Shuijin Hu

Agricultural soils in the southeastern U.S., marked by high rainfall and warm temperatures, are often characterized with low organic C and soil pH. Organic farming relies on organic inputs and fundamentally alters the sources and forms of reactive carbon (C) and nitrogen (N) inputs. It also induces changes in soil physical and geochemical properties that may profoundly affect the abundances, composition and activities of soil microbes, including nitrifiers (i.e., ammonia-oxidizing bacteria and archaea) and diverse types of denitrifiers. However, there is still a lack of a holistic picture of organic farming effects on N-cycling microbes and their activities. We hypothesize that organic farming, if properly adopted, may induce consistent and predictable changes to foster the development of microbial communities for N retention and mitigation of N2O emissions. We plan to test our three specific hypotheses on long-term (19-yr) cropping systems at the Center for Environmental Farming Systems (Goldsboro, NC) as well as on multiple organic farms across North Carolina. Three major questions will guide our proposed research: 1) To what extent are these differences driven by long-term shifts in the microbial community? 2) What are the primary drivers and/or environmental factors that affect the composition and activities of nitrogen-cycling microbes? 3) To what extent are these differences driven by the quality and quantity of fertilizer inputs? Answering these questions will advance understanding of N transformations in organic systems and facilitate development of management regimes that enhance N use efficiency and ecosystem N retention, while reducing N2O emissions.??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????

The backbone of the FSRU will continue on: replicated plots of farming systems managed with farm-scale equipment. Within that context, new research questions have emerged. This research involves measuring outcomes never before measured or nesting new subplots within the experimental framework. From the social sciences, we can ask how these systems interact with sustainability in the real world. How do farmers weigh the choices in selecting farming practices from these various systems? What factors play roles in farming practices that cannot be captured in an experimental protocol? In this proposal, we have attracted researchers new to CEFS who have fresh ideas on relating this experiment to the sustainability issues of our time. Most of these questions were never envisioned when the experiment was first designed. From research on which farming systems emit the most greenhouse gases, to work on how land tenure affects the ability of farmers to adopt sustainable practices, the new research projects run the gamut of disciplines.

The backbone of the FSRU will continue on: replicated plots of farming systems managed with farm-scale equipment. Within that context, new research questions have emerged. This research involves measuring outcomes never before measured or nesting new subplots within the experimental framework. From the social sciences, we can ask how these systems interact with sustainability in the real world. How do farmers weigh the choices in selecting farming practices from these various systems? What factors play roles in farming practices that cannot be captured in an experimental protocol? In this proposal, we have attracted researchers new to CEFS who have fresh ideas on relating this experiment to the sustainability issues of our time. Most of these questions were never envisioned when the experiment was first designed. From research on which farming systems emit the most greenhouse gases, to work on how land tenure affects the ability of farmers to adopt sustainable practices, the new research projects run the gamut of disciplines.

The backbone of the FSRU will continue on: replicated plots of farming systems managed with farm-scale equipment. Within that context, new research questions have emerged. This research involves measuring outcomes never before measured or nesting new subplots within the experimental framework. From the social sciences, we can ask how these systems interact with sustainability in the real world. How do farmers weigh the choices in selecting farming practices from these various systems? What factors play roles in farming practices that cannot be captured in an experimental protocol? In this proposal, we have attracted researchers new to CEFS who have fresh ideas on relating this experiment to the sustainability issues of our time. Most of these questions were never envisioned when the experiment was first designed. From research on which farming systems emit the most greenhouse gases, to work on how land tenure affects the ability of farmers to adopt sustainable practices, the new research projects run the gamut of disciplines.

Agriculture is the primary economic activity undergirding human survival and quality of life and global economic development. To grow agricultural productivity we will establish an interdisciplinary graduate training program to address Plant Production within the Targeted Expertise Shortage Area (TESA) of Food Production. The goals of this program are: 1) comprehensively train three PhD fellows, each in a core discipline within plant production with cross-training in complementary areas; 2) provide experiential training within a technology rich, multidisciplinary research and Extension platform; and 3) graduate students proficient at integrating computational, environmental, biological and physical data into decision tools for increased yield and economic sustainability. This will be achieved through: recruitment of top tier, diverse Fellows; intensive advising and mentoring by exemplary faculty; outstanding academic, international, and industry-based research opportunities; leadership and professional development training, and internships with local Agbiotech companies. Fellows?????????????????? research will be grounded in the innovative research platform (AMPLIFY), a strategic industry-academia- producer partnership conducting interdisciplinary multi-scale systems research to advance high- yield sustainable agriculture to meet our world??????????????????s growing food requirements. Success will be measured by: 1) diversity of recruits; 2) presentations at professional conferences and publication in refereed journals; 3) timely degree completion; and 4) successful placements in industry, academia, or government appropriate to TESA. This NNF is relevant to the USDA/NIFA Challenge Area, Plant Production. Measurable impacts on TESAs include a more diverse scientific workforce trained in skills necessary to address complex challenges facing agriculture.

The rhizosphere microbiome, including saprophytic microbes and arbuscular mycorrhizal fungi (AMF), plays a major role in plant nutrient and water acquisition. Endophytes, bacterial or fungal symbionts living within the plant, are ubiquitous and can confer some beneficial effects on host plants through improving plant growth and tolerance to abiotic and biotic stresses. They can be particularly useful for forage and fuel crops such as switchgrass that will preferentially be planted on marginal lands where environmental stresses are routine. The primary objective of this study is to assess the impact of endophytic bacteria on AMF in roots, the rhizosphere microbiome (with a focus on N-cycling microbes), and plant nutrient acquisition, using switchgrass a model plant. Results from this study will help understand the drivers that control tripartite interactions among plants, endophytes in roots, and soil microbes in the context of plant C allocation for microbes in exchange for nutrient acquisition.

The backbone of the FSRU will continue on: replicated plots of farming systems managed with farm-scale equipment. Within that context, new research questions have emerged. This research involves measuring outcomes never before measured or nesting new subplots within the experimental framework. From the social sciences, we can ask how these systems interact with sustainability in the real world. How do farmers weigh the choices in selecting farming practices from these various systems? What factors play roles in farming practices that cannot be captured in an experimental protocol? In this proposal, we have attracted researchers new to CEFS who have fresh ideas on relating this experiment to the sustainability issues of our time. Most of these questions were never envisioned when the experiment was first designed. From research on which farming systems emit the most greenhouse gases, to work on how land tenure affects the ability of farmers to adopt sustainable practices, the new research projects run the gamut of disciplines.

We will develop metaproteomics methods to study the metabolism, physiology and interactions of root-associated microorganisms, which play important roles in plant growth and health. This proposal will lay the groundwork for root and soil microbiota metaproteomics by (1) developing and validating protein extraction and cleanup methods for root-associated microbes using root material from two plant species with a defined microbial community; (2) optimizing the LC-MS/MS workflow to achieve a high metaproteome coverage; and (3) applying the developed workflows to two model systems for plant-microbe interactions to demonstrate the application of the method.

The Long-Term Farming System Research trial (FSRU) at 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, environmental conservation, etc.). 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 NGO's 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 prepares for 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. The majority 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, the university is in the middle of rapid turnover. Eight of the faculty involved with this grant were not involved with the establishment of the FSRU. This experiment is key for recruiting new faculty to work in sustainable agriculture. New research questions in soil processes, insect ecology, livestock productivity, and socioeconomic impact of cropping systems were developed for this grant in response to board input and new expertise at our institutions. We hope to use this grant to prepare a solid future for the FSRU over the coming decades.

Southeastern agricultural systems have been designed around the economic realities of the past several decades. No-till agriculture, with all of its soil conservation benefits, has been widely adopted in the Southeast because it is also a cheaper way to farm. Climate change poses new challenges and opportunities for our farmers that have not been factored into the current economic model. The challenge will come from increasingly erratic weather patterns with drought becoming more frequent and intense. Efforts need to begin now to increase the water holding capacity of our soils if we are to maintain productivity during these periods of drought. The opportunity presented by climate change lies in the positive role that agriculture can play in mitigating the emissions from other industries. Agriculture is one of the few economic sectors that might have a net negative impact on greenhouse gas emissions. The key to understanding how agriculture will both adapt to climate change and mitigate greenhouse gas emissions is to understand how cropping systems impact the carbon and nitrogen cycles. Research by the partners on this proposal suggests that long held assumptions about Southeastern cropping systems on carbon sequestration and N2O emissions are not supported by data from long terms systems trials. No-till was long presumed to be the best system for sequestering carbon. A growing body of literature suggests this is not true, particularly in the warm, humid conditions of the Southeast. No-till soils accumulate limited amounts of C because most of the organic matter inputs are on the surface and subject to rapid decomposition. Another factor preventing carbon accumulation is the relatively low level of organic matter inputs on most no-till farms. Few of these farms use cover crops, animal wastes or other organic matter inputs. Even ones that utilize practices such as cover cropping seldom manage for maximal biomass accumulation. How much carbon could accumulate in systems that explicitly include sequestration as a design goal? What economic incentives would be needed to make those designs a reality? It is critical that we understand how long term additions of complex carbon-based inputs can contribute to C storage in agroecosystems.