of the ongoing project for presentation to the West Michigan Sustainability Forum. Applications have been made to present the findings to date to the Pennsylvania PASA conference and the Ohio Cultivate'24 conference for greenhouse growers and educators in July of 2023. Articles are being written for publication in trade magazines. The general public will soon be able to view information on this work in the technical information section on the PittMoss website. Research at the University of Arkansas has been completed and Dr. Dickson is preparing academic journal articles for peer review and eventual publication in horticultural journals. Changes/Problems:The schedule that was originally laid out was delayed by two primary events: The COVID-19 pandemic and health issues experienced by Dr. Bethke. The COVID-19 pandemic caused global supply chain problems and significant delays in processing equipment upgrades at the PittMoss plant. Various health problems resulted in Dr. Bethke requiring three separate hospitalizations related to knee infections, a knee joint replacement, and a subsequent second infection that partially incapacitated him for much of the originally scheduled granting period. Despite the delays, grant work has proceeded as originally planned with only minor adjustments. A nine-month extension to the grant has allowed the work to be performed systematically and effectively. Significant progress has been made in understanding the properties of hemp as it relates to the production of sustainable substrates. Failure to have the upgraded equipment running in time for grant-related trial blending required hand blending of the substrate formulations for the University of Arkansas's and Dr. Bethke's first grow trials. This delay turned out to be beneficial for University of Arkansas's Dr. Ryan Dickson, since scheduling of the research greenhouse and staff had to be delayed due to other projects and staffing issues. As a result, the long term crop originally planned for this study had to be changed from chrysanthemums to a dwarf fruiting tomato. This was also the case for the work by Dr. Bethke, and at his operation, dwarf sunflowers replaced the chrysanthemums. The hemp incorporated in those trials was processed by an outside vendor and should have had a slightly finer texture than the hemp that was actually delivered for inclusion in the blends. The coarser hemp particles in the test blends required a change at the University of Arkansas from planned subirrigation to surface irrigation due to the reduced hydraulic conductivity of the substrate. That was not an issue for the work at Dr. Bethke's facility, since his plan always included surface irrigation. A second problem discovered in the first growth trial was high boron levels in the batch of PittMoss paper aggregate used for the trial blends. The minor level of toxicity was discovered soon after the trials began. High boron content damaged three of the ten trial blends (those containing 100, 66, and 33 percent PittMoss) and put those blends outside of the normal boron tolerances. By comparison, the trials of hemp in combination with coconut coir and with sphagnum peat functioned normally. Additionally, some surprising discoveries as a result of these first growth trials included observations that the biological activity in blends incorporating hemp was very high. As a result, the soluble (available) nitrogen was consumed faster than it was supplied via fertigation. That very rapid nitrogen consumption resulted from high microbial demand. This effectively taught us that we needed to further evaluate the nitrogen dynamics in blends containing hemp. Some additional studies were undertaken to determine the quantity and rate of the observed nitrogen drawdown. Further learning in the first grow trials was a result of the high pH problem that developed. It became apparent that the particular hemp supply that was used contained very high soluble potassium, resulting in a high pH in the blends containing hemp. That observation raised the question of variability in sources of industrial hemp and where the resource was grown. Together, the high potassium coupled with the higher pH of the hemp created some nutrient imbalances in the trials at both growing operations. These problems can and should be addressed in future studies. What opportunities for training and professional development has the project provided?The project has provided a number of opportunities for personal and professional development within the PittMoss company and at the University of Arkansas. Employees at PittMoss LLC have learned about the growing and processing of industrial hemp and have developed some expertise in processing the raw fibers. Some of the employees have been exposed for the first time to the concept of sustainable substrate production using industrial hemp. Managers and equipment operators have observed and developed information to be used in processing protocols. Management personnel at the company have learned about the hemp market. A summer employee who is a master's degree student from The Ohio State University visited to observe the research being done at the University of Arkansas and communicate with the researchers. This employee subsequently helped prepare and edit the interim report for this project to the USDA. A research consultant who works closely with PittMoss, Dr. Charles L. Bethke, has learned about the properties and characteristics of industrial hemp and how it can be manipulated through processing and the introduction of additives to become an excellent growing substrate component. Graduate and undergraduate students and the research professor at the University of Arkansas (Dr. Ryan Dickson) had the opportunity to participate in the development of sustainable growing substrates. They learned more about controlled plant growth studies through the practice of plant growth monitoring, data collection and analysis, and production of a final report. Dr. Dickson expanded his knowledge of industrial hemp as a sustainable growing media component and plans to submit articles to academic, trade, and professional publications. How have the results been disseminated to communities of interest?Early opportunities for presenting hemp as a sustainable growing substrate arose in a meeting of the West Michigan Sustainable Forum on July 27th and again at the Green Storm Water Task Force (division of West Michigan Sustainability Forum) on September 22nd. These opportunities included summarized presentations of findings introducing using industrial hemp in growing substrates to promote local economic circularity. Possible uses of hemp in animal bedding to protect ammonium release despite surface runoff and erosion were also discussed. Looking ahead, applications have been made to present results at the Cultivate'24 National Greenhouse Growers Conference in July 2024 and to a SARE conference in February 2024. Many other future oral presentations, workshops, and web documents are planned. The results from the work at the University of Arkansas are to be submitted for peer review and journal publication. Upon completion, segments of the observations and results of work performed by Dr. Bethke will be submitted to trade magazines for popular publication and dissemination. What do you plan to do during the next reporting period to accomplish the goals?During the remainder of the contracted work period, a number of projects will continue as planned, and a few additional investigations will be started toward completion of this SBIR Level 1 project. Most of these investigations are in pursuit of the original work plan, while others are a follow-up from what has been learned to date while studying industrial hemp as a growing substrate. ONGOING WORK TOWARD TAILORING CHEMICAL PROPERTIES: The high potassium levels identified in the primary supply of hemp used in this project raised questions about the consistency of mineral content from various hemp suppliers. Laboratory analyses surveying mineral content of a few different hemp sources is currently in process. These analyses are examining a small sample of assorted industrial hemp from different producers, specifically by examining chemical levels that can influence growing horticultural plants. Incubation and growth trials have shown that nitrogen is transformed from soluble, plant-available forms to organically complexed forms as a result of microbial activity on hemp fibers in the substrate. Projects are underway to test different sources of nitrogen to address problem of "nitrogen drawdown" by hemp fibers that has been observed in the trials to date. Completed work to date has shown that hemp fibers have a higher pH than is optimal for plant growth, which limits the ratio of hemp that can be used in a growing blend. Lowering the pH of hemp to make it optimal is analogous to raising the pH of sphagnum peat to make it desirable. Work is underway to test mineral and organic additives to lower the pH of hemp fibers to allow broader applications of the hemp fibers in growing mixes. Test blends will continue to be formulated and growth trials will be performed at Dr. Bethke's greenhouse with comparisons to existing commercial blends. CONTINUED PURSUITS IN DEVELOPING OPTIMAL PHYSICAL PROPERTIES: Further definition of the influences of the particle sizes of industrial hemp particles on water holding and aeration are underway using a modified porometer method. These measurements will elucidate the influence of different particle sizes on the physical properties of hemp when blended with other media components. The mechanical manipulation used to produce well-formed particles in the PittMoss patented manufacturing process will advance the use and application of hemp-based substrates. Building on observations and test runs performed to date, additional test runs will advance our knowledge of how hemp fibers will intermix with other components to produce well-formed particles. Test runs are planned to further these evaluations. Postproduction measurements of the changes in physical properties of hemp-containing substrates which were used to produce crops can serve to more accurately define the influence of cropping on the structure of blends containing hemp. To this end, physical property measurements, including modified porometer tests, are being completed. INVESTIGATIONS INTO ENVIRONMENTAL PROPERTIES: At this time, growth trials are being completed in which the water use efficiency of hemp-containing blends is being compared to commercial blends. The ratio of water runoff to applied water is being compared across different blends. As more information on water capture and runoff is obtained, more environmentally compatible blends can be designed and pollution from container grown crops reduced. Measurements of nutrient runoff after surface irrigation are also being made to determine the absorption of nutrients by blends containing hemp. These measurements will help define the value of hemp in reducing nutrient pollution as a result of container crop production. FURTHER EVALUATIONS INTO THE IMPACT ON CROP PRODUCTION MANAGEMENT: Crop growth trials continue as support for testing various blends. Water application studies are underway comparing the quantities of water required by blends containing varying amounts of hemp. Influences on time-to-wilt (often referred to as "shelf-life") after full saturation are being compared. These data will help produce a blend that prolongs the time after watering before plants wilt. This information will help produce blends that improve performance in retail, large-scale growing, and home consumer environments.

Impacts
What was accomplished under these goals? The tasks are segmented into the following activity groups. 1 - IDENTIFYING & ACQUIRING INDUSTRIAL HEMP SUPPLIES: Increasing our understanding of the industry and acquire raw material was achieved through online learning, visits to industrial hemp growers, and research field days at Penn State and Cornell. During the field days, company employees learned more and began to network with the actors in the hemp industry. As a result, raw materials, including whole-stalk and processed bast and hurd fibers, were acquired and continue to be purchased. 2 - PROCESSING TESTS RUNS: Ussing the PittMoss patented proprietary processing system evaluations were made on how whole-stalk hemp and hurd fiber feedstocks fared in the system. The objective was to make particles suitable for finished growing mixes. Screen sizes and processing rates we observed. Key findings included clogging of the system by the bast fibers and high dust production when processing hemp fibers. Alterations to feed rates were successful in reducing clogging problems. Dust abatement measures will be necessary in full-scale production systems. Surprisingly, it was observed that screen sizes had only a minor impact on the final array of particle sizes. 3 - CHEMICAL AND PHYSICAL PROPERTY EVALUATIONS: Evaluations of processed hemp materials to obtain particle sizes and forms most suitable for use in growing substrates is a major objective of the project. Primary evaluations of the processed hemp fibers were performed at the Ambridge, PA lab. Soluble salt and pH levels, along with wettability, moisture content, and particle size distributions were determined for the various hemp materials and some blends. Some of the physical property evaluations, including water holding properties, that were planned as purchased lab work from NCSU had to be transferred to Dr. Bethke's research facility because the NCSU lab discontinued their public testing services. A modified porometer test measuring aeration, water holding (at saturation), percent space occupied by solids, and wet and dry bulk densities were performed by Dr. Bethke. These measurements help to determine the influences which different hemp materials as well as different particle sizes and forms have on the aeration and water holding required in a high-performance growing substrate. Determinations of the chemical nature of the fibers was performed by Dairy Land Labs in Wisconsin. Differences in the percentages of sugars, starches, cellulose, and lignin within the whole-stalk hemp and hurd fibers were observed. Detailed chemical evaluations, including the soluble and total nutritional contents (done via saturated media analysis and acid digestion, respectively) of hemp fibers and trial blends were made by three outside labs. Of special interest were the forms of nitrogen and the levels of major and minor nutrients present and their relative plant availability. Findings that require special consideration are the very high levels of potassium, high pH levels, and the low nitrogen content (which indicates a high carbon-to-nitrogen ratio of hemp). These findings resulted in the expansion of the project to include evaluation of methods to lower pH and supply sufficient nitrogen. To address the high potassium levels, the project requires a broader analysis of hemp grown on other lands to determine variability in potassium and other minerals present in the fibers. The proportion of hemp able to be included in high-performing mixes may be limited by high potassium levels. 4 - PHYSICAL PROPERTY MANIPULATIONS: Advances in material processing were significantly delayed due to supply chain problems which impacted plant upgrades involving equipment delivery and installation. That delayed additional processing evaluations. To meet time constraints for the spring 2023 grow trials at the University of Arkansas and at Dr. Bethke's greenhouse, test blends were formulated using the best pre-processed, whole-stalk ground hemp provided by a supplier. The trial blends were sent to the University of Arkansas's and Dr. Bethke's greenhouses. Subsequently, plant upgrades were completed, and processing methods and the evaluation thereof have continued. 5 - NUTRITIONAL LAB ANALYSES: Testing to define the nutritional balance of hemp raw materials and produced blends included saturated media analysis (SME) to evaluate water-soluble nutrients and acid digestion to provide total mineral content. Those were performed by three different external labs. Furthermore, pH and soluble salts (EC) determinations were made by the University of Arkansas and by Dr. Bethke. Variations in pH and soluble salts in the test blends corresponded to the content of hemp in the trial blends. The PittMoss component in four of the blends showed high pH levels and very low nitrate-nitrogen levels. These analyses showed a correlation between the high pH and EC levels and the hemp and the high potassium content. From these lab tests and subsequent first growth trials, it became apparent that the pH, potassium, and very low nitrogen levels had to be addressed in further work. These properties are being considered and adjusted as the project progresses. 6 - CROP GROWTH TRIALS: Trials at the University of Arkansas have been completed on three crops. The findings are to be published in the final Phase 1 final report. The "Proof of Concept" applying the first iteration of hemp-containing blends showed that the crops grew effectively in blends containing hemp in combination with sphagnum peat, coconut coir, and PittMoss paper-based materials. Key findings included the discovery that hemp fibers were too coarse for effective subirrigation, and surface irrigation is the preferred water delivery method for high-hemp substrates. Additionally, incorporated at higher rates, the soluble salts and pH levels tended to be high. This project was slightly confounded because the batch of PittMoss used for this work carried high pH and high boron levels. Overall, crops grew best in blends that contained 33% or less of this version of hemp fibers. Growth trials at Dr. Bethke's greenhouse showed similar results. These grow trial projects provided solid information for further investigations with improved hemp particle sizes and development and better nutrient balances in blend formulations. 7 - EVALUATION OF THE IMPACT OF CROPPING: The correlations between crop performance and some of the physical and chemical properties will be presented in the final report. Preliminary observations indicate that the physical properties of hemp can be impacted by cropping to a small degree: bast fibers decay more rapidly, while the hurd fibers are more resilient. Chemically, the apparent high buffering and nutrient absorption provided by the hemp is expected to show nutrient capture that persists throughout production. 8 - ANALYZING LEACHATES: Leachate analysis from produced crops has been postponed until the more well-developed formulations are in place. Plans are in place to collect and measure leachates from simulating production runoff to provide estimates of potential environmental impacts. 9 - ANALYSIS OF DATA AND COMPILATION OF FINDINGS: Findings from the evaluations of hemp fibers and how manipulation of those fibers influences their properties have contributed to the formulation of trial blends in an iterative fashion. Compiling findings of subsequent iterations, formulating new blends, then testing the impact of the new blend the properties has guided development of substrates throughout this project. The path to determining how hemp can be a viable sustainable substrate for uses in growing blends is made clearer by data compilation and analysis at each step along the way. The final report will summarize those developments. 10 - FINAL REPORTS AND PRESENTATIONS: Educational efforts and the transfer of information is already being developed. Details are provided in another section of this REEport filing.

Publications