ALTERNATIVE SUBSTRATES FOR NURSERY CROP PRODUCTION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0220675
• Project Start Date: Aug 1, 2009
• Project End Date: Sep 30, 2014
• Program Code: [(N/A)]- (N/A)

Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695

Performing Department
Horticultural Science

Non Technical Summary
The nursery industry relies chiefly on pine and Douglas fir bark substrates for their potting mix due to several desirable characteristics including light-weight, optimal physical properties including high porosity (air and water filled pores) and disease suppression as well as reasonable cost and availability. Changes in the current market, however, threaten availability of this resource to the nursery industry. A recent survey found decline in pine bark availability across the southeast and elsewhere with associated increased cost due to less domestic forestry production, importing logs without adhering bark, increasing rate of in forest wood harvesting that leaves bark behind on the forest floor, and utilization of pine bark as a fuel source. Consequently, less than 5 percent of the forest product inventory of pine bark is available for horticultural use. Alternative substrates with desirable horticultural characteristics should be investigated to mitigate the potential impact the loss of pine bark could have on the multi-billion dollar green industry. Many studies have investigated the use of industrial and agriculture wastes as substitutes for bark including animal wastes, cotton gin, municipal leaf and sewage sludge, rice hulls, rubber tire chips, spent mushroom compost, and coconut coir dust. Many of these alternative substrate components show promise, in that, they are non-toxic to plants and can be successfully used to amend conventional substrates. However, cost, regional availability, research-based guidelines for use and a limited supply of uniform and consistent quality reduce their widespread use. The use of wood and other alternative materials to replace pine bark as a substrate is a relatively new concept in the U.S. that is beginning to receive widespread attention in the industry.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	2122	1060	40%
205	2122	1060	40%
205	2123	1060	20%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 205 - Plant Management Systems;

Subject Of Investigation
2123 - Bedding/garden plants; 2122 - Potted plants;

Field Of Science
1060 - Biology (whole systems);

Keywords

alternative substrate

nursery substrate

wood substrate

nursery production

physical properties

pine bark

Goals / Objectives
A. Determine physical and hydrophysical properties on alternative materials including wood substrates and cotton stalk compost derived from different particle sizes and with the addition of various amendments including peat moss, compost, and sand. Properties to be determined include: particle size distribution, container capacity, air space, bulk density, hydraulic conductivity, total porosity, available water, unavailable water, percolation, and water release curves. B. Determine growth parameters for wood substrates when mixed with processed cotton stalk compost for nursery stock in comparison to that achieved in the traditional pine bark. C. Determine rates of decomposition of wood and cotton stalk substrates during short-term (1 growing season) and long-term (2 growing seasons) crop production. Results from these objectives will be relayed directly to the nursery industry through trade journals, trade shows, and industry meetings.

Project Methods
Objective A: Wood substrates will be constructed from freshly harvested loblolly pines trees that will have been processed through several hammer mill screens to produce mixes with different particle sizes including: 3/16 inch, 1/4 inch, and 5/8 inch. These wood mixes will be tested alone and in addition to being amended with pine bark or other alternative substrate components. Total Porosity (TP), Container Capacity (CC), Available Water (AW), and Air Space (AS) will be determined using the NCSU Porometer. All data will be subjected to linear and quadratic regression procedures with PROC REG using SAS statistical software. Objective B: Determining growth parameters for wood substrates and other alternative substrate components. This experiment will be a randomized complete block design. Wood substrates will be constructed from freshly harvested loblolly pines trees that will be processed through a 5/8 inch hammer mill screen. This wood substrate will be amended with cotton stalk compost at the following 20% increments (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100). Rooted stem cuttings of Cotoneaster dammeri C.K. Schneid Skogholm will be potted into each substrate in 4-L containers (trade 1 gal). After 112 days, plant shoots will be removed. Roots of the corresponding plants will be placed over a screen and washed with a high pressure water stream to remove substrate. Shoots and roots will be dried at 65 C (150 F) for 5 days and weighed. All data will be subjected to ANOVA procedures with PROC GLM using SAS statistical software. Objective C: Determining rates of decomposition of wood substrates. Wood substrates will be constructed from freshly harvested loblolly pines trees that will be processed through several hammer mill screens to produce mixes with different particle sizes including: 3/16 inch, 1/4 inch, and 5/8 inch. Different particle sizes will be tested to determine the effect size has on decomposition and substrate stability in containers over a production period (5 months). Substrate physical properties analysis will be determined at the Horticultural Substrates Laboratory. Physical properties and particle size distribution will be determined initially (time of potting), and every three months thereafter on three replicate substrate samples taken from containers for up to two years (nine total measurements). Substrate shrinkage (volume loss) will also be measured initially and every three months by measuring the height of the substrates in containers.

Progress 08/01/09 to 09/30/14

Outputs
Target Audience: Horticultural bark suppliers Horticultural peat suppliers Horticultural potting mix and soil manufactures/distributors Greenhouse growers Nursery Growers Other horticulture/agriculture scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Events conducted and concluded in the last year include particpation in local, state, regional, national, and international research conferences and meetings. These conferences allowed for dissemination of research data to the industry as well as to other researchers. On-site training has been conducted with individials who have visited our campus facilities. How have the results been disseminated to communities of interest? Trade magazines Research Meeting/Symposium proceedings Research Journals What do you plan to do during the next reporting period to accomplish the goals? Continue current research. Expand upon new areas of interest and potential. Continue publishing in various sources to best distribute the information generated from the project.

Impacts
What was accomplished under these goals? All members of the research group, including gradaute students conducted research trials at the guidance of the project leader to facilitate the goals and objectives outlined in the project description. The data from the research was published in a variety of places and were distributed throughout the scientific communities as well as local, regional, and national industry/grower audiences. The research team as hosted many growers and substrate manufacturers to our facilities on NC State University's campus and research field stations over the past year. During these visits, people from the industry have been able to ask questions and receive updated information about new greenhose and nursery crop production.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Judd, L.A., B.E. Jackson, T.C. Yap, and W.C. Fonteno. 2014. Mini-Horhizotron: an apparatus for observing and measuring root growth of container-grown plant material in situ. HortScience 49:1424-1431.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Fields, J.S., W.C. Fonteno, B.E. Jackson, J.L. Heitman, and J.S. Owen, Jr. 2014. Hydrological properties, moisture retention, and draining profiles of wood and traditional components for greenhouse substrates. HortScience 49:827-832.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Fields, J.S., W.C. Fonteno, and B.E. Jackson. 2014. Hydration efficiency of traditional and alternative greenhouse substrate components. HortScience 49:336-342.
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Judd, L.A., B.E. Jackson, and W.C. Fonteno. 2014. Rhizometrics: A review of three in situ techniques for observation and measurement of plant root systems in containers. Acta. Hort. 1034:389-397.

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: Greenhouse and nursery growers in the state of North Carolina and across the Southeastern United States. Other academic reseachers in the area of crop production, soils, and soilless media. Company (private and otherwise) R&D personnel. Horticultural Substrate Manufacturers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Events and services associated with the past year include participation in local, state, regional and national research conferences. These conferences allowed for dissemination of research data to the industry and other researchers as well as the opportunity to converse, plan and collaborate with colleagues at other Institutions. I made several site visits to nursery and greenhouse operators as well as grower association meetings and substrate manufacturing facilities to assist and consult individuals/groups with issues relating to crop production. I also had many conversations (phone calls and emails) with individuals inquiring if they could participate and benefit from our research. Products of this year include the completion of research for the three graduate students in my research program. Research topics included water relations/availability of greenhouse and nursery substrates, quantifying and enhancing root growth is container grown horticulture crops, and the utilization of pine wood chips as an alternative to perlite in greenhouse crop production. Participants: Dr. Bill Fonteno co-advises one of my two current graduate students. Bill provides many resources and lab space as well as technical expertise to aid in the development and implementation of all floriculture research. Target audiences: Audiences impacted and exposed to research from this program include 1) growers, substrate manufacturers and other industry officials through trade shows and trade magazines 2) graduate students at NC State University and from other universities, 3) undergraduate students in classes 4) fellow scientists and industry folks at research conferences. Project Modifications: None to report during this reporting period. PARTICIPANTS: Brian Jackson (PI) Bill Fonteno (Co-PI and collaborator NCSU) Ted Yap - graduate student (NCSU) Lesley Judd - graduate student (NCSU). Laura Kaderabek, Abby Wunch, Corey Ames - undergraduate students (NCSU) TARGET AUDIENCES: Audience: Greenhouse growers in NC and the Southeast Nursery growers in NC and in the Southeast Pine bark suppliers in NC and the Southeast Substrate manufacturers nationwide Efforts: Teaching 5 courses in Department of Horticulture at NCSU Attending and hosting grower and substrate industry meeting. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period How have the results been disseminated to communities of interest? Attendance to industry (local, regional, national, international) trade-show, conferences, meetings and present research summaries. One-on-one interaction with growers, extension agents, substrate manufactures, and other academic researchers. Write and publish articles in trade magazines and industry bulletins. Abstracts and proceedings from local and regional meetings and publication of research findings in scientific refeered journals. What do you plan to do during the next reporting period to accomplish the goals? Continue the program of my graduate students and their research programs. Focus more on the porcessing/manufacturing of substrates and substrate components in an attempt to better understand their use and behavior (and potential) during crop production. Continue to look at the need and development of light weight, local, and sustainable materials.

Impacts
What was accomplished under these goals? Three graduate students were trained during the reporting year, and all completed the second year of their Master's program and graduated in May 2013. All three students conducted many research trials (as part of their dissertation) which directly relate to the objectives (purpose) of the work outlined/summarized in this project. All three students will be completing their research papers for publication in scientific journals in the coming year. All three students also went on to further their education with PhD degrees at different schools. In addition to the training of these students, both growers and substrate manufacturers were updated on all the process from my research program, developments in substrate research, and new issues that our industry faces. This research team has hosted several growers and substrate manufacturers to our facilities on NC State University's campus and research field stations over the past year. During these visits, folks from the industry have been able to ask questions and receive updated information about new greenhouse and nursery crop production strategies that they have been able to take back to their farms and companies and utilize/implement.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Fonteno, W.C., J.S. Fields, and B.E. Jackson. A pragmatic approach to wettability and hydration of horticultural substrates. In: Proc. Int. Symp. Growing Media, Composting, and Substrate Analysis held in Barcelona, Spain on Oct. 17-21, 2011. Acta. Hort. 1013:139-146.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Bilderback, T.E, J.S. Owen, Jr. J.E. Altland, G.B. Fain, B.E. Jackson, E.D. Riley, H.T. Kraus and W.C. Fonteno. 2013. Strategies for developing sustainable substrates in nursery crop production. Acta Hort. 1013:43-56.
• Type: Books Status: Published Year Published: 2013 Citation: Bilderback, T., C. Boyer, M. Chappell, G. Fain, D. Fare, C. Gilliam, B. E. Jackson, J. Lea-cox, A. LeBude, A. Niemiera, J. Owen, J. Ruter, K. Tilt, S. Warren, S. White, T. Whitwell, R. Wright, and T. Yeager. 2013. Best management practices: guide for producing container-grown plants. 3rd Ed. Southern Nurserymens Assoc., Marietta, GA
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Yap, T.C., B.E. Jackson, W.C. Fonteno, J.L. Heitman. 2013. Measuring substrate water potential changes during plant wilt. Southern Nursery Assoc. Research Conf. Proceed. 58:143-146.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Kaderabek, L.E., E.C. Lookabaugh, W.G. Owen, L.A, B.E. Jackson, H.D. Shew, and D.M. Benson. 2013. Measuring disease severity of Pythium spp. and Rhizotonia solani in substrates containing pine wood chips. Southern Nursery Assoc. Research Conf. Proceed. 58:135-140.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Judd, L.A., B.E. Jackson, and W.C. Fonteno. 2013. Mini-horhizotron: a novel technique for observing and quantifying root systems of plants in pot culture. Southern Nursery Assoc. Research Conf. Proceed. 58:18-23.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jackson, B.E. and W.C. Fonteno. 2013. Current issues and recent advances in the container substrate industry. 2013. Southern Nursery Assoc. Research Conf. Proceed. 58:13-17.

Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: Activities related to this project included the design, implementation and analysis of research projects relating to nursery and greenhouse substrates. These experiments were focused on answering questions and problems from growers and substrate manufactures in the state and region. Events and services associated with the past year include participation in local, state, regional and national research conferences. These conferences allowed for dissemination of research data to the industry and other researchers as well as the opportunity to converse, plan and collaborate with colleagues at other institutions. I made several site visits to nursery and greenhouse operators as well as grower association meetings and substrate manufacturing facilities to assist and consult individuals/groups with issues relating to crop production. I also had many conversations (phone calls and emails) with individuals inquiring if they could participate and benefit from our research. Products of this year include the completion of research for the three graduate students in my research program. Research topics included water relations/availability of greenhouse and nursery substrates, quantifying and enhancing root growth is container grown horticulture crops, and the utilization of pine wood chips as an alternative to perlite in greenhouse crop production. The three graduate students will be completing their degrees in the spring of 2013 and will disseminate their research findings in horticulture trade magazines, scientific journals and at research conferences in the summer of 2013. In addition to the graduate students in my program, there was one undergraduate student worker who was heavily involved with assisting the graduate students and conducting his own independent research projects. This student has decided to pursue a Master's degree in Horticulture here at NCSU. Participants: Dr. Bill Fonteno co-advises one of my three graduate students. Bill provides many resources and lab space as well as technical expertise to aid in the development and implementation of all floriculture research. Target audiences: Audiences impacted and exposed to research from this program include 1) growers, substrate manufacturers and other industry officials through trade shows and trade magazines 2) graduate students at NC State University and from other universities, 3) undergraduate students in classes 4) fellow scientists and industry folks at research conferences. Project Modifications: None to report during this reporting period. PARTICIPANTS: Brian Jackson (PI) Bill Fonteno (Co-PI and collaborator NCSU) Garrett Owen - graduate student (NCSU) Lesley Judd - graduate student (NCSU) Jeb Fields - graduate student (NCSU) Ted Yap - undergraduate student (NCSU) Mike Evans - professor university of Arkansas (mentor and collaborator) TARGET AUDIENCES: Audience: Greenhouse growers in NC and the Southeast Nursery growers in NC and in the Southeast Pine bark suppliers in NC and the Southeast Substrate manufacturers nationwide Efforts: Teaching 5 courses in Department of Horticulture at NCSU Attending and hosting grower and substrate industry meetings Develop new root growth apparatus (Mini Horhizotron) for observing, studying and quantifying root growth of horticulture crops. This can benefit researchers and teachers/students. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Both growers (greenhouse and nursery) and substrate (potting mix) manufacturers have been informed and updated on the latest research and findings associated with peat and pine bark related issues in the state of NC and in the Southeast US. The past two years have seen many problems and challenges within the substrate/potting mix industry but these have been met with innovation and new products that have continued to make growers successful. This research team has hosted several growers and substrate manufacturers to our facilities on NC State University's campus and research field stations over the past year. During these visits, folks from the industry have been able to ask questions and receive updated information about new greenhouse and nursery crop production strategies that they have been able to take back to their farms and companies and utilize/implement.

Publications

• Fields, J.S., W.C. Fonteno and B.E. Jacskon. 2012. Hydrologic Properties of Potential Wood Components for Greenhouse Substrates. HortScience 47:abstract
• Fields, J.C., B. E. Jackson, and W. C. Fonteno. 2012. Pine Bark Physical Properties Influenced by Bark Source and Age. Comb. Proc. Intl. Plant Prop. Soc. 62:(in press)
• Yap, T.C. and B.E. Jackson. 2012. Root Growth of Horticultural Crops as Influenced by Pine Bark Age, Wood and Sand Amendment. Comb. Proc. Intl. Plant Prop. Soc. 62:(in press)
• Fonteno, W.C. and B.E. Jackson. 2011. Improving Greenhouse Substrates. Greenhouse Production News 24-28.
• Owen, W.G., B.E. Jackson and W.C. Fonteno. 2012. Liming Requirements for Greenhouse Substrates Containing Wood Aggregates. HortScience 47:abstract
• Owen, W.G., B.E. Jackson, W.C. Fonteno, and B.E. Whipker. 2012. Pine Wood Chips as an Alternative to Perlite: Cultural Parameters to Consider. Comb. Proc. Intl. Plant Prop. Soc. 62:(in press)
• Judd, L.A., B.E. Jackson, W.C. Fonteno and J.C. Domec. 2012. Measuring Hydraulic Conductance as a New Technique for Assessing Root Growth in Greenhouse Substrates. HortScience 47:abstract
• Judd, L.A., B.E. Jackson, and W.C. Fonteno. 2012. Novel Methods for Observing and Quantifying Root Growth of Horticultural Crops. Comb. Proc. Intl. Plant Prop. Soc. 62:(in press)

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: Activities associated with this project include: The recruitment of three graduate students to work on alternative substrates. The students are fully devoted to this project with areas of specialization including 1) substrate water relations and physical properties, 2) root growth of greenhouse crops and 3) effect of fertilizer, lime and PGR on plants grown in wood-based substrates. An undergraduate student is also working with the research team as part of an independent study program. Events where I participated to disseminate information gleaned from my program include 1) Workshops at nurseries, talks at grower meetings and field days, attendance to the American Society of Horticultural Science to give talks and present posters, attendance to the International Society of Horticultural Science to present an oral presentation. The only services performed were numerous counseling/consulting (not paid) phone calls with greenhouse and nursery growers and horticultural mix manufacturers who were seeking guidance in applying research information from our program into their businesses. Many conversations with individuals inquiring if they could participate and benefit from our research. No products have been generated from my program to date. PARTICIPANTS: Dr. Bill Fonteno co-advises one of my three graduate students. Bill provides many resources and lab space as well as technical expertise to aid in the development and implementation of all floriculture research. Dr. Ted Bilderback served on the committee of a graduate student and advised in the planning and conducting of experiments for nursery crops. Dr. Helen Kraus served on the committee of a graduate student and advised in the planning and conducting of experiments for nursery crops. TARGET AUDIENCES: Audiences impacted and exposed to research from this program include 1) growers and industry officials through trade magazines 2) graduate students at NC State University and from other universities, 3) undergraduate students in classes (Nursery Crops class and Floriculture class), 4) growers are grower meetings and field days, 5)fellow scientists and industry officials at research conferences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
My research program/area continues to generate an incredible response from nursery and greenhouse growers (in North Carolina, the southeast, across the country, and internationally) who are interested in how these new materials can be incorporated into their production systems (thereby saving them money). There has also been a lot of interest from large horticulture substrate (growing media) companies as they also are looking for begin producing these wood-based substrates and being offering them for sale to growers. I have built strong working relationships with many companies who have (and are) in turn providing support in the way of research supplies and operating dollars. Many growers and industry leaders have asked us here at NCSU to lead the way in providing new information on these substrates and they are looking to us to lead the way developing these materials.

Publications

• Jackson, B.E., R.D. Wright, and M.C. Barnes. 2011. Effect of loblolly pine harvest season, storage method, and storage duration on pine tree substrate quality and plant growth. (Submitted HortScience)
• Bilderback, T.E., J.S. Owen, Jr., E.D. Riley, B.E. Jackson, H.T. Kraus, W.C. Fonteno, J. Altland, and G.B. Fain. 2011. Strategies for developing sustainable substrates in nursery crop production. Acta. Hort. (In press)
• Jackson, B.E., W.C. Fonteno, T.E. Bilderback, and H.T. Kraus. 2011. Wood substrates in United States horticultural crop production: development and use. Acta. Hort. (In press)
• Fonteno, W.C., J.S. Fields, and B.E. Jackson. 2011. A pragmatic approach to wettability and hydration of horticultural substrates. Acta. Hort. (In press)

Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: For the project "Alternative Substrates for Nursery Crop Production": Development of new information from this project over the past year has been distributed to several nursery and greenhouse crop growers in North Carolina, as well as the southeast United States via several avenues. Our research team has hosted several growers and substrate manufacturers to our facilities on NC State University's campus and research field stations over the past year. During this visits, these folks from the industry have been able to ask questions and receive updated information about new nursery crop production strategies that they have been able to take back to their farms and companies and utilize/implement. In addition, I have visited several farms, nurseries, and substrate companies in the past year to work with them in incorporating new data and research results into their production. Results from work completed on this project have been presented in the Southern Nursery Association Research Conference Proceedings (January 2010). PARTICIPANTS: The only individuals who worked on this project are those listed as contributors. Myself (Brian Jackson), Drs Wiliam C. Fonteno, Ted E. Bilderback and Helen T. Kraus. TARGET AUDIENCES: Nursery and Greenhouse Growers in the state of North Carolina as well as the southeast United States. Substrate (potting mix) manufacturers across the United States. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The use of freshly harvested and processed pine trees as a container substrate for nursery crops production is a relatively new concept, and fundamental knowledge of the construction wood-based substrate for optimal physical properties is insufficient. Outcomes during the first year of this project focused on establishing processing procedures of wood-based alternative substrate materials. Resources within the Department of Horticultural Science provided by members of my collaborative research team allowed for work to be completed in a timely fashion, while being able to make some key discoveries even in the first year. The improvement of wood-based substrates hydro-physical properties (rewettability, infiltration, hydraulic conductivity, etc.) can be substantially important in more accurately managing irrigation during cultivation, all of which can be more consistently managed depending on how the wood is processed. We have found that producing a smaller wood particle size increases inputs such as labor, energy cost for grinding, and require a more expensive hammer mill designed to move material (coarse pine chips) through a smaller screen. One factor that has been observed to effect wood grinding rates, is the moisture content (%) of the wood at the time of processing/grinding. the amount of moisture in wood chips directly influences the processing rate (reduction of particle size in a hammer mill), with higher moisture increasing processing/grinding time and decreasing wood substrate output from the hammer mill. As a result of the longer grinding time of moist wood chips (>50% moisture), the amount of fines has also been observed by this team to increase. Another factor to be considered when processing wood for use as a container substrate is the type of equipment used for processing (grinding) wood chips. Hammer mills appear to be the best choice for this task, but mills can vary considerably between brands (horse power, air handling devices, motor rpm, hammer tip speed) which will effect the amount of wood that can be processed. Work is ongoing to further expand our knowledge of the processing of wood-based materials for use in the nursery industry.

Publications

• Jackson, B.E., T.E. Bilderback, and H.T. Kraus. 2010. What to do when pine bark runs short: physical properties of pine bark alternatives. Southern Nursery Assoc. Research Conf. 55:413-418.