AGRICULTURAL GREENHOUSE WARMING POTENTIAL AND SOIL CARBON SEQUESTRATION IN ORGANIC AND LONG TERM ROTATIONAL SYSTEMS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 0230680
• Grant No.: 2012-51106-20026
• Cumulative Award Amt.: $716,773.00
• Proposal No.: 2012-02977
• Project Start Date: Sep 1, 2012
• Project End Date: Aug 31, 2016
• Grant Year: 2012
• Program Code: [112.E]- Organic Transitions

Recipient Organization
UNIV OF MARYLAND
(N/A)
COLLEGE PARK,MD 20742

Performing Department
Environmental Science and Technology

Non Technical Summary
There is a need to document farming systems effects on greenhouse gas emissions and soil carbon sequestration, especially in organic systems that include long and diverse crop rotations that have been shown to achieve equivalent yields and greater economic efficiency when competing in the economic market against conventional systems. A number of issues stand in the way of evaluating how farming systems perform in terms of sustainability: 1) Measuring soil carbon sequestration requires long-term management in a defined and monitored system experiment or natural experiment on-farm; 2) Measuring greenhouse gases accurately requires standardized methods that are comparable to internationally recognized methodologies; these are labor intensive; 3) Few studies are designed to study biochemically linked carbon and nitrogen in agroecosystems in a combined manner, even though many organic and long rotation farming systems add carbon and nitrogen in biochemically linked forms (green manure, manure, compost); 4) Many models used for extended prediction of soil carbon sequestration and greenhouse gas flux use algorithms that link carbon and nitrogen, but were parameterized based on conventional and short-term rotational agroecosystems in which there are weaker linkages between these cycles. In this research outline we propose a suite of experiments that will utilize unique sites: the Beltsville Farming Systems Project (FSP), the Mixture Injection Trial (MIT), and on-farm evaluation of farming systems to examine performance and ecosystem services provided by a diverse array of realistic long rotation organic farming systems.

Animal Health Component

30%

Research Effort Categories

Basic

70%

Applied

30%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0110	1070	20%
102	0110	1100	20%
102	1510	1070	10%
102	1510	1100	10%
102	1545	1070	10%
102	1545	1100	10%
102	1570	1070	10%
102	1570	1100	10%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships;

Subject Of Investigation
1510 - Corn; 0110 - Soil; 1570 - Rye; 1545 - Durum wheat;

Field Of Science
1070 - Ecology; 1100 - Bacteriology;

Keywords

greenhouse gases

organic farming

sequestration models

carbon sequestration

poultry litter injection

Goals / Objectives
The long-term goals of this project are to improve farm management impact on greenhouse gas emissions and soil carbon sequestration in organic grain production systems and to synthesize and disseminate the most current research-based knowledge addressing organic grain production. This work will fill a critical knowledge gap that is not otherwise being met. We have worked with our stakeholders to develop the following four objectives outlined in a conceptual map in figure 3. Objectives: 1) Understand organic till, conventional no-till and organic no-till farming systems with respect to effects of animal manures, fertility timing and placement, cover crop management and tillage on greenhouse gas emissions; 2) Compare how organic farming systems that include diverse and long-term rotation accumulate soil organic carbon and improve soil quality indicators despite often employing frequent tillage and cultivation; 3) Evaluate empirical data collected in realistic crop rotations with models currently used to predict greenhouse gas emissions, soil carbon sequestration and soil health in organic systems where carbon and nitrogen inputs are biochemically linked; and 4) Disseminate the knowledge gained from on-station and on-farm research using on-farm field days, scientific and extension publications and information and webinars via the eOrganic Grain Cropping Systems Community of Practice (COP). We will also facilitate educational outreach focused on agroecological research experience by providing internships to six college and six high school students that have expressed interest in conducting real-world agroecosystems research. Students in the internship programs will be required to pursue a research question within the context of the proposed research and then present their work at the Beltsville Agricultural Research Center Science Competition (poster competition).

Project Methods
Fluxes of N2O, CO2, and CH4 will be measured from 17 FSP and 18 MIT treatments on a weekly basis using standard GRACEnet protocols. Three field replicates will be sampled. Samples will be analyzed for N2O, CO2, and CH4. Soil nitrate, dissolved organic carbon (DOC) and electrical conductivity (EC) will be measured continuously using Decagon data loggers during the growing season from areas near the chambers. We will calculate Global Warming Potential (GWP) using greenhouse gas flux and soil C sequestration data, and published values of CO2 emissions from agricultural field operations and input manufacturing processes and transportation. Soil carbon sequestration will be addressed using data on soil C and N measured from soil cores taken to a depth of 1 m by subplot in all 68 FSP plots and on-farm in the winter of 2013. Cores will be taken using a Concord hydraulic probe mounted on a pick-up truck. Samples will be divided in increments of 0-10 10-20 20-30, 30-50, and 50-100 cm depth, dried. A similar set of cores will be taken from all on-farm field plots identified by farmers as differing in the history or crop rotation diversity. All soils from farms will be handled similarly to the FSP soils. Our research outcomes will provide empirical values for parameters used in the models We will run the models for each system and compare the modeled results to the empirically measured results and use sensitivity analysis to determine parameters that work well in the model and those that need adjustment when applied to farming systems that use high residue cover crops or alternative farming practices. We will use Akaike Information Criterion (AIC) comparisons to identify model parameters. The AIC is a relative goodness of fit procedure that can be applied to any statistical model. It scores each model based on a ratio of model bias to total variance in the model construction. This approach will allow us to run each ecosystem model (Daycent, DNDC, Roth-C) and identify model parameters that are most sensitive to organic management and those that are most bias when comparing conventional and organic practices. The Cornell Soil Health index will be determined for each site and the data will be used as a baseline for determination of how soils change over time under farming practices that are currently understood to improve soil health. In addition Soil Health Indices will be evaluated in comparison to the ecosystem models being tested. Correlation between Soil Health Indices and ecosystem model predictions will be identified to aid in understanding of how integrated indices such as soil health relate, total soil carbon, ecosystem model estimates of GHG emission and soil organic matter.

Progress 09/01/12 to 08/31/16

Outputs
Target Audience:Final results of our research were shared at national and regional scientific meetings. Specifically three graduate students presented at meetings and shared the results of thier work. We also submitted four manuscripts. Three of those manuscripts are in the process of being revised for resubmission and one is still under review. A fithm manuscript is still in preparation. These research results were also shared at a USDA-ARS Beltsville field day and in a University of Maryland Extension webinar. Changes/Problems:The portion of this research that is still being analyzed is the work done on other farms within the State of Maryland. Although the main experiments took place at the USDA-ARS Beltsville, we had planned to sample a number of farmers' fields to a depth of 1-m and to compare these microbial comminities and soil health parameters to those observed in our USDA trials. This part of the project proved difficult to accomplish. The farmers that had initially agreed to work with us proved difficult to contact and sampling around their farm schedule proved challenging. As a result, we decided to sample at the University of Maryland Experiment State farms which provided field samples comparable to the private farms we had planned to sample. Those samples were taken in Spring 2016 and are currently being analyzed by a technician that was employed on the project and continues to work for BARC. We plan to prepare a final scientific publication from those results. What opportunities for training and professional development has the project provided?This project supported the training of three master's degree students and numerous undergraduates. The three master's students all graduated successfully and each have two publications that are in some stage of publication. One of the master's students is now a PhD student at Standford University. Another is a current PhD student at UMD. The third student is a tier two technichian at the University of Maryland Baltimore medical school. Over the course of the project there were 13 undergraduates supported. These stufents recieved training in agricutlural science and were given opporutnities to conduct scientific research. At least three of those students are now graduate students. How have the results been disseminated to communities of interest?The results of this work were included in a fact sheet and also shared via two webinars that were hosted by University of Maryland Extension. The general public, particularly school childen were reached via outreach events. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? This project accomplished several of the goals that were specified.Using sites within the Long term farming systems project and a Manure Injection Trial, we measured greenhouse gas emissions and combined that with measures of microbial diversity to understand the mechanisms that lead to increased N2O emissions. N2O emissions increased with increasing applicaiton of animal manures and these data were used to build a new model for N2O that more accurately reflects the dynamics of gas production when the crop is grown after a cover crop of rye/vetch as been roller crimped. We found that N2O is emissions are greatest under a cover crop thatch layer that results in increased surface soil moisture. Combined with these measures, we examined the spatial extent of denitrifying communities using quantitiave PCR. We were able to model the spatial variability of the denitrifying and nitrifying communities and establish that there were great populations of these microogranism in the near surface and also surrounding the roots. Part of the manure injection trial also tested subsurface banding of poultry litter in comparison to broadcasting. We observed no difference in the amout of emissions from the subsurface band versus broadcast. We advocate for the use of subsurface banding to maintian more nutrients within the system and have shown that there are no increased deterimental effects. We also examined carbon sequestraiton at the plow layer when crops are grown in long term organic rotations. We characterized the soil microbial communities at these same locaitons. Our research showed that microbial communities differ in the upper soils due to management regime, particularly when diverse cover crop mixes are used. We also showed that carbon did increase at the plow layer when cover crops were used over an 18 year period. These microbial communities drastically changed just above and just below the plow layer suggesting that management can have long term legacy effects. Our last goal was to dissiminate this research to a wide audience and this was accomplished through numerous outlets.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Dlott, G., J. Maul, J. Buyer, S. Yarwood. 2015. Microbial rRNA:rDNA gene ratios may be unexpectedly low due to extracellular DNA preservation in soils. Journal of Microbiological Methods 115: 112-120
• Type: Journal Articles Status: Under Review Year Published: 2016 Citation: Davis, B., S. Mirsky, B. Needleman, M. Cavigelli, S. Yarwood, J. Maul. Under review. A novel method for estimating nitrous oxide flux from single point flux measurements. Journal of Environmental Quality
• Type: Journal Articles Status: Other Year Published: 2017 Citation: Bowen, H., J. Maul, H. Poffenberger, S. Mirsky, M. Cavigelli, S. Yarwood. In prep. Spatial patterns of denitrification genes change in agricultural soils in response to fertilizer placement and cover crop species. Applied and Environmental Microbiology
• Type: Journal Articles Status: Other Year Published: 2017 Citation: Dlott, G., J.E. Maul, J. Buyer, M. Cavielli, D.J. Epp Schmidt?, S. Yarwood. In prep. Legacy and Maintenance of a Soil Plow Layer (Ap Horizon) Affects Dispersal Patterns of Bacteria and Archaea. Soil Biology and Biochemistry
• Type: Journal Articles Status: Under Review Year Published: 2017 Citation: B.W. Davis, S.B. Mirsky, B.A. Needleman, M.A. Cavigelli, S. Yarwood Manuscript: Nitrous oxide emissions increase exponentially with N rate from cover crops and poultry litter Journal: Nutrient Cycling in Agroecosystems
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Michel Cavigelli Soil health in organic cropping systems, Albert Lea Seeds, Albert Lea, MN, Nov. 20, 2015 (all expenses paid)
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Understanding agricultures role in causing and preventing climate change PASA Conference, State College, PA, Feb. 5-6 (all expenses paid)
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Impact of grain farming on climate change, Maryland Nutrient Managers Webinar, March 22, 2016
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Cover crops and soil health, Northeast SARE Managing Soil Health with Cover CropsBeyond the Basics Meeting, Baltimore, MD, March 30, 2016.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Long-term research at the USDA-ARS Farming Systems Project, University of North Carolina--Greensboro, April 22, 2016 (all expenses paid).
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Soil health in organic cropping systems, Organic Confluences Conference (The Organic Center), Washington, DC, May 23, 2016.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Organic corn production, National Corn Growers Association Meeting, Washington, DC, July 19, 2016.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Agricultural Research at the Beltsville Agricultural Research CenterAddressing Unprecedented Food Production and Environmental Challenges, Mishkan Torah Synagogue, Greenbelt, MD,
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Michel Cavigelli Long-term agroecological research at the USDA-ARS Farming Systems Project, Beltsville, Maryland. ASA-CSSA-SSSA Annual Meeting, Nov. 15-18, 2015, Minneapolis, MN.
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Steven Mirsky University of Maryland, College Park
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Steven Mirsky Virginia Tech, Blacksburg, VA
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Steven Mirsky ASA, CSSA, & SSSA. St. Paul, Minnesota Agencies, NGOs, Farmer/Ag. Professional conferences, and Private Sector
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Steven Mirsky The Nobel Foundation
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Steven Mirsky Organic Trade Association
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Yarwood, S. Swedish Agricultural Univeristy (SL�), Ume�, Sweden: August 14, 2015. Title: How does human landuse impact soil microbial commuities?
• Type: Conference Papers and Presentations Status: Other Year Published: 2016 Citation: Yarwood, S. Villanova University, Villanova, PA: November 3, 2016. Title: Shaping the soil microbiome: How do humans impact microbes and can we use that knowledge for good?
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Bowen, H., H. Poffenbarger, J. Maul, S. Mirsky, S. Yarwood. Ecological Society of America MidAtlantic Chapter, College Park, MD: March 29, 2014. Title: Analysis of the microbial controls on nitrogen movements and tranformation in agricultural sol.
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Bowen, H., H. Poffenbarger, J. Maul, S. Mirsky, M. Cavigelli, S. Yarwood. University of Maryland AGNR Open House, Clarksville, MD: October 11, 2014. Title: Spatial distribution of nitrogen cycling microorganisms in agricultural soil
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Dlott, G., D. J. Epp Schmidt, J. Maul, M. Cavigelli, J. Buyer, S. A. Yarwood. University of Maryland AGNR Open House, Clarksville, MD: October 11, 2014. Title: Tillage effects persist long after no-till conversion: Carbon and microbial community evidence.
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Davis, B., S. Mirsky, B. A. Needelman, M.A. Cavigelli, J. Maul, S.A. Yarwood. Soil Science Society of America, Long Beach, CA: November 3, 2014. Title: Nitrous oxide emissions from subsurface banded poultry litter in a cover crop-based corn system.
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Dlott, G.A., D. Epp Schmidt, J. Maul, M.A. Cavigelli, J.S. Buyer, S.A. Yarwood. Soil Science Society of America, Long Beach, CA: November 3, 2014. Title: Microbial communities and carbon dynamics across a depth profile in an organic and conventionally managed agricultural soil.
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Bowen, H., J. Maul, S. Mirsky, M.A. Cavigelli, S.A. Yarwood. Soil Science Society of America, Long Beach, CA: November 4, 2014. Title: Spatial analysis of the nitrogen cycling microbial communities in agricultural soils.
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Dlott, G., D. J. Epp Schmidt, J. Maul, M. Cavigelli, J. Buyer, S. A. Yarwood. UMDBARC symposium, National Agricultural Library, Beltsville, MD: November 13, 2014. Title: Tillage effects persist long after no-till conversion: Carbon and microbial community evidence.
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Bowen, H., H. Poffenbarger, J. Maul, S. Mirsky, M. Cavigelli, S. Yarwood. University of Maryland AGNR Open House, Clarksville, MD: November 13, 2014. Title: Spatial distribution of nitrogen cycling microorganisms in agricultural soil.
• Type: Conference Papers and Presentations Status: Other Year Published: 2012 Citation: Jude Maul, 2012, poster, BARC-UMD symposium, Soil Denitrification Potential and Gene Diversity of Nirk, Nirs and Nosz; Field Scale Comparisons Across Farming Systems.
• Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Jude Maul, 2013, webinar, UMD extension, Biological Nitrogen Fixation 101.
• Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Jude Maul 2013, invited talk, Purdue University, Soil Denitrification Potential; Field Scale Comparisons Among Diverse Farming Systems
• Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Jude Maul 2013, invited talk, USDA-Ft. Pierce, Soil Denitrification Potential and Gene Diversity of Nirk, Nirs and Nosz; Field Scale Comparisons Across Farming Systems.
• Type: Conference Papers and Presentations Status: Other Year Published: 2014 Citation: Jude Maul 2014, poster, Argonne National Lab Soil Metagenomics meeting, Microbial communities and carbon dynamics across a depth profile of organic and conventionally managed agricultural systems in the Mid-Atlantic region
• Type: Conference Papers and Presentations Status: Other Year Published: 2015 Citation: Jude Maul 2015, invited talk, USDA-NIFA, How Research on Organic Farming, The Original Multifunctional Agriculture, Can Inform Scientific Progress.