REDUCING NITROGEN LOSSES FROM AGRICULTURAL SYSTEMS: INCORPORATING BIOCHAR INTO FARMSTEAD MANAGEMENT STRATEGIES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1005591
• Grant No.: 2015-67019-23573
• Cumulative Award Amt.: $467,969.00
• Proposal No.: 2014-06975
• Project Start Date: May 15, 2015
• Project End Date: May 14, 2019
• Grant Year: 2015
• Program Code: [A1401]- Foundational Program: Soil Health

Recipient Organization
UNIV OF WISCONSIN
21 N PARK ST STE 6401
MADISON,WI 53715-1218

Performing Department
Biological Systems Engineering

Non Technical Summary
The livestock industry continues to face air and water quality issues related to manure and agricultural by-products. In order to increase sustainability of agricultural facilities a large body of research and outreach has been conducted to develop and implement practices that limit environmental impact. Unfortunately many of these practices have focused on individual sustainability indicators (one impact such asphoshprus loss tosurface water)and not the system as a whole (ingoring other potential unintended consequneces). To increase overall sustainability we need to evaluate systems over a wide range of sustainability indicators to make recommendations that do not trade one problem for another. This research proposes to evaluate additional sustainability aspects, particularly those related tonitrogen cycling, to treatment and management systems that have been developed to reduce environmental impacts. This includes runoff treatment systems which have been designed to reduce contaminated runoff reaching surface waters, but may not have been evlauated in terms of leaching to groundwater or air emissions. This reach will also look at manure storage which was designed to reduce surface water impacts (by reducing applicaiton of manure in the winter and when it is supposed to ain) but has resulted in increased greenhouse gas and ammonia emissions.This proposal aims to evaluate biochar additions to runoff treatment systems to reduce nitrate leaching, and to manure storage and digestion systems to reducenitrogen emission losses, primarily ammonia, while maintaining the other environmental benefits these systems have been designed to achieve. The proposed research will measure subsurface nitrate concentrations from biochar amended filter strip plots, and evaluate various biochar amended manures during digestion, storage, and land application to assessnitrogen gaslosses. This will allow researchers to make recommendations on amending these systems with biochar to limitnitrogen loss and therefore increasenitrogen useefficiency. Emissions data will also be integrated into a life cycle assessment to quantify overall system impacts. The overall goal is to reduce the unintended consequneces of these beneficial treatment practices for agricultural runoff.

Animal Health Component

80%

Research Effort Categories

Basic

(N/A)

Applied

80%

Developmental

20%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
403	0199	2020	100%

Knowledge Area
403 - Waste Disposal, Recycling, and Reuse;

Subject Of Investigation
0199 - Soil and land, general;

Field Of Science
2020 - Engineering;

Keywords

agricultural runoff

biochar

nitrogen cycling

nitrogen losses

Goals / Objectives
This research proposes to evaluate nitrogen cycling in livestock treatment and management systems that have been developed to reduce environmental impacts. Runoff treatment systems have been dessigned to reduce the impact of runoff from agricultural farmsteads to surface water systems. These systems are intended to reduce the loss of nitrogen to surface water but in doing so there are potnetially negative unintended consequences such as nitrate leaching to groundwater as the water infiltrates the treatment area. This proposal aims to evaluate biochar additions to runoff filter strip treatment systems to reduce nitrate leaching (as it has shown potential to reduce nitrogen leaching in soil columns). We will also measure emissions from these systems to enssure that we are not releasing the nitrogen in forms that will result in air quality degradation. Teh overall goal is to improve filter strip teratment systems to reduce the impact of agricultural runoff to all environmental ipact areas.The second overreaching goal of this research focuses on manure storage systems. It has been found that manure storage systems (which are also implmented to protect surface and ground water) are large sources of greenhouse gas and ammonia emissions. It has been found that installing an anaerobic digester has reduced greenhouse gas emissions in storage but has actually increased ammonia emissions. In order to reduce the nitrogen losses in these systems a biochar cover, which will float when added to manure storages, will be evaluated to reduce nitrogen losses from these systems in an attempt to reduce the notrogen losses from manure storage systems. Biochar will be evaluated in manure with and without digesters.Finally, data from each of these research project will be added to a manure system life cycle assessment to quantify overall system impacts. Life cycle assessment will allow researchers to evaluate if this change in practice will result in a net reduction in emissions across the system. This will aid in preventing recommendations which will then have unintended consequences in other parts of the system which could result in an overall increase in emissionsSpecific objectives for this project will explore the impact of biochar additions to manure and wastewater systems. These objectives include:Evaluate the nitrogen removal efficiency of biochar amended filter strip plots (measuring runoff, infiltrate, and emissions)Evaluate the impact of manure amended with biochar to biogas production during anaerobic digestion and nitrogen emissions following digestionMeasure the nitrogen emissions from processed and unprocessed manure during storage when covered with biocharEvaluate the nitrigen emissions from biochar amended manure when land applied following storageIncorporate results from biochar additions into a life cycle assessment for dairy manure management systems to assess overall impacts of biochar management strategies.

Project Methods
The methods for each objective are detailed below.Objective 1: Evaluate the N removal efficiency of biochar amended filter strip plotsAmending the subsurface soil of filter strips with biochar is proposed to decrease the nutrient losses through subsurface leaching.Six filter strip plots are proposed to examine the effects of biochar (one treatment and one control each with three replicates). Three of the plots will contain soil while the remaining three will contain a soil mix with 5% biochar by mass. The winter months will not be evaluated until there is a thaw/melt scenario to represent field conditions. The filter strip plots are designed with an impermeable membrane liner to collect wastewater which has infiltrated the soil media.Any water that exits the system on the surface is also collected. The initial wastewater applied, the subsurface leachate, and the surface runoff will be characterized for nitrogenandtotal phosphorus.Gas emissions will be collected after each application and monitored for GHG's (CH4, CO2, N2O) and ammonia.Data will be used to determine impact of biochar to N and P removal efficiency. Mass balances will be developed for each of the control and biochar amended plots. Loading rates and removal efficiencies will be reported for each system.Objective 2: Evaluate the impact of manure amended biochar to biogas production during anaerobic digestion and N emissions following digestionBiochar will be added to manure to assess the increase in biogas production andevaluate the impact to N emissions following digestion. Biochar contains a significant amount of C as well as provides a media for microbial growth. Trials will be conducted in a respirometer to determine the impact of biogas quantity and quality with increasing doses of biocharand determine if additional carbon or media for microbial growth in the primary driver for increasaed biogas production. To assess carbon biochar will be ground and finely (destroying structure), and to assess the media impact biochar structure will be maintained and will be added in a mesh bag to allow for the biochar to remain submerged by weighing down. These trails will be completed with 4 replications in a 24 cell respirometer system. The biochar additions will be added to dairy manure and digestedat mesophilic temperatures (~100 degrees F) for approximately 28 days or when the biogas production is static. The biogas is quantified by the respirometer and collected in Tedlar gas bag and evaluated using a gas chromatographconfigured to measure the concentration of CH4, CO2, and H2S.Following digestion the effluent will be placed in an open storage container to determine the emissions following digestion.Objective 3: Measure the N emissions from processed and unprocessed manure during storage when covered with biochar and thermally treated woodIn order to reduce N emissions in manure storage, covers will be addedto evaluate the emissions reduction during storage. The addition of a surface mat is intended to provide a physical barrier to reduce ammonia losses as well change the surface biochemistry to further reduce losses. In order to conduct this research 55 gallon drums will be filled with the three manure sources (manure slurry, digested manure slurry, digested separated manure liquids) and three treatments (manure, manure with a biochar cover, and manure with a therally treated wood cover) with three replicates for each, totaling 27 barrels. The manure sources will be collected from a local dairy with a plug flow digester and screw press separator. Manure streams will be collected directly before and after processing. Barrels will be filled with manure leaving ~8 inches of headspace at the top of the barrel andare open to the environment when measurements are not being taken.Barrels are stored in a temperature controlled environment (ranging from 40-65 degrees F). Once a week a dynamic chamber lid is put over each barrel and gas emissions are measured. Manure samples will be taken with a sludge judge (to obtain a sample from the entire depth spectrum) from each barrel at the beginning of the experiment and monthly throughout storage.Objective 4: Evaluate the N emissions from amended manure when land applied following storageFollowing storage, the manure storage systemfrom objective 3with the greateststorage emissions reductionswill be applied to field plots using surface application. Each storage barrel will be applied to 2 field plots to increase replication in the land application plots to 6 replicates for each treatment combination. The field plots will have anchors installed (identical to those described in the filter strip plots) to monitor emissions from the each plot throughout the growing season on a weekly basis. This will allow researchers to determine if the covered manure storages were able to limit ammonia emissions not only during storage but also in the land application portion. This is critical because if the ammonia losses increase significantly in the land application portion then the application of the cover is not successful in reducing overall N emissions.Objective 5: Incorporate results from biochar additions into a life cycle assessment for dairy manure management systems to assess overall impacts of biochar management strategiesA life cycle assessment (LCA) for dairy manure management systems has recently been completed by the PI (Aguirre-Villegas et al. 2014). The information produced from the manure storage and land application research will be updated in a farm scale LCA to evaluate the overall impacts of integrating biochar management strategies with other technology choices for dairy manure management systems. This assessment will include the production of the biochar to evaluate overall system emissions.Analysis of ResultsThe experimental design is represented above and outlines specific treatments for each objective. Filter strip plots will be analyzed using a repeated measures ANOVA design. Analysis will be conducted based on the null hypothesis that the treatment means are of no significant difference.Main effects for the biochar treatments will be done using SAS lsmeans and the best fit model as determined by the data and ANOVA significance.All respirometer and storage experiments will have treatments assigned randomly to minimize error.Field plots will be a randomized block design to account for timing issues related to measurements.Statistical analysis will be conducted using ANOVA in SAS to determine the statistical significance of treatments on each measured manure parameter.Assumptions that residuals are normally distributed and the variances are homogenous will be evaluated using normal probability plots and side-by-side box plots to ensure their validity, and adjusted using grouping and data transformations when necessary.When ANOVA is significant, difference of least squares means will be used to compare the treatment means and their interactions.Project EvaluationThe project data will be evaluated by peer review through publication of developed materials and acceptance at national conference for presentation. For specific objectives data must show statitical significance to be shown to have an effect on the outcomes.For internal measures of project sucess throghout the project, a timeline has been developed with goals for each of the outlined objectives above. Sucessful completion will be indicated by completion of outlined tasks for each objective. For each objectiveto be sucessful researchers must (1) complete outlined tasks on time with data that meets quality standards, (2) data must be statitically evalauted, (3) data must be accepted by peer review (publications and conference acceptance). Any part that does not meet these specifications will be re-evaluated and a new plan must be developed with justification for the change and a new timeline developed.

Progress 05/15/15 to 05/14/19

Outputs
Target Audience:Target audiences include other academics who were addressed via published work and many presentations to the scientific community. In addition, data was presented to industry partners who are interested in integrating biochar into agricultural systems. Finally, we also presented data to agricultural producers at a variety of meetings. Changes/Problems:In addition to the work proposed, we had to develop/evaluate some methodologies regarding nitrate and ammonia extraction from biochar as literature was suggesting there were errors in these measurements. We needed to take some time to do this evaluation as it was critical to evaluating the outputs of this work and we are publishing the results. In addition, we moved to a more controlled laboratory study to better understand the mechanisms that impact nitrogen cycling as it was determined this was critical to make any advances. However, we still accomplished the outlined goals in the proposal. What opportunities for training and professional development has the project provided?The project has provided many opportunities for undergraduate and graduate students to gain laboratory skills in evaluating manure and biochar systems. It has also allowed for students to make posters and presentations. How have the results been disseminated to communities of interest?The results have been presented to academics, industry representatives, government officials, and producers. The project resulted in one producer adding biochar to their digester directly. There has been increased requests for the information produced from this work and we will continue to disseminate the information through a variety of channels over the next few years. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We evaluated the impact to nitrogen cycling in a number of agricultural systems to further derive benefits from integration. Specifically, by objective: 1.Evaluate the nitrogen removal efficiency of biochar amended filter strip plots. We developedfilter strip plot trials with and without biochar at an active dairy to evaluate the treatment in the surface and subsurface effluent when silage runoff was applied to the filter strips. In these systems, we found that neither system resulted in surface runoff. We also found that both biochar and non biochar amended plots had similar performance for subsurface effluent quality for biochemical oxygen demand and phosphorus. However, biochar treated plots had an increased reduction in cumulative total nitrogen leaching with a 40% reduction in cumulative nitrate leaching when biochar was incorporated at 2.5% by mass in the plough layer. It seems the biochar amended plots increased retention of both organic nitrogen and nitrate as compated to the plots without biochar which lead to the reduced leaching. 2. Evaluate the impact of manure amended with biochar to biogas production during anaerobic digestion. Biochar was added directly to laboratory anaerobic digestion systems and was found to not impact biogas production. However, while biogas production was not increased, the hydrogen sulfide production was reduced significantly which can be important for reducing costs of these systems. Additionally, it was found that sulfate sorption is not likely the mechanism for reduction so other mechanisms must be evaluated. 3. Measure nitrogen emission from manure during storage when covered with biochar. Manure was stored in barrels for seven weeks and covered with biochar and other treated biomass. It was found that biochar covers reduce ammonia emissions by over 90%. However, in assessing the biochar and the mass balance, the majority of the reduction was due to the physical cover not the soprtion of ammonia by the biochar. 4. Evaluate emissions from biocharamended soils when nitrogen wastewater is applied. Soil columns were designed to assess the mechanism for reduced nitrogen leaching and ammonia and nitrous oxide were also measured to determine the impact to nitrogen cycling. It was found that biochar amended soils reduced nitrous oxide emissions. In addition, biochar columns showed that organic nitrogen and nitrate retention in the biochar soil matrix resulted in reduced nitrogen leaching. 5. Incorporate biochar manure storage cover data into a lifecycle assessment. An existing manure based life cycle assessment model that was used to assess a wood biochar cover. The cover was able to reduce overall ammonia emissions.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Sanford, J., R.A. Larson, and T. Runge. 2019. Nitrate sorption to biochar following chemical oxidation. Science of the Total Environment, 669:938-947. https://doi.org/10.1016/j.scitotenv.2019.03.061
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Holly, M.A. and R.A. Larson. 2017. Thermochemical Conversion of Biomass Storage Covers to Reduce Ammonia Emissions from Dairy Manure. Water, Air, & Soil Pollution, 228(11):434.
• Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Wang, H., R.A. Larson, and T. Runge. 2019. Integrating biochar in manure based anaerobic digestion systems to reduce hydrogen sulfide in biogas. Bioresource Technology Reports, in review, revisions requested.
• Type: Journal Articles Status: Other Year Published: 2019 Citation: Walsh, J., R.A. Larson and J. Sanford. 2019. Evaluation of biochar nitrate extraction methods.
• Type: Journal Articles Status: Submitted Year Published: 2019 Citation: Sanford, J. and R.A. Larson. 2019. Treatment of horizontal silage bunker runoff using biochar amended vegetative filer strips. Agriculture, Ecosystems & Environment, in review.
• Type: Journal Articles Status: Submitted Year Published: 2019 Citation: Sanford, J. and R.A. Larson. 2019. Nitrogen cycling in sandy loam soil columns amended with biochar. Science of the Total Environment, in review.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Larson, R.A., J. Sanford, M. Holly, and T. Runge. Incorporating Biochar into Farmstead Management Strategies to Reduce Nitrogen Losses. 2018 ASABE Annual International Meeting, July 29  August 1, 2018, Detroit, MI.
• Type: Conference Papers and Presentations Status: Other Year Published: 2018 Citation: Larson, R.A. and H. Wang. 2018. Anaerobic Digestion: Incorporating Biochar to Manage Hydrogen Sulfide. Biocycle 18th Annual Conference REFOR18, October 15-18, 2018, Raleigh, NC.

Progress 05/15/17 to 05/14/18

Outputs
Target Audience:At this point, our target audience has been primarily other researchers of various levels. However, we have had some interaction with producers, people within the biochar industry, and some policy makers. Changes/Problems:We had to request an extension year as the field work relies on rainfall and we wanted more events than we were able to accomplish in the first three years. We expanded objective four in order to better understand the mechanisms behind the impact of nitrogen cycling when biochar is amended in fields. This was necessary as the recent flood of papers in this area has developed a general idea that biochar impacts the nitrogen cycling but we need to further start to refine why this is happening so we can improve this. We also expanded some work on biochar to look at oxidation of biochars for nitrate sorption as we found this to be a very unexpected but interesting application of biochar for reducing agricultural nitrogen losses. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Yes, we work with producers through our extension program and have provided the information on biochar. Our anaerobic digester studies revealed a decrease in hydrogen sulfide production which we are exploring further which one digester decided to implement. Further details will be shared through the extension program of the PI on a regular basis. What do you plan to do during the next reporting period to accomplish the goals?We have a timeline to complete the entire project by the next reporting period. We are currently on time to complete the field and lab work by the end of 2018, and will use the remaining few months in 2019 to complete any analysis and get the papers completed and submitted. We see no problems in completing the work in the final extension year.

Impacts
What was accomplished under these goals? Our research has shown ways that we can mitigate environmental impacts from manure systems by incorporating biochar. For example, we can reduce nitrogen emission losses during manure storage by applying biochar as a cover. We have also found that biochar can be modified to sorb nitrate, which can be used to protect water supplies. Objective 1-75%complete: We have constructed six large filter strips plots at a dairy farm in Wisconsin, three of which are amended with corn cob biochar. We are continuing to collect samples and have currently collected over ten storms, where samples include runoff, leachate, and emissions to understand the impact to treatment performance and complete N mass balances for these systems. Objective 2-100% complete: We have evaluated a number of biochars and steam treated biomasses in manure storage systems to reduce ammonia emissions following digestion. The trials show biochar is over a 90% reduction in ammonia emissions in these systems. We have also added biochar to digestion systems and found it reduces H2S production without impacting methane production. The results of this objective are now published. We found that when biochar was incorporated within the digester itself, it did not impact the biogas production, but it did significantly reduce the hydrogen sulfide. This was of great enough interest to operators that we have presented at meetings and one operator tested at a large scale. Objective 3: This objective is 100% complete. Biochar made from multiple feedstocks (birch and corn cobs) was able to reduce ammonia emissions from manure storage by greater than 90% when applied on the surface or mixed in with the manure. The majority of the reduction was due to the physical cover although the biochar was capable of nitrogen sorption it was not the main mechanism for reduction. This work is now published Objective 4- 50% complete: A change in this objective based on recent literature publications was to instead of just measure the emissions, was to change the experimental set up to examine the mechanism for the changes in nitrogen cycling in manure/soil systems when biochar is added. After completing other work and assessing current literature, we realized we needed to expand this objective to understand the mechanism by which biochar is affecting the nitrogen cycling within soils to impact the emissions and water laching. Therefore, we have expanded this objective to complete a more detailed analysis to examine nitrogen cycling in soils when amended with biochar and receiving nitrogen applications from manure and feedlot runoff. This study is now designed and constructed and we will be collecting data over the next few months for assessment. Objective 5-40% complete: We have collected the biochar data, and are currently beginning to incorporate into the LCA model.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Holly, M.A. and R.A. Larson. 2017. Thermochemical Conversion of Biomass Storage Covers to Reduce Ammonia Emissions from Dairy Manure. Water, Air, & Soil Pollution, 228(11):434.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Holly, M.A. and R.A. Larson. 2017. Effects of Manure Storage Additives on Manure Composition and Greenhouse Gas and Ammonia Emissions. Transactions of the ASABE, 60(2): 449-456.

Progress 05/15/16 to 05/14/17

Outputs
Target Audience:As our project is still in progress, out target audience has largely been the research team itself. However, we have also reached out to producers and practicing engineers in the field for key design features related to runoff and filter strips design. In addition, we have been working with producers and industry in terms of applications to digesters. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The incorporation of biochar produced some immediate opportunities to provide producers with a strategy to reduce H2S production and has been presented at conferences. In addition, the filter strip discussions have been relevant to recent developments on filter strip design and management and the experiment has been refined to answer some critical questions for the future of filter strips. How have the results been disseminated to communities of interest?We are working with digester operators and NRCS and other engineers who design filter strips. The incorporation of biochar produced some immediate opportunities to provide producers with a strategy to reduce H2S production and has been presented at conferences. What do you plan to do during the next reporting period to accomplish the goals?We have clear timelines for each of the remaining tasks under each objective as discussed in the accomplishments.

Impacts
What was accomplished under these goals? Currently, we have complete the following activities under each of the specific objectives mentioned above: Objective 1-60%complete: We have constructed six large filter strips plots at a dairy farm in Wisconsin, three of which are amended with corn cob biochar. We have seeded and are currently collecting sample from runoff, leachate, and emissions to understand the impact to treatment performance and complete N mass balances for these systems. Objective 2-80% complete: We have evaluaed a number of biochars and steam treated biomasses in manure storage systems to reduce ammonia emissions following digestion. The trials show biochar is over a 90% reduction in ammonia emissions in these systems. We have also added biochar to digestion systems and found it reduces H2S production without impacting methane production. The results of this objective are currently in review for publication. We found that when biochar was incorporated within the digester itself, it did not impact the biogas production, but it did significantly reduce the hydrogen sulfide. This was of great enough interest to operators that we have presented at meetings and one operator tested at a large scale. Objective 3: This objective is 100% complete; the work is in review for publication. Biochar made from multiple feedstocks (birch and corn cobs) was able to reduce ammonia emissions from manure storage by greater than 90% when applied on the surface or mixed in with the manure. The majority of the reduction was due to the physical cover although the biochar was capable of nitrogen sorption it was not the main mechanism for reduction. Objective 4-25% complete: A long term study has been designed and the manure will be collected a stored at the end of this year to be land applied in the spring. Objective 5-10% complete: We have collected the biochar data, and are currently beginning to incorporate into the LCA model.

Publications

• Type: Journal Articles Status: Under Review Year Published: 2017 Citation: Holly, M.A. and R.A. Larson. 2017. Evaluation of Biochar, Activated Biochar, and Steam Treated Wood as Dairy Manure Storage Covers for Ammonia Mitigation. Journal of Environmental Quality. In Review.

Progress 05/15/15 to 05/14/16

Outputs
Target Audience:Currently, we are in the laboratory and beginning field research phases of the work, therefore the target audience of the information has been graduate students and other researchers. However, the end goal of the work it targeted toward producers and other stakeholders so there has been some effort to include them in understanding the process, including providing information at events such as farm technology days to begin to make them aware of some of the issues so when the work is complete we can provide solutions. Changes/Problems:The mechanisms that were previously thought to bind nitrogen in biochar were not fully understood and we took some additional time to better evaluate these mechanisms as it is critical to project completion. This did not significantly delay our progress but we did delay the start of the filter strip work until 2016 to ensure project success. We were able to modify biochar to sorb nitrates and to sorb ammonia gas for the different applications which will help up achieve our objectives (which we were very excited about). The greater change is in the manure storage emissions portion of the study. As we completed our current manure storage studies (from storage through land application), we have concluded that the land application portion of the study was not significant asall treatment differences in gas emissions were during storage and there were notreatment differences in emissions after land application (when the manure was incorporated). Therefore, we have targeted more of the remaining studies to the manure storage portion and less to land application as we believe this is the target area for reductions in ammonia emissions. In addition, as we begin to look at the potential of integrating biochar into manure systems, manure storage systems have greater feasibility as compared to land application due to the large biochar volumes that would be necessary in field applications. What opportunities for training and professional development has the project provided?We have continued to train graduate students in the field of agricultural engineering focusing onmanure and bioprocessing. Students have begun to learn integration of these two fields. We have had a great deal of interest in the study from producers in Wisconsin, although more results are needed to make recommendations for use. How have the results been disseminated to communities of interest?We have begun to share the results with those in the research community, however it is premature to share the results with producers. We are looking to complete specific aspects related to incorporating biochar to increase nitrate sorption this year so we can begin to make practice recommendations. However, we have begun to discuss the issues that the project aims to address with producers so that they have an understanding of the issues when the results from the project are complete. What do you plan to do during the next reporting period to accomplish the goals?We have a significant amount of laboratory and field work planned for the upcoming year with students hired to complete. Lab and field work: For objective 1: we will be installing the filter strip plots in the Spring of 2016 for analysis of the nitrogen removal efficiency when amended with biochar. The field scale plots will be implemented at the USDA dairy facility located in Prairie du Sac, WI. A control filter strip as well as a biochar amended strip (with replicates) will be installed to compare treatment differences in nitrogen when runoff is applied to the systems over a minimum of one year. Runoff will be collected at the site and metered onto the systems where surface and subsurface samples will be collected for analysis. Additionally, gas emission samples will be collected to aid in the determination of the mass balance for nitrogen fate in these systems. Sample collection and data analysis will occur throughout the year. For objective 2 & 3: small laboratory scale manure storage systems have been designed for measurement of emissions from manure storage to begin at the end of year 1. This study will look at the ability of different biochars and steam exploded wood to mitigate nitrogen and methane emissions when applied as a cover to manure storage and when mixed directly in with the manure storage systems. Emissions measurements will continue for a minimum period of 45 days for each trial to determine the mitigation potential and fate of nitrogen in the system (whether it remains in the manure or is sorbed in the biochar or lost to emissions). In addition, the biochars selected for the study (they have already been tested for their ability to sorb ammonia and nitrate in preliminary studies) will also be added to manure before digesting in a controlled laboratory setting. The emissions following digestion will be measured to determine the impact if adding biochar prior to digestion.

Impacts
What was accomplished under these goals? We have completed the research design for objective one and will be installing the filter strip systems in the spring of 2016. We have evaluated the impact to objective 2, amending manure with biochar to assess biogas production during digestion and will complete additional studies to evaluate the nitrogen emissions following digestion in early 2016. We conducted trail to evaluate the impact to manure storage emissions when biochar is added as a cover (obj. 3), we have since targeted specific biochar characteristics to increase the ammonia adsorption capacity for these systems and will be conducting additional studies in early 2016.

Publications