Tag: manure management

Posted on

Closing the Loop: Extension’s Role in Driving Circularity in Manure Management

Purpose

Circular agriculture is a farming strategy designed to minimize inputs and environmental impact by improving soil health, reducing waste, and reusing materials. In the context of livestock production and manure management, circularity emphasizes nutrient recycling, minimizing environmental losses, and balancing nutrient inflows and outflows to sustain agricultural systems. These priorities have long been a focus of Extension efforts across livestock-intensive regions.

This work examines the role of Extension in defining, branding, and messaging circularity within manure management. Our objective is to highlight past progress, explore future opportunities, and establish consistent messaging across farmers, industry, and the public. Through multiple analyses, we demonstrate how minor alterations in messaging can tailor information to address different audience concerns.

What Did We Do?

To evaluate the evolution of manure management and its role in circular agriculture, we conducted several analyses:

    • Historical Nutrient Flow & Circularity Metrics 

Using historical data, we traced changes in nutrient use efficiency due to advancements in cropping systems, manure handling, and livestock genetics. 

Findings illustrate continuous improvement in livestock production systems and highlight key drivers of efficiency.

Improvements were attributed to livestock performance, crop performance, and manure management, helping identify areas requiring greater emphasis for future progress.

    • Nutrient Separation vs. Direct Manure Application 

We compared traditional manure application with nutrient separation techniques to assess their impact on nutrient circularity and economic viability. Nutrient separation could include solid liquid separation systems, but ideally will be based on systems that target partitioning of N and P, to better focus on how nutrient flows are impacted.

    • Comparing Manure & Municipal Waste Management 

By comparing manure management practices with municipal waste handling systems, we examined how these comparisons shape public perception.

Extension’s role includes bridging the gap between agricultural decision-making and a public that is increasingly disconnected from farming, requiring clear, relatable messaging.

What Have We Learned?

The analysis highlights several key takeaways:

    • Livestock & Crop Improvements Have Driven Nutrient Use Gains – While significant progress has been made, additional focus on manure management is needed to accelerate circularity.
    • Decision Tools Can Be Re-Branded – Farmers and industry stakeholders can benefit from repurposed decision-support tools that incorporate circularity metrics to inform practical manure management choices.
    • Public Understanding Requires Clear Communication – Agricultural waste and manure management must be explained in ways that connect with non-farm audiences, emphasizing environmental and health benefits.
    • Multimodal Messaging Enhances Engagement – Using a combination of visual graphics, infographics, and multimedia content, Extension can effectively communicate circularity’s value to diverse audiences.

Future Plans

To strengthen Extension’s role in promoting circularity in manure management, future efforts will focus on:

    • Developing targeted messaging for farmers, industry professionals, and the general public to improve adoption of circular manure management practices.
    • Creating practical decision-support tools that incorporate circularity metrics to assist in manure management planning.
    • Enhancing outreach efforts through multimedia resources, including infographics, videos, and interactive educational tools.
    • Strengthening connections between manure management and broader sustainability discussions by aligning messaging with climate resilience, water quality, and regenerative agriculture initiatives.

Authors

Presenting & Corresponding author

Daniel Andersen, Associate Professor, Iowa State University, Dsa@iastate.edu

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2025. Title of presentation. Waste to Worth. Boise, ID. April 7–11, 2025. URL of this page. Accessed on: today’s date. 

Posted on

Changes in amount and location of US dairy manure production from 1970-2023

Purpose

We estimated milking cow manure production for US states from 1970 to 2023 with the aim to provide a broad perspective to stakeholders who manage and optimize the use of dairy manure. Stakeholders include producers and those working on their behalf such as agronomists, applicators, engineers, extension agents, researchers, governmental agencies, cooperatives, and markets.

It is hoped that with increased understanding of how manure production has changed over time and location stakeholders can better understand trends and historical conditions which impact their efforts.

What Did We Do?

We estimated milking cow manure production for 48 US states from 1970 to 2023 using an empirical equation estimating manure production as a function of milk production published by the American Society of Agricultural and Biological Engineer’s Manure Production and Characteristics standard. To apply this equation to each state we utilized two data sources produced by the United States Department of Agriculture’s National Agricultural Statistics Service (NASS), annual milk production and annual milking cow herd size. To gain further insight data sources reporting the number of dairy farms and land available for manure application in each state were additionally gathered from NASS and reported in combination with manure production. The workflow and references for combining this data are displayed in the following figures.

Figure 1. Workflow to estimate annual dairy manure production using ASABE’s Manure Production and Characteristics standard and NASS milk cow production and cow herd inventory data sources.
Figure 1. Workflow to estimate annual dairy manure production using ASABE’s Manure Production and Characteristics standard and NASS milk cow production and cow herd inventory data sources.
Figure 2. Workflow to estimate number of dairies and acres for manure application from NASS data sources.
Figure 2. Workflow to estimate number of dairies and acres for manure application from NASS data sources.

What Have We Learned?

Nationally annual dairy manure production has decreased from 1970-2023 by approximately 4% (2.2 billion gallons). From 1998 to 2023 annual dairy manure production increased by approximately 13% (6.4 billion gallons). Although national milking cow numbers generally declined from 1970 to 1998 then nearly remained constant until 2023, this trend was offset by continual increase in manure production per cow from 1970-2023 due to the direct relationship with milk production, which has continued to increase from 1970-2023. Also, the annual number of gallons of manure per dairy farm has increased from 1970-2023 due to a decrease in number of dairies combined with an increase in manure production per cow. It is accepted that the US dairy industry has consolidated over time, this data supports that its’ manure production has consolidated as well.  The author posits based on experience and this analysis that nationally, over time, manure systems in support of livestock production have contributed to an increase in volume of manure being managed to date. As dairy cows move to increasing levels of confinement, from pasture and lots which utilize land base as a manure system to barns with more engineered manure systems, greater collection of manure occurs and therefore must be managed. Regarding the impact of the specific type of engineered manure systems impact on volume of manure that must be managed the author posits this currently varies based on the kind of manure system selected, either adding or subtracting to the managed manure stream, which is a function heavily dependent on local climate (precipitation, evaporation, and length of storage period) and technology adoption (covers, flush systems, separation, and advanced treatment). In the upper Midwest with relatively high precipitation, low evaporation, and long winter periods dairy manure systems are predominantly collect and store only, overall adding to the volume of manure to be managed as additional precipitation is also captured by the uncovered nature of most storages in this region.

Figure 3. National change in manure and milk production, milking cow inventory, and number of dairies from 1970 to 2023.
Figure 3. National change in manure and milk production, milking cow inventory, and number of dairies from 1970 to 2023.

At the state level the change in manure production has varied. From 1970 to 2023, 12 states have increased manure production, the remaining 26 states have decreased manure production. This has resulted in a change in the location of where manure is produced. In 2023, most manure was produced in a few states. In 2023, 10 states produced 70% of the total annual US dairy manure production, with 6 states producing over 50%.

Figure 4. 2023 annual milking cow manure production, millions of gallons, and percent change of annual milking cow manure production from 1970 to 2023.
Figure 4. 2023 annual milking cow manure production, millions of gallons, and percent change of annual milking cow manure production from 1970 to 2023.

Future Plans

Authors seek to maintain this data analysis in a method available to stakeholders, additionally incorporating manure production from swine, beef, and poultry into it, and updating it as future NASS reports are published.

Authors

Presenting & corresponding author

Mike Krcmarik, Professional Engineer, mikekrcmarik@gmail.com

Additional Information

Email corresponding author for copy of all data and figures used in this analysis, including figures published on the poster only.

Acknowledgements

    • American Society of Agricultural and Biological Engineers, Engineering Practices Subcommittee of the ASAE Agricultural Sanitation and Waste Management Committee responsible for standard ASAE D384.2 Manure Production and Characteristics used in this analysis.
    • United States Department of Agriculture’s National Agricultural Statistics Service responsible for the various surveys and reports used in this analysis.
    • Allen Young, Eric County Soil and Water Conservation District (New York) providing valuable review and discussion.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2025. Title of presentation. Waste to Worth. Boise, ID. April 7–11, 2025. URL of this page. Accessed on: today’s date.

Posted on

Effective community co-creation approaches for livestock manure management

Due to a technical glitch, we did not get this presentation recorded. Please accept our apologies.

Purpose

Climate solutions are often talked about in a vacuum and conversation participants can sometimes overlook unintended consequences upon local environment and health. Solutions to mitigate methane from livestock agriculture are no exception to these climate discussions, and can impact other potential pollutants including ammonia, nitrous oxide, and odors. Moreover, it can be a particularly difficult space to work in climate and environmental justice, as many different communities are seemingly villainized and pit against each other, which make climate solutions even harder to implement.

What Did We Do?

Environmental Defense Fund is in the midst of an ongoing pilot project to engage communities in workshops around solutions regarding manure management. The goal of these workshops is to demonstrate best practices for effective collaboration and solution co-creation between farmers/producers and communities that can then be taken to local policymakers and stakeholders to implement. In this way, we can co-create solutions that align with community concerns, climate change mitigation, and feasibility for farmers.

What Have We Learned?

Community co-creation is possible, and even stakeholders who may seem hyper-polarized can still sit together at the same table to work together with ample time, transparency, and trust. Policy implications are enormous here and this session will discuss learnings we have regarding common misconceptions and myths around working with different affected stakeholders, as well as necessary guardrails surrounding commonly discussed methane mitigation technologies.

Future Plans

We will continue to work with the affected communities, including community groups and producer groups, to find common ground, with the hope of making these processes shareable across the country.

Authors

Presenting & corresponding author

Mindi W. DePaola; Senior Manager, Community and Equity, Ag Methane; Environmental Defense Fund, mdepaola@edf.org

Acknowledgements

We’d like to thank groups who have continued to give us time, as time is the biggest resource. These groups include White Earth Nation, EJCAN, Leadership Counsel for Environmental Justice, and MN Milk. NOTE: these are not necessarily official partners but again, want to acknowledge their time spent meeting with EDF.

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2025. Title of presentation. Waste to Worth. Boise, ID. April 7–11, 2025. URL of this page. Accessed on: today’s date.

Posted on

Advanced Multi-Stage Wastewater Treatment for Sustainable Dairy Farm Management

Purpose

Dairy farms employing flushing systems often encounter significant challenges in managing substantial volumes of recycled water, which can have environmental, economic, and operational implications. This study aims to evaluate a multi-stage process designed to improve solid/nutrient extraction from flushed water already treated by a pull-plug sediment basin system.

What Did We Do?

We implemented a three-stage sequential treatment process comprising coagulation, Fenton oxidation, and membrane filtration. In the first stage, coagulation was performed using aluminum sulfate (Al₂(SO₄)₃) to remove colloidal solids from the treated barn flushing water. The optimal alum dosage (500–7,000 mg/L) was determined based on turbidity, total solids, and chemical oxygen demand (COD) removal.

The second stage involved Fenton oxidation, where hydroxyl radicals generated from hydrogen peroxide (H₂O₂) and an iron catalyst (Fe²⁺) further degraded organic pollutants. Utilizing response surface methodology (RSM), we optimized the concentrations of H₂O₂ (500–1,800 mg/L), FeCl₃ (250–950 mg/L), and reaction time (15–50 min) to achieve a balance between treatment effectiveness and cost efficiency.

In the final stage, ultrafiltration and reverse osmosis were employed to remove dissolved ions, ensuring compliance with discharge standards.

What Have We Learned?

Fig. 1. Removals of turbidity (a), total solid (b), COD (c), and impacts on pH (d) at various alum treatment concentrations.
Fig. 1. Removals of turbidity (a), total solid (b), COD (c), and impacts on pH (d) at various alum treatment concentrations.

The results indicated that turbidity removal peaked at a dosage of 5,000 mg/L of Al₂(SO₄)₃, while total solids and COD removal stabilized at 4,000 and 5,000 mg/L, respectively. Although turbidity initially increased following the coagulant addition, the formation of aluminum hydroxide flocs facilitated effective pollutant removal. To balance reagent costs and treatment efficiency, a dosage of 4,000 mg/L alum was selected. After coagulation, the coagulated supernatant underwent fenton oxidation.

 

Turbidity removal (%)

Fig. 2. The removal of turbidity (%) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).
Fig. 2. The removal of turbidity (%) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).

Response surface analysis confirmed that optimal turbidity removal was achieved with H₂O₂ concentrations of 1,280-1,800 mg/L and FeCl₃ concentrations of 550-950 mg/L. Furthermore, a minimum mixing of 36 minutes was necessary to attain maximum efficiency.

Total solid removal (%)

Fig. 3. The removal of total solid (%) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).
Fig. 3. The removal of total solid (%) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).

For total solids removal, effective interaction was observed at H₂O₂ levels of 500–1,240 mg/L and FeCl₃ concentrations of 250–450 mg/L. Mixing times exceeding 43 minutes were found to reduce removal efficiency.

COD removal (%)

Fig. 4. The removal of COD (%) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).
Fig. 4. The removal of COD (%) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).

COD removal was most effective within the H₂O₂ range of 500–760 mg/L and FeCl₃ concentrations of 450–950 mg/L, while mixing time had minimal impact.

Cost ($)

Fig. 5. The treatment cost ($) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).
Fig. 5. The treatment cost ($) at the interactions between H2O2 and FeCl3 (a), between H2O2 and time (b), and between FeCl3 and time (c).

Regarding treatment cost, H₂O₂ was identified as the most influential cost factor due to its higher price. To balance removal efficiency and cost, the optimized conditions were determined as 563.3 mg/L H₂O₂, 568.4 mg/L FeCl₃, and a 33-minute reaction time, according to the calculations of RSM model. This setup achieved 86.4% turbidity removal, 18.7% total solids removal, and 81.5% COD removal at a treatment cost of $0.03 per liter of wastewater.

Future Plans

The next phase of the study will focus on membrane filtration experiments to further remove dissolved ions and ensure compliance with discharge standards. Additionally, a systematic economic analysis will assess cost-effectiveness, scalability, and operational feasibility for large-scale dairy farm applications.

Authors

Presenting author

Moh Moh Thant Zin, Post-doctoral researcher, University of Missouri-Columbia

Corresponding author

Teng-Teeh Lim, Extension Professor, University of Missouri-Columbia, limt@missouri.edu

Acknowledgements

Funding is provided by USDA-NIFA, grant award (2018-68011-28691) and University of Missouri Extension.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2025. Title of presentation. Waste to Worth. Boise, ID. April 7-11, 2025. URL of this page. Accessed on: today’s date.

Posted on

Application of Sonar Depth Finder in Lagoon Sludge Survey

Purpose

Regular monitoring of lagoon depths is crucial for effective manure management and environmental compliance. Traditional methods, using a disc on a rope or a marked stick from a boat can be time-consuming and pose safety risks, especially in larger or deeper lagoons. This study aimed to determine the feasibility of using low-cost sonar depth finders for lagoon sludge measurement.

What Did We Do?

Depth measurements were conducted by using sonar devices and compared with traditional methods at a 2.5-acre dairy lagoon that received effluent from a pull-plug sediment basin. The sonar devices, along with a cell phone (data logger) were mounted on an air-filled float and dragged across lagoon surface, enabling measurements without the need for a boat.

Fig. 1. Lagoon depth measurement was conducted using a small kayak (left); practical and simple lagoon depth measurement by dragging air-filled float with sonar ball and cellphone (as data logger) across lagoon surface (right).
Fig. 1. Lagoon depth measurement was conducted using a small kayak (left); practical and simple lagoon depth measurement by dragging air-filled float with sonar ball and cellphone (as data logger) across lagoon surface (right).
Fig. 2. Field measurement points on the lagoon surface for the liquid depth measurement using disc on a rope and a sonar ball sensor. The white dots are measurement points to compare sonar ball method and disc on a rope method, the blue lines were measurement paths dragging a small air-filled float carrying sonar ball
Fig. 2. Field measurement points on the lagoon surface for the liquid depth measurement using disc on a rope and a sonar ball sensor. The white dots are measurement points to compare sonar ball method and disc on a rope method, the blue lines were measurement paths dragging a small air-filled float carrying sonar ball

What Have We Learned?

Fig. 3. Liquid depth measurement devices applied: disk on a rope (left), wood stick with depth markings (middle), and two types of commercial sonar balls (right).
Fig. 3. Liquid depth measurement devices applied: disk on a rope (left), wood stick with depth markings (middle), and two types of commercial sonar balls (right).
Fig. 4. Comparison of depth measurements using different measurement methods.
Fig. 4. Comparison of depth measurements using different measurement methods.

The disc on a rope (standard) and wood stick method resulted in similar values. Meanwhile, the sonar balls tend to slightly underestimate depth, with a margin of error below 15%, while the errors were higher for very shallow areas.

Fig. 5. Linear regression of depths, comparing the Deeper Sonar PRO+ and Deeper Fishfinder START, with disc on a rope values.
Fig. 5. Linear regression of depths, comparing the Deeper Sonar PRO+ and Deeper Fishfinder START, with disc on a rope values.

Linear regression models revealed strong correlations between sonar readings and the disc-on-a-rope method, with R² values of 0.899 for the PRO+ model, and 0.9377 for the START model. Applying a correction model to the sonar data could further enhance the measurement accuracy. This study demonstrated that integrating sonar measurements with periodic sludge sampling provides a practical, safe, and reliable approach to improving lagoon management.

Authors

Presenting author

Moh Moh Thant Zin, Post-doctoral researcher, University of Missouri-Columbia

Corresponding author

Teng-Teeh Lim, Extension Professor, University of Missouri-Columbia, limt@missouri.edu

Additional author(s)

Zonggang Li, Gilbert Mitto, Manobendro Sarker, Rana Das, Cuong Duong, University of Missouri-Columbia.

Acknowledgements

This research was supported by USDA-NIFA, grant award (# 2018-68011-28691), and University of Missouri Extension.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2025. Title of presentation. Waste to Worth. Boise, ID. April 7–11, 2025. URL of this page. Accessed on: today’s date.

Posted on

Application of Manure on Growing Crops

Scheduling conflicts, equipment breakdowns, and wet field conditions can wreak havoc on spring manure application and planting schedules. This webinar will provide valuable insights into maximizing the efficiency and timing of manure application for growing crops, especially corn. By exploring innovative techniques for liquid manure application and the potential for in-season poultry litter application, participants will learn possible ways to navigate challenges in crop management while ensuring nutrient efficiency and maintaining crop yield and quality. This presentation was originally broadcast on January 17, 2025. Continue reading “Application of Manure on Growing Crops”

Posted on

Engaging Farm Safety and Manure Management: Innovative Teaching Methods in Action

The agricultural industry consistently has the highest risk for occupational injuries and fatalities.  This session will share some proven techniques for making changes to farm safety practices and manure management that could positively impact generations to come.  We will explore dynamic and interactive teaching methodologies that could be adapted for use in at your facility and in your training programs.  These methods employ activity-based learning, where participants have the opportunity to learn, apply and discuss real-world scenarios in a safe environment. This presentation was originally broadcast on November 22, 2024. Continue reading “Engaging Farm Safety and Manure Management: Innovative Teaching Methods in Action”

Posted on

Managing Dairy Manure for Increased Soil Health and Forage Production Sustainability

Manure is a valuable source of crop-essential nutrients that, when managed carefully, can help build soil organic matter, enhance nutrient cycling, and improve overall soil health and climate resilience over time. In 2022, a statewide on-farm research project was initiated in New York State to quantify the nitrogen (N) replacement value, corn silage or grain yield, and soil health enhancements of various manure sources. Between 2022 and 2023, eleven on-farm field trials were implemented. Yield data are being used to quantify differences in most economic N rate between manured and non-manured strips, and to quantify the yield impact of the manure applications. In 2024, eight additional trials were added using various manure sources. Results so far indicate that manure can offset N fertilizer needs and increase corn silage yield beyond its nutrient contributions, but impacts are field-specific, reflecting differences in field histories and growing conditions. Assessments of soil microbial biomass for sites in 2023 and 2024 reflected the manure history for trial locations and suggest that mid-season assessments may help identify where nitrogen fertilizer addition is beneficial for the crop and where not. Assessment of variability of different manure sources point to the importance of manure sampling and analyses. Preliminary results will be shared. This presentation was originally broadcast on October 18, 2024. Continue reading “Managing Dairy Manure for Increased Soil Health and Forage Production Sustainability”

Posted on

The Role of Agriculture in Atmospheric Nitrogen Deposition: Sources, Impacts, and Management

Agriculture is the largest source of ammonia emissions and contributes to nitrogen deposition which can impact ecosystem health. This webinar introduces the topic of nitrogen deposition and provides an overview of the role of the National Atmospheric Deposition Program (NADP) in determining nitrogen deposition sources. In addition, the speakers provide an overview of a region being impacted by agriculture related nitrogen deposition and discusses agricultural management practices that may reduce ammonia emissions and nitrogen deposition. This presentation was originally broadcast on September 20, 2024. Continue reading “The Role of Agriculture in Atmospheric Nitrogen Deposition: Sources, Impacts, and Management”

Posted on

Staying in the Loop: Circularity in Integrated Crop and Livestock Production

Have you heard or read about circularity and the circular economy? These buzzwords describe sustainability concepts that are being adopted in many sectors, including food animal production. This webinar shares definitions for these concepts and how they can inform thinking about changes to animal systems and manure management. This presentation was originally broadcast on June 21, 2024. Continue reading “Staying in the Loop: Circularity in Integrated Crop and Livestock Production”