Progress 09/01/20 to 08/31/24
Outputs
Target Audience:The target audience includes but is not limited to, University students, extension specialists, organic farmers, stakeholders, and the public. We leveraged the strength of Clemson University as a land grant university and Rodale Institute to disseminate research-based knowledge to the target audience by using the two institutions' extensive extension networks. In addition, results were delivered to the academic and professional communities through publications in peer-reviewed journals and presentations at professional conferences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project provided funding and salary support for two graduate students to complete their graduate training. Meanwhile, the project provided field and experimental plots to support the dissertation research of a third graduate student. Research committees were organized for each graduate student. Regular meetings were organized to discuss research issues and progress. The students were supervised and trained throughout their research on this project. In addition, the students were provided travel grants to participate in various academic and professional meetings. The project also offered hands-on research experience for four high school students. How have the results been disseminated to communities of interest?We took advantage of the extensive extension network of Clemson University and Rodale Institute to disseminate the research outcomes. Field day demonstrations, virtual seminars, newsletters, and social media were fully utilized to transmit the research-based information. Presentations at academic conferences and publications in peer-reviewed journals have also been used. More details can be found in the above sections. In addition, the team advertised and delivered the significance of organic agriculture to the public by organizing an in-person workshop, participating in elementary schools4H activities, broadcasting an interview from a local radio station, and donating project vegetables to a local food bank. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Obj. 1: Quantified diverse organic inputs and evaluate how the inputs affect soil microbial communities To estimate the cover crop production potential, aboveground biomass was collected weekly or biweekly during the whole winter season and weighted. The biomass data were then used to develop a growth model. The model suggested that to maximize cover crop biomass production, fertilization or adjusting plating and termination timing (allowing maximal growth duration) may be essential. Soil DNA was extracted. 16S and ITS rRNA sequencing were also conducted. The abundance of N cycle functional genes was also determined by qPCR. Both cover crops and manure application increased N availability but posed limited and distinct short-term effects on soil microbial communities. For instance, 1) only manure compost application resulted in higher fungal abundance; 2) when compared to the control, manure compost increased the abundance of ammonia-oxidizing archaea (AOA) only in the mixture of rye and vetch; 3) vetch plots had a higher abundance of ammonia-oxidizing bacteria (AOB) than other cover crop plots. Continue organic inputs from cover crop residues and manure compost had limited and inconsistent impacts on microbial alpha diversity compared to the control during the experiment. However, the inputs from the rye (nonlegume cover crop) posed different impacts on microbial diversity than the vetch (legume cover crop). In addition, the inputs from cover crops and manure composts modified microbial community composition and structure, positively correlated to soil inorganic N concentrations and cumulative N inputs. Main conclusions: 1) Cover crop biomass production potential can be estimated with growing degree day and soil N availability; 2) to improve positive cover crop impacts, increasing biomass production with fertilization may be necessary; 3) N availability is at least as important as organic substrate availability in regulating soil microbial communities in sandy soils; and 4) Cover crop impacts on soil microbial community is specie-specific, likely due to their difference in tissue biochemistry. Obj. 2: Quantify the interactive impacts of diversified organic inputs and tillage on soil biogeochemical properties and soil health Soil samples were analyzed for various soil physical, chemical, and biological health indicators associated with C, N, and P processes. Regardless of tillage practice, continuous annual cover cropping and manure compost application did not produce proportional responses in measured soil physio-biogeochemical properties. Generally, consistent positive responses were mainly observed for biological indicators during the cover crop growing season, highlighting the importance of cover crop root impacts. Regardless of tillage type, applications of manure compost and incorporation of cover crops did not result in higher active C concentrations and SOC content at the end of the experiment. Main conclusions: 1) increasing organic inputs by integrating winter cover crops cannot enhance SOC content and soil health, at least in the short-term; 2) compared with conservation tillage, conventional tillage did not result in decreased SOC content and soil health in the short-term, which was likely partially compensated by cover crop residue returns; and 3) managing SOC with diverse organic inputs alone may not improve the sandy soils effectively, where nutrients are commonly limited. Obj. 3: Evaluate how diversified management influences vegetable performance Vegetable yields were estimated by harvesting the yields in the middle row of each plot. Compared to conventional tillage, conservation tillage impeded vegetable growth, reducing the yields, especially for tomatoes. However, except for corn yield, neither cover crop incorporation nor manure compost application changed the vegetable yields. Regardless of manure compost application, vetch and its mixture with rye increased sweet corn yields. Cover crop biomass production was positively correlated to tomato yields in the 2022 and 2023 seasons, which was not observed for sweet corn and cucumber production. Main conclusions: 1) cover crop biomass production can be linked to vegetable yields; 2) excessive N availability can reduce vegetable yields; and 3) different vegetables can respond differently to the same management practices. Obj. 4: Provide a transdisciplinary pedagogical framework that delivers enhanced educational opportunities for undergraduate/graduate students Three graduate students were trained in this interdisciplinary project, covering soil biogeochemistry, microbial ecology, agronomy, and environmental sciences. They were encouraged and supported to present their research at the Agronomy Society of America-Crop Science Society of America-Science Society of America International Annual Meeting, AGU Annual Meeting, and American Society for Microbiology Annual Meeting. Four high school summer interns were recruited and trained through the collaborations between Clemson University and South Carolina Governor's School for Science and Mathematics. The hands-on experience provided an excellent opportunity for them to understand real-world challenges and the scientific ways to address them. Obj. 5: Disseminate research-based knowledge to promote the adoption of diversifying management practices We took advantage of the extensive extension network of Clemson University and Rodale Institute to disseminate the research outcomes. During the project, six field-day demonstrations were conducted in South Carolina and Georgia. One online seminar was delivered during the Covid-19 pandemic. Project information and progress were published and advertised in newsletters (e.g., Clemson Newsstand and Rodale Institute Newsletter), social media (e.g., LinkedIn and Instagram), and other online platforms (e.g., Vegetable Growers News). Research data and results were also presented at academic conferences and peer-reviewed journals. In addition, a group of scientists of the multistate research project NC1178 toured the research field at SC. Broad impacts: This specific project addressed whether/how diverse organic inputs can be managed along with conservation tillage to improve the health of the sandy Coastal Plain soils to support organic vegetable production. The research outcomes advance our knowledge and understanding of how standard management practices affect soil physio-biogeochemical processes critical to organic vegetables' productivity, profitability, and sustainability. The extension and outreach outcomes provide research-based information to regional producers to improve ecosystem services and environmental stewardship of their farms and their quality of life. More specifically, the research provides an empirical model to optimize cover crop management (Obj. 1) for better environmental (Obj. 1&2) and agronomic (Obj. 3) outcomes (i.e., improved soil health with reduced resource inputs and increased production). The project cultivated well-trained personnel who will effectively work in soil sciences and relevant disciplines to explore and address the current agricultural and environmental challenges (Obj. 4). Meanwhile, the project provides information to optimize organic inputs and tillage to restore soil health and resilience in sandy Coastal Plain soils, keeping organic vegetables productive and sustainable (Obj. 5). Moreover, this project will increase public awareness of soil health and environmental literacy, encourages the participation of diverse groups to improve their environment and life of quality through research and education and help clientele and stakeholders to manage their soils and farms better while maintaining and improving environmental stewardship.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2024
Citation:
Wang, Z., Saski, C., Williamson, C., Campbell, B., Ye, R., 2024. Crop
cover and manure compost: Their varied effects on nitrogen availability and
nitrogen cycling functional gene abundances in sandy soils for organic
farming. Applied Soil Ecology 200, 105446.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Wang, Z., Ye, R., & Saski, C. (2023) Hairy Vetch and Manure Compost
Enhanced Soil Nitrogen Availability and Altered Bacterial Community
Structure in Organic Production. ASA, CSSA, SSSA International Annual
Meeting, St. Louis, MO.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Oliver, F. E., & Ye, R. (2023) Carbon and Nitrogen Cycling As Influenced
By Tillage, Cover Crops, and Manure in Organic Agriculture. ASA, CSSA,
SSSA International Annual Meeting, St. Louis, MO.
https://scisoc.confex.com/scisoc/2023am/meetingapp.cgi/Paper/153605
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Wang, Z., Ye, R., & Saski, C. (2023) Hairy Vetch and Manure Compost
Improved Soil Nitrogen Availability and Reduced Bacterial Diversity in
Organic Vegetable Production ASA, CSSA, SSSA International Annual
Meeting, St. Louis, MO.
https://scisoc.confex.com/scisoc/2023am/meetingapp.cgi/Paper/151988
|
Progress 09/01/22 to 08/31/23
Outputs
Target Audience:The target audience includes but is not limited to, University students, extension specialists, organic farmers, stakeholders, and the public. We will leverage the strength of Clemson University as a land grant university and Rodale Institute to disseminate research-based knowledge to the target audience by using the two institutions' extensive extension networks. In addition, results will be delivered to the academic and professional communities through publications in peer-review journals and presentations at professional conferences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Three graduate students were hired to work on this project. They were trained and supervised throughout their research. The students were provided travel grants to participate in the Tri-Societies Annual International meeting. A high school summer intern from South Carolina Governor's School was recruited through Clemson University Summer Program for Research Interns. The student got hands-on experience in field and laboratory research. How have the results been disseminated to communities of interest?The disseminative efforts include: Field day demonstration was conducted at the 2022 Pee Dee REC Annual Field Day. We organized a field tour and onsite demonstration for a group of research scientists associated with the Multistate research project NC1178. Dr. Ye presented the project results in a Departmental seminar. More than 50 visitors from different organizations, companies, and universities toured the project at the GA site. These visitors included extension agents, university professors, students, schoolteachers, VPs of companies, consultants, and local farmers. The Southeast Organic Center was visited by Asst. Prof. Leonardo Bastos and his team from the University of Georgia in May 2023. We conducted a series of drone flights over cover crops. Post was shared on LinkedIn and Instagram. The LinkedIn post got 79 likes, 4 comments, and 6 reposts. The Instagram postreceived 2535 impressions, 101 likes, 1 comment, 1 share, and 2 saves. Rodale Institute publishedan electronicNewsletter on June 30 highlighting this research project, which has over 30,000 subscribers, half identifying as farmers or agricultural professionals (available online at mailchi.mp/rodaleinstitute/research-training-and-education-for-farmers-in-the-southeast). What do you plan to do during the next reporting period to accomplish the goals?We are completing the 2023 season with tomatoes. More analyses are scheduled. However, to make the search a two-full-cycle rotation, while minimizing the Covid-19 impacts, we requested a no-cost extension and got approval. We will continue to repeat the experiment at GA and SC sites following the procedures detailed in the granted proposal for the next reporting period. No major changes are expected. Major activities are described by objectives as follows. Objective 1:We will continue the molecular approaches on microbial communities, including PCR, DNA sequencing, and metagenomic analyses, to determine the abundance and diversity of specific functional groups and the composition and metabolic potentials of microbial communities. We will start to compare the treatment impacts across the GA and SC sites. Objective 2:We will use soil health assessment frameworks to evaluate short-term changes in soil health indicators in response to organic inputs and tillage. Objective 3: We will analyze the nutrient contents of the tomatoes and sweet corn and estimate the nutrient use efficiencies of the tomatoes and sweet corn under different management treatments. Objective 4: We will help the students to complete their dissertation research and present findings at professional meetings. More efforts will be focused on publishing the research data. Objective 5: We will prepare slides and handouts for presentations on field days, workshops, and academic conferences.
Impacts
What was accomplished under these goals?
Issues being addressed: Increasing demands for organic vegetables has created high-value opportunities for conventional producers to transition to organic in southeastern states of the USA, where the organic production acreages lag nations' leading states. However, growers in the region are facing unique challenges in soils, which typically have low soil organic carbon, meager soil fertility, and poor soil structure. Increasing organic inputs (e.g., manure, compost, and cover crop), along with conservation tillage, is widely considered one of the best management strategies to address such soil health issues; yet the diverse available organic sources and their distinguished physiochemical properties, in combination with various management practices across spatial and temporary scales, may make desired economic and environmental outcomes less predictable. The project aims to investigate the interactive effects of diversifying organic C inputs and tillage on soil microbial community, soil health, and organic yields in the context of improving the soils, plants, and the environment. What we did and potential impacts: Field experiments were carried out simultaneously at the Pee Dee Research and Education Center of Clemson University (South Carolina) and the Southeast Organic Center of Rodale Institute (Georgia). Organic inputs were diversified by planting different cover crops and their mixtures, along with manure application. Through field and laboratory studies, we investigated the interactive effects of diversifying organic inputs and tillage on soil microbial community composition, soil carbon dynamics, nutrient cycling, soil health, and organic yields. The goal is to advance our knowledge and understanding of how management practices affect soil physio-biogeochemical processes that are important to the productivity, profitability, and sustainability of organic vegetables, providing research-based information to regional producers to improve ecosystem services and environmental stewardship of their farms, and their quality of life. The field experiment will be repeated on the same site for three years. Progresses and accomplishments by objectives: The following describes research activities and accomplishments by objectives: Obj. 1: Evaluate how diversified organic inputs interact with tillage affecting soil microbial diversity and the functional groups associated with soil organic carbon (SOC), nitrogen (N), and phosphorus (P) cycling DNA samples were extracted from both SC and GA sties. qPCR was conducted to understand the abundance of bacteria, archaea, and fungi populations, as well as the N functional genes. Samples were also sent to commercial labs for sequencing. We are completing the analyses of sequencing data. Preliminary data (SC site) suggested, Both cover crops and manure did not change the abundance of bacteria and archaea communities. Manure application, but not cover crops, increased the abundance of fungi communities. In addition, the vetch plots had higher ammonia-oxidizing bacteria gene (AOB amoA) abundance than others, while manure application resulted in higher fungi abundance than the control plots. Planting hairy vetch decreased microbial diversity. Neither cover crop integration nor manure application changed the abundance of AOA-amoA, comammox clade A, comammox clade B, and nifH gene copies. Cover crop integration increased the AOB-amoA abundance, which, however, depended on the species. Higher AOB-amoA abundance was only observed in plots planted with VE when compared to the control plots. Obj. 2: Quantify the interactive impacts of diversified organic inputs and tillage on (a) C, N, and P biogeochemical processes and (b) short-term changes in soil health The preliminary results indicated limited impacts of cover cropping and manure application on the measured soil properties despite significantly different organic inputs, which however were not affected by tillage. Some examples of significant impacts include: Manure application increased soil EC, which was only observed in hairy vetch plots. Higher nitrate (NO3-) was found in the vetch plots when compared to the rye and control plots. Plots with manure application had higher ammonia (NH4+) concentrations than those without. The N-acetyl-β-D-glucosaminidase activity was higher in vetch plots than in rye and control plots and leucine aminopeptidase activities were higher in manure plots than in the non-manure plots. Regardless of manure application, cover cropping increased organic mineralization rates. Obj. 3: Evaluate how diversified management influences the nutritional quality and yields of the vegetables In the 2022 season, sweet corn was planted in both SC and GA sites. The SC data suggested both cover crop and manure application affected the yields, while tillage had no impacts. In general, manure application increased the yield. Planting cereal rye decreased corn yield, which however was not observed for the vetch and the mixtures of vetch and rye. The data in the GA site is being analyzed. Obj. 4: Provide a transdisciplinary pedagogical framework that delivers enhanced educational opportunities for undergraduate/graduate students One MS student completed his thesis research on this project and graduated. Two more Ph.D. students are still in training with dissertation research on Objectives 1, 2, and 3. One of the Ph.D. students will have his comprehensive exam scheduled in October 2023, while another one has his dissertation research approved by the advisory committees. The students presented their research at the 2023 Tri-Societies Annual Meeting, one of whom won 2nd place in the graduate student presentation competition. One high school summer intern participated in the project. Obj. 5: Disseminate research-based knowledge to promote the adoption of diversifying management practices The disseminative efforts include: Field day demonstration was conducted at the 2022 Pee Dee REC Annual Field Day. We organized a field tour and onsite demonstration for a group of research scientists associated with the multistate research project NC1178. Dr. Ye presented the project results ata Departmental seminar. More than 50 visitors from different organizations, companies, and universities toured the project at the GA site. These visitors included extension agents, university professors, students, schoolteachers, VPs of companies, consultants, and local farmers. The Southeast Organic Center was visited by Asst. Prof. Leonardo Bastos and his team from the University of Georgia in May 2023. We conducted a series of drone flights over cover crops. Post was shared on LinkedIn and Instagram. The LinkedIn post got 79 likes, 4 comments, and 6 reposts. The Instagram postreceived 2535 impressions, 101 likes, 1 comment, 1 share, and 2 saves. Rodale Institute publishedan electronicNewsletter on June 30 highlighting this research project, which has over 30,000 subscribers, half identifying as farmers or agricultural professionals (available online at mailchi.mp/rodaleinstitute/research-training-and-education-for-farmers-in-the-southeast).
Publications
|
Progress 09/01/21 to 08/31/22
Outputs
Target Audience:Research products/outcomes will be directed to graduate and undergraduate students, extension specialists, organic farmers, and the general public. Results will be delivered to the academic communities through publications in peer-review journals and presentations in professional conferences. We will leverage the strength of Clemson University as a land grant university and Rodale Institute to disseminate research-based knowledge to farmers, stakeholders, and the general publics by using the university's extension network. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students were hired to work on this project. They were trained and supervised throughout their research. Another PhD student was hired with financial supports from Clemson University (will start in August 2022) to investigate the green house gases emission dynamics. This graduate student will take advantage of the established field plots and experimental settings to complete his dissertation. How have the results been disseminated to communities of interest?Due to the Covid-19 pandemic, in person extension activities were limited. This research project was presented to and discussed with local farmers on a field day at GA. The research was advertised to farmers, the public, extension agents, and academic communities through extension outlets of the Clemson University (e.g., Clemson News, extension handouts) and Rodale Institute (e.g., webinar and regular field tour). What do you plan to do during the next reporting period to accomplish the goals?Despite the legacy impacts and delays by the Covid-19 pandemic, we were able to implement the planned activities at both SC and GA sites in the past year. No major changes are expected. We will continue to analyze the data and follow the procedures detailed in the granted proposal for the next reporting period. Major activities are described by objectives as follows. Objective 1:we will continue the molecular approaches on microbial communities, including PCR, DNA sequencing, and metagenomic analyses, to determine the abundance and diversity of specific functional groups and the composition and metabolic potentials of microbial communities. Objective 2:we will use soil health assessment frameworks to evaluate short-term changes of soil health indicators in response to organic inputs and tillage (2020-2022). In addition to complete the analyses of soil carbon and nitrogen dynamics, we will conduct phosphorous fractionation analyses to investigate the distribution and stability of phosphorus introduced by manure application. Objective 3:We will prepare to analyse nutrient contents of the tomatoes from 2021 season and estimate nutrient use-efficiencies of the tomatoes under different management treatments.Sweet corn isgrowing in the field now. We will estimate the yield and nutrients of the corn after harvest and determine the nutrient use efficiency. Objective 4:We will help the MS student to complete his thesis writing and publish his research data. The PhD student will continue his dissertation research, especially the changes of microbial diversity and community compositions, while reporting research progresses and issues to his advisory committee. The newly hired PhD student will take advantage of the established field plots and experimental settings to start his dissertation research. An advisory committee will be organized to discuss the research and education plans. In addition, the students will spend some time in Co-PIs' lab to get some training on laboratory and analytical skills. Objective 5:We will prepare slides and handouts for presentations in field days, workshops, and academic conferences, e.g., 2022 Pee Dee REC Field Day and Southeast Organic Center Field Day.
Impacts
What was accomplished under these goals?
Issues being addressed:Increasing demands for organic vegetable has created high-value opportunities for conventional producers to transition to organic in southeastern states of USA, where the organic production acreages lags nations' leading states. However, growers in the region are facing unique challenges in soils, which typically has low soil organic carbon, meager soil fertility, and poor soil structure. Increasing organic inputs (e.g. manure, compost, and cover crop), along with conservation tillage, is widely considered one of the best management strategies to address such soil health issue; yet the diverse available organic sources and their distinguished physiochemical properties, in combination with various management practices across spatial and temporary scales, may make desired economic and environmental outcomes less predictable. What we did and potential impacts:In this specific project, we tried to address whether this diversity in organic inputs (both quality and quantity) can be managed to improve underground biodiversity and the soil processes underpinning soil health and the productivity of organic vegetables in southeastern Ultisols, and whether tillage affects the outcomes. Field experiments were carried out simultaneously at Pee Dee Research and Education Center of Clemson University (South Carolina) and Southeast Organic Center of Rodale Institute (Georgia). Organic inputs were diversified by planting different cover crops and their mixtures, along with manure application. Through field and laboratory studies, we investigated the interactive effects of diversifying organic inputs and tillage on soil microbial community composition, soil carbon dynamics, nutrient cycling, soil health, and organic yields. The goal is to advance our knowledge and understanding of how management practices affect soil physio-biogeochemical processes that are important to the productivity, profitability, and sustainability of organic vegetables, providing research-based information to regional producers to improve ecosystem services and environmental stewardship of their farms, and their quality of life. The field experiment will be repeated on the same sitesfor three years. Progresses and accomplishments by objectives:The project was jeopardized by Covid-19 pandemic in 2020-2021 season, delaying some of our work and analyses. During the 2021-2022, we were able to resume all the planned activities as detailed in the proposal and managed to catch up the delays. We followed the same experimental design as the first year at SC and GA. After terminating the tomato in August 2021, we planted cucumbers in both SC and GA sites.Cucumbers were harvested in November at SC but were not able to reach maturityat GA. It is likely that local climate was not favorable for two vegetable seasons in the summer. Soil samples were collected prior to planting cover crops and analyzed in the soil lab at Pee Dee Research and Education Center. Cover crops were planting in mid-November 2021 at SC and GA, and terminated in April, followedby sweet corn planting in late April. The following describes research activities and accomplishments by objectives: Obj. 1: Evaluate how diversified organic inputs interact with tillage affecting soil microbial diversity and the functional groups associated with soil organic carbon (SOC), nitrogen (N), and phosphorus (P) cycling We diversified the organic inputs by planting different cover crops with varied biomass production potentials, which was further augmented by manure application in the winter. The preliminary data suggested the diversifying framework worked very well for consecutive two years. Diversified organic materials, as well as varied nutrient sources, were introduced as proposed. We are trying to estimate (by modeling) how much of cover crop biomass and C/N inputs can be generated per the local climate and planting time and rates. Preliminary data suggested that the production at both GA and SC were relatively low(~4,000 kg ha-1) when compared to other regions. We were able to extract DNA from 2020 and 2021 soil samples collected from both SC and GA sties. Preliminary data suggested one season of cover cropping did not change the abundance of ammonia oxidation bacteria (AOB) and archaea (AOA), which were not affected by manure application and tillage. DNA samples will be sent for sequencing.More data is being analyzed. Obj. 2: Quantify the interactive impacts of diversified organic inputs and tillage on (a) C, N, and P biogeochemical processes and (b) short-term changes of soil health We have completed all the planned soils analysescollected from both sites (four sample eventsfrom 10/2020 to 5/2022)and are analyzing the data to understand short-term changes of soil carbon, nitrogen, and phosphorus in the context of pool size, distribution, transformation. The preliminary results suggested that varied organic inputs created by cover cropping and fertilization changed soil pH, nutrient availability, microbial respiration, and enzyme activities. These effects varied by the sources of the organic inputs. No significant changes in potential mannerization of organic N and labile organic C were observed, regardless of cover crop species, tillage types and fertilization schemes. Obj. 3: Evaluate how diversified management influences nutritional quality and yields of the vegetables For the first season (2020), we did not observe significant impacts of cover cropping and fertilizationon the marketable yield of the tomatoes, but did find that conservation tillage (i.e., reduced tillage)reduced tomatoyields in both sites, especially at SC, where low plant height and vegetation were found, likely resulted from the soil hard-pan impeding plant root growth. For the cucumber at the SC site, higher yields were found in plots with conservation tillage than those with conventional tillage, while planting cereal rye reduced the yields when compared to planting hairy vetch,the mixture of hairy vetch and cereal rye, and no cover crop control. Obj. 4: Provide a transdisciplinary pedagogical framework that delivers enhanced educational opportunities for undergraduate/graduate students One MS and one PhD students were hired to work on this project.Both have their research proposal approved by their advisory committees. The MS student is writing his thesis on changes in soil healthindicators and expected to graduate in December 2022. The PhD student will have his comprehensive exam in November 2022, who is trained on soil microbial community composition and functional groups associaed with nitrogen cycling.Both will present their research in the 2022 Tri-Societies Annual Meeting. Obj. 5: Disseminate research-based knowledge to promote the adoptions of diversifying management practices Due to the Covid-19 pandemic, the Pee Dee Research and Education Center canceled in personfield day for two consecutive years (2020-2021). However, an extension handout was created by the station, which was distributed to local farmers and available online for free download. The handout includes descriptions for this specific project and some preliminary results. A webinar was also organized and presented on January 26, 2022 to provide research updates from this project. In addition, this research project was advertised to farmers, stake holders, the general publics, and academic communities through the extension outlets of both Clemson University and Rodale Institute.
Publications
|
Progress 09/01/20 to 08/31/21
Outputs
Target Audience:Research products/outcomes was directed to graduate and undergraduate students, extension specialists, organic farmers, and the general public. Results will be delivered to the academic communities through publications in peer-review journals and presentations in professional conferences. Research data may be stored in public data repository for free access. We will leverage the strength of Clemson University as a land grant university to disseminate research-based knowledge to farmers, stakeholders, and the general publicby using the university's extension network. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students were hired to work on this project. Advisory committees were identified to mentor the two graduate students. They were trained and supervised throughout their research. How have the results been disseminated to communities of interest?Due to the Covid-19 pandemic, our extension activities were limited. This research project was presented to and discussed with local farmers on a field day at GA. The research was advertised to farmers, the general public, extension agents, and academic communities through extension outlets of the Clemson University and Rodale Institute. A field day at the Pee Dee Research and Education Center was scheduled on 9 September 2021, in which we will disseminate the results from this work. What do you plan to do during the next reporting period to accomplish the goals?We have been greatly affected by the Covid-19 pandemic. However, we were able to managethe field while collecting soil and plant samples as planned in both SC and GA sites in the past year. No major changes are expected. We will continue to analyze the first-year data and follow the procedures detailed in the granted proposal for the next reporting period. Major activities are described by objectives as follows. Objective 1: we will continue the molecular approaches on microbial communities, including PCR, DNA sequencing, and metagenomic analyses, to determine the abundance of specific functional groups and the composition and metabolic potentials of microbial communities. Objective 2: we will use soil health assessment frameworks to evaluate short-term changes of soil health indicators in response to organic inputs and tillage. In addition to complete the analyses of soil carbon and nitrogen dynamics, we will conduct phosphorous fractionation analyses to investigate the distribution and stability of phosphorus introduced by manure application. Objective 3: The tomatoes in the fields are fruiting. We will prepare to harvest the tomatoes, estimate the yield and nutritional quality of the tomatoes, and compare nutrient use-efficiencies of the tomatoes under different management treatments. We have selected cucumber as the crop after tomato. The seeds were secured and will be planted directly to the field. Objective 4: The graduate students will have their respective committee meetings to discuss their research and education plans, while reporting their progresses and issues. In addition, the students will analyze their data, prepare slides, and present their research results to their host department. Both students are expected to spend some time in Co-PIs' lab to get some training on laboratory and analytical skills. Objective 5: We will complete analyzing the first-year data from both field sites and prepare slides for presentations in field days, workshops, and academic conferences. Extension press publications may also be expected.
Impacts
What was accomplished under these goals?
Issues being addressed: Increasing demands for organic vegetable has created high-value opportunities for conventional producers to transition to organic in southeastern states of USA, where the organic production acreages lags nations' leading states. However, growers in the region are facing unique challenges in soils, which typically has low soil organic carbon, meager soil fertility, and poor soil structure. Increasing organic inputs (e.g. manure, compost, and cover crop), along with conservation tillage, is widely considered one of the best management strategies to address such soil health issues; yet the diverse available organic sources and their distinguished physiochemical properties, in combination with various management practices across spatial and temporary scales, may make desired economic and environmental outcomes less predictable. What we did and potential impacts: In this specific project, we tried to address whether this diversity in organic inputs can be managed to improve underground biodiversity and the soil processes underpinning soil health and the productivity of organic vegetables in southeastern soils, and whether tillage affects the outcomes. Field experiments were carried out simultaneously at Pee Dee Research and Education Center of Clemson University and Southeast Organic Center of Rodale Institute. Organic inputs were diversified by planting different cover crops and their mixtures, along with manure application. Through field and laboratory studies, we investigated the interactive effects of diversifying organic inputs and tillage on soil microbial community composition, soil carbon dynamics, nutrient cycling, soil health, and organic yields. The goal is to advance our knowledge and understanding of how management practices affect soil physio-biogeochemical processes that are important to the productivity, profitability, and sustainability of organic vegetables, providing research-based information to regional producers to improve ecosystem services and environmental stewardship of their farms, and their quality of life. Progresses and accomplishments by objectives: We conducted the field experiments in two certified organic fields at SC and GA simultaneously. The experiments have treatments of cover crop (cereal rye, hairy vetch, their mixtures, and no cover crop control) and manure application (with vs. without) randomly imbedded in the tillage treatment (conventional vs. conservation). Each treatment and their combinations were repeated four times in the fields, resulting in 64 plots in total on both sites. Cover crops were planted in November 2020 and terminated in April 2021. Chicken litterwas applied in January 2021. Amelia tomatoes were transplanted in April and May 2021 at SC and GA sites, respectively. Soil samples were collected at the beginning of the experiments and prior to the termination of cover crops and analyzed in the soil lab at the Pee Dee Research and Education Center. The following describes research activates and accomplishments by objectives: Obj. 1: Evaluate how diversified organic inputs interact with tillage affecting soil microbial diversity and the functional groups associated with soil organic carbon (SOC), nitrogen (N), and phosphorus (P) cycling We diversified the organic inputs by planting different cover crops with varied biomass production potentials, which was further augmented by manure application in the winter. The preliminary data suggested the diversifying framework worked very well. Diversified organic materials, as well as varied nutrient sources, were introduced as proposed. We are trying to estimate (by modeling) how much of cover crop biomass can be generated per the local climate and planting time and rates. We were able to extract DNA from soil samples collected from both SC and GA sties. We are conducting real time quantitative PCR and conventional PCR (products will be sent out for sequencing) to estimate the abundance of specific functional groups, community composition. Obj. 2: Quantify the interactive impacts of diversified organic inputs and tillage on (a) C, N, and P biogeochemical processes and (b) short-term changes of soil health We have completed the analyses of all the soils sample collected from both field sites and are analyzing the data to understand short-term changes of soil carbon, nitrogen, and phosphorus in the context of pool size, distribution, transformation. A range of soil health indicators were selected and analyzed. We are analyzing the data to identify the short-term treatment effects. The preliminary results suggested that organic inputs changed soil pH, nutrient availability, and microbial activities, but these effects varied by the sources of the organic inputs. Obj. 3: Evaluate how diversified management influences nutritional quality and yields of the vegetables After terminating cover crops, tomatoes was trans-planted from the greenhouse on 15 April, 2021. The tomato was managed as proposed, including staking, irrigation, and the applications of organic pesticide, fungicide, and bactericide. The tomatoes are still growing. The yield and nutritional analyses will be estimated after harvest. Obj. 4: Provide a transdisciplinary pedagogical framework that delivers enhanced educational opportunities for undergraduate/graduate students Two graduate students were hired to work on this project, both of which are co-advised by PI and one of the Co-PIs. An advisory committee with professionals of varied disciplines was organized for each of the students, assuring their successful training. Obj. 5: Disseminate research-based knowledge to promote the adoptions of diversifying management practices Our research and extension activities were greatly affected by the Covid-19 pandemic, as a result of modified operation of Clemson University, travel ban, and longer time to secure lab and field supplies. We are still analyzing some of the first-year data. However, this project was presented on the field day of the Southeast Organic Center Farmer Gathering (11/17/2020, Rodale Institute). In addition, this research project was advertised to farmers, stake holders, the general public, and academic communities through the extension outlets of both Clemson University and Rodale Institute.
Publications
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