Progress 07/20/12 to 09/30/16

Outputs
Target Audience:Undergraduate and graduate students, agricultural producers, extension agents and other agriculture professionals, waste recycling professionals, greenhouse operators Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Creative Inquiry classes were conducted in fall and spring semesters each year of the project where undergraduate and graduate students gained experience with design, operation and evaluation of different on-farm energy systems described above. A total of six training workshops on alternative farm energy systems (black soldier fly compost systems and alternative greenhouse heating systems) were conducted at Clemson University with 168 participants including farmers, Extension agents and other agriculture professionals and students. Training participants gained an understanding of the concepts underlying the various systems, and were able to gain hands-on experience with the systems at demonstration sites where the systems have been installed or performed. An additional six training workshops focusing on use of cover crops in no-till vegetable production were held over two years at the Clemson Organic Farm, the Clemson Coastal Research and Education Center and at local farms with 144 participants. These workshops included classroom sessions and hands-on demonstrations in the field of cool and warm season cover crops and best management practices including termination methods. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? On-farm bioenergy production can help to offset the increasing costs of petroleum based fuels and fertilizers and improve farm profitability. Furthermore, compared to petroleum-based energy, bioenergy can reduce carbon dioxide emissions through its role in the carbon cycle. The goal of the proposed research is to help farmers increase energy self-reliance and reduce their energy costs, andto provide them with information on how to create value-added products through bioconversion of waste materials. An additional project was initiated to develop less energy intensive weed management strategies for vegetable production based on cover crops and no-till management. Objectives: 1). Design, build and evaluate a Black Soldier Fly composting system at the Clemson Organic Farm for bioconversion of food and farm waste into compost, animal feed, and oil for biodiesel fuel production. Please note: this project replaced the anaerobic digester project initially planned because of a change in graduate student research preference. 2). Compare the costs and energy savings of hydronic heating and passive solar components with conventional greenhouse heating systems for season extension vegetable production at the Clemson Organic Farm. 3) Determine the feasibility of an organic no-till system to reduce energy requirements for weed management and fertility in warm-season vegetable production. Objective 1. Design, build and evaluate a Black Soldier Fly (BSF) composting system for bioconversion of food and farm waste into compost, animal feed, and oil for biodiesel fuel production. Research during the reporting period focused on development and optimization of rearing methods for BSF. Experiments were conducted in the greenhouse to compare different media and media moisture levels for development of BSF larvae into adults. Mature larvae were placed into plastic boxes with different types of media including vermiculite, wood chips from landscape waste, processed mulch from landscape waste, and compost that was developed from food waste combined with mulch from landscape waste. Processed mulch and compost resulted in highest levels of adult emergence of between 70-85%. Separate experiments to compare different media moisture levels for adult emergence indicated that moisture levels between 50-85% were optimum, and levels below 25% were sub-optimal for adult emergence. However, adults from the highest moisture level of 80-85% exhibited malformed wings upon eclosion. Collectively the experiments demonstrated that artificial BSF rearing including pupation and adult emergence, egg-laying, and larval development could be conducted inside a temperature controlled space such as a heated greenhouse or high tunnel. Objective 2. Compare the costs and energy savings of hydronic heating and passive solar components with conventional greenhouse heating systems for season extension vegetable production at the Clemson Organic Farm. Experiments were conducted during 2014-2016 to evaluate hydronic heating with and without Remay row covers for cold protection. Lettuce was grown in a high tunnel at the Clemson organic farm and temperatures were monitored during January and early February. Hydronic heat was applied through EPDM tubing placed on the ground adjacent to crops to transfer warm water heat to protect plants against freezing temperatures. Water was heated through a hybrid electric water heater/compost heating system. Heat generated by the compost warmed the water that in-turn flowed to the water heater to supplement electric heat. A randomized block design was used to evaluate hydronic heating with and without Reemay row covers. Temperature sensors placed outside the high-tunnel, and adjacent to plants in all treatment plots were used to monitor temperatures, and HoboWare™ data logger software was used to record and compare temperatures. Results indicated that hydronic heat alone did little to protect plants from extreme nighttime minimum temperatures and therefore should not be used for cold protection inside high tunnels. However, combining row covers with hydronic heat doubled the cold protection of the row cover. Thicker density row covers provided greater cold protection than medium thickness row covers. However, when row covers were combined with hydronic heat, medium thickness covers provided slightly greater cold protection than medium thickness covers, probably because of greater solar radiation through the thinner row covers. Compared to control, hydronic heat alone increased lettuce yield (by weight) 17% , by 70% when medium row covers were used and 88% when row covers were combined with hydronic heat. Objective 3. Determine the feasibility of an organic no-till system to reduce energy requirements for weed management and fertility in warm-season vegetable production. Field experiments were conducted at the Clemson Organic Farm in 2014 and 2015. The experimental design was a 2 by 3 factorial randomized complete block design replicated three times. The treatments consisted of two levels of tillage [no-till (NT) and conventional tillage (CT)] of a cereal rye/crimson clover cover crop biculture and three levels of N fertilization (0, 58, and 116 kg ha-1 N) for tomato and summer squash production. The experiment was replicated three times for each vegetable crop. Management times were recorded for each treatment. Seedbed preparation labor was higher in CT plots compared to NT. Mowing + disking required 191% and 300% more labor in 2014 and 2015, respectively, compared to NT roller-crimping. Managing weeds was also more labor-intensive in CT plots. Weed labor was 400% and 338% greater in CT tomato and squash plots, respectively, compared to NT plots in 2014. In 2015, weed labor was 45% greater in CT tomato plots compared to NT; squash plot weed management was comparable between tillage treatments. NT cover crop plots became weedy later in the season particularly in 2014 when regrowth of the previous summer's cover crop (Japanese millet) required routine mowing to keep the millet from overwhelming the NT plots. Average percent ground cover at 6 weeks after termination in NT plots was 35% (tomatoes) and 25% (squash) in 2014 and 10% (tomatoes) and 10% (squash) in 2015. Overall, the results demonstrated that considerable labor was saved using no-till practices, which translated to greater yields per unit of labor compared to conventionally tilled methods. Vegetable yields per unit of labor (seedbed preparation + weeding) were significantly greater in both NT crops in both years studied.

Publications

• Type: Theses/Dissertations Status: Accepted Year Published: 2017 Citation: Jadrnicek, S. 2017. Integrating row covers and hydronic heating for high tunnel season extension vegetable production. Thesis in partial fulfillment of the requirements for the degree of Master of Science, Department of Plant and Environmental Sciences, Clemson University.
• Type: Theses/Dissertations Status: Accepted Year Published: 2016 Citation: Robb, D. 2016. Weeds, nitrogen and yield: measuring the effectiveness of an organic no-till system. Thesis in partial fulfillment of the requirements for the degree of Master of Science, Department of Plant and Environmental Sciences, Clemson University.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience: Undergraduateand graduatestudents Agricultural producers Extension agents and other agriculture professionals Wasterecycling professionals Greenhouse operators Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Please refer to the section below How have the results been disseminated to communities of interest?Creative Inquiry classes were conducted in fall and spring semesters where undergraduate and graduate students gained experience with design, operation and evaluation of different on-farm energy systems described above. A total of six training workshops on alternative farm energy systems were conducted at Clemson University with 168 participants including farmers, Extension agents and other agriculture professionals and students (all objectives). Training participants gained an understanding of the concepts underlying the various systems, and were able to gain hands-on experience with the systems at demonstration sites where the systems have been installed or performed. What do you plan to do during the next reporting period to accomplish the goals?Graduate students working on the greenhouse heating, black soldier fly and cover cropping/no-till projects will submit theses as part of graduation requirements, and results of these studies will be developed as articles for submission to scientific journals. Additional outreach in the form of training workshops will be conducted to communicate results of the projects to farmers and other program stakeholders. Additional field research will be done to develop best management practices for organic no-till vegetable production using both cool and warm season cover crops, and to evaluate multi-species cover crops for weed and soil health management in vegetable production.

Impacts
What was accomplished under these goals? On-farm bioenergy production can help to offset the increasing costs of petroleum based fuels and fertilizers and improve farm profitability. Furthermore, compared to petroleum-based energy, bioenergy can reduce carbon dioxide emissions through its role in the carbon cycle. There are many ways to turn biological materials into energy and to reduce on-farm energy costs, although at present only a few represent practical and cost-effective options for small, limited resource farming operations. The goal of this research is to help farmers increase energy self-reliance and reduce their energy costs, and also to provide them with information on how to create value-added products through bioconversion of waste materials. An additional project was initiated to develop less energy intensive weed management strategies for vegetable production based on cover crops and no-till management. A pilot project was begun in 2012 to compost food waste from Clemson dining halls using black soldier fly (BSF) larvae (Hermetia illuscens) as an alternative to disposal of waste in landfills. BSF larvae that grow in the food waste are harvested and processed as animal feed, and also pressed to remove their oil, which is then trans-esterified into biodiesel for use in university vehicles. In 2014, larger scale digesters utilizing commercial Protopod™ units were established at the Cherry Crossing Recycling Center and the Organic Farm on Clemson campus. Expansion of the system could potentially convert over 200,000 lbs of solid food waste annually from campus dining halls that would normally be deposited in landfills into 4-5 tons of animal feed, 4,000 gallons of petro-diesel, and 17 tons of compost for crop production. However, BSF require warm temperatures for development, therefore BSF development and waste-digestion cannot occur during cold-weather months without an artificial rearing system that can provide a constant source of larvae for the waste-digestion process. Research during the reporting period was done to optimize artificial rearing procedures for BSF. The research was conducted by a graduate student in collaboration with personnel from the Clemson Sustainable Agriculture Program, Clemson Biosystems Engineering, Clemson Recycling, and undergraduate Creative Inquiry class projects. Heating is one of the greatest expenses in the operation of greenhouses used for season-extension vegetable production in cold winter climates. In addition to monetary cost, the use of fossil fuels for greenhouse heating has negative environmental consequences. Experiments were done at the Clemson University Organic Farm to compare the efficiency of different "Bio- Integrated" greenhouse heating systems that utilize natural processes to generate heat including solar energy and thermophilic composting. In 2014-2015, a hydronic heating system with and without Reemay™ row covers was evaluated for a second year for winter high-tunnel lettuce production. Information from the project will be used to develop recommendations for growers on design, construction and operation of low cost, sustainable heating systems for season extension greenhouse production. Objective 1. Design, build and evaluate a Black Soldier Fly (BSF) composting system for bioconversion of food and farm waste into compost, animal feed, and oil for biodiesel fuel production. Research during the reporting period focused on development and optimization of rearing methods for BSF. Experiments were conducted in the greenhouse to compare different media and media moisture levels for development of BSF larvae into adults. Mature larvae were placed into plastic boxes with different types of media including vermiculite, wood chips from landscape waste, processed mulch from landscape waste, and compost that was developed from food waste combined with mulch from landscape waste. Processed mulch and compost resulted in highest levels of adult emergence of between 70-85%. Separate experiments to compare different media moisture levels for adult emergence indicated that moisture levels between 50-85% were optimum, and levels below 25% were sub-optimal for adult emergence. However, adults from the highest moisture level of 80-85% exhibited malformed wings upon eclosion. Collectively the experiments demonstrated that artificial BSF rearing including pupation and adult emergence, egg-laying, and larval development could be conducted inside a temperature controlled space such as a heated greenhouse or high tunnel. Objective 2. Compare the costs and energy savings of hydronic heating and passive solar components with conventional greenhouse heating systems for season extension vegetable production at the Clemson Organic Farm. Second-year experiments with lettuce were done to evaluate hydronic heating with and without Remay row covers for cold protection. Lettuce was grown in a high tunnel at the Clemson organic farm and temperatures were monitored during production in January and early February. Hydronic heat was applied through EPDM tubing placed on the ground adjacent to crops to transfer warm water heat to protect plants against freezing temperatures. Water was heated through a hybrid electric water heater/compost heating system. Heat generated by the compost warmed the water that in-turn flowed to the water heater to supplement electric heat. A randomized block design was used to evaluate hydronic heating with and without Reemay row covers and compared to a control without hydronic heat or row cover. Temperature sensors placed outside the high-tunnel, and adjacent to plants in all treatment plots were used to monitor temperatures, and HoboWare™ data logger software was used to record and compare temperatures. Results of the second year experiments indicated that hydronic heat applied through tubing placed adjacent to the plants in combination with row cover provided the greatest cold protection and lettuce yields, compared to row covers or hydronic heating alone. Objective 3. Determine the feasibility of an organic no-till system to reduce energy requirements for weed management and fertility in warm-season vegetable production. Field experiments were conducted at the Clemson Organic Farm. The experimental design was a 2 by 3 factorial randomized complete block design replicated three times. The treatments consisted of two levels of tillage [no-till (NT) and conventional tillage (CT)] of a cereal rye/crimson clover cover crop biculture and three levels of N fertilization (0, 58, and 116 kg ha-1 N) for tomato and summer squash production. The experiment was replicated three times for each vegetable crop. Seedbed preparation labor was higher in CT plots compared to NT. Mowing + disking required 191% and 300% more labor in 2014 and 2015, respectively, compared to NT roller-crimping. Managing weeds was also more labor-intensive in CT plots. Weed labor was 400% and 338% greater in CT tomato and squash plots, respectively, compared to NT plots in 2014. In 2015, weed labor was 45% greater in CT tomato plots compared to NT; squash plot weed management was comparable between tillage treatments. NT cover crop plots did become weedy later in the season particularly in 2014 when regrowth of the previous summer's cover crop (Japanese millet) required routine mowing to keep the millet from overwhelming the NT plots. Average percent ground cover at 6 weeks after termination in NT plots was 35% (tomatoes) and 25% (squash) in 2014 and 10% (tomatoes) and 10% (squash) in 2015. Overall, the results demonstrated that considerable labor was saved using no-till practices, which translated to greater yields per unit of labor compared to conventionally tilled methods. Interestingly, fertility level had no impact on yield of tomato or squash in either NT or CT plots. Vegetable yields per unit of labor (seedbed preparation + weeding) were significantly greater in both NT crops in both years studied.

Publications

• Type: Theses/Dissertations Status: Under Review Year Published: 2016 Citation: Optimization of Black Soldier Fly Rearing Methods To Supplement Natural Populations in Composting Systems
• Type: Theses/Dissertations Status: Submitted Year Published: 2016 Citation: Weeds, Nitrogen and Yield: Measuring the Effectiveness of an Organic No-till System

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Undergraduate and graduate students Agricultural producers Extension agents and other agriculture professionals Waste recycling professionals Greenhouse operators Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Please refer to the section below. How have the results been disseminated to communities of interest? Creative Inquiry classes were in fall and spring semesters where undergraduate and graduate students gained experience with design, operation and evaluation of different on-farm energy systems described above. 10 students enrolled in the course to study bio-conversion of food and farm waste using the black soldier fly composting system (Objective 2), and 8 students were involved with the course project described under Objective 3 to evaluate hydronic heating and row covers for season extension, high tunnel lettuce production. A total of six training workshops on alternative farm energy systems were conducted at Clemson University with 143 participants including farmers, Extension agents and other agriculture professionals and students (Objective 3). Training participants gained an understanding of the concepts underlying the various systems, and were able to gain hands-on experience with the systems at demonstration sites where the systems have been installed. What do you plan to do during the next reporting period to accomplish the goals? Additional studies will be done to develop protocols for rearing black soldier fly during cold weather months. A graduate student has been recruited to evaluate different pupation media and moisture levels for optimal adult emergence, and to optimize conditions for adult mating and egg-laying. Creative Inquiry class projects will be done to evaluate a system to pump air into the compost for bottom collection of larvae, and to to monitor compost pH, humidity, temperature, and CO2 levels for optimal larval development. Further studies will be done to refine the compost heating system to generate warm water for greenhouse heating, and also to develop a system to capture CO2 generated from the compost and divert to adjacent high-tunnels to increase crop yields. Studies will also be done to determine whether sloping the roofs of greenhouses and high-tunnels to increase sun access will translate into increased crop yields.

Impacts
What was accomplished under these goals? On-farm bioenergy production can help to offset the increasing costs of petroleum based fuels and fertilizers and improve farm profitability. Furthermore, compared to petroleum-based energy, bioenergy can reduce carbon dioxide emissions through its role in the carbon cycle. There are many ways to turn biological materials into energy and to reduce on-farm energy costs, although at present only a few represent practical and cost-effective options for small, limited resource farming operations. The goal of the proposed research will be to help farmers increase energy self-reliance and reduce their energy costs, and to provide them with information on how to create value-added products through bioconversion of waste materials. Every year roughly 440,000 pounds of food waste is created by Clemson University's two dining halls . A pilot project was begun in 2012 to compost the food waste using the black soldier fly larvae (Hermetia illuscens) as an alternative to disposal of waste in landfills. BSF larvae that grow in the food waste are harvested and processed as animal feed, and also pressed to remove their oil, which is then trans-esterified into biodiesel for use in university vehicles. This collaborative project involved personnel from the Clemson Sustainable Agriculture Program, Clemson Biosystems Engineering, Clemson Recycling, and undergraduate Creative Inquiry class projects. A pilot-scale bio-digester was constructed using BSF larvae to process approximately 500 lbs of food waste per week. BSF larvae were analyzed to evaluate their quality as a potential animal feed supplement, and the quality of compost produced by BSF was evaluated for potential as a crop soil amendment. In 2014, larger scale digesters utilizing commercial Protopod™ units were established at the Cherry Crossing Recycling Center and the Organic Farm on Clemson campus. Expansion of the system could potentially convert over 200,000 lbs of solid food waste annually from campus dining halls that would normally be deposited in landfills into 4-5 tons of animal feed, 4,000 gallons of petro-diesel, and 17 tons of compost for crop production. Heating is one of the greatest expenses in the operation of greenhouses used for season-extension vegetable production in cold winter climates.In addition to monetary cost, the use of fossil fuels for greenhouse heating has negative environmental consequences. Experiments were done at the Clemson University Organic Farm to compare the efficiency of different "Bio-Integrated" greenhouse heating systems that utilize natural processes to generate heat including solar energy and thermophilic composting. In 2014, a hydronic heating system with and without Reemay™ row covers was evaluated for winter high-tunnel lettuce production. Information from the project will be used to develop recommendations for growers on design, construction and operation of low cost, sustainable heating systems for season extension greenhouse production. Objective 1. Design, build and evaluate a scale-appropriate anaerobic digester system to generate biogas to provide supplemental greenhouse heating and to refrigerate the walk-in cooler at the Clemson Organic Farm. Project collaborators were unable to identify a graduate student to conduct research on this objective, therefore this objective has been removed from the overall project. Objective 2. Design, build and evaluate a Black Soldier Fly (BSF) composting system for bioconversion of food and farm waste into compost, animal feed, and oil for biodiesel fuel production. Research in 2014 focused on development of BSF rearing protocols to encourage reproduction throughout the winter. The Protopod™ units with compost and BSF were placed inside compost wind-rows adjacent to a high-tunnel at the Clemson Organic Farm. The external compost provided additional heat for BSF development and BSF adults emerging from the Protopod™ could fly into the adjacent, heated high-tunnel where mating could occur. Creative Inquiry courses were organized in spring and fall semesters whereby students worked with project staff to collect and process plant and food waste from the farm and campus dining halls and convert it into oils, protein for animal feed and compost. Students were involved with planning and operation of the system, and learned about the importance of implementing sustainability programs to minimize landfill waste and to explore alternatives to produce clean renewable energy. Students also gained experience with analytical techniques for evaluating the quality of BSF compost and larvae as animal feedstock. The composted waste was subjected to analysis for carbon, nitrogen, micro-nutrients and moisture content. As was done last year, BSF larval development was monitored and larvae were analyzed for suitability as animal feed including protein, fiber, fat and mineral content. Dried larvae contained 41% crude protein, 16% fat, and significant concentrations of critical minerals and nutrients. The dried compost contained 71% organic matter, 4% total nitrogen, and 42% carbon with a C:N ratio of 11.25%. Compost also contained 2.3% phosphorous, 3% potassium, and significant amounts of plant micronutrients, demonstrating the potential value of BSF compost as a soil amendment in greenhouse production. Calculations indicated that BSF conversion of 200,000 lbs of campus dining hall waste annually into oil, animal feed and compost was valued at $11,000, not counting savings in landfill costs. Objective 3. Compare the costs and energy savings of hydronic heating and passive solar components with conventional greenhouse heating systems for season extension vegetable production at the Clemson Organic Farm. Research in 2013 demonstrated that passive solar, aquaponic, and compost heating systems all have potential for use in sustainable season extension greenhouse production of crops in cold weather climates. Research in 2014 focused on experiments to evaluate placement of EPDM tubing adjacent to crops to transfer warm water heat to protect plants against freezing temperatures (hydronic heating). Water was heated through a hybrid electric water heater/compost heating system. Water was piped through a compost pile adjacent to the high tunnel. Heat generated by the compost warmed the water that in-turn flowed to the water heater to supplement electric heat. Experiments were conducted to evaluate cold-weather production of lettuce inside a high-tunnel at the Clemson Organic Farm. A randomized block design was used to evaluate hydronic heating with and without Reemay row covers. Temperature sensors placed outside the high-tunnel, and adjacent to plants in all treatment plots were used to monitor temperatures, and HoboWare™ data logger software was used to record and compare temperatures. On the coldest night with an outside air temperature of 12°F, the temperature adjacent to plants in the hydronic heating + row cover treatment was 41°F, a difference of 29°. Temperature differences among other treatments compared to outside temperature averaged 15°, 13°, and 7° for row cover only, hydronic heating only, and control (no protection), respectively. There was a direct relationship between the degree of cold protection in the different treatments and average lettuce harvest weight. The highest average plant weight of 109 grams was recorded in hydronic heating + row cover treatment. Weights in the row cover only, hydronic heating only, and control averaged 83, 70, and 65 grams, respectively. The results demonstrate that a combination of hydronic heating plus row covers provided the greatest protection against sub-freezing temperatures and correspondingly the highest lettuce yields at harvest.

Publications

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Undergraduate and graduate students; Extension agents, farmersand other agriculture professionals; Waste recycling professionals; Greenhouse operators Changes/Problems: Objective 1. Design, build and evaluate a scale-appropriate anaerobic digester system to generate biogas to provide supplemental greenhouse heating and to refrigerate the walk-in cooler at the Clemson Organic Farm. Project collaborators were unable to identify a graduate student to conduct research on this objective, therefore this objective has been removed from the overall project. What opportunities for training and professional development has the project provided? Creative Inquiry classes were offered during spring and fall semesters where undergraduate students gained experience with design, operation and evaluation of different on-farm energy systems described above. Approximately 12 students enrolled in the course to study bio-conversion of food and farm waste using the black soldier fly composting system (Objective 2), and 8 students were involved with the course project described under Objective 3 to evaluate various passive solar and hydronic heating components for season extension, high tunnel vegetable production. The PI presented results of first year greenhouse experiments listed under Objective 3 at the 25th Congress of the Scandinavian Plant Physiology Society held in August, 2013 in Helsingor, Denmark. Project collaborators organized a training workshop on August 30, 2013 at Clemson University entitled “Implementing a black soldier fly waste recycling operation on your farm” with 38 participants. How have the results been disseminated to communities of interest? The farm energy systems described under Objectives 2 and 3 above are used for stakeholder training and demonstration at the Clemson Organic Farm. Approximately 85 farmers, Extension agents and other agriculture professionals have participated in farm tours and other training events during 2013 where information on the alternative energy systems have been presented. In addition, a separate training workshop on bioconversion of food and farm waste using black soldier fly composting systems was organized in August at the Clemson Organic Farm with 38 participants. What do you plan to do during the next reporting period to accomplish the goals? Future plans include additional work to optimize bio-conversion of waste using the black soldier fly composting system. Studies will be done to evaluate different waste feedstocks and to evaluate different strategies for cold-season composting and production of black soldier fly larvae. We will continue to evaluate the passive solar, hydronic, and compost heating systems for season extension greenhouse vegetable production. Studies will also be done to evaluate the alternative greenhouse heating systems in combination with low-cost, conventional methods such as use of row covers for cold protection.

Impacts
What was accomplished under these goals? On-farm bioenergy production can help to offset the increasing costs of petroleum based fuels and fertilizers and improve farm profitability. Furthermore, compared to petroleum-based energy, bioenergy can reduce carbon dioxide emissions through its role in the carbon cycle. There are many ways to turn biological materials into energy and to reduce on-farm energy costs, although at present only a few represent practical and cost-effective options for small, limited resource farming operations. The goal of the proposed research will be to help farmers increase energy self-reliance and reduce their energy costs, and to provide them with information on how to create value-added products through bioconversion of waste materials. A pilot project to evaluate a black soldier fly (BSF) waste recycling system was begun in April 2012. This collaborative project involved personnel from the Clemson Sustainable Agriculture Program, Clemson Biosystems Engineering, and an undergraduate Creative Inquiry class project to create value-added co-products from waste. A pilot-scale bio-digester was constructed at the Clemson Organic Farm using BSF larvae to process approximately 500 lbs of food waste per week. BSF larvae were analyzed to evaluate their quality as a potential animal feed supplement, and the quality of compost produced by BSF was evaluated for potential as a crop soil amendment. The pilot project scalable design will facilitate system expansion to potentially produce 4,000 gallons of petro-diesel annually through pupae lipid production, and to divert over 200,000 lbs of solid food waste that would normally be deposited in landfills. Heating is one of the greatest expenses in the operation of greenhouses used for season-extension vegetable production in cold winter climates.In addition to monetary cost, the use of fossil fuels for greenhouse heating has negative environmental consequences. Experiments were done at the Clemson University Organic Farm to compare the efficiency of three “Bio-Integrated” greenhouse heating systems that utilize natural processes to generate heat including solar energy and thermophilic composting. Results will be used to develop recommendations for growers on design, construction and operation of low cost, sustainable heating systems for season extension greenhouse production. Objective 1. Design, build and evaluate a scale-appropriate anaerobic digester system to generate biogas to provide supplemental greenhouse heating and to refrigerate the walk-in cooler at the Clemson Organic Farm. Project collaborators were unable to identify a graduate student to conduct research on this objective, therefore this objective has been removed from the overall project. Objective 2. Design, build and evaluate a Black Soldier Fly (BSF) composting system at the Clemson Organic Farm for bioconversion of food and farm waste into compost, animal feed, and oil for biodiesel fuel production. A pilot system was installed at the Farm adjacent to a hoop house-type greenhouse to facilitate year round production of BSF larvae. Creative Inquiry courses were organized in spring and fall semesters whereby students worked with project staff to collect and process plant and food waste from the farm and campus dining halls and convert it into oils, proteins and compost. Students were involved with planning and operation of the system, and learned about the importance of implementing sustainability programs to minimize landfill waste and to explore alternatives to produce clean renewable energy. Students also gained experience with analytical techniques for evaluating the quality of BSF compost and larvae as animal feedstock. The composted waste was subjected to analysis for carbon, nitrogen, micro-nutrients and moisture content. BSF larval development was monitored and larvae were analyzed for suitability as animal feed including protein, fiber, fat and mineral content. Dried larvae contained 41% crude protein, 16% fat, and significant concentrations of critical minerals and nutrients. The dried compost contained 71% organic matter, 4% total nitrogen, and 42% carbon with a C:N ratio of 11.25%. Compost also contained 2.3% phosphorous, 3% potassium, and significant amounts of plant micronutrients, demonstrating the potential value of BSF compost as a soil amendment in greenhouse production. Objective 3. Compare the costs and energy savings of hydronic heating and passive solar components with conventional greenhouse heating systems for season extension vegetable production at the Clemson Organic Farm. Three systems were evaluated in separate greenhouses at the Clemson University Organic Farm. The Passive Solar system was installed in a 9 x 14 meter greenhouse covered with double-layer, polyethylene film with 14, 190 liter steel barrels filled with water to capture solar heat energy. An Aquaponic System consisted of a 5.5 x 18 m greenhouse with single-layer polyethylene film that contained a concrete-lined pond connected to ebb and flow and floating aquaponic systems. A Thermophilic Compost System consisted of a 4.5 x 14 meter greenhouse with single-layer polyethylene film that contained three soil beds for vegetable production. A 10.7 meter-long compost pile containing food waste from campus dining halls was placed in contact with the west side of the greenhouse wall. Hobo® sensors were used to monitor inside greenhouse air temperature and outside ambient air temperature. A sensor was also placed inside one water barrel in the passive solar greenhouse to record barrel water temperature, and in the compost pile to record compost temperature. Data loggers were used to record and store temperature data and readings were compiled every 15 minutes using Hobo® software. Temperatures were recorded for 31 days in January and February of 2013. A Least Squares Analysis of Variance was done to compare differences between average nighttime temperatures inside each greenhouse with the average outside nighttime air temperature. The average nighttime temperatures inside the Passive Solar and the Aquaponic greenhouses averaged 2.81º and 3.42º (C) warmer, respectively, than the average nighttime outside temperatures. The water filled barrels in the Passive Solar greenhouse collected solar energy during the day and contributed up to 9400 BTUs/barrel with an average of 4,500 BTUs/barrel/night. Although levels of cold protection were similar in both greenhouses, the differences between inside and outside temperatures were significantly greater (P > 0.05) in the Aquaponic Greenhouse (i.e. the insulated pond and attached aquaponics system kept the Aquaponic Greenhouse warmer than the insulated Passive Solar Greenhouse with water barrels). Average nighttime temperatures in the Compost greenhouse (#3) were 2.11ºC warmer than the outside. The temperature in the adjacent compost pile averaged 46.7º C during the testing period with a maximum temperature of 60º C. Least Squares Analysis was also done on temperature data taken only on nights when temperatures were at or below freezing (0º C) to evaluate and compare the efficiency of greenhouses on the coldest nights. This analysis indicated that temperature differences between inside and outside temperatures were greatest in the Passive Solar Greenhouse (4.97º C), followed by the Aquaponic Greenhouse (4.26ºC) and the Compost Greenhouse (2.39ºC). Temperature difference values for all greenhouses were significantly different (P>0.05). These results suggest that all of the systems described above have potential for use in sustainable season extension greenhouse production of crops in cold weather climates. Our preliminary data indicate that the Aquaponic and Passive Solar systems may have the potential to generate more heat than the composting system. It is possible that the level of cold protection provided by these systems may be even greater under colder conditions.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Zehnder, G.W. and S. Jadrnicek. 2013. Biointensive greenhouse heating techniques for season extension vegetable production. Abstract, 25th Congress of the Scandinavian Plant Physiology Society, 11-15 August 2013, Helsingor, Denmark. p. 53.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Black Soldier Fly Composting System. The objective of this project is to construct a scalable biosystem for conversion of food wastes into biodiesel fuel, renewable gasification feedstock, animal protein feed and compost. A pilot system was installed at the Clemson Student Organic Farm adjacent to a hoop house-type greenhouse to facilitate year round production of Black Soldier Fly (BSF) larvae. A Creative Inquiry course was organized in spring semester whereby students worked with project staff to collect and process plant and food waste from the farm and campus dining halls and convert it into oils, proteins and compost. The composted waste was subjected to analysis for nitrogen, C:N ratio, micro-nutrients and moisture content. BSF larvae were analyzed for suitability as animal feed including protein, fiber, fat and mineral content. BSF development was monitored in the first year and recommendations to improve BSF output will be incorporated into the development of a larger system in 2013/2014. Bio-Integrated Greenhouse Heating Systems for Season Extension Vegetable Production. Currently, greenhouses cost anywhere from $5,000 to $10,000 annually in energy costs, and use of fossil fuel-based heat contributes to creation of greenhouse gas emissions and climate change. Experiments were initiated to compare the performance of four Bio-Integrated (BI) solar heating systems and a compost heating system in adjacent greenhouses. BI elements include north-south orientation of greenhouses whereby a combination of slope, reflected light from rainwater harvesting ponds, water filled barrels and shallow solar ponds capture and store solar energy. The sloped greenhouses facilitate convective heating and cooling while allowing harvesting of rainwater for use as thermal mass and for reflection. Other alternative greenhouse heating systems included compost heating from a compost pile adjacent to the greenhouse, and an aquaponics system installed in one of the greenhouses. A system of temperature sensors and data loggers was used to measure and compare temperatures inside the different greenhouses and to determine heat gains compared to outside winter air temperatures. PARTICIPANTS: (1) Caye Drapcho, Associate Professor; Biosystems Engineering. Provided expertise on design of waste bioconversion systems. (2) Shawn Jadrnicek, Organic Farm Manager. Coordinated development of the Bio-Integrated Greenhouse Heating Systems and supervised students working on the project. (3) David Thornton, Research Associate; Biosystems Engineering. Provided expertise on the Black Soldier Fly composting system and supervised undergraduate students working on the project. (4) Terry Walker, Professor; Biosystems Engineering. Provided expertise on design of waste bioconversion systems. (5) Clemson University School of Agriculture, Forestry and Environmental Sciences (6) Clemson University Biosystems Engineering Program (7) College of Environmental Engineering and Earth Sciences (8) Clemson Institute for Economic and Community Development (9) Clemson University Calhoun Fields Organic Farm (10) Clemson University Creative Inquiry Undergraduate Research Program TARGET AUDIENCES: Undergraduate and graduate students, Extension agents and other agriculture professionals, waste recycling professionals, greenhouse operators PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Black Soldier Fly Composting System. Students enrolled in the creative inquiry course were involved with planning and operation of the system, and learned about the importance of implementing sustainability programs to minimize landfill waste and to explore alternatives to produce clean renewable energy to reduce our carbon footprint. Students also gained experience with analytical techniques for evaluating the quality of BSF compost and BSF larvae as animal feedstock. Data from the pilot system will be used in development of a larger system in the second project year. Bio-Integrated Greenhouse Heating Systems for Season Extension Vegetable Production. The greenhouse with water barrels and hydronic heating demonstrated the highest heat gains, averaging 10 degrees F warmer than outside minimum temperatures. The water filled barrels collecting the reflected and direct solar energy contributed up to 9400 BTUs/barrel with an average of 4,500 BTUs/barrel a night. A second greenhouse with in-ground vegetable production adjacent to reflecting ponds averaged 1.7 degrees F warmer than outside temperatures with 2 degrees of protection on the coldest nights. The third greenhouse with an insulated pond and attached aquaponics system with heat from an electric water heater supplemented by heat generated from the compost pile averaged 7.0 degrees F warmer than outside minimums with an additional degree of protection on coldest nights. This system kept the greenhouse almost as warm as the insulated larger greenhouse. A fourth greenhouse with an unheated pond maintained an average temperature 1.4 degrees F warmer than the outside minimum temperature. Despite the minimal heat gain, the pond in this greenhouse contributed an average of 68,000 BTUs with a maximum of 175,000 BTUs, indicating heat loss through the un-insulated sides of the greenhouse pond. The fifth greenhouse with attached compost pile maintained an average temperature 4 degrees F warmer than the outside minimum temperature. The attached compost pile averaged a temperature of 116 degrees F during the testing period with a maximum of 140 degrees F. Rain events resulted in a decrease in compost temperature and periodic turning increased temperatures slightly.

Publications

• No publications reported this period