How systems impact long-term sustainability of soil and water resources,
system differences in resilience to perturbations in weather, inputs and market prices, and
how systems impact biodiversity, pest dynamics and ecological services of agriculture.
- Published a review of interviews from 30 fresh fruit and vegetable growers about their perceptions and motivations for selling produce to low-income consumers. http://rafiusa.org/wp-content/uploads/2015/06/RAFI_Farmer_Interviews_Final_.pdf
- Interviewed about 25 row crop growers about their decision making when it comes to environmental practices and organic certification; we plan to conduct 5 more, and use the results to design a survey to learn more about the land tenure/contract issue and how it affects growers’ decisions.
- Cover crop plots established and tracked on 16 farms in North Carolina to examine cover crop impacts on soil moisture and nitrogen availability.
- Research at the FSRU was highlighted at the regional Cover Crop Conference including a stop on the field day where approximately 350 participants examined how we study the impact of cover crops on greenhouse gas emissions from soils.
- Soil collected from the Integrated Crop Animal treatments in 2015 for evaluation of soil biological activity in a greenhouse trial; study conducted by visiting scientist, Tangriani Simioni Assmann from the Technical University of Parana in Pato Branco, Parana, Brazil; manuscript in development
- Soil sampled in transition phase from pasture to cropping in the Integrated Crop Animal plots in 2016 for evaluation of soil bulk density, soil carbon and nitrogen fractions, nutrient concentrations, and soil biological activity; study conducted by PhD sandwich student, Joao Bonetti from Federal University of Rio Grande do Sul in Porto Alegre, Brazil; oral presentation made at the Annual Meeting of the Soil Science Society of America in Phoenix AZ in November 2016; manuscript in development
- As part of a series of wheat nitrogen timing and rate trials across North Carolina, two experiments were conducted in 2016/17 on no-tillage wheat following corn in the ICA plots; study conducted in collaboration with visiting PhD sandwich student, Bernardo Borin from Federal University of Rio Grande do Sul in Porto Alegre, Brazil; manuscript in development
- As an extension of the FSRU experiment with utilization of native warm-season grasses in the ICA treatments, the adjacent agroforestry experiment has developed a similar species mixture and serves as a long-term corollary experiment for the evaluation of unique farming systems for the region, including silvopasture grazing of cattle, hay production, harvest of forages for biofuel, and conservation reserve forages that are not harvested; several field day events were held to showcase this research, including the NRCS Pastureland Ecology Course in 2017, NC Beef Field Day in 2016, Southern Cover Crops Conference in 2016, Brazilian agroforestry tour group in 2015, and several smaller groups over the years
- Blog posts of the silvopasture experiment are available – NACD, http://www.nacdnet.org/2016/08/31/silvopasture-getting-closer-look-southeast/; CALS, https://sustainability.ncsu.edu/blog/2017/06/06/made-in-the-shade-research-focuses-on-combining-forestry-and-livestock-grazing/; CEFS, https://cefs.ncsu.edu/silvopasture-integrating-agriculture-and-forestry/;
- Video presentation at agroforestry event – University of Missouri Center for Agroforestry, https://www.youtube.com/watch?feature=player_embedded&v=V7NlZJZwu4c
- Journal article on greenhouse gas emissions from agroforestry system – Nutrient Cycling in Agroecosystems, https://link.springer.com/article/10.1007/s10705-016-9809-7
- Agroforestry experiment has made the transition from a tree-crop system to a silvopasture system. Native warm-season grasses were successfully established and tree growth has been rapidly increasing. Several embedded research projects were established in this long-term experiment, including measurement of (a) greenhouse gases from soil as a function of location in the agroforestry design, (b) native warm-season grass establishment with disking and no-tillage seedbed preparation, (c) incoming solar radiation as affected by position in the system, and (d) soil organic carbon and nitrogen as affected by distance from trees.
- Integrated-crop animal treatment has received two embedded treatments in the transition from pasture to cropping phase. Pasture termination method (plow, disk, and no-tillage) is being evaluated in 2016 for effects on crop growth and soil organic carbon and nitrogen fractions. Nitrogen fertility of the pasture-crop rotation is being investigated during corn production in 2016.
- Hosted CEFS interns for research experiences in 2015, 2016 and 2017. Approximately 12 interns each year.
- Hosted “Soilbration” at CEFS to celebrate 20 years of sustainable agricultural research. By collaborating with the Natural Resources Conservation Service, we were able to host almost 500 participants at the event.
- Co-sponsored climate change conferences with the Abundance Foundation three years in a row. Multiple scientists from our group have presented.
- Hosted 15-20 sustainable agriculture workshops each year at CEFS.
- We measured three fractions of soil labile organic matter among four treatments after amendments (manure in organic, UAN fertilizer in conventional). Potassium permanganate oxidizable carbon (POX-C) increased with decreasing tillage among organic treatments, while no-till management in the conventional treatment maintained residual labile organic matter despite receiving no organic inputs. A similar trend is followed by microbial biomass carbon and nitrogen.
- Soil N2O production rates differed significantly among systems, fungal contribution accounted consistently for > 30% of total soil N2O production. Fungal ability of N2O production has been increasingly documented, yet its ecological importance and controlling factors remains unclear. Our result indicated that fungi could play an important role in soil N2O production in diverse ecosystems and soil pH is a critical control factor.
- Invertebrate predator/prey ratios vary substantially amongst systems with surprisingly low ratios in our crop/animal systems where perennial hay and pasture is rotated with row crop production. Preliminary results indicate invertebrates play an important role in residue decomposition rates that may in turn impact greenhouse gas emissions.
- As an extension of the project to discern effects on soil and productivity responses, an agroforestry experiment has been maintained with funding from US-Forest Service and USDA-Agricultural Research Service. This study is transitioning from alley-cropping to silvopasture, and therefore, will allow us to characterize both forestry and agriculture in the same system.
- Houghton, S., O’Sullivan, J., Simon, M., & Stewart, A. (2013). How is it that NC tobacco farmers are deciding to plant organic crops? Sharing our theories when they are square pegs for round holes. Paper presented at the Annual Meetings of the Academy of Management, Orlando, FL, 9 – 13, August.
- A group of 5 agricultural extension agents from “Instituto Ouro verde” in Brazil visited the FSRU on 3/30/15. The purpose of the visit was for them to know the FSRU, exchange experiences about resilient agriculture, and create connections for potential future collaboration.
- A group of about 15 people from various programs of the Center for Environmental Farming Systems (CEFS) visited the FSRU on 5/6/2015. The objective of the visit was to inform other CEFS member about the FSRU in general.
- A group of 5 member of NCSU-Entomology group visited the FSRU on 5/18/15. The purpose was to have a general tour of the research station with focus on sustainability.
- As part of the 2015 CEFS Internship program, a group of 15 undergrad and graduate student visited the FSRU on 6/9/2015. The purpose was for the students to know about the various programs and research opportunities that the FSRU offers to students and researches.
- We are finishing surveys of farmers using a range of conservation practices. So far, the largest explanatory variable has been the stability of their land tenure. Farmers predominantly on land with short-term leases are reluctant to invest in conservation practices where the return to investments in soil and water conservation practices accrue slowly. A new collaborator, Dara Bloom, has joined the team to conduct research on how land tenure impacts sustainability.
Educational & Outreach Activities
- Graduate student theses completed:
- Bloszies, Sean – Ph.D. 2015 Microbial activity and greenhouse gases production from the soil.
- Adams, Paul – M.S. 2015. “Above and Below Ground Biological Interactions in Corn (Zea Mays) and Soybean (Glycine max) under Various Agriculture Production Systems”.
- Ross, Natalie – M.S. 2016. “Development and Application of a Continuous Flow-Through Chamber Technique to Measure Nitrous Oxide Emissions from Agroecosystems in the Southeast”
- Knight, Alexandra – Ph.D. 2016. “Greenhouse Gas Emissions in Long Term Agricultural Production Systems”.
- Cruz, Angel – M.S. Does Diversity Matter? Examining Agroecosystems Impacts of Beneficial Soil Microorganisms Diversity.
- Chen, Huaihai – Ph.D. Fungal Nitrous Oxide Production in Agro-ecosystems: Importance Relative to Bacteria and Responses to Abiotic Factors.
- Monthapo, Nape – Ph.D. Fungal Potential in Soil Nitrous Oxide Production and its PH and Moisture Dependence in Diverse Managed Ecosystems.
- Vann, R., S. Reberg-Horton, H. Poffenbarger, G. Zinati, J. Moyer and S. Mirsky. Starter fertilizer for managing cover-crop-based organic corn. Agronomy Journal. In press doi:10.2134/agronj2016.09.0506
- Roper, W., D. Osmond, J. Heitman, M. Wagger and C. Reberg-Horton. Soil health indicators do not differentiate agronomic management of North Carolina Soils. Soil Science Society of America Journal. In press. doi: 10.2136/sssaj2016.12.0400
- *Wells, M.S., S.C. Reberg-Horton, S.B. Mirsky, J.E. Maul, and S. Hu. 2017. In situ validation of fungal N translocation to cereal rye mulches under no-till soybean production. Plant and Soil 410:153-165.
- Wu, Keke; Chen, Dima; Tu, Cong; Qiu, Yunpeng; Burkey, Kent O; Reberg-Horton, S Chris; Peng, Shaolin; Hu, Shuijin. CO2-induced alterations in plant nitrate utilization and root exudation stimulate N2O emissions. Soil Biology and Biochemistry 106:9-17.
- *Wells, M.S., S.C. Reberg-Horton, and S.B. Mirsky. 2016. Planting date impacts on soil water management, plant growth and weeds in cover-crop-based no-till corn production. Agronomy Journal 108:162-170.
- *Wells, M.S., C. Brinton, and S.C. Reberg-Horton. Weed suppression and soybean yield in a no-till cover-crop mulched system as influenced by six rye cultivars. Renewable Agriculture and Food Systems 31:429-440.
- Franzluebbers, A.J. 2015. Farming strategies to fuel bioenergy demands and facilitate essential soil services. Geoderma 259-260:251-258.
- Franzluebbers, A.J. 2016. Should soil testing services measure soil biological activity? Agric. Environ. Letters 1:150009, doi:10.2134/ael2015.11.0009.
- Atwell, R.A. and S.C. Reberg-Horton. Row spacing and seeding rate effects on canola population, weed competition, and yield in winter organic canola production. Agronomy Journal (Accepted).
- Nape V. Mothapo, Huaihai Chen, Marc A. Cubeta, Wei Shi. Nitrous oxide producing activity of diverse fungi from distinct agroecosystems. Soil Biology and Biochemistry. 66:94-101.
- Huaihai Chen, Nape V. Mothapo, Wei Shi. 2014 The significant contribution of fungi to soil N2O production across diverse ecosystems. Applied Soil Ecology. 73:70-77.
- Fox, AF, Reberg-Horton SC, Orr DB, Moorman CE, Frank SD. 2013 Crop and field border effects on weed seed predation in the southeastern U.S. coastal plain. Agriculture, Ecosystems & Environment. 177:58–62.
- Moorman CE, Plush CJ, Orr DB, Reberg-Horton C. 2013. Beneficial Insect Borders Provide Northern Bobwhite Brood Habitat. PLoS ONE 8(12): e83815. doi:10.1371/journal.pone.0083815
- Moorman, C. E., C. J. Plush, D. Orr, C. Reberg-Horton, and B. Gardner. 2013. Small mammal use of field borders planted as beneficial insect habitat. Wildlife Society Bulletin 37:209-215.
- Plush, C. J., C. E. Moorman, D. Orr, and C. Reberg-Horton. 2013. Overwintering sparrow use of field borders planted as beneficial insect habitat. Journal of Wildlife Management 77:200-206.
- Presentations at conferences:
- Bowen, S.K.,Bloom, J.D., Scott, M., Lutton, M. “Making Markets Fair: Challenges from Farmers’ Perspectives.” Presentation at the Rural Sociological Society Annual Meeting, August 9, 2016, Toronto, Ontario, Canada.
- Bloom, J. Dara, Sarah Bowen, and Michelle Eley. 2016. “Bridging the gap between producers and under-resourced consumers.” Presented at the 2016 CFSA Sustainable Agriculture Conference, Durham, NC, November 5, 2016.
- Ross, N., W. Robarge, S.C. Reberg-Horton and J. Grossman. Development of a Continuous-Flow Chamber Technique to Measure Nitrous Oxide Emissions from Agroecosystems in the Southeast. Proc. of Amer. Soc. of Agron.
- Knight, A. M., W.J. Everman, S. Reberg-Horton, and S. Hu, D.L. Jordan and N. Creamer. 2015. Nitrous Oxide Emissions in Long Term Cropping Systems. Proc. of Amer. Soc. of Agron.
- Knight, A. M., W.J. Everman, S. Reberg-Horton, and S. Hu, D.L. Jordan and N. Creamer. 2015. Nitrous Oxide Output Based on Weed Management Systems. Proc. of Weed Sci. Soc. of Amer. (119).
- Knight, A. M., W.J. Everman, S. Reberg-Horton, and S. Hu, D.L. Jordan and N. Creamer. 2015. Nitrous Oxide Emissions Impacted by Weed Management. Proc. of South. Weed. Sci. Soc. (133).
- Atwell, R.A., S.B. Mirsky, H. Poffenbarger, and S.C. Reberg-Horton. (2015). Cover crop mixture proportion and starter fertilizer effects on weed competition and yield in organic rotational no-till maize production. In 2015 annual meeting abstracts. ASA/CSSA/SSSA, Minneapolis, MN. Oral Presentation.
- Atwell, R.A., S.C. Reberg-Horton, S.B. Mirsky, M.S. Castillo, and R.J. McGee. (2015). Identifying regionally adapted winter pea genotypes that maximize grain, forage, and cover crop potential in the southeast USA. In 2015 annual meeting abstracts. ASA/CSSA/SSSA, Minneapolis, MN.
- Pershing, M.R., C. Crozier, M. Shroeder-Moreno, D.L. Osmond, A.J. Franzluebbers. 2015. Flush of CO2 as a short-term biological indicator of soil nitrogen mineralization in the southeast. Ann. Mtg. Am. Soc. Agron., Crop Sci. Soc. Am., and Soil Sci. Soc. Am., Minneapolis, MN, 15-18 November 2015.
- Michelle Schroeder. “Sustainable Ag and Long Term Farming Research at CEFS and NCSU”. University of Zagreb, Croatia. Dec 9, 2015.
- L. Zhang, C. Tu, Y.P. Qiu, S.C. Reberg-Horton and S. Hu. 2014. Arbuscular mycorrhizal fungi markedly reduce N2O emissions from an organic soil. 99th Annual meeting of Ecological Society of America. Sacramento, August 10-15, 2014.
CEFS Farming System Research Unit has been identified as an ideal location to test how different cropping systems compare in terms of greenhouse gas emissions, particularly N2O. Biogeochemists consider that one of agriculture’s largest roles in greenhouse gas emissions is via N2O emission, which on a molar basis has 310 times the global warming potential of CO2. Reliable comparisons of greenhouse gas emissions require what FSRU has to offer, i.e. a replicated systems trial at least ten years old with ample data on individual components of the systems. We hosted six graduate student theses on the topic of greenhouse gases and two new scientists on the topic, Wayne Robarge and Alan Franzluebbers. CEFS is also working with Environmental Defense Fund to incorporate our results into a
national model of N2O emissions, particularly to revise estimates from the Southeast, which appear to be severely overestimated by the Midwestern models.
In addition to the greenhouse gas group, we continue to conduct the farming systems trial with adjustments to farm protocols to mimic the evolving farming systems in the region. For instance, our trial has seen large increases in glyphosate-resistant Palmer Amaranth in the conventional treatments, but this weed remains infrequent in the organic systems. We have shifted the conventional systems to greater use of pre-emergent herbicides, similar to most farmers in eastern North Carolina dealing with the evolution of this glyphosate-resistant weed. A new collaborator, Wes Everman, is working with us to test the viability of new weed-seed-destroying machines that attach to combines and how effective they may be over the long term in both our conventional and organic treatments in nested subplots. Both the experience with greenhouse gases and evolution of glyphosate resistance make an important point about the value of long-term cropping systems trials. They are not just tools for testing a priori hypotheses, to which short-term experiments are tied. They also generate hypotheses and serve as a platform for continuously answering questions that were initially unanticipated.
A new research direction in the social sciences is also taking shape with new collaborators Sarah Bowen and Dara Bloom (Sociology) and Kenrett Jefferson-Moore (Economics). Combined, they are examining how the farming systems in our trial are being conducted around the state and what social and economic constraints determine farmers’ choices of cropping system. Findings so far suggest land tenure/contracting issues are playing an important role in attitudes towards conservation and a follow up survey is being designed around this issue.