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iAVs Research: Overview

iAVs research focused on developing a simple, adaptable food production system for diverse environments, especially arid and desertifying regions. Guided by the KISS principle (Keep It Simple, Stupid), the system was designed for easy adoption in resource-limited settings. The research prioritized addressing water scarcity and soil degradation, rather than solely maximizing production output.

iAVs is distinguished by its rigorous scientific foundation. Dr. McMurtry’s research, including controlled experiments, detailed data collection, and peer-reviewed publications, validates the system’s effectiveness and reliability for integrated food production. A key differentiator is iAVs’ use of sand as a biofiltration and plant growth medium, setting it apart from hydroponics-based aquaponic systems.

It’s important to note that iAVs is distinct from “Sandponics” and traditional “aquaponics.” iAVs is a unique methodology with historical precedence. Broadly applying the term “aquaponics” can lead to confusion and misrepresent the specific advantages and principles of iAVs.

iAVs is open-source, freely available for global use and implementation. The research aimed to create a foundational model for adaptation and improvement. The principles and findings offer valuable insights for individuals, entrepreneurs, and large-scale operations seeking sustainable food production solutions.

Important Note:

The findings of these studies should not be interpreted in isolation but as part of a broader investigation into the iAVs. While the studies provides valuable data on nutrient dynamics, the comprehensive understanding required for formulating practical recommendations on feeding rates and system design necessitates considering the collective findings of all iAVs research papers.

The recommendations presented on this iAVs website and its educational materials are not derived from any single study in isolation but rather are the result of a combination of findings and insights gathered across multiple interconnected research papers, as well as preliminary studies that were not reported.

The series of iAVs studies represents an iterative process of investigation. Early experiments explored the basic feasibility of integrating aquaculture with sand-cultured vegetables using recirculating water and established initial parameters such as fish stocking density, feeding regime, and sand composition. Subsequent studies systematically investigated the impact of varying the tank-to-biofilter volume ratio (BFV) on fish growth, water quality, nutrient dynamics, and overall productivity.

The iAVs recommendations on component ratios are based on the optimized balance identified across these experiments for achieving desired outcomes in fish and vegetable production while maintaining water quality.

Research into mineral nutrient concentration and uptake by plants provided crucial data on the nutritional needs of the plants when solely relying on fish waste.

In essence, the iAVs comprehensive recommendations are a synthesis of the knowledge gained from years of research, with each study building upon the findings of the previous one to refine the understanding of the complex interactions within the iAVs. Therefore, to fully grasp the rationale behind the website’s advice, it is essential to appreciate the collective contribution of these research papers.

How they did it:

The researchers connected in-ground tanks, where they raised tilapia fish (all-male) to sand biofilters that also acted as growing beds for tomatoes, using a system that recirculates water. They pumped ‘waste’ from the fish tanks directly onto sand biofilters, which served several functions: they filtered the water, supported plant growth, and helped break down organic matter.

Shallow furrows were used in the sand beds for the distribution of irrigation water drawn from the bottom of the fish tanks. Builder’s Grade sand was used which is critical to avoid clogging. The bottom of the biofilters were sloped to facilitate drainage back to the fish tanks, while the furrows are level.

The irrigation was at regular times, 8 times a day, between sunrise and sunset. Furrows were used to allow even distribution of water (and nutrients). The nutrient-laden water flooded the furrows in biofilters, percolated through the sand medium, leaving the solid ‘waste’ on the surface of the furrows, and then drained back to the fish tank by gravity.

The researchers changed the size of the biofilters compared to the size of the fish tanks. They created four different setups with these ratios: 0.67 to 1, 1 to 1, 1.5 to 1, and 2.25 to 1. This means that for every part of the fish tank, the biofilters were 0.67 times, 1 time, 1.5 times, and 2.25 times that size. The fish tank always held 0.5 m³ (or 500 liters) of water, while the size of the biofilters changed.

A variety of plants were used, with tomato and cucumber being prominent in multiple experiments. Bush beans were also frequently studied. Tomatoes were transplanted as seedlings at a density of 4 plants m-2. Cucumber were transplanted as seedlings at a density of 4 plants m-2 in some studies and 6.7 plants m-2 in other experiments.

The fish were fed at 8:00 AM and 1:00 PM. They ate all the food within 15 minutes after it was given to them. The fish food used didn’t have any vitamins or minerals added to prevent harmful levels of these substances from building up and becoming toxic for the plants.

The tanks were recharged with city water equal to evapotranspiration when the volume reached 75% capacity (approximately weekly). The experiments were conducted in a double-layered polyethylene covered greenhouse in Raleigh, NC. 

By using the sand beds for these different roles, the researchers aimed to keep the system simple and easy to manage. This setup was created to recycle water efficiently, reducing the need for water changes and complicated filtration systems.

Who funded the research:

Dr. Mark McMurtry provided the majority of the funding. Additional support came from a USDA grant focused on new farming methods in the Southeast and a grant from the Orange Presbytery of the Presbyterian Church in North Carolina.

1987: Mineral Content and Yield of Bush Bean, Cucumber, and Tomato Cultivated in Sand and Irrigated with Recirculating Aquaculture Water. 

North Carolina Agricultural Research Service., No. 11019 (1987).   Min Nut+’86

M. R. McMurtry NSCU, Paul V. Nelson Professor, Department of Horticultural Science, and D.C. Sanders, Professor, Department of Horticultural Science, NCSU.

  1. Assessing the Combination of Fish Farming and Plant Growing: The main objective was to see if it was possible to successfully grow fish (specifically tilapia) and vegetables together in a closed system that recycles water. The goal was to find out if this system could keep the water clean enough for the fish while also supplying enough nutrients for the plants to thrive.
  2. Testing Sand for Water Filtration: A unique part of this research was using sand as a way to filter the water. The researchers wanted to find out if sand could effectively clean the water from the fish tank by removing harmful waste substances (like ammonia and nitrates) and, at the same time, help provide nutrients for the plants.
  3. Measuring Vegetable Production with Aquaculture Water: The study aimed to measure how much produce could be grown from bush beans, cucumbers, and tomatoes using water from the tilapia tank for irrigation. This was compared to traditional soil-based growing methods to see if the combined system could yield similar or better results.
  4. Understanding Nutrient Flow: The researchers wanted to learn how nutrients moved throughout the system. This involved looking at the minerals in the fish feed, the water, the sand, and the plants to determine if the plants were effectively taking in the nutrients from the fish waste.
  5. Monitoring Water Quality: A key part of the study was keeping an eye on water quality, checking factors like oxygen levels, pH, ammonia, and nitrite levels to make sure they stayed healthy for the tilapia.
  1. Successful Integration: The researchers managed to connect fish production with vegetable growing in a closed water system. While the water quality for tilapia was generally good, the oxygen levels were occasionally low.
  2. Sand as a Useful Filter: The sand used in the system worked well as a filter, effectively cleaning the water by removing waste from the fish and helping beneficial microbes thrive.
  3. Good Vegetable Yields: The crops grown using water from the fish tanks showed quick growth and produced a lot of fruits. For many of these crops, the harvests were comparable to or even better than those grown in traditional soil. Bush beans and cucumbers had notably higher yields in this integrated system compared to the ones grown in soil. While tomato plants faced challenges from bacterial wilt in the integrated system, the best plots still produced encouraging results.
  4. Nutrient Uptake: The plants successfully took up nutrients from the fish waste, although some nutrient levels in the plant tissues were lower than ideal. This suggests there’s room for improvement to ensure plants get all the nutrients they need.
  5. Water Quality Management: The system kept the water quality suitable for tilapia, keeping harmful nitrogen compounds at safe levels. The pH of the water remained stable without needing to add alkaline substances.
  6. Fish Growth: The tilapia showed good growth rates and efficiently turned feed into body mass, indicating that the environment was favorable for fish farming.

The researchers concluded that this co-production concept is particularly well-suited for regions with limited resources, such as sandy soils, low rainfall, and/or inadequate nutrition levels. Further research and optimization could make this system even more efficient and sustainable.

1990: Sand culture of vegetables using recirculating aqua cultural effluents.

Journal of Applied Agricultural Research; Vol. 5, No. 4, pp. 280-284.    J. Ap Ag Research 5-4

M. R. McMurtry NSCU, Paul V. Nelson, Professor, Department of Horticultural Science, D.C. Sanders, Professor, Department of Horticultural Science, NCSU and L. Hodges.

  1. Determine if vegetables grown in sand beds can effectively filter recirculated water from a tilapia aquaculture system. The primary aim was to see if the plants could remove enough waste products from the fish tank water to maintain water quality suitable for tilapia.
  2. Assess if the vegetables can receive adequate mineral nutrition solely from fish waste in the recirculating water. The researchers wanted to know if the fish waste provided enough nutrients for healthy plant growth without the need for supplemental fertilizers.
  3. Demonstrate the feasibility of an integrated, recirculatory system for concurrent production of vegetables and fish. The overall goal was to show that this type of system could work in practice.
  1. Water Quality: The sand-cultured vegetables effectively maintained acceptable water quality for tilapia, keeping nitrite and ammonia levels below toxic thresholds. Dissolved oxygen was low relative to requirements for good fish growth rates.
  2. Fish Growth: Tilapia showed good growth rates, with a feed conversion ratio of 1:1.3.
  3. Vegetable Yield: Bush beans, cucumbers, and tomatoes all produced good yields in the sand beds, and in some cases, yields were higher than those in the soil control plots.
  4. Nutrient Levels: Nutrient levels in the recirculating water were minimal, but plant growth was adequate due to the constant replenishment of nutrients. Some nutrients in the plant tissue were below sufficiency standards but above deficiency levels.
  5. Nutrient Distribution: Nutrient levels in the sand medium increased near the irrigation furrows.

The vegetables effectively filtered the water, maintaining water quality for the fish, and the fish waste provided adequate nutrients for plant growth. This system offers the potential for sustainable and efficient food production by conserving water, soil, and plant nutrients.

1990: Food Value, Water Use Efficiency, and Economic Productivity of an Integrated Aquaculture-Olericulture System as Influenced by Tank to Biofilter Ratio.  

HortTech [submitted twice, not published, claimed to be aquaculture and not horticulture).  94 HortTech Text v.2.3      94 HortTech Table

M. R. McMurtry NSCU, D.C. Sanders, Professor, Department of Horticultural Science, NCSU, B.C. Haning, Department of Plant Pathology NCSU, and Paul C. St. Amand, Agronomy Department, Kansas State University.

  1. Evaluate Fish and Vegetable Yields: Determine how the ratio of biofilter volume to fish tank volume (BFV) affects the yields of both fish (tilapia) and vegetables (tomato, cucumber) per unit of water used and per unit of nutrient input.
  2. Assess Water Utilization Efficiency: Measure the efficiency of water utilization in food production, specifically in terms of grams of protein per liter and kilocalories per liter.
  3. Project Economic Productivity: Estimate the economic productivity per composite unit area (combining fish tank and biofilter area) as influenced by the BFV ratio.
  1. Water Usage: Total water inputs increased with increasing biofilter volume.
  2. Fish Yield: Fish biomass increase per liter of total water used generally decreased with increasing biofilter volume. However, annualized fish production rates ( kg/m3/yr ) increased with increasing biofilter volume.
  3. Vegetable Yield: Fruit yield (tomato, cucumber) per liter of total water used generally increased with increasing biofilter volume. However, yield per plant decreased with increasing biofilter volume.
  4. Food Value (Calories & Protein):
    • Calories per liter of water used in the combined yields did not differ by treatment.
    • Total protein production per liter of water used decreased with increasing biofilter volume.
    • Both caloric value and protein production in the combined outputs increased with biofilter volume irrespective of water consumption.
  5. Economic Productivity: The combined value of annualized fish and tomato production per composite unit area was highest at lower biofilter ratios.

The study demonstrated that the biofilter-to-tank volume ratio significantly influences the productivity and efficiency of an integrated aquaculture-olericulture system. While increasing the biofilter volume generally improved vegetable yields and total caloric/protein output, it tended to decrease fish yield per liter of water used and overall economic productivity per unit area. Therefore, optimizing the BFV ratio is crucial to balance fish and vegetable production and maximize the economic benefits of such integrated systems.

1990: Nutrient dynamics in an integrated recirculatory aquaculture-vegetable production system

Proc. XXIIIrd International Horticultural Congress, Florence, Italy. Aug 27 -Sept. 1.

*** Unavailable ***

1990: Yield of Tomato Irrigated with Recirculating Aquaculture Water as Influenced by Quantity of Fish Waste Products Supplied

Paper

M. R. McMurtry NSCU, D.C. Sanders, Professor, Department of Horticultural Science, NCSU, R. P. Patterson, Department of Soil Science, NCSU.

  1. Determine the influence of biofilter volume (BFV) on tomato yield when using recirculating aquaculture water as the irrigation source.
  2. Assess how biofilter volume affects the total yield per unit of nutrient input derived from fish waste products.
  3. Integrate Olericulture with recirculatory aquaculture
  1. Biological filtration, aeration, and mineral assimilation by plants maintained water quality suitable for tilapia growth.
  2. Fruit yields were significantly higher than those reported in previous integrated aquaculture systems.
  3. Plants assimilated an increasing percentage of the nutrient input with increasing BFV.
  1. Increasing biofilter volume (BFV) led to higher total yields per biofilter but lower yields per individual plant. This suggests a trade-off between maximizing overall production and maximizing the efficiency of nutrient use per plant.
  2. The study demonstrated the feasibility of integrating tilapia aquaculture with tomato hydroponics using recirculating water. The plants effectively removed nutrients from the water, maintaining water quality for the fish, while the fish waste provided nutrients for the plants.
  3. The system achieved high tomato yields compared to previous integrated aquaculture systems, indicating the potential for this approach to be a productive and sustainable method for food production.
  4. The authors suggest that further research is needed to determine the optimal ratios between feed input, fish biomass, water volume, and biofilter volume for different fish and vegetable species combinations.

1993: Mineral nutrient concentration and uptake of tomato irrigated with recirculating aquaculture water as influenced by quantity of fish waste products supplied.

 J. Plant Nutrition Vol. 16 (3), pp. 407-419 .    J.Plt Nutrition 16-3-93

M. R. McMurtry NSCU, D.C. Sanders, Professor, Department of Horticultural Science, NCSU, Paul V. Nelson, Professor, Department of Horticultural Science and A. Nash.

The primary objective of this study was to investigate the mineral nutrient concentration, balance, and accumulation in tomato plants grown in sand biofilters and irrigated with recirculating aquaculture wastewater. Specifically, the researchers aimed to determine if fish waste products alone could provide sufficient nutrients for tomato growth and to identify any nutrient imbalances or deficiencies that might occur. They also wanted to see how different ratios of fish tank volume to biofilter volume affected nutrient uptake.

  1. Nutrient Sufficiency/Deficiency: N, P, K, and Mg were generally at sufficient levels in plant tissue when fish waste was the primary nutrient source. However, Calcium (Ca) was often low, and Sulfur (S) was high. Micronutrients were assimilated in excess of sufficiency, but no toxicity symptoms were observed.
  2. Biofilter Volume Ratio (BFV) Effects:
    • Experiment 1: Minerals assimilated by all plants collectively in each biofilter increased with BFV. The percentage of total inputs assimilated by the plants also increased with BFV.
    • Experiment 2: The P and K concentrations in leaves decreased with increasing BFV while S, Cu, and B concentrations generally decreased with BFV. In general, Mg concentration in leaves increased with BFV.
  3. Fish Biomass/Feed Rate: The metabolic by-products from each kg increase in fish biomass provided adequate nutrition for 2 tomato plants for a period of 3 months. Under reduced feed rates applied to mature fish, K became limiting.
  4. Nutrient Imbalances: The study identified potential imbalances in the fish feed formulation, suggesting that it was relatively low in Ca and high in S and certain micronutrients (Fe, Mn, Zn, Cu) relative to tomato plant needs.
  5. Nutrient Uptake: Mineral uptake by the plants in Experiment 2 in excess of input quantities were found for K, Ca, Mg, S, Fe, Zn, Cu and B. This was attributed to the availability of residual nutrient from previous experiments including fish feed, dolomitic lime, and the root masses of prior crops.

The study demonstrated that recirculating aquaculture water can provide a substantial portion of the nutrients required for tomato growth. However, the fish feed formulation used in the study was not perfectly balanced for tomato nutrient requirements. The researchers suggested specific modifications to the fish feed mineral content (increasing N and Ca, decreasing P, K, S, Fe, Mn, Cu, and Zn) to better meet plant needs while still remaining within the range of fish requirements. The study also highlighted the importance of optimizing the ratio between fish biomass, feed input, water volume, and biofilter volume to ensure adequate nutrient supply for the plants.

1993: Yield of tomato irrigated with recirculatory aquaculture water.

 J. Production Agriculture., Vol.6, no. 3, pp. 331-2, 428-432.   J Prod Ag 6-3-93

M. R. McMurtry NSCU, D.C. Sanders, Professor, Department of Horticultural Science, NCSU, R.P. Patterson, NCSU, and A. Nash

  1. How biofilter volume affects tomato yield.
  2. How biofilter volume influences the total yield of tomatoes per unit of nutrient input (from fish ‘waste’).
  1. Yield per Biofilter: In both experiments (using different tomato cultivars), the total yield of tomatoes per biofilter increased as the biofilter volume increased.
  2. Yield per Plant: Conversely, the yield of tomatoes per plant decreased as the biofilter volume increased. This suggests that with smaller biofilter volumes, each plant had access to more nutrients.
  3. Nutrient Use Efficiency: The study found that with increasing biofilter volume, the plants assimilated a greater percentage of the nutrients from the fish waste. This means the system became more efficient at converting fish waste into tomato production as the biofilter size increased relative to the fish tank.
  4. Correlation between Fish and Tomato Production: The study found a positive correlation between fish biomass increase and tomato yield per biofilter.
  5. Fruit Quality: There was no significant difference in fruit quality distribution across treatments.

The study concluded that while increasing biofilter volume led to higher overall tomato yields per biofilter, it reduced the yield per individual plant. Larger biofilters also resulted in more efficient nutrient extraction from the aquaculture water. The researchers suggest that optimizing the ratio between feed input, fish biomass, water volume, and biofilter volume is crucial for maximizing the productivity of iAVs.

1997: Efficiency of Water Use of an Integrated Fish/Vegetable Co-Culture System.

J. World Aquaculture Society. 28 (4):  J. WAS 94 Text_alpha Cit     J. WAS 94 Figures    J. WAS 94 Tables   J.WAS 94 Table 3 final

M. R. McMurtry NSCU, D.C. Sanders, Professor, Department of Horticultural Science, NCSU, Jennifer D. Cure, Department of Horticultural Science, NCSU, R.G. Hodson, Department of Zoology NCSU, B.C. Haning, Department of Plant Pathology NCSU, and Paul C. St. Amand, Agronomy Department, Kansas State University.

  1. Design and test a recirculating fish-vegetable co-culture system: The primary aim was to create a system that efficiently uses water for producing high-quality food.
  2. Achieve functional and technological simplicity: The system should be easy to operate and maintain, without relying on complex technologies or excessive labor.
  3. Investigate the impact of different component ratios: Specifically, the study examined how varying the ratio of biofilter volume (BFV) to fish rearing tank volume affects fish and vegetable productivity, water use efficiency, and overall economic productivity.
  1. Water Use: Daily water consumption increased with higher BFV/tank ratios. Leakage was a significant factor in water loss, especially in Experiment 2.
  2. Production:
    • In Experiment 1, fish and tomato production increased with higher BFV/tank ratios.
    • In Experiment 2, fish production was not significantly affected by BFV/tank ratio, but tomato yield still increased with higher ratios.
    • Total energy and protein production (fish + tomatoes) generally increased with higher BFV/tank ratios.
  3. Water Use Efficiency:
    • Fish production per liter of water decreased with increasing BFV/tank ratio.
    • Tomato production per liter of water tended to increase with increasing BFV/tank ratio.
    • Overall water use efficiency for total energy production (fish + tomatoes) did not significantly differ with biofilter volume.
    • Water use efficiency for total protein production (fish + tomatoes) decreased significantly with increasing BFV/tank ratio.
  4. Projected Returns: The system showed potential for economic returns comparable to traditional greenhouse tomato production.

The study successfully implemented a recirculating fish-vegetable co-culture system with high water use efficiency and functional simplicity. The ratio of biofilter to fish rearing capacity significantly impacts the balance between fish and vegetable productivity. The system’s component ratios can be manipulated to favor fish or vegetable production based on local market demands or dietary needs, making it a potentially valuable approach in regions with limited water resources and a high demand for quality food. Future research should focus on optimizing the system for specific regional conditions and goals.

1997: Effects of Biofilter / Rearing Tank Volume Ratios on Productivity of a Recirculating Fish/Vegetable Co-Culture System.

 J. of Applied Aquaculture. 7(4): 33-51. Volume 28. December 1997,

M. R. McMurtry NSCU, D.C. Sanders, Professor, Department of Horticultural Science, NCSU

  1. Design a simplified, easy-to-maintain recirculating fish culture and vegetable crop production system. The system should improve water and nutrient utilization efficiency.
  2. Evaluate the effects of different biofilter volume (BFV)/culture tank volume ratios on the performance of the system. This includes assessing fish and crop growth, water quality, organic content of the sand beds, and signs of clogging.
  3. Reduce or eliminate the need for water flushing and fertilizer additions by using higher BFV/tank volume ratios to control nitrate-N and phosphate-P concentrations through plant uptake.
  1. Biofilter Function and Water Quality:
    • Increasing the BFV/tank volume ratio generally led to lower concentrations of total ammoniacal nitrogen (TAN) and nitrite.
    • Dissolved oxygen levels increased with higher BFV/tank ratios.
    • pH was more stable in systems with larger biofilters, requiring less lime to maintain optimal levels.
  2. Fish Growth:
    • Fish biomass increase and growth rates generally increased with higher BFV/tank ratios, indicating improved water quality.
  3. Vegetable Yield:
    • Yield per plant tended to decrease with increasing BFV/tank ratio.
    • Yield per plot (biofilter area) increased with increasing BFV/tank ratio.
  4. Nutrient Dynamics:
    • Nutrient concentrations in the irrigation water were generally low, indicating efficient nutrient uptake by the plants.
    • Potassium levels were found to be low, and zinc levels were high relative to other ions, but no deficiency or toxicity symptoms were observed in the plants.
  5. Biofilter Performance:
    • No clogging or channeling was observed in the sand beds, even after three years of operation.
    • Organic carbon content in the sand medium was relatively low.
  1. Enhanced biofilter/culture tank volume ratios resulted in a functionally well-balanced fish/vegetable co-culture system.
  2. The system demonstrated good productivity with excellent economy of water, nutrient, and lime amendment.
  3. The design represents a step towards a highly productive, low-tech system with efficient use of water, chemical, and labor resources.
  4. The study highlights the value of an enhanced plant growth-filtration component in a balanced fish-vegetable co-culture system.
  5. Further research is needed to optimize fish and vegetable production, including intensifying fish stocking density, testing potassium amendment, and implementing continuous culture.

iAVs Research Group

iAVs is a reputable and scientifically supported system for sustainable agriculture, thanks to the thorough research and interdisciplinary collaboration led by Dr. Mark R. McMurtry and his team. Active from 1984 to 1994, the iAVs research group comprised seven co-investigators across five disciplines, with additional support from nine principal consultants.

This team also benefited from collaboration with faculty from 16 departments across four colleges at North Carolina State University (NCSU) and other institutions. The variety of expertise within the team, ranging from horticultural science to environmental engineering, underscores the system’s strong foundation in rigorous scientific research and interdisciplinary collaboration.

Notably, 10 team members received the honor of being named “Fellows” in their respective professional disciplines.  The Fellows came from various professional organizations, including the American Academy for the Advancement of Science and the American Society of Agricultural and Biological Engineers, American Society of Horticultural Science, and of Crop Science, et al. Their pioneering research has not only been cited in numerous journal articles but has also undergone rigorous testing and validation.

You can see the full list at: IAVS Personnel Resources-E and also read about them below;

Dr. Mark R. McMurtry, Ph.D. Horticultural Science, Integrated Bio-production Systems, Environmental Design, International Development.

Dr. Mark R. McMurtry is the “Inventor of Record” of iAVs technology at North Carolina State University in Raleigh, North Carolina (1984-1994). He holds a Master’s Degree in Environmental Design, a Master’s Degree in Technology for International Development, and a PhD in Horticultural Science.

He collaborates in the development and maintenance of this teaching, resource, and blog website, supporting private, commercial, governmental, NGO/PVO, and UN/FAO cooperative implementations of resource-conservative food security development in regions of existing and expanding need.

Douglas C. Sanders, Ph.D., FASHS. Horticultural Science and Plant Physiology

Douglas C. Sanders (deceased) was a distinguished scientist and Professor at the Department of Horticultural Science at NCSU. Sanders was an expert in the field of olericulture and was a renowned authority in the field of plant physiology. He holds the title of Fellow of the American Society for Horticultural Science (FASHS).

Paul V. Nelson, Ph.D., FASHS. Botanical Mineral Nutrition & Greenhouse Management.

Dr. Paul V. Nelson earned his Ph.D. from Cornell University in 1964 and is a Fellow of the American Society for Horticultural Science (FASHS)

Dr. Nelson is a renowned professor in the Department of Horticultural Science at North Carolina State University with a distinguished career spanning decades of research, teaching, and industry impact in floriculture and greenhouse management. His work has fundamentally shaped modern understanding of plant nutrition and greenhouse cultivation practices worldwide.

Dr. Nelson has made substantial contributions to the academic literature with authorship of 78 journal articles and 101 popular press publications. His landmark textbook “Greenhouse Operation and Management,” currently in its seventh edition, which is recognized as the leading textbook in greenhouse management throughout the Western Hemisphere. This authoritative text is marketed worldwide as a standard reference for both university courses and industry practitioners.

One of the key members of the iAVs Research Group, Dr. Nelson graciously provided the greenhouse space for the initial, formal iAVs research.  In fact, absent his early support, iAVs would have likely not happened.

Merle H. Jensen, Ph.D. Agricultural Program Development (UAZ ERL)

He was an emeritus professor at the University of Arizona and is known for his work on the use of sand as a substrate for growing plants. Jensen’s research showed that sand was an effective substrate for growing plants and that it had several advantages over other substrates.

One of Jensen’s most publicly visible achievements was his role as the project leader in the design and development of the agricultural systems for “The Land” pavilion at Walt Disney World’s EPCOT Center in Orlando, Florida. The Land Pavilion was a showcase for sustainable agriculture and featured several innovative agricultural systems, including hydroponics and aquaculture. Jensen’s work at The Land involved designing comprehensive agricultural display systems that demonstrated future-focused solutions for food production. He personally led the design and installation of sand filters used in the facility’s groundbreaking systems.

Jensen founded the Controlled Environment Agriculture Center (CEAC) at the University of Arizona, which he helped develop into a world-class research facility. His expertise in controlled environments led to a collaboration with NASA.

Jensen formed an association with Dr. Mark McMurtry in 1983 and served as a principal consultant in iAVs research group. His research on sand as a plant substrate and water filtration medium contributed fundamental knowledge that enabled the development of iAVs principles

Barry A, Costa-Pierce, Ph.D. FAAAS International Aquaculture Development (ICLARM)

Dr. Barry Antonio Costa-Pierce is a globally respected scientific leader in aquaculture, aquatic ecosystems, fisheries, and sustainable food systems. With a career spanning over 40 years, his groundbreaking work bridges ecological, social, and food production paradigms, making a substantial impact on global aquaculture practices.Dr. Costa-Pierce holds a Ph.D. in Oceanography and Aquaculture from the University of Hawai’i, an M.S. in Zoology and Limnology from the University of Vermont, and a B.A. in Zoology from Drew University. He has held prestigious positions throughout his career, including serving as an Emeritus Professor of Fisheries and Aquaculture at the University of Rhode Island and Marine Sciences at the University of New England. Currently, he is a Professor II at Nord University in Norway, contributing to sustainable marine bio-resource education.

A pioneer in “Ecological Aquaculture,” Dr. Costa-Pierce has dedicated his career to developing holistic and sustainable aquaculture systems. His work includes contributions to the FAO’s “Ecosystem Approach to Aquaculture,” which emphasizes sustainability, ecosystem health, and community well-being. Such principles are mirrored in the iAVs methodology, aligning with its emphasis on resource efficiency and promoting food security through integrated systems.Dr. Costa-Pierce’s roles as Editor of Aquaculture for 20 years and his leadership in globally significant research initiatives—such as NSF-funded SEANET and Sweden’s Blue Foods Center—showcase his ability to connect science, policy, and practice. His contributions to iAVs research reflect this deep integration of knowledge and application.

Dr. Costa-Pierce’s accolades include being an elected Fellow of the American Association for the Advancement of Science (AAAS), receiving a Doctor Honoris Causa from the University of Gothenburg, Sweden, and serving as Chair for the University of the Arctic Thematic Network on Ocean Food Systems. His ongoing work in Norway, Sweden, Saudi Arabia, and Hawaii highlights his global influence.

Ronald G. Hodson, Ph.D. Aquatic Ecosystems , Fisheries Management & Genetics

Ronald G. Hodson holds a Ph.D. in Aquatic Ecology and has dedicated his career to studying and managing aquatic ecosystems. With a specialization in fisheries management and genetics, Hodson has conducted extensive research on the interactions between aquatic organisms, their environment, and the genetic factors influencing their growth and survival.

Blanche C. Haning, Ph.D. Integrated Pest Management and Plant Pathology

Blanche C. Haning, Ph.D., is an expert in Integrated Pest Management and Plant Pathology. NCSU.

Robert P. Patterson, Ph.D., FCSSA. Agronomy, Soil Fertility, & Plant Physiology

Robert P. Patterson holds a Ph.D. in Agronomy and has dedicated his career to researching and promoting sustainable agricultural practices. With a specialization in soil fertility and plant physiology, Patterson has conducted extensive research on the interactions between plants, soil, and nutrients. NCSU.

Edward A. Estes, Ph.D. Agricultural and Aquacultural Economics

Dr. Edward A. Estes holds a Ph.D. in Agricultural and Biological Engineering, specializing in sustainable agriculture and an expert in Aquacultural Economics. He has dedicated his career to researching and promoting innovative solutions for sustainable food production. Dr. Estes has conducted extensive research on aquaponics and hydroponics systems, focusing on optimizing nutrient cycling, water management, and plant growth in controlled environments.

J. Lawrence Apple, Ph.D. International Development, Plant Pathology

J. Lawrence Apple, Ph.D., is an expert in International Development and Plant Pathology and has dedicated his career to researching and implementing sustainable agricultural practices in the context of international development. With a specialization in international development, Apple has conducted extensive research on the intersection of agriculture, food security, and sustainable development.

Marc A. Buchanan, Ph.D. Agricultural Ecology and Soil Science

Marc A. Buchanan, Ph.D., is an expert in Agricultural Ecology and Soil Science with a specialization in agricultural ecology, Buchanan has conducted extensive research on the interactions between agriculture, ecosystems, and soil health.

Stanley W. Buol, Ph.D. Geomorphology. Mineralogy and Soil Genesis

Stanley W. Buol, Ph.D., is an expert in Geomorphology, Mineralogy, and Soil Genesis and has dedicated his career to researching and understanding the formation and properties of soils. Buol has conducted extensive research on the processes that shape soils and the factors influencing their composition and fertility.

JoAnn Burkholder, Ph.D., FAAAS. Phycology and Aquatic Ecology

J. Burkholder is an expert in Aquatic Ecology with a specialization in Phycology, the study of algae. Throughout her career, she has focused on the ecological dynamics of aquatic systems, particularly the interactions between algae and their environment. is a researcher who has been honored as a Fellow of the American Association for the Advancement of Science (AAAS) for her contributions to the field of aquatic ecosystems  and sustainable agriculture.

James E. Easley, Ph.D. Aquacultural Economics and Business

Donald Huisingh, Ph.D. Ecology and Environmental Resource Recovery

Donald Huisingh, Ph.D., is a globally recognized distinguished expert in the field of Ecology and Environmental Resource Recovery.

Thomas Losordo, Ph.D. Recirculatory Aquaculture

Thomas Losordo, Ph.D., is a expert in the field of Recirculatory Aquaculture Systems (RAS) and has made substantial contributions to the development and advancement of sustainable aquaculture practices.

L. George Wilson, Ph.D., FASHS Horticultural Science and Extension

George Wilson, Ph.D., is a distinguished expert in the field of Horticultural Science’s role in international development. Dr. Wilson holds the title of Fellow of the Crop Science Society of America (FCSSA).

Peter Cooke, Ph.D. Intensive Aquaculture Systems (Disney World, EPCOT)


Robert Jack Downs, Ph.D. Controlled Environment Agricultural Research

Downs became a prominent botanist and plant physiologist, significantly contributing to the development of controlled-environment plant research. His work at the USDA’s Beltsville Research Center also laid a foundation for advancements in plant-environment interaction studies. He is best known as the first director of the North Carolina State University (NCSU) Phytotron, which opened in 1968.

phytotron is a specialized facility designed to grow plants under strictly controlled environmental conditions. It allows researchers to study plant responses to various factors such as light, temperature, humidity, CO₂ levels, water, nutrients, and soil composition. Downs played a pivotal role in establishing this facility as a hub for advancing plant science research in the southeastern United States.

Robert Jack Downs significantly influenced Dr. Mark McMurtry and the iAVs research through his expertise in controlled-environment plant studies. Downs demonstrated the critical importance of managing all environmental factors—such as light, temperature, humidity, and nutrients—in optimizing plant vigor, disease resistance, and yield. His work underscored the principle that precise regulation of environmental variables, tailored to the species and growth phase, minimizes stressors and pressures on plants, resulting in healthier outcomes for both plants and ecosystems.

Downs’ teachings reinforced the understanding that every environmental factor contributes cumulatively to plant vigor and yield, affecting not only individual organisms but also the broader biome.


Kevin Fittsimmons, Ph.D. Intensive and Recirculatory Aquaculture (ERL)


H. Douglas Gross, Ph.D. Crop Science and International Agric. Development


Larry D. King, Ph.D. Sustainable (Low-input) Agricultural Systems


John Lavine, D.V.M Veterinary Medicine, Cichlidae spp. Specialist


Michael Linker, Ph.D. Entomology and Integrated Pest Management


Steve Malvestuto, Ph.D. Fisheries Assessment and Development


George A. Marlowe, Ph.D. Horticulture Research and Development (AVRDC)


Robert H. Miller, Ph.D. Soil Nutrition and Microbial Ecology


Richard A. Neal, Ph.D. International Aquaculture Development (USAID)


Edward Noga, D.V.M Veterinary Medicine, Aquatic vertebrates


Glenn W. Patterson, Ph.D. International Agro-Industries Development (ATI)


Pedro A. Sanchez, Ph.D., FAAAS Tropical Soils Management

PA Sanchez is a researcher who has been honored as a Fellow of the American Association for the Advancement of Science (AAAS) for his contributions to the field of soil science and sustainable agriculture in international development.


John C. Sager, Ph.D., FASABE Controlled Environmental Life Support Systems (NASA)


Ronald Sneed, Ph.D., FASABE Agricultural Engineering, Irrigation Systems

R Sneed is a researcher who has been honored as a Fellow of the American Society of Agricultural and Biological Engineers for his contributions to the field of controlled environmental agriculture. 


Kenneth Sorrenson, Ph.D. Entomology and Greenhouse Pest Management


Carolyn A. Williams, Ph.D. Vegetable Horticulture and Physiology


Reed Altman, M.S. Aquaculture Development (US Peace Corps)

Reed Altman is an aquaculture specialist who has dedicated his career to promoting sustainable aquaculture practices around the world. He holds a Master of Science degree in Aquaculture Development from the US Peace Corps and has worked with various organizations to develop aquaculture projects in Africa, Asia, and Latin America.


Ray Campbell, Ph.D. Plant Nutrition and Tissue Analysis (NCDA)


Dale E. Ettel, Ph.D. Fish Feed Formulation (Purina Mills, Inc.)


Vincent M. Foote, FIDSA Integrated Systems Design


Nancy Mingus, M.S. Plant Tissue Analysis


Boone. M. Mora, D.V.M. Commercial IAVS Demonstration project


Brandy Noon, M.A. Presentation and Graphics Design


Stephen F. Pekkala, AIA Architecture and Development Programming


Martin L. Price, Ph.D. Development Assistance and Networking (ECHO)


Ray Tucker, Ph.D. Soil Fertility and Analysis (NCDA)

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