Progress 09/01/15 to 08/31/21
Outputs
Target Audience:The targeted audiences includes: 1) the small-scale limited resource hydroponics/aquaponics industry; 2) Greenhouse producers of vegetables, herbs and spices for local farmers markets, grocery stores and restaurants; 3) the general agricultural audience and consumers of hydroponic vegetable crops; 4) manufacturers of greenhouses and hydroponics equipment, tools and fertilizers; 5) amateur horticulturists, part-time farmers and persons interested in food or flower crop production enterprises under protected structures; 6) urban gardeners; 7) master gardeners, agricultural extension specialists and trainers; 8) K-12, community college students, and teachers; and 9) undergraduate and graduate students of universities in Missouri and North Central United States. Changes/Problems:This project has been terminated. What opportunities for training and professional development has the project provided?This project has trained a Lincoln University of Missouri student at the Master's degree level in environmental science at the College of Agriculture and Environmental Sciences. One graduate student, one research technician, one post-doctoral research associate and three undergraduate student research assistants were trained to acquire plant-nutrient management research skills in a nonrecirculating hydroponic production system under controlled environment agriculture conditions, as well as the use of related research apparatus and nutrient-solution analysis instrumentation. How have the results been disseminated to communities of interest?New information generated from the research project was disseminated to the public (current and prospective hydroponic and aquaponic growers)-through onsite, educational presentations at the Sustainable Hydroponic Research Center located at Lincoln University's George Washington Carver Memorial Research Farm in Jefferson City, Missouri. The center received more than 200 visitors over the reporting period of this research project from November 2015 through September 2021. The Project Director (PD) also conducted annual onsite field day workshops throughout the project duration. In addition, findings from this research were presented to audiences of scientists at the Annual Conferences of the American Society of Horticultural Science over the same period What do you plan to do during the next reporting period to accomplish the goals?This project has been terminated. Manuscripts currently in preparation will be submitted for publication in peer review scientific journals. Additional research findings from more recent experiments on nitrate and phosphate losses as leachate from a commercial module non-recirculating hydroponic system will be presented at the 2022 annual conference of the American Society for Horticultural Science.
Impacts
What was accomplished under these goals?
Project Objectives 1. The o evaluate the capacity of selected organic, inorganic and mixtures of soilless root support substrates (SRSS) to reduce the leaching of nitrate and phosphorus from non-recirculating hydroponic systems (NRHS). 2. To assess the growth and yield responses of leafy vegetables to selected organic, inorganic and mixtures of SRSS in non-recirculating hydroponic systems (NRHS). Research Approach Soilless Root Support Substrates. The capacity of 1) organic (100% Coconut Coir) versus inorganic (100% Perlite), 2) (100% perlite versus DM6-G® rockwool propagation blocks (DM6-G®) underlaid with or without 1-liter of granulated horticultural charcoal); and 3) 100% Perlite versus 2:1 Perlite/Vermiculite mixture [v/v; PLVM]) to reduce nitrate and phosphate leaching as flow-through fertilizer solution (leachate) to the drainage system were compared during several cropping cycles of Collards (Brassica oleracea L. Acephala) cv. Champion, and Swiss chard (Beta vulgaris L.) cv. Acelga in NRHS in controlled environment hydroponic greenhouses (CEHG). Objective 1. The NRHS design and the leachate collection apparatus consisted of 7.6-liter black plastic pots filled with the organic or inorganic mixture (with Perlite as the control SRSS) and inserted into Perlite Bato-Buckets from which excess nutrient solution delivered to the SRSS via drip-emitters flows to a drainage channel. The nutrient solution source was either Peters Excel CAL-MAG™ 15-5-15 (15N-2.2P-12.5K) or Oasis™ 16-4-17 Horticulture Fertilizer (16N-1.75P-14.1K supplied at 200 mg nitrogen/liter plus micronutrients, which the NRHS was set to deliver to each pot at pH 5.8 - 7.2. Leachates from both SRSS were sampled weekly from the completely randomized block experiment for the determination of nitrate and phosphate concentration. The leachates were chemically analyzed using the Dionex™ ICS-5000+ Capillary High Performance Ion Chromatograph System equipped with conductivity detector. Differences in the capacity of the SRSS to reduces nitrate and phosphate leaching, and all data collected from these experiments were statistically analyzed using the SAS software (SAS Institute Inc., Cary, NC.). Objective 2. At the end of each cropping cycle the growth yield response of the fully expanded leaves of both Collards and Swiss chard leafy vegetable crops at market maturity were assessed by leaf count (LC) per plant, leaf area (LA; Collard), leaf fresh weight (LFW) and dry weight (LDW). Other growth components (unit leaf dry weight [LDW/plant divided by LC]), and leaf dry weight ratio (LDW/LFW). Leaves were harvested sequentially over several cropping cycles and differences were determined by repeated measures analysis. Research Findings from Objective 1 100% Coconut Coir versus 100% Perlite. Compared with the source solution the inorganic (Perlite) and organic (Coconut Coir) SRSS reduced the mean nitrate concentrations of the leachate by 40% and 50%, and the phosphorus by 45% and 38%, respectively, over the 93-day and 56-day cropping cycles for Collards and Swiss chard, respectively. Mean leachate concentration of nitrate was 54 and 49 mg/L per plant from inorganic and organic SRSS, respectively. Mean concentration of phosphorus in the leachate from both the organic and inorganic SRSS was consistently in the range 9.0 to 10.5 mg/L, and the differences in leachate concentration of phosphorus between the organic and inorganic SRSS were not statistically significant. DM6-G® Rockwool Propagation Blocks versus Perlite. Compared with the inflow nutrient solution, both perlite and rockwool significantly reduced leachate nitrate by ~48% (p = 0.0008) and 47% (p = 0.0266), and leachate phosphate by ~46% (p = 0.0004) and 45% (p = 0.0001), respectively, over a 49-cropping cycle of Swiss chard. DM6-G® removed 2% more nitrate (p = 0.0564), but 11% less phosphate (p = 0.0557) from the leachate compared with Perlite. Charcoal filtration of leachate had no significant (p = 0.05) effect on the concentration of nitrate or phosphate leached from either DM6-G® or Perlite. Perlite/Vermiculite (2:1 PVLM) versus Perlite. Across both SRSS for measurements taken during a 158-day cropping cycle of Swiss chard the concentration of nitrate and phosphate in the leachate decreased by 82% and 56%, respectively, compared with the source nutrient solution. Leachate nitrate decreased by 63% and 96% with Perlite and PLVM, respectively, compared with the nitrate concentration of the source nutrient solution sampled from the point of delivery to the SRSS in pots. Leachate phosphate decreased by 30% and 90% with Perlite and PLVM, respectively, compared with phosphate in the source nutrient solution. This change represents 34% and 61% reduction in leachate nitrate and phosphate by Perlite and PLVM, respectively. Research Findings from Objective 2 .100% Coconut Coir versus 100% Perlite. The organic (Coconut Coir) SRSS increased the leaf dry weight (LDW) and yield (leaf count [LC] and leaf fresh weight [LFW]) of Swiss chard compared to Perlite. These differences were statistically significant for LC (p = 0.0162), LFW and LDW (p < 0.001), respectively. Coconut Coir increased LC, LFW and LDW by 12%, 38% and 28%, respectively, compared with Perlite. These results indicate that the organic SRSS controlled source pollution of nitrate and promoted greater yield of Swiss chard in NRHS, compared with Perlite. With Collards the inorganic (Perlite) SRSS increased LDW and yield (LC and LFW) compared to the organic (Coconut Coir) by 2%, 12% and 19%, respectively; but these differences were not statistically significant (p = 0.05) during a 93-day cropping cycle. Leaf dry weight constitutes only about 46% of shoot dry matter accumulation-the rest is stem tissue. DM6-G® Rockwool Propagation Blocks versus Perlite. Swiss chard had significantly (p < 0.05) greater leaf yield: LC and LFW per plant, as well as LDW in Perlite than the DM6-G®. Leaf count, LFW and LDW were 12%, 39%, 24% greater for crop grown in Perlite than DM6-G®. The DM6-G® had smaller volume for root growth (40 cubic inch [0.655 liter]) compared with ~210 cubic inch (3.44 liter) for Perlite. The smaller volume of the DM6-G® significantly reduced the root volume of Swiss chard, compromised the water relations and thus reduction in growth. These findings indicate that although there was no significant (p = 0.05) SRSS effect on leaching, both SRSS reduced nitrate and phosphate leaching by over 40% during the 49-day cropping cycle. Perlite/Vermiculite (2:1 PVLM mix) versus Perlite. Except for leaf count at 63-DAT (14% increase with PLVM mix over Perlite), the effect of SRSS on yield was not significant (p = 0.5446). However, the marketable leaf yield (LFW and LDW) of Swiss chard was significantly increased with PLVM compared to Perlite during the 158-day cropping cycle. At 63-DAT, seedlings grown with PLVM had higher leaf fresh weight (LFW; 36% [p = 0.0013]) and LDW (32% [p = 0.0101]) per plant than with Perlite. Similarly, during a second harvest at 158-DAT, PLVM increased leaf count, LFW and LDW of seedlings by 22%, 34%, respectively, compared with Perlite (p = 0.001).
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Egilla, Jonathan N., Isabelle Nyirakabibi. 2019. Nutrient Element Interactions with Leaf Growth of Collards in Response to Hydroponic Solution Composition. HortScience 54(9): S112-113. (Abstr.)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Egilla, Jonathan N., I. Nyirakabibi, A. Ikem, J. Garth, and M. Dolan-Timpe. 2018. Nitrate and phosphate losses from organic versus inorganic soilless root support substrates during nonrecirculating hydroponic culture of Swiss Chard (Beta vulgaris L.). (Abstr. # 202). The 115th Annual Conference of the American Society for Horticultural Science. Washington DC. July 30-August 04 2018.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Egilla, Jonathan. N., Isabelle Nyirakabibi, Abua Ikem and Jimmie Garth. 2017. Relative nitrate and phosphate leaching reduction capacity of soilless root support substrates during nonrecirculating hydroponic culture of Swiss chard (Beta vulgaris L.). HortScience 52(9): S132. (Abstr.)
|
Progress 09/01/19 to 08/31/20
Outputs
Target Audience:The targeted audiences includes: 1) the small-scale limited resource hydroponics/aquaponics industry; 2) Greenhouse producers of vegetables, herbs and spices for local farmers markets, grocery stores and restaurants; 3) the general agricultural audience and consumers of hydroponic vegetable crops; 4) manufacturers of greenhouses and hydroponic equipment, tools and fertilizers; 5) amateur horticulturists, part-time farmers and persons interested in food or flower crop production enterprises under protected structures; 6) urban gardeners; 7) master gardeners, agricultural extension specialists and trainers; 8) K-12, community college students, and teachers; 9) undergraduate and graduate students of universities in Missouri and North Central United States. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project will continue to train a research technician to acquire plant-nutrient management research skills in a non-recirculating hydroponic production under controlled environment agriculture conditions, as well as the use of related research apparatus and nutrient-solution analysis instrumentation. This project is also training an undergraduate student in agriculture at Lincoln University of Missouri on methods of data collection, recording, and the principles of environmental stewardship in hydroponic crop production. How have the results been disseminated to communities of interest?Research findings from this project was disseminated to the public (current and prospective hydroponic and aquaponic growers)-through onsite, educational presentations at the Sustainable Hydroponic Research Center located at Lincoln University's George Washington Carver Memorial Research Farm in Jefferson City, Missouri. The center received over 50 visitors during the current reporting period. The Project Director (PD) also conducted an onsite training of prospective hydroponic and aquaponic producers several times during the reporting period. What do you plan to do during the next reporting period to accomplish the goals?Continue to conduct replicated experiments with the optimized leachate collection apparatus to generate additional data on nitrate and phosphate losses as leachate from a commercial module non-recirculating hydroponic system. More soilless root support substrates will be tested as data collection and analysis from this experiment continues. The PD will continue to educate hydroponic growers, Lincoln University students and the public about strategies to control environmental pollution with nitrate and phosphate from non-recirculating hydroponic systems. In addition, continue the training of a research technician and undergraduate student on the use of hydroponic and plant nutrition instrumentation, data collection and recording in electronic media, as well as the principles of environmental stewardship. The PD will generate research data for abstracted presentations at future scientific conferences, including the American Society of Horticultural Science, as well as peer review publications from experiments completed during this and the next reporting period.
Impacts
What was accomplished under these goals?
Project Objective 1. To evaluate the capacity of an organic (100% Coconut Coir) and inorganic (100% Perlite) soilless root support substrates (SRSS) to reduce the leaching of nitrate and phosphorus during a cropping cycle of Collards (Brassica oleracea L. Acephala) cv. Champion in non-recirculating hydroponic systems (NRHS) Experiment. The capacity of the 100% Coconut Coir and inorganic (Perlite) SRSS to control nitrate and phosphorus leaching as flow-through fertilizer components (leachate) to the drainage system were compared during a cropping cycle of Collards in (7.6-liter) black plastic pots filled with either of the two SRSS and inserted into a standard Perlite Bato-Buckets from which excess nutrient solution delivered to the SRSS via drip-emitters flows to a drainage channel. The nutrient solution source was Oasis 16-4-17 Horticulture Fertilizer™ (16N-1.75P-14.1K) plus micronutrients supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver to each pot at pH 6.5 - 7.2. Leachates from both SRSS were sampled weekly for the determination of nitrate and phosphorus concentration. Fully expanded leaves of the Collard crop at market maturity were harvested 75 days after establishment in hydroponic culture. Results. Compared with the source solution the Perlite and Coconut Coir SRSS reduced the mean nitrate concentrations of the leachate by 40% and 50%, and the phosphorus by 45% and 38%, respectively during a 93-day cropping cycle of Collards. Mean leachate concentration of nitrate was 54 and 49 mg/L per plant from inorganic and organic SRSS, respectively. Mean concentration of phosphorus in the leachate from both the organic and inorganic SRSS was consistently in the range 9.0 to 10.5 mg/L, and the differences in leachate concentration of phosphorus between the organic and inorganic SRSS were not statistically significant. Project Objective 2. To assess the growth and yield responses of Collards (Brassica oleracea L. Acephala) cv. Champion to Coconut Coir and Perlite SRSS in non-recirculating hydroponic systems (NRHS) Experiment. The growth and marketable yield response of the Collards crop (grown as described under objective 1 above) to either the 100% Coconut Coir or Perlite SRSS in a NRHS. Results. With Collards Perlite increased LDW and yield (LC and LFW) compared to the Coconut Coir by 2%, 12% and 19%, respectively; but these differences were not statistically significant (p = 0.05) during a 93-day cropping cycle. Leaf dry weight constitutes only about 46% of shoot dry matter accumulation-the rest is stem tissue. Growth reduction of Collards in the organic SRSS (with higher water holding capacity) may have resulted from excess moisture in the root environment, which indicates that better regulation of the fertigation system is required with this substrate to optimize growth and leaf yield in NRHS compared to Perlite.
Publications
|
Progress 09/01/18 to 08/31/19
Outputs
Target Audience:The targeted audiences include: 1) the small-scale limited resource hydroponics/aquaponics industry; 2) Greenhouse producers of vegetables, herbs, and spices for local farmers markets, grocery stores, and restaurants; 3) the general agricultural audience and consumers of hydroponic vegetable crops; 4) manufacturers of greenhouses and hydroponic equipment, tools and fertilizers; 5) amateur horticulturists, part-time farmers and persons interested in food or flower crop production enterprises under protected structures; 6) urban gardeners; 7) master gardeners, agricultural extension specialists, and trainers; 8) K-12, community college students, and teachers; 9) undergraduate and graduate students of universities in Missouri and North Central United States. Changes/Problems:The current COVID-19 crisis has hindered my ability to hire and utilize the support of technical staff and undergraduate Student Research Assistants for this project since late February 2020. If this situation persists until May 2020, I would not be able to conclude this project by 30 August 2020. What opportunities for training and professional development has the project provided?This project has trained a Lincoln University of Missouri student at the Master's degree level in environmental science at the College of Agriculture and Environmental Sciences. The graduate student, a research technician and an undergraduate student research associate were trained to acquire plant-nutrient management research skills in a nonrecirculating hydroponic production system under controlled environment agriculture conditions, as well as the use of related research apparatus and nutrient-solution analysis instrumentation. How have the results been disseminated to communities of interest?New information generated from the research project was disseminated to the public (current and prospective hydroponic and aquaponic growers)-through onsite, educational presentations at the Sustainable Hydroponic Research Center located at Lincoln University's George Washington Carver Memorial Research Farm in Jefferson City, Missouri. The center received about 30 visitors during the current reporting period. The Project Director (PD) also presented the findings from this research to an audience of scientists at the Annual Conference of the American Society of Horticultural Science, held in Las Vegas, Nevada from July 21 to 25, 2019. What do you plan to do during the next reporting period to accomplish the goals?The PD will continue to conduct full-scale replicated experiments in controlled environment hydroponic greenhouses with the optimized leachate collection apparatus to generate additional data on nitrate and phosphate losses as leachate from a commercial module nonrecirculating hydroponic system. More soilless root support substrates will be tested as data collection and analysis from this experiment continues. The PD will continue to educate hydroponic growers, Lincoln University students and the public about strategies to control environmental pollution with nitrate and phosphate from nonrecirculating hydroponic systems. In addition, continue the training of a research technician and undergraduate student on the use of hydroponic and plant nutrition instrumentation, data collection and recording in electronic media, as well as the principles of environmental stewardship. The PD will generate research data for abstracted presentations at future scientific conferences, including the American Society of Horticultural Science, as well as peer-review publications from experiments completed during this and the next reporting period.
Impacts
What was accomplished under these goals?
Objective 1:To determine the relative capacity of 100% Perlite or a 2:1 Perlite: Vermiculite mixture (v/v) as inorganic soilless root support substrates to reduce nitrate and phosphate leaching during hydroponic culture of Swiss chard (Beta vulgaris, L.) in a nonrecirculating hydroponic system. Experiment 1: The capacity of 100% Perlite (Perlite) and a 2:1 Perlite: Vermiculite mixture (v/v; PLVM mix) to reduce nitrate and phosphate leaching as flow-through fertilizer components (leachate) out of a nonrecirculating hydroponic system (NRHS) were compared during a 158-day cropping cycle of Swiss chard under a controlled environment hydroponic greenhouse (CEHG). The NRHS design and the leachate collection apparatus consisted of 2-Ggallon™ (7.6-liter) black plastic pots filled either with Perlite or PLVM mix and inserted into standard Dutch-Hydro-Buckets from which excess nutrient solution delivered to the inorganic soilless root support substrates (SRSS) via drip-emitters flows to a vegetated drainage channel. The nutrient solution source was a soluble fertilizer (15N-2.2P-12.5K plus micronutrients) supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver into each 2-7.6-liter pot at pH 6.5 - 7.2 during the cropping cycle. Mean day/night ambient temperature and relative humidity were 31.4/16.5 C and 72.8/53.1%, respectively, during the cropping cycle. The Swiss chard seedlings at the third true-leaf stage were grown in either Perlite or PLVM mix SRSS until termination harvest at 158 days after transfer into hydroponic culture (DAT). Hydroponic nutrient solution delivered to the top of the SRSS in the pots and the leachate from each SRSS was sampled weekly for determination of nitrate and phosphate concentration. The sampling started when the seedlings were fully established and capable of active nutrient absorption (~15 to 20-DAT). The hydroponic nutrient solution and leachate samples were analyzed to determine the relative efficacy of either the Perlite or PLVM mix to reduce nitrate and phosphate leaching during the NRHS cropping of Swiss chard using the Dionex™ ICS-5000+ Capillary High-Performance Ion Chromatography System equipped with a conductivity detector. Results: Across SRSS, the concentration of nitrate and phosphate in the leachate decreased by 82.4% and 56.0% with Perlite and PLVM mix, respectively, compared with the source nutrient solution. Leachate nitrate concentration decreased by 62.5% and 96.4%, respectively, in Perlite and PLVM mix, respectively, compared with the nitrate concentration of the source nutrient solution sampled from the emitter (at the point of delivery to the SRSS in pots). Similarly, the leachate phosphate concentration decreased by 28.7% and 89.5% with Perlite and PLVM mix, respectively, compared with the phosphate concentration of the source nutrient solution. This change represents 33.9% and 60.8% reduction in leachate nitrate and phosphate concentrations by Perlite and PLVM mix, respectively. Objective 2: To determine the comparative response of the marketable leaf yield of Swiss chard (Beta vulgarisL.) to 100% Perlite or 2:1 Perlite: Vermiculite mixture (v/v) as inorganic soilless root support substrates in a nonrecirculating hydroponic system Experiment 2: The growth and marketable leaf yield response of Swiss chard cv. Acelga to inorganic SRSS were assessed in a NRHS under CEHG as described under experiment 1 above. Swiss chard seedlings at the third true-leaf stage were grown either with Perlite or PLVM mix SRSS, and at market maturity, leaves were harvested repeatedly from the same seedlings at 63- and 158-DAT. The nutrient solution source was a soluble fertilizer (15N-2.2P-12.5K) plus micronutrients) supplied at 200 mg N per liter, which the NRHS was set to deliver into each 7.6-liter plastic pot at pH 6.5-7.2 during the cropping cycle. Mean day/night ambient temperature and relative humidity were 31.4/16.5C and 72.8/53.1%, respectively, during the cropping cycle. Results: With the exception of leaf count (LC) at 63-DAT (14.2% increase with PLVM mix over Perlite), SRSS had no significant effect on leaf count (p = 0.5446). However, leaf fresh weight (FW) yield and leaf dry weight (LDW) of Swiss chard was significantly increased with the PLVM mix compared to Perlite SRSS during the 158-day cropping cycle. At 63-DAT, seedlings grown with PLVM mix had higher LFW (35.7% [p = 0.0013]) and LDW (31.8% [p = 0.0101]) per plant than with Perlite. Similarly, during the second harvest at 158-DAT, PLVM mix increased LC, LFW and LDW of seedlings by 22.2%, 33.6%, and 34.1%, respectively, compared with Perlite (p = 0.001). Summary: Crop yield data from this study shows that the PLVM mix increased the leaf fresh weight yield of Swiss chard significantly (p < 0.05) by an average of 35% over Perlite when used as a SRSS in NRHS. This increase translates into higher sales income for the grower provided the equivalent cost of production per unit area. In addition, the 33.9% and 60.8% reduction in nitrate and phosphate concentrations of the leachate with PLVM mix compared to Perlite represents a significant decrease in point source pollution, because no special equipment or crop management changes are necessary to achieve the above benefits besides the small additional cost of adding vermiculite to the SRSS.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Egilla, Jonathan N., Isabelle Nyirakabibi. 2019. Nutrient Element Interactions with Leaf Growth of Collards in Response to Hydroponic Solution Composition. HortScience 54(9): S112-113. (Abstr.)
|
Progress 09/01/17 to 08/31/18
Outputs
Target Audience:The targeted audiences includes: 1) the small-scale limited resource hydroponics/aquaponics industry; 2) Greenhouse producers of vegetables, herbs and spices for local farmers markets, grocery stores and restaurants; 3) the general agricultural audience and consumers of hydroponic vegetable crops; 4) manufacturers of greenhouses and hydroponic equipment, tools and fertilizers; 5) amateur horticulturists, part-time farmers and persons interested in food or flower crop production enterprises under protected structures; 6) urban gardeners; 7) master gardeners, agricultural extension specialists and trainers; 8) K-12, community college students, and teachers; 9) undergraduate and graduate students of universities in Missouri and North Central United States. Changes/Problems:The PD has request for one-year no-cost extension of this project, due to a delay of greenhouse repairs. The new expiration date of the projectwill be on 8/31/2019 from 8/31/2018. What opportunities for training and professional development has the project provided?This project has initiated the training of a Master's degree student in environmental science at the College of Agriculture and Environmental Sciences, Lincoln University of Missouri. The graduate student and a research technician are being trained to acquire plant-nutrient management research skills in a non-recirculating hydroponic production under protected agriculture conditions, as well as the use of related research apparatus and nutrient-solution analysis instrumentation. This project is also training an undergraduate student in agriculture at Lincoln University of Missouri on methods of data collection, recording, and the principles of environmental stewardship in hydroponic crop production. How have the results been disseminated to communities of interest?New information generated from the research project was disseminated to the public (current and prospective hydroponic and aquaponic growers)-through onsite, educational presentations at the Sustainable Hydroponic Research Center located at Lincoln University's George Washington Carver Memorial Research Farm in Jefferson City, Missouri. The center received about 35 visitors during the current reporting period. The Project Director (PD) also conducted an onsite field day workshop on August 10, 2018. In addition, findings from this research were presented to an audience of scientists at the Annual Conference of the American Society of Horticultural Science, held in Washington DC from July 31 to August 03, 2018. What do you plan to do during the next reporting period to accomplish the goals?The PD will continue to conduct full-scale replicated experiments in controlled environment hydroponic greenhouses with the optimized leachate collection apparatus to generate additional data on nitrate and phosphate losses as leachate from a commercial module non-recirculating hydroponic system. More soilless root support substrates will be tested as data collection and analysis from this experiment continues. The PD will continue to educate hydroponic growers, Lincoln University students and the public about strategies to control environmental pollution with nitrate and phosphate from non-recirculating hydroponic systems. In addition, continue the training of a Lincoln University of Missouri graduate student, research technician and undergraduate student on the use of hydroponic and plant nutrition instrumentation, data collection and recording in electronic media, as well as the principles of environmental stewardship. The PD will generate research data for abstracted presentations at future scientific conferences, including the American Society of Horticultural Science, as well as peer review publications from experiments completed during this and the next reporting period.
Impacts
What was accomplished under these goals?
Objective 1: To determine the relative capacity of perlite or 2:1 perlite + vermiculite mixture (v/v) as inorganic soilless root support substrates to reduce nitrate and phosphate leaching during hydroponic culture of Swiss chard (Beta vulgaris L.) in a non-recirculating hydroponic system Experiment 1: The capacity of 100% perlite and a 2:1 perlite + vermiculite inorganic mixture (v/v; PLVM) to control nitrate and phosphate leaching as flow-through fertilizer components (leachate) out of the hydroponic system were compared during a 158-day cropping cycle of Swiss chard in a non-recirculating hydroponic system (NRHS) under controlled environment hydroponic greenhouse (CEHG). The NRHS design and the leachate collection apparatus consisted of 2-Ggallon™ (7.6-liter) black plastic pots filled either with 100% perlite or PLVM and inserted into standard Dutch-Hydro-Buckets from which excess nutrient solution delivered to the inorganic soilless root support substrates (SRSS) via drip-emitters flows to a vegetated drainage channel. The nutrient solution source was a soluble fertilizer (15N-2.2P-12.5K plus micronutrients) supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver into each 2-Gallon™ pot at pH 6.5 - 7.2 during the cropping cycle. Mean day/night ambient temperature and relative humidity were 31.4/16.5 C and 72.8/53.1%, respectively, during the hydroponic cropping cycle. Swiss chard seedlings at the third true-leaf stage were grown in either 100% perlite or PLVM inorganic SRSS until termination harvest at 158 days after transfer into hydroponic culture (DAT). Hydroponic nutrient solution from the delivery system and leachate from each of the SRSS were sampled weekly for determination of nitrate and phosphate concentration. The sampling started when the seedlings were fully established and capable of active mineral nutrient absorption (~15-20 DAT). These hydroponic nutrient solution and leachate samples will be analyzed subsequently to determine the relative efficacy of either the 100% perlite or PLVM to reduce nitrate and phosphate leaching during the NRHS cropping of Swiss chard, and the results will be included in a subsequent report. Objective 2: To determine the comparative response of the marketable leaf yield of Swiss chard (Beta vulgaris L.) to 100% perlite versus 2:1 perlite + vermiculite mixture (v/v) as inorganic soilless root support substrates in a non-recirculating hydroponic system Experiment 2: The growth and marketable leaf yield response of Swiss chard cv. Acelga to inorganic SRSS were assessed in a NRHS under CEHG as described under Experiment 1 above. Swiss chard seedlings at the third true-leaf stage were grown in either 100% perlite or 2:1 perlite + vermiculite mixture (v/v) inorganic SRSS, and marketable leaves were harvested repeatedly from the same seedlings at 63- and 158-DAT. The nutrient solution source was a soluble fertilizer (15N-2.2P-12.5K plus micronutrients) supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver into each 2-Gallon™ pot at pH 6.5 - 7.2 during the cropping cycle. Mean day/night ambient temperature and relative humidity were 31.4/16.5 oC and 72.8/53.1%, respectively, during the cropping cycle. Results: With the exception of leaf count (LC) at 63-DAT in which a 14.2% increase with PLVM over 100% perlite SRSS was not significant (p = 0.5446), the marketable leaf yield and biomass of Swiss chard leaf was significantly increased with PLVM compared to 100% perlite SRSS during the 158-day cropping cycle. At 63-DAT, seedlings grown with PLVM had higher leaf fresh weight (LFW; 35.7% [p = 0.0013]) and leaf dry weight (LDW; 31.8% [p = 0.0101]) per plant than with 100% perlite. Similarly, during the second harvest at 158-DAT, PLVM increased leaf count, LFW and LDW of seedlings by 22.2%, 33.6% and 34.1%, respectively, compared with 100% perlite (p = 0.001). The crop yield data from this study shows that the 2:1 perlite-vermiculite mixture (v/v) increased the marketable leaf fresh weight yield of Swiss chard significantly (p < 0.05) by an average of 35% over 100% perlite only, when used as a SRSS in a NRHS. This increase translates into higher sales income for the grower with equivalent cost of production per unit area.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Egilla, Jonathan N., I. Nyirakabibi, A. Ikem, J. Garth, and M. Dolan-Timpe. 2018. Nitrate and phosphate losses from organic versus inorganic soilless root support substrates during nonrecirculating hydroponic culture of Swiss Chard (Beta vulgaris L.). (Abstr. # 202). The 115th Annual Conference of the American Society for Horticultural Science. Washington DC. July 30-August 04 2018.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Egilla, Jonathan. N., Isabelle Nyirakabibi, Abua Ikem and Jimmie Garth. 2017. Relative nitrate and phosphate leaching reduction capacity of soilless root support substrates during nonrecirculating hydroponic culture of Swiss chard (Beta vulgaris L.). HortScience 52(9): S132. (Abstr.)
|
Progress 09/01/16 to 08/31/17
Outputs
Target Audience:The target audiences include (1) the small-scale limited resource hydroponics/aquaponics industry, (2) greenhouse producers of vegetables, herbs and spices for local farmers markets, grocery stores and restaurants.(2) the general agricultural audience and consumers of hydroponic vegetable crops. (3) Manufacturers of greenhouses and hydroponic equipment, tools and fertilizers. (4) Amateur horticulturists, part-time farmers and persons interested in food or flower crop production enterprises under protected structures; (5) urban gardeners; (6) master gardeners, agricultural extension specialists and trainers. (7) K-12 and community college students and teachers, (8) undergraduate and graduate students of universities in Missouri and North Central United States. Changes/Problems:There are no changes to this research project, but the following problems persisted during the 2016-2017 reporting period. 1). Facilities problem: Two consecutive lightning strikes on the protected structures (greenhouses) in which my experiments were being conducted in March and April 2016 rendered them nonfunctional, and I was able to continue experiments planned for my current research project until November 3, 2017. a) The environmental control system (cooling, exhaust and cooling) of both greenhouses remained disabled between March 2016 and January 2017. b) The hydroponic fertilizer delivery systems remained nonfunctional in both greenhouses as at November 3, 2017. One fertilizer injector component has been reinstalled and the meters purchased. Timers for the hydroponic fertilizer delivery systems will be purchased and installed. The above situation impeded my ability to resume proposed experiments during the period between March 2016 and November 2017, and would delay the eventual and final completion of this project. 2). Graduate Student Recruitment: To date, I have been unable to find and recruit a graduate student of U.S. nationality or residency for my research project. This situation is mainly perpetuated by the widely publicized fiscal problem of our institution since the onset of my Capacity Building Grant award in September 2015, and the prevailing uncertainty concerning the continuation of our graduate degree program in agriculture at Lincoln University. What opportunities for training and professional development has the project provided?This project has initiated the training of a research technician in the Cooperative Research department of Lincoln University on the conduct of a plant-nutrient management research in a non-recirculating hydroponic system under protected agriculture conditions, and use of related apparatus, nutrient-solution analysis instrumentation. Training opportunity is being provided for an undergraduate student at Lincoln University on the use of plant nutrient-solution analysis instrumentation, data collection and recording, as well as the principles of environmental stewardship in hydroponic crop production. How have the results been disseminated to communities of interest?Information generated from the research objectives and methodology was disseminated to the public: current and prospective hydroponic and aquaponic growers, through onsite educational presentations at the Hydroponic Research Center of Lincoln University's George Washington Carver Memorial Research Farm in Jefferson City, Missouri. The P.I. led over 20 prospective growers and educators from within and outside the state of Missouri on educational tours of the research and production facilities during the 2016-2017 reporting period. Twelve K-12 students from high schools in counties throughout central Missouri were trained in aspects of hydroponic production technology during a summer institute session organized for undergraduate student recruitment on Lincoln University campus in June 2017. What do you plan to do during the next reporting period to accomplish the goals?Continue to conduct full-scale replicated experiments in controlled environment hydroponic greenhouses with optimized leachate collection apparatus to generate additional data on the nitrate and phosphorus concentration of leachate from a standard commercial module of a non-recirculating hydroponic system. More SRSS and vegetable crops will be tested as data collection and analysis from this project continues. Continue to educate hydroponic growers, Lincoln University students and the public about strategies to minimize environmental pollution with nitrate and phosphorus from non-recirculating hydroponic systems. Train Lincoln University undergraduate students on the use of hydroponic and plant nutrition instrumentation, data collection and recording in electronic media, as well as the applications of these data in environmental stewardship. Generate data for abstracted presentations at future annual conferences of the American Society of Horticultural Science, the 1890 Association of Research Directors (ARD) conferences, as well as a peer review publication from experiments completed before and during the next reporting period.
Impacts
What was accomplished under these goals?
Objective 1: To evaluate the relative capacity of two inorganic soilless root support substrates (SRSS): perlite and rockwool to reduce nitrate and phosphate leaching, and to compare leaf yield of Swiss chard (Beta vulgaris L.) cv. Acelga from both SRSS in a small-scale non-recirculating hydroponic system (NRHS). Experiment Conducted. The capacity of 100% perlite and DM6-G® rockwool propagation blocks to control nitrate and phosphorus leaching as flow-through fertilizer solution (leachate) to the drainage system were compared during a 49-day cropping cycle, following seedling establishment of Swiss chard in a controlled environment hydroponic greenhouse (CEHG). The NRHS design and the leachate collection apparatus consisted of either 1-Ggallon pot™ (3.8-liter) black plastic pots filled with perlite or DM6-G® rockwool propagation blocks (RPB; 4-inch square x 2.5 inch deep) inserted into a standard Perlite Bato-Buckets from which excess nutrient solution delivered to the SRSS via drip-emitters flows to a drainage channel. The nutrient solution source was a soluble fertilizer (15N-2.2P-12.5K plus micronutrients) supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver to each pot at pH 6.5 - 7.2 during the cropping cycle. Leachate from the SRSS flowed to drainage with or without subsequent passage through a 2-liter layer of granulated horticultural charcoal, respectively. Mean temperature and relative humidity were 22.9oC and 63.2%, respectively. Swiss chard seedlings were grown from the third true-leaf stage until harvesting at 74 days after transfer (DAT) into hydroponic culture. Weekly leachate sampling from the NRHS for determination of nitrate and phosphate concentration started only when the seedlings were fully established and capable of active mineral nutrient absorption (25 DAT). The samples were analyzed for nitrate and phosphate using the Dionex™ ICS-5000+ Capillary High Performance Ion Chromatograph System equipped with conductivity detector. Results: Compared with the inflow nutrient solution, both perlite and rockwool significantly reduced leachate nitrate concentration by ~48.2% (p = 0.0008) and 46.7% (p = 0.0266), and leachate phosphate concentration by ~45.9% (p = 0.0004) and 44.6% (p = 0.0001), respectively, over a 49-day sampling period. Rockwool removed 1.83% more nitrate (p = 0.0564), but 11.16% less phosphate (p = 0.0557) from the leachate compared with perlite. Charcoal filtration of leachate had no significant (p = 0.05) effect on the concentration of nitrate or phosphate leached from either perlite or rockwool. Nutrient-solution delivery rate in this study was 33 ml per minute for 8 minutes per plant, per day for established seedlings during the summer months at a density of 2.2 plants per meter sq. (436 plants per acre). Perlite retained 38.07 mg nitrate /L and 2.62 mg phosphate/L; this is equivalent to preventing the loss of 4.38 kg nitrate and 11.48 g phosphate per acre per day. Similarly, rockwool, which retained 40.05 mg nitrate /L and 2.44 mg phosphate/L, prevented the loss of 4.61 kg nitrate and 11.23 g phosphate per acre per day. Objective 2: To compare the leaf yield of Swiss chard (Beta vulgaris L.) cv. Acelga, grown in two inorganic soilless root support substrates (SRSS): perlite and rockwool in a small-scale non-recirculating hydroponic system (NRHS). Experiment Conducted. The growth and marketable yield response of Swiss chard cv. Acelga to the two inorganic SRSS (100% perlite or DM6-G® rockwool propagation blocks) were evaluated in a NRHS as described under objective 1 above. Results: Crop grown in perlite had significantly (p < 0.05) higher marketable yield: leaf count (LC) and leaf fresh weight (LFW) per plant, as well as leaf dry weight (LDW) and leaf water content (LWC) than rockwool. Leaf count, LFW, LDW and LWC were 12.1%, 39.2%, 23.5% and 1.8% higher for crop grown in perlite than rockwool. The DM6-G® RPB had smaller volume for root growth (40 cubic inch [0.655 liter]) compared with 1-Gal™ (~210 cubic inch [3.44 liter]) of perlite. Apparently, the smaller volume of the rockwool blocks negatively affected the water relations of the crop, and consequently reduction in growth.
Publications
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Progress 09/01/15 to 08/31/16
Outputs
Target Audience:The targeted audiences include (1) the small-scale limited resource hydroponics/aquaponics industry, (2) greenhouse producers of vegetables, herbs and spices for local farmers markets, grocery stores and restaurants.(2) the general agricultural audience and consumers of hydroponic vegetable crops. (3) Manufacturers of greenhouses and hydroponic equipment, tools and fertilizers. (4) amateur horticulturists, part-time farmers and persons interested in food or flower crop production enterprises under protected structures. (5) Urban Gardeners. (6) Master gardeners, agricultural extension specialists and trainers. (7) K-12 and community college students and teachers, (8) undergraduate and graduate students of universities in Missouri and North Central United States. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project has initiated the training of a research technician in the agriculture department of Lincoln University on the conduct of a plant-nutrient management research in a non-recirculating hydroponic system under protected agriculture conditions, and use of related apparatus, nutrient-solution analysis instrumentation. Training opportunity is being provided for undergraduate students in agriculture at Lincoln University on the use of plant nutrient-solution analysis instrumentation, data collection and recording, as well as the principles of environmental stewardship in hydroponic crop production. How have the results been disseminated to communities of interest?Information generated from the research objectives and methodology was disseminated to the public: current and prospective hydroponic and aquaponic growers, through onsite educational presentations at the Hydroponic Research Center of Lincoln University's George Washington Carver Memorial Research Farm in Jefferson City, Missouri. The center received over 35 visitors during the fiscal year from within and outside the state of Missouri. On 12 July 2016, the project director conducted a workshop for 25 Mandela Fellows from 19 countries and an Agribusiness faculty participating in a Business and Entrepreneurship Leadership Development training program on Lincoln University campus. Seven K-12 students from high schools around Missouri were trained in aspects of hydroponic production during a summer institute session organized for undergraduate student recruitment on Lincoln University campus. What do you plan to do during the next reporting period to accomplish the goals?Continue to conduct full-scale replicated experiments in controlled environment hydroponic greenhouses with the optimized leachate collection apparatus to generate additional data on the nitrate and phosphorus concentration of leachate from a standard commercial module of a non-recirculating hydroponic system. More SRSS and vegetable crops will be tested as data collection and analysis from this project continues. Continue to educate hydroponic growers, Lincoln University students and the public about strategies to control environmental pollution with nitrate and phosphorus from non-recirculating hydroponic systems. Train Lincoln University undergraduate students on the use of hydroponic and plant nutrition instrumentation, data collection and recording in electronic media, as well as the applications of these data in environmental stewardship. Generate data for abstracted presentations at future annual conferences of the American Society of Horticultural Science, as well as a peer review publication from experiments completed during the next reporting period.
Impacts
What was accomplished under these goals?
Objective 1: To evaluate the capacity of organic versus inorganic SRSS to reduce the leaching of nitrate and phosphorus from non-recirculating hydroponic systems (NRHS) with minimum hypoxia at the root system. Experiment Conducted. The capacity of the organic (100% Coconut Coir™ [C-Coir]) and inorganic (Perlite) SRSS to control nitrate and phosphorus leaching as flow-through fertilizer components (leachate) to the drainage system were compared during a cropping cycle of Swiss chard in a controlled environment hydroponic greenhouse (CEHG). The NRHS design and the leachate collection apparatus consisted of 1Ggallon pot™ (3.8-liter) black plastic pots filled with either of the two SRSS, and inserted into a standard Perlite Bato-Buckets from which excess nutrient solution delivered to the SRSS via drip-emitters flows to a drainage channel. The nutrient solution source was Peters Excel CAL-MAG™ 15-5-15 (15N-2.2P-12.5K plus micronutrients) supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver to each pot at pH 5.8 - 7.2. Leachates from both SRSS were sampled weekly for the determination of nitrate and phosphorus concentration. Fully expanded leaves of the Swiss chard crop at market maturity were harvested 75 days after establishment in hydroponic culture. Results: Compared with the source solution the inorganic and organic SRSS reduced the nitrate nitrogen (nitrate-N) concentrations of the leachate by 39.5% and 51.3%, and the phosphorus by 45.4% and 38.4%, respectively, over the 75-day sampling period. Mean leachate concentration of nitrate-N was 53.5 and 49.3 mg/L per plant from inorganic and organic SRSS, respectively. At the nutrient-solution delivery rate of 132 ml per plant per day, and a density of 2.2 plants per meter sq. (200 plants per 1000 sq. ft.), 2.64 liters of fertilizer solution was applied per plant per day. This is equivalent to the loss of 28.25 g and 26.03 g of nitrate-N per day in run-off fertigation solution into drainage water systems from the inorganic and organic SRSS, respectively. Although not statistically significant, this represents ~8% reduction in nitrate-N loss per plant from the organic, compared with the inorganic SRSS. Mean concentration of phosphorus in the leachate from the organic and inorganic SRSS were 10.1 and 9.8 mg/L, respectively. Similarly, these differences in leachate concentration of phosphorus between the organic and inorganic SRSS were not statistically significant. The electrical conductivity (EC, mS/cm) of the leachate from the inorganic (pH 8.0), and the organic (pH 7.8) SRSS increased by 3.6% and 26%, respectively, compared with the source solution. Objective 2: To assess the influence of Coconut Coir (organic) and Perlite (inorganic) soilless root support substrates on the yield of Swiss chard cv. Acelga. Experiment Conducted. The growth and marketable yield response of Swiss chard cv. Acelga to either the organic (100% Coconut Coir™ [C-Coir]) or inorganic (Perlite) SRSS were evaluated in a NRHS. Results: C-Coir, the organic SRSS increased the overall growth (leaf dry weight [LDW]) and marketable yield (leaf count [LC] and leaf fresh weight [LFW]) of Swiss chard cv. Acelga over Perlite. These differences were statistically significant for LC (p = 0.0162), LFW and LDW (p < 0.001), respectively. The organic substrate increased LC, LFW and LDW by 11.5%, 37.6% and 28.2%, respectively, over the inorganic SRSS. These results indicate that the organic SRSS controlled source pollution of nitrate and promoted greater yield of Swiss chard in NRHS, compare Objective 1: To evaluate the capacity of organic versus inorganic SRSS to reduce the leaching of nitrate and phosphorus from non-recirculating hydroponic systems (NRHS) with minimum hypoxia at the root system. Experiment Conducted. The capacity of the organic (100% Coconut Coir™ [C-Coir]) and inorganic (Perlite) SRSS to control nitrate and phosphorus leaching as flow-through fertilizer components (leachate) to the drainage system were compared during a cropping cycle of Swiss chard in a controlled environment hydroponic greenhouse (CEHG). The NRHS design and the leachate collection apparatus consisted of 1Ggallon pot™ (3.8-liter) black plastic pots filled with either of the two SRSS, and inserted into a standard Perlite Bato-Buckets from which excess nutrient solution delivered to the SRSS via drip-emitters flows to a drainage channel. The nutrient solution source was Peters Excel CAL-MAG™ 15-5-15 (15N-2.2P-12.5K plus micronutrients) supplied at 200 mg nitrogen/liter, which the NRHS was set to deliver to each pot at pH 5.8 - 7.2. Leachates from both SRSS were sampled weekly for the determination of nitrate and phosphorus concentration. Fully expanded leaves of the Swiss chard crop at market maturity were harvested 75 days after establishment in hydroponic culture. Results: Compared with the source solution the inorganic and organic SRSS reduced the nitrate nitrogen (nitrate-N) concentrations of the leachate by 39.5% and 51.3%, and the phosphorus by 45.4% and 38.4%, respectively, over the 75-day sampling period. Mean leachate concentration of nitrate-N was 53.5 and 49.3 mg/L per plant from inorganic and organic SRSS, respectively. At the nutrient-solution delivery rate of 132 ml per plant per day, and a density of 2.2 plants per meter sq. (200 plants per 1000 sq. ft.), 2.64 liters of fertilizer solution was applied per plant per day. This is equivalent to the loss of 28.25 g and 26.03 g of nitrate-N per day in run-off fertigation solution into drainage water systems from the inorganic and organic SRSS, respectively. Although not statistically significant, this represents ~8% reduction in nitrate-N loss per plant from the organic, compared with the inorganic SRSS. Mean concentration of phosphorus in the leachate from the organic and inorganic SRSS were 10.1 and 9.8 mg/L, respectively. Similarly, these differences in leachate concentration of phosphorus between the organic and inorganic SRSS were not statistically significant. The electrical conductivity (EC, mS/cm) of the leachate from the inorganic (pH 8.0), and the organic (pH 7.8) SRSS increased by 3.6% and 26%, respectively, compared with the source solution. Objective 2: To assess the influence of Coconut Coir (organic) and Perlite (inorganic) soilless root support substrates on the yield of Swiss chard cv. Acelga. Experiment Conducted. The growth and marketable yield response of Swiss chard cv. Acelga to either the organic (100% Coconut Coir™ [C-Coir]) or inorganic (Perlite) SRSS were evaluated in a NRHS. Results: C-Coir, the organic SRSS increased the overall growth (leaf dry weight [LDW]) and marketable yield (leaf count [LC] and leaf fresh weight [LFW]) of Swiss chard cv. Acelga over Perlite. These differences were statistically significant for LC (p = 0.0162), LFW and LDW (p < 0.001), respectively. The organic substrate increased LC, LFW and LDW by 11.5%, 37.6% and 28.2%, respectively, over the inorganic SRSS. These results indicate that the organic SRSS controlled source pollution of nitrate and promoted greater yield of Swiss chard in NRHS, compared with inorganic SRSS. Data from ongoing studies will determine the efficacy of C-Coir in minimizing source control of phosphorus pollution in NRHS relative to Perlite. d with inorganic SRSS. Data from ongoing studies will determine the efficacy of C-Coir in minimizing source control of phosphorus pollution in NRHS relative to Perlite.
Publications
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