CEFS Long-Term Systems Research: Providing the Building Blocks for Resilient Food Production Systems

2012 Annual Report for LS12-247

Project Type: Research and Education
Funds awarded in 2012: $300,000.00
Projected End Date: 12/31/2015
Region: Southern
State: North Carolina
Principal Investigator:
Dr. Chris Reberg-Horton
North Carolina State University

CEFS Long-Term Systems Research: Providing the Building Blocks for Resilient Food Production Systems


The Long-Term Farming System Research trial (FSRU) at the Center for Environmental Farming Systems (CEFS) was initiated in 1998 and comprises more than 200 acres with 5 different systems replicated 3 times. The objectives for initiating this trial 13 years ago were to research: 1) how the various systems impact long-term sustainability of soil and water resources, 2) whether some systems are more resilient to perturbations in weather, input and market prices, and 3) how the systems impact biodiversity, wildlife, pest dynamics and the ecological services of farmland. Our study is designed to provide a better understanding of how different systems interact with and impact the natural resource base and economic viability of farms, as well as identify alternative approaches with potential for synergistic effects, such as diversification, access to direct markets, and environmental conservation.

Over time the FSRU systems experiment has become irreplaceably unique for several reasons. First is the comprehensive nature of the systems being studied and their relevancy in the South. Second, the scale (200 acres) and large plot size gives us the ability to study important production system dynamics (e.g., insect and disease management) that others cannot, making our results more relevant to producers. We are also a model of interinstitutional collaboration with involvement of various departments and colleges at each 1890 and 1862 Land Grant university, the NC Department of Agriculture and Consumer Services, and NGOs as diverse as Carolina Farm Stewardship Association and the NC Farm Bureau. Our systems experiment has also integrated outreach at every level with farmer involvement in both research and educational programming. These funds will set our project on a path of long-term sustainability at a critical time as the state undergoes major budget cuts that put the experiment at risk. The NC Department of Agriculture and both universities are cutting personnel and operating support. Short-term grant funding has been indispensable with starting this project, but after 13 years of piecing together support we have learned that maintaining the core components of a systems trial is extremely difficult with sporadic funding.

We are also preparing the FSRU for a new future. Half of our advisory board are new members of CEFS. Their guidance on what is the current thinking of the farm community lends new vitality to our work. Similarly, retirements at the university are at the highest rate in decades. Eight of the faculty involved with this grant are new hires and were not involved with the establishment of the FSRU. This experiment is key to recruiting these faculty to work in sustainable agriculture.

Objectives/Performance Targets

Resiliency is the ability to recover from or adjust easily to change. Agriculture can expect rapid change in coming decades due to rising global temperatures, expanding populations, and volatility in commodity and fuel prices. Some farmers associated with CEFS have already successfully transitioned to fewer external inputs, greater market diversity, and sustainable production practices that will give their farms the long term stability required in a changing environment. The FSRU at CEFS aims to understand how resiliency is achieved and to demonstrate long-term impacts of various farming systems.
The farming systems being compared in our long-term trial include: a) Best Management Practices (BMP), b) Integrated Crop/Animal System, c) Organic Production System, d) Plantation Forestry System, and e) Old Field Successional System. Within each type of system, multiple rotational approaches are tested. For example, within the organic system, four possible rotations are used to test different approaches to organic weed control. The objectives of this grant were to expand the avenues whereby we measure the resiliency of these systems. New efforts in greenhouse gas mitigation and socioeconomic impact of farming systems have been started.
The objectives of the new greenhouse gas project are to:
Objective 1: Quantify the greenhouse gas emissions and soil C and N in three organic and tillage management regimes and three paralleled conventional systems.
There is a dearth of information regarding N2O emissions in agricultural soils of the SE US coastal plains. Organic and reduced tillage are believed to reduce GHG emissions and promote soil C and N sequestration. However, lack of long-term field data critically constrains our prediction of the net potential of C sequestration and GHG mitigation.
Objective 2: Determine the impact of invertebrates on residue decomposition and soil C stabilization.
Populations and activities of soil invertebrates such as earthworms, nematodes, mites and collembolans are often higher in organic and reduced or no-tillage systems (Beare et al. 1992; Overstreet et al. 2010; Rahmann 2011). These organisms play important roles in residue decomposition and soil C turnover and stabilization as well as in nutrient release from microbial biomass. Yet, their functions have rarely been determined in field.
Objective 3: Assess the effects of AM fungi on soil aggregation and N retention in organic systems.
Experimental evidence has shown that agricultural practices, such as tillage to diminish AM extra-radical hyphae abundance and root colonization (Kabir et al. 1997), and reduce AM fungal species composition and abundance (Douds et al. 1995) and elimination of synthetic chemicals (fungicides in particular) in organic systems should also reduce the disruption of AM fungal hyphae (Gosling et al. 2006). Yet few have examined how various long-term agriculture systems can affect AM impacts on C and N dynamics.
Objective 4: Ascertain the role of cover crops and weeds in mediating soil N availability
The implications of cover cropping and weeds on N dynamics can be profound. Each flush of weeds results in substantial uptake of N that is temporarily immobilized in weed seedling biomass (Bast 2012). The N does not remain there long. These young tissues decompose rapidly after cultivation, releasing N back into the soil (Bast 2012). During those first 2 months, multiple weed-mediated N cycles serve to keep inorganic N from accumulating in the soil. These cycles could result in either increased or decreased rates of N loss from the system overall.
Most N loss occurs early in a cropping cycle when then crop is young and does not need substantial amounts of N yet for growth. Row crops, such as corn, are particularly ineffective due to the wide between row spacing of plants. Organic corn in North Carolina is grown on row spacings between 30” and 38”. Weeds that emerge between rows are taking up N that could be lost to leaching. The Southeast is particularly susceptible to early season losses because of sandy soils and large rain events (Hubbard & Sheridan 1989). Conventional systems that include preemergence herbicides do not develop the large weed flushes that characterize organic systems.
Objective 5: Education and outreach through developing new curricula on greenhouse gases and agriculture for student training and stakeholders
Despite the public nature of the greenhouse emissions debates, few curricula have been established for engaging stakeholders and students in how these issues affect agriculture. An iterative process is needed that draws on farmer/student concerns and regional differences in farmer practices. Curriculum development will have the direct input of these groups during the first year of the project. Contrary to popular opinion, a majority of farmers believe climate change is occurring in some regions (Arbuckle et al. 2011).

The objectives for our renewed socioeconomic focus are:
Objective 1: Construct system budgets to evaluate the economic feasibility of each system and Objective 2: Construct an agricultural calendar detailing labor and equipment needs across the year. Together, the budget and calendar will serve as powerful educational and decision-making tools for farmers, researchers, and policy-makers.
We recognize that farmers’ decisions are not solely based on economic parameters; institutionalized practices and beliefs are equally powerful forces in shaping behavior. What sociocultural factors most influence farmer decisions to adopt sustainable agricultural practices? And what conditions create a social and cultural context that allows sustainable agriculture to thrive? Using the budgets and agricultural calendars as bridging devices, the socioeconomic team will conduct semi-structured interviews in years 2 and 3 with three groups of farmers (n=10 per group): those using sustainable farming practices; those who previously adopted sustainable practices but have discontinued; and those who have never adopted sustainable practices. To select and recruit farmers for interviews, we will draw from CEFS’s extensive contacts, which include both conventional and sustainable growers. We will purposively sample to ensure variation according to key criteria such as gender, race/ethnicity, farm size, crops, and type of market (i.e., direct vs. commodity markets). These exploratory interviews will contribute to a better understanding of the needs of sustainable farmers and communities.


With this SARE funding as leverage, CEFS received additional funding from NIFA in 2012 to instrument the systems project with greenhouse gas monitoring equipment. We have installed 36 gas sampling chambers in a subset of the treatments in the long-term systems trial. A gas chromatograph has been installed onsite capable of simultaneous monitoring of N2O, methane and CO2.
Four graduate students have been recruited to work on the greenhouse gas project. They will all be involved in monitoring the gases and in conducting nested experiments aimed at determining which aspects of the systems are key regulators of gas emissions.
Co-sponsored and provided many of the speakers the for the “Farming Strategies in Today’s Changing Climate” conference held in Pittsboro, NC by the Abundance Foundation. CEFS faculty and staff that gave presentations and held discussions included Frank Louws on annual vegetables, Chris Reberg-Horton on annual row crops, Jean-Marie Luginbuhl on mixed livestock, and Steve Washburn on dairy.
Hosted a regional field day highlighting the research program at CEFS. The event was attended by 280 people from around the region. Six full size buses transported the attendees to stations around the facility that highlighted the following research programs at CEFS: 17 faculty participated by showing their research at the station, 12 of which are cooperating faculty on the long-term plots. In addition to the oral presentations, 38 posters from research projects on the station were presented. Proceedings of the event were published and can be found at http://www.cefs.ncsu.edu/fieldday2012/fielddayproceedings2012.pdf
Conducted a soil sampling of all the long-term plots. Over 20 people participated in a one-day event that took samples from 5 GPS designated points in each of the 42 plots. The samples were subdivided for multiple research projects across departments. Some of the measurements made include: microbial community structure as characterized by phospholipid fatty acid biomarkers, nematodes, soil microarthropods, microbial biomass C and N, total C and N, extractable n, and soil respiration.
Published 19 research articles in 2012 from work at the station. A complete list is available at: http://www.cefs.ncsu.edu/publications/journals.html
Applied to the Long-term Agricultural Research Network that the USDA has started for sites such as CEFS. The network is meant to provide a platform for connecting long-term research sites analogous to the Long-term Ecological Research Network for natural ecosystems. So far, the agricultural network is a voluntary collaboration with zero financial support. The lack of funding further highlights the crucial role that SARE support has provided, both at CEFS and other long-term sites around the country.

Impacts and Contributions/Outcomes

A comprehensive review of the impact of the long-term systems trial is beginning on schedule in year 2 of the project. A survey and semi-structured interviews are being conducted by CEFS faculty and an impact assessment is being conducted by an outside contractor.