Determination of gas emissions from manure sources in animal feeding operations

Determination of gas emissions from manure sources in animal feeding operations

Summary

Air pollutants from animal feeding operations (AFOs) cause public health and environmental problems, becoming critical issues for farm workers and populations living near livestock production sites. In addition to degradation of the local air quality, AFOs emit greenhouse gases, contributing to climate change. While best management practices (BMPs) play an important role in accomplishing emission mitigation, developing effective BMPs requires accurate on-farm determination of emissions that reflects region-specific climatic conditions and operation practices. The project proposes developing a novel emission measurement system that can be used for establishment of site-specific BMPs and for evaluation and improvement of efficiency of currently available BMPs for livestock producers in the West. As a multi-component project, the project scope also includes dissemination of project information and findings through several channels, including professional presentations and a website, as well as education and outreach programs.

This annual report focuses on project activities, carried out during the year 2013, including development of a chamber-based gas emission measurement system, laboratory and field emission measurements of targeted gases (i.e. ammonia – NH₃, methane – CH₄, carbon dioxide – CO₂ and nitrous oxide – N₂O) and public dissemination of project information and findings.

Objectives/Performance Targets

To improve the sustainability of livestock production in the western region, this project aims to reduce the environmental impacts of beef and dairy operations, particularly by minimizing gas emissions from manure management practices. Specific objectives of this project are listed as follows:

Objective 1:  To develop a gas emission measurement system that can be used as a tool for establishing site-specific BMPs to reduce gaseous emissions from AFOs and for evaluating efficiency of current BMPs for the producers in the West.

Objective 2:  To measure gaseous emissions from AFOs in the Intermountain West and develop site-specific BMPs, as well as improve current BMPs for the western region.

Objective 3:  To disseminate project information, collected emission data and findings from the project to stakeholders, including livestock producers, agricultural professionals, and local, state and federal agencies to (a) address the adverse effects of gas emissions from AFOs on public health and the environment and (b) introduce respective BMPs for alleviating air quality issues.

Accomplishments/Milestones

Objective 1:  The automated multiplexing system for chamber-based monitoring of greenhouse and regulated gas emissions from manure sources was successfully developed to examine spatial and temporal variability in emissions associated with manure management practices. The system relies on a Fourier Transformed Infrared (FTIR) spectroscopy analyzer. Evaluation of the measurement system performance was based on laboratory experiments using methane gas (CH₄) to assess the accuracy and precision of the chamber system. A method to generate constant emission of methane gas was developed using the gradient-based technique as the reference gas fluxes. Three different emission rates were simulated to evaluate the accuracy of the system measurements. Statistical analyses, including ANOVA, were performed to determine the significance of gas flux estimates using the chamber-based estimate. A p-value = 0.05 was considered to be statistically significant. The ANOVA tests indicated no statistically significant differences among estimated fluxes from each of the 12 chambers evaluated, with the resulting p-values of 0.54, 0.58 and 0.80 for the measurements in three different emission rates. In addition, the multi-chamber system measurement in reference to the gas fluxes estimated by the gradient-based method showed excellent accuracy with the measurement biases less than 1%. Additional discussions on the measurement accuracy of the system are given in Sutitarnnontr et al. (2013).

Objective 2:  The multiplexing system, which facilitates automation of multiple chambers and management of chamber air flow, was employed to assess the spatial variability of emissions from different manure types (i.e. dairy manure, beef manure, dairy compost and beef compost) and manure management practices (i.e. different timings of incorporation) at the USU Greenville Research Farm (1857 North 800 East, North Logan, UT). The experiments were conducted with complete randomized design with triplicate of each treatment. The dairy and beef manure samples were collected from the USU’s Caine Dairy Farm (4300 South Hwy 91, Wellsville, UT) and Animal Science Farm (3580 South Hwy 91, Wellsville, UT), respectively. Figure 1 illustrates gas emission measurements from manure management practices under field conditions in August and September 2013. The preliminary data analyses suggest that applying composted manures instead of farm yard manures as fertilizer would significantly reduce CO₂, CH₄ and NH₃ emissions. In addition, NH₃ emissions can be decreased up to 82% with the immediate incorporation applications. The detailed analyses are being performed that will provide more insightful information on alternative manure management practices to reduce gas emissions from manure sources.

Objective 3: Led by Dr. Rhonda Miller, an agricultural environmental quality specialist, a demonstration of the prototype of the measurement system was provided to the producers and agricultural professionals at the Intermountain Irrigated Pasture Research Facility (1317 South 800 West, Lewiston, UT) on July 31, 2013 (Figure 2). The system demonstration was part of the field day tour of the Pasture Symposium 2013 organized by the Utah State University Extension Program. A total of approximately 100 participants, including livestock producers, local, state, and federal agencies, and relevant stakeholder groups attended the demonstration, providing valuable feedback and concerns on the gas emission regulations that are anticipated in the near future.

The project was also introduced to public at the first Science Unwrapped (SU) of Fall 2013 on September 6, 2013 at the Eccles Science Learning Center, Utah State University. The Science Unwrapped is USU’s monthly science outreach event, hosted by the College of Science, with participants from across the campus, including a mix of university students and faculty, people of all ages and many backgrounds from the community, and high school (and some junior high) students from the area. The major topic of the SU of Fall 2013 series was on the Science of Air Pollution, covering the science and technology and the chase for evidence that has led to the current understanding of especially the PM 2.5 (fine particulate matter with a diameter of 2.5 microns or less) and emissions from animal feeding operation problem in the Cache Valley, Utah. A poster (see the attachments) and measurement system demonstration were presented as an informational After-Activity to provide project information and answer questions on potential environmental impacts of degradation of air quality from livestock productions.

In addition to the outreach activities described above, oral and poster presentations were made at four professional meetings as follows. All poster presentations in electronic format can be found in the attachments section of this annual report.

(1)  Sutitarnnontr. P, E. Hu, R. Miller, M. Tuller, and S.B. Jones. 2013. Drying and Rewetting Effects on Gas Emissions from Dairy Manure in Semi-arid Regions. 2013 Livestock and Poultry Environmental Learning Center National Conference “Waste to Worth: Spreading Science and Solutions”, Denver, CO, April 1 – 5, 2013. Available online at: http://www.extension.org/pages/67670/drying-and-rewetting-effects-on-gas-emissions-from-dairy-manure-in-semi-arid-regions#.UrOJRtJDtI4

(2)  Miller. R, P. Sutitarnnontr, E. Hu, M. Tuller, J. Walworth, and S.B. Jones. 2013. Best Management Practices for Reducing Gas Emissions from Manure Application in Semi-Arid Regions. 2013 Livestock and Poultry Environmental Learning Center National Conference “Waste to Worth: Spreading Science and Solutions”, Denver, CO, April 1 – 5, 2013. Available online at: http://www.extension.org/pages/67662/best-management-practices-for-reducing-gas-emissions-from-manure-application-in-semi-arid-regions#.UstQbdJDtI4

(3)  Sutitarnnontr. P, E. Hu, M. Tuller, R. Miller, and S.B. Jones. 2013. Effectiveness of Manure Incorporation in Reducing Gas Emissions. 2013 Spring Runoff Conference “Water, People and Sustainability: Integrating Physical, Social and Ecological Dimensions”, Eccles Conference Center, Utah State University, Logan, UT, April 9 – 10, 2013.

(4)  Sutitarnnontr. P, E. Hu, R. Miller, M. Tuller, and S.B. Jones. 2013. Measurement Accuracy of a Multiplexed Portable FTIR – Surface Chamber System for Estimating Gas Emissions. 2013 ASABE International Annual Meeting, Kansas City, MO, July 21 – 24, 2013.

(5)  Sutitarnnontr. P, E. Hu, M. Tuller, and S.B. Jones. 2013. Determination of Physical and Hydraulic Properties of Cattle Manure Using Soil Analysis Techniques. 2013 ASA, CSSA, and SSSA International Annual Meeting, Tampa, FL, November 3 – 6, 2013.

• 2013 Science Unwrapped Presentation
• 2013 Waste to Worth Presentation
• 2013 SSSA Annual International Meeting Presentation
• Figures 1 & 2
• 2013 Spring Runoff Conference Presentation
• 2013 ASABE Annual International Meeting Presentation

Impacts and Contributions/Outcomes

The following are the measurable impacts and outcomes achieved from the project in the year 2013:

1. The project yielded a novel emission measurement system for assessment of gas emissions from AFOs. Application of the developed measurement technology is not limited to AFOs, targeted in this project, but will also be applicable for other agricultural management systems and natural ecosystems.

2. The project increased knowledge, created awareness, and developed skills of project participants on integrated sustainable livestock production, encouraging knowledge transfer among all stakeholders in the field.

More comprehensive results will be summarized in the project final report and to be published when the detailed analyses are complete. Reduction of gas emissions from applying site-specific BMPs will be demonstrated by comparing emission rates monitored among BMP treatments. At least 50% of the livestock producers, participating in the education and outreach programs, are expected to implement BMPs to reduce gas emissions from farming operations. With implementation of the project BMP findings, air pollution complaints and health risks related to air pollution are anticipated to be reduced. The current available BMPs will be improved to be more efficient and practical in reduction of the environmental impacts as appropriate for the producers in the West. Overall, the project will improve air quality and sustain farmer worker health in AFO facilities where BMPs are implemented. In addition, this project prepares producers and small livestock farmers for compliance with existing and anticipated regulations related to gas emissions.

The successful implementation of the BMPs by the livestock producers through this project will not only help protect the environment, improve human health and minimize greenhouse gas emissions in the West, but also serve as a model for the region, thereby improving the sustainability of animal feeding operations.

Sutitarnnontr. P, E. Hu, R. Miller, M. Tuller, and S.B. Jones. 2013. Measurement Accuracy of a Multiplexed Portable FTIR – Surface Chamber System for Estimating Gas Emissions. ASABE Paper No. 13-1620669. St. Joseph, Mich.: ASABE.

We thank Professor Markus Tuller of the University of Arizona for his assistance and advice in designing and developing the gas measurement chambers. Special thanks go to Bill Mace for technical assistance, Ricardo Tejeda and J.C. Almonte for their assistance with design and development of the microcontroller unit and system interfaces for the multiplexing system.

Collaborators: