Impact of swine manure on soil health properties: A systematic review

Purpose

As the campaign to improve agricultural soil health has gained momentum among conservationists and researchers worldwide, a comprehensive assemblage of outcomes from manure and soil health-related research studies is important. Particularly, the identification of knowledge gaps is an important step to direct future research that informs soil health improvement outreach programs. A thorough review of data reporting the effects of swine manure on soil health properties that is applicable to agricultural producers is lacking. Although previous research studies have looked at the effects of manure on individual soil properties, there are conflicting conclusions. Livestock manure literature reviews fail to consider inconsistent methodologies between individual research studies and whether research is applicable to producers utilizing manure as amendments to improve soil health, and none of the reviews focus on swine manure or swine manure by-products. The objectives of this review were (a) to synthesize literature describing effects of swine manure on soil properties that affect soil health and (b) to identify knowledge gaps and research needs to further our understanding of this topic.

What Did We Do?

We conducted a systematic literature review based on peer-reviewed studies that evaluated the effect of swine manure on soil health properties. First, we identified studies using three criteria: species (swine, pig, hog), manure source (i.e., solid [SM] or liquid manure [LSM], compost, deep pack), and soil property (i.e., soil organic carbon [SOC], total nitrogen, soil pH, bulk density, available water capacity). Second, studies had to meet the following criteria in order to be included: (a) the studies were replicated field experiments, (b) manure was the only differing factor between or among treatments, and (c) data means of organically amended treatments and controls were included. In total, 40 peer-reviewed studies were included in this review.

What Have We Learned?

Recycling of manure locally prior to importing inorganic fertilizer (IF) has the potential to reduce nutrient imbalances and improve soil health. Based on this review, swine manure has the potential to add significant amounts of organic carbon to the soil and to improve soil health metrics. In general, the application of swine manure increases soil organic matter (SOM) and SOC, decreases soil bulk density, and increases microbial biomass carbon Soil organic carbon and total N tended to be highest when manure and inorganic fertilizer were applied to the field (Figure 1). Soil chemical properties did not seem to change much when manure was applied to the soil surface or incorporated into the topsoil. The duration of swine manure application (annually) did not seem to increase the percent change in most chemical properties; however, this could be due to a lack of data. The percent change in SOC did increase when the swine manure was applied for a longer time period (Figure 1), and we would expect to see a similar trend with SOM and total carbon if there were more data. Few articles had data on soil physical and biological properties. Depending on soil type, swine manure has the potential to increase available water holding capacity and saturated hydraulic conductivity. Although more research is needed, it can be inferred that swine manure additions increase microbial activity, which promotes healthier soils and better crop yields.

Figure 1: Average percent change in soil organic carbon (SOC) and total nitrogen (TN) based on amendment type, application method, soil texture, and duration of swine manure application. Black circles represent outlier data, and diamonds represent mean. IF = inorganic fertilizer; LSM = liquid swine manure; M + IF = manure (liquid and solid) plus inorganic fertilizer; SM = solid swine manure

Future Plans

Previous literature reviews failed to account for differences in methodologies between individual research studies and whether research is applicable to producers utilizing swine manure as amendments to improve soil health (i.e., unreasonable application rates of swine manure, overapplication of nutrients). The evaluation of the effect of swine manure on soil health properties is difficult to do based on current literature because (a) there are few comprehensive studies (i.e., only one study reported properties from chemical, physical, and biological categories) and (b) there are non-consistent research methodologies between studies. Therefore, we recommend redirecting research studies to demonstrate the value of manure to the suitability of agricultural cropping systems. Future swine manure research should include (a) a range of soil physical, chemical, and biological properties, (b) initial soil data prior to manure application, and (c) manure type, application method, application rate, total carbon and nitrogen of the manure, duration of swine manure application, and swine manure application timing. In addition, future research should also focus on the short- and long-term effects of a single application of manure to support an effort to identify optimal frequency of application for improving soil health. More research is also needed to compare the effects of manure and inorganic fertilizer additions on crop yield and soil health by balancing nitrogen, phosphorus, and potassium additions.

Authors

Jenifer L. Yost, Research Soil Scientist, USDA-ARS

Corresponding author email address

jenifer.yost@usda.gov

Additional authors

Amy M. Schmidt, Livestock Manure Management Engineer, University of Nebraska-Lincoln; Rick Koelsch, Livestock and Bio Environmental Engineer, University of Nebraska-Lincoln; Kevin Kruger, Research Support Scientist, University of Idaho; Linda R. Schott, Nutrient and Waste Management Extension Specialist, University of Idaho

Additional Information

For more information about this project, please check out our Open Access journal article. The citation for the journal article is:

Yost, J.L., Schmidt, A.M., Koelsch, R., and Schott, L.R. (2022). Effect of swine manure on soil health properties: A systematic review. Soil Science Society of America Journal.

https://doi.org/10.1002/saj2.20359

This research was presented at the ASA, CSSA, SSSA International Annual Meeting in Salt Lake City, Utah, in November of 2021. The link to the recorded presentation is found in the citation below:

Yost, J. L., Schmidt, A. M., Koelsch, R., & Schott, L. R. (2021). Impact of Swine Manure on Soil Health Properties: A Systematic Review [Abstract]. ASA, CSSA, SSSA International Annual Meeting, Salt Lake City, UT. https://scisoc.confex.com/scisoc/2021am/meetingapp.cgi/Paper/138180

Acknowledgements

This project was supported by funding from the National Pork Checkoff. The authors would also like to thank Meg Clancy and Drew Weaver for their assistance.

 

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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

The MAnure PHosphorus EXtraction (MAPHEX) System for Removing Phosphorus, Odor, Microbes, and Alkalinity from Dairy and Swine Manures

Abstract

Animal manures contain nutrients [primarily nitrogen (N) and phosphorus (P)] and organic material that are beneficial to crops. Unfortunately, for economic and logistics reasons, liquid dairy and swine manure tends to be applied to soils near where it is generated. Over time, P concentrations in soils where dairy manure is applied builds up, often in excess of crop demands. We previously (Church et al., 2016, 2017) and have subsequently built, a full-scale version of a MAnure PHosphorus EXtraction (MAPHEX) System capable of removing greater than 90 percent of the P from manures. While originally designed to remove phosphorus, we have also shown that the MAPHEX System was also capable of removing odor and microbes, and of concentrating alkalinity into a solid, economically transported form. We have also lowered daily operating costs by testing the effect of lower-cost chemicals as alternatives to ferric sulfate, and by showing that the diatomaceous earth (DE) filtering material can be recycled and reused. We are currently building a system capable of treating over 100,000 gallons of Dairy Manure per day. This system is planned to be operational for demonstrating starting summer 2022.

Purpose

Swine and dairy manures are typically in slurry form and contain nutrients [primarily nitrogen (N) and phosphorus (P)] and organic material that are beneficial to crops. Unfortunately, the concentrations of nutrients in both manures are too low to make transportation of bulk manures over large distances economically viable. Furthermore, since it must be transported in tanks, that transportation is inconvenient as well. Therefore, these manures tend to be applied to soils near where they are generated, and, over time, P concentrations in soils increase to the point that soil P concentrations are often in excess of crop demands. Furthermore, because of the implication that P runoff from agricultural operations plays an important role in eutrophication of streams and other water bodies, farmers are experiencing increasing pressures and regulation to not apply animal manures to those soils.

We previously reported on an invention that 1) is designed to be a solution to the P overloading that happens when unnecessary P is added to agricultural soils, 2) is scalable such that it can be used as a mobile system, and 3) has shown to be capable of removing greater than 90 percent of the P from a wide range of dairy manures, while retaining greater than 90% of the N in the final effluent for beneficial use by the farmer.

What Did We Do?

We subsequently built a full-scale version of a MAnure PHosphorus EXtraction (MAPHEX) System capable of removing greater than 90 percent of the P from manures and have tested it on dairy manures. We also focused our efforts on lowering the daily operating costs of the system by developing a method to recover and reuse the diatomaceous earth used in the final filtration step, and testing alternative, lower cost chemicals that can be used in the chemical treatment step. We also performed pilot-scale tests on swine manures.

What Have We Learned?

The full-scale MAPHEX System removed greater than 90% of P from a wide variety of dairy manures, while leaving greater than 90% of the N in the final effluent to be used beneficially to fertigate crops. The System was also shown to recover and concentrate alkalinity into a solid form on a farm that used greater amounts of lime during manure handling, remove 50% of the odor from dairy manure and to remove greater than 80% of Total coliforms and E. Coli. Furthermore, the System has not shown to alter the pH of the final effluent respective to raw manures as other treatment technologies can. We have lowered daily operating costs by testing the effect of lower-cost chemicals as alternatives to ferric sulfate, and by showing that the diatomaceous earth (DE) filtering material can be recycled and reused.

In pilot-scale swine testing, we found that the MAPHEX System can remove greater than 96% of the phosphorus in swine manures. This essentially P free effluent can be beneficially used for fertigation without further loading the receiving soils with P. Scaling up the pilot-scale testing has the potential to reduce swine manure storage volumes to allow for mitigation of overflow problems during large storms. Furthermore, the pilot-scale study suggests that capital equipment costs and treatment costs for swine manure would be lower than for treating dairy manure.

Future Plans

We are currently building a simplified version of the MAPHEX System that will be capable of treating over 100,000 gallons of dairy manure per day. This system is planned to be operational for demonstrating starting summer 2022. We plan to use this simplified version for demonstration tests, and use the results obtained to model the effects of using MAPHEX technology compared to conventional manure handling practices on two paired watersheds. We also plan to demonstrate the full-scale system on a wide range of swine manures with on-farm testing.

Author

Clinton D. Church, Research Chemist, USDA-ARS University Park, PA

Corresponding author email address

Cdchurch.h2o@netzero.com

Additional Information

Church, C. D., Hristov, A. N., Bryant, R. B., Kleinman, P. J. A., & Fishel, S. K. (2016). A novel treatment system to remove phosphorus from liquid manure. Applied Engineering in Agriculture, 32: 103 – 112. doi:10.13031/aea.32.10999

Church, C. D., Hristov, A. N., Bryant, R. B., & Kleinman, P. J. A. (2017). Processes and treatment systems for treating high phosphorus containing fluids. US Patent 9,790.110B2.

Church, C. D., Hristov, A. N., Kleinman, P. J. A., Fishel, S. K., Reiner, M. R., & Bryant, R. B. (2018). Versatility of the MAPHEX System in removing phosphorus, odor, microbes, and alkalinity from dairy manures: A four-farm case study. Applied Engineering in Agriculture, 34: 567 – 572. doi:10.13031/aea12632

Church, C. D., Hristov, A., Bryant, R. B., & Kleinman, P. J. A. (2019). Methods for Rejuvenation and Recovery of Filtration Media. USDA Docket Number 129.17. U.S. Patent Application Serial No. 62/548,23

Church, C. D., S. K. Fishel, M. R. Reiner, P. J. A. Kleinman, A. N. Hristov, and R. B. Bryant. 2020. Pilot scale investigation of phosphorus removal from swine manure by the MAnure PHosphorus Extraction (MAPHEX) System. Applied Engineering in Agriculture 36(4): 525–531. doi: 10.13031/aea13698

https://www.ars.usda.gov/people-locations/person/?person-id=40912

https://tellus.ars.usda.gov/stories/articles/mining-manure-for-phosphorus/

https://agresearchmag.ars.usda.gov/2016/dec/phosphorus/

https://jofnm.com/article-112-Packaging-phosphorus-for-the-future.html

https://lpelc.org/versatility-of-the-manure-phosphorus-extraction-maphex-system-in-removing-phosphorus-odor-microbes-and-alkalinity-from-dairy-manures/

 

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. 2022. Title of presentation. Waste to Worth. Oregon, OH. April 18-22, 2022. URL of this page. Accessed on: today’s date.

Industry Initiatives for Environmental Sustainability – a Role for Everyone

This webinar introduces current and future industry-based initiatives for environmental sustainability in the livestock and poultry sector, and how Livestock and Poultry Environmental Learning Community learners can play a critical role in their region. This presentation was originally broadcast on September 17, 2021. Continue reading “Industry Initiatives for Environmental Sustainability – a Role for Everyone”

Evaluation of current products for use in deep pit swine manure storage structures for mitigation of odors and reduction of NH3, H2S, and VOC emissions from stored swine manure

The main purpose of this research project is an evaluation of the current products available in the open marketplace for using in deep pit swine manure structure as to their effectiveness in mitigation of odors and reduction of hydrogen sulfide (H2S), ammonia (NH3), 11 odorous volatile organic compounds (VOCs) and greenhouse gas (CO2, methane and nitrous oxide) emissions from stored swine manure. At the end of each trial, hydrogen sulfide and ammonia concentrations are measured during and immediately after the manure agitation process to simulate pump-out conditions. In addition, pit manure additives are tested for their impact on manure properties including solids content and microbial community.

What Did We Do?

Figure 1. Reactor simulates swine manure storage with controlled air flow rates.

We are using 15 reactors simulating swine manure storage (Figure 1) filled with fresh swine manure (outsourced from 3 different farms) to test simultaneously four manure additive products using manufacturer recommended dose for each product. Each product is tested in 3 identical dosages and storage conditions. The testing period starts on Day 0 (application of product following the recommended dosage by manufacturer) with weekly additions of manure from the same type of farm. The headspace ventilation of manure storage is identical and controlled to match pit manure storage conditions. Gas and odor samples from manure headspace are collected weekly. Hydrogen sulfide and ammonia concentrations are measured in real time with portable meters (both are calibrated with high precision standard gases). Headspace samples for greenhouse gases are collected with a syringe and vials, and analyzed with a gas chromatograph calibrated for CO2, methane and nitrous oxide. Volatile organic compounds are collected with solid-phase microextraction probes and analyzed with a gas chromatography-mass spectrometry (Atmospheric Environment 150 (2017) 313-321). Odor samples are collected in 10 L Tedlar bags and analyzed using the olfactometer with triangular forced-choice method (Chemosphere, 221 (2019) 787-783). To agitate the manure for pump-out simulation, top and bottom ‘Manure Sampling Ports’ (Figure 1) are connected to a liquid pump and cycling for 5 min. Manure samples are collected at the start and end of the trial and are analyzed for nitrogen content and bacterial populations.

The effectiveness of the product efficacy to mitigate emissions is estimated by comparing gas and odor emissions from the treated and untreated manure (control). The mixed linear model is used to analyze the data for statistical significance.

What we have learned?

Figure 2. Hydrogen sulfide and ammonia concentration increased greatly during agitation process conducted at the end of trial to simulate manure pump-out conditions and assess the instantaneous release of gases. The shade area is the initial 5 minutes of continuous manure agitation.

U.S. pork industry will have science-based, objectively tested information on odor and gas mitigation products. The industry does not need to waste precious resources on products with unproven or questionable performance record. This work addresses the question of odor emissions holistically by focusing on what changes that are occurring over time in the odor/odorants being emitted and how does the tested additive alter manure properties including the microbial community. Additionally, we tested the hydrogen sulfide and ammonia emissions during the agitation process simulating pump-out conditions. For both gases, the emissions increased significantly as shown in Figure 2. The Midwest is an ideal location for swine production facilities as the large expanse of crop production requires large fertilizer inputs, which allows manure to be valued as a fertilizer and recycled and used to support crop production.

Future Plans

We develop and test sustainable technologies for mitigation of odor and gaseous emissions from livestock operations. This involves lab-, pilot-, and farm-scale testing. We are pursuing advanced oxidation (UV light, ozone, plant-based peroxidase) and biochar-based technologies.

Authors

Baitong Chen, M.S. student, Iowa State University

Jacek A. Koziel*, Prof., Iowa State University (koziel@iastate.edu)

Daniel S. Andersen, Assoc. Prof., Iowa State University

David B. Parker, Ph.D., P.E., USDA-ARS-Bushland

Additional Information

  • Heber et al., Laboratory Testing of Commercial Manure Additives for Swine Odor Control. 2001.
  • Lemay, S., Stinson, R., Chenard, L., and Barber, M. Comparative Effectiveness of Five Manure Pit Additives. Prairie Swine Centre and the University of Saskatchewan.
  • 2017 update – Air Quality Laboratory & Olfactometry Laboratory Equipment – Koziel’s Lab. doi: 10.13140/RG.2.2.29681.99688.
  • Maurer, D., J.A. Koziel. 2019. On-farm pilot-scale testing of black ultraviolet light and photocatalytic coating for mitigation of odor, odorous VOCs, and greenhouse gases. Chemosphere, 221, 778-784; doi: 10.1016/j.chemosphere.2019.01.086.
  • Maurer, D.L, A. Bragdon, B. Short, H.K. Ahn, J.A. Koziel. 2018. Improving environmental odor measurements: comparison of lab-based standard method and portable odour measurement technology. Archives of Environmental Protection, 44(2), 100-107.  doi: 10.24425/119699.
  • Maurer, D., J.A. Koziel, K. Bruning, D.B. Parker. 2017. Farm-scale testing of soybean peroxidase and calcium peroxide for surficial swine manure treatment and mitigation of odorous VOCs, ammonia, hydrogen sulfide emissions. Atmospheric Environment, 166, 467-478. doi: 10.​1016/​j.​atmosenv.​2017.​07.​048.
  • Maurer, D., J.A. Koziel, J.D. Harmon, S.J. Hoff, A.M. Rieck-Hinz, D.S Andersen. 2016. Summary of performance data for technologies to control gaseous, odor, and particulate emissions from livestock operations: Air Management Practices Assessment Tool (AMPAT). Data in Brief, 7, 1413-1429. doi: 10.1016/j.dib.2016.03.070.

Acknowledgments

We are thankful to (1) National Pork Board and Indiana Pork for funding this project (NBP-17-158), (2) cooperating farms for donating swine manure and (3) manufacturers for providing products for testing. We are also thankful to coworkers in Dr. Koziel’s Olfactometry Laboratory and Air Quality Laboratory, especially Dr. Chumki Banik, Hantian Ma, Zhanibek Meiirkhanuly, Lizbeth Plaza-Torres, Jisoo Wi, Myeongseong Lee, Lance Bormann, and Prof. Andrzej Bialowiec.

 

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. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

 

Sidedressing Corn: Swine Manure via Dragline Hose Produces Yields Comparable to Synthetic Fertilizer

Spring in the upper Midwest can be short, resulting in challenges for producers to apply manure and plant crops in a timely manner to maximize yield. This results in a significant       amount of manure applied in the fall after the crop is harvested. Fall applied manure has ample time to mineralize and leave the root zone before next season’s crop can utilize the nutrients. These nutrients can end up in rivers and other freshwater bodies decreasing water quality. Sidedressing manure in growing crops could provide producers with another window of opportunity to apply their manure, maximize nutrient uptake efficiency, and protect water quality. The summer of 2018 was the start of a two-year, on-farm study researching the effectiveness of sidedressing slurry swine manure to corn via dragline hose. The swine manure was compared to sidedressed anhydrous ammonia, 32% urea ammonium nitrate (UAN), and a  control that received no additional nitrogen at the time of sidedressing.

What we did

Corn was planted May 7th with a 12-row planter equipped to apply an in-furrow and top dressed liquid fertilizer. The total fertilizer applied at planting was 40.7 lbs of nitrogen (N), 19.8 lbs of P2O5 phosphorus (P), and 14.4 lbs of sulfur (S) per acre.

Sidedressing the nitrogen sources

We sidedressed all treatments on June 4-5 with 140 pounds of available N, except the control which had no additional N applied. All the equipment applied nutrients between 30-inch rows and fit a 12-row planter to match up on odd rows.

  • Anhydrous ammonia treatment = 12-row toolbar and tractor were supplied by the farmer.
  • Finishing hog manure dragline hose treatment = The toolbar for the dragline hose sidedress was supplied by Bazooka Farmstar. The toolbar is a coulter till 28-foot bar with 30-inch spacing.
  • UAN treatment = The tool bar for the UAN sidedress application was provided by a local farmer.
  • Control treatment = The control treatment did not receive any fertilizer at sidedress.
Swine manure slurry being applied via dragline hose and Bazooka Farmstar sidedress bar.
Swine manure slurry being applied via dragline hose and Bazooka Farmstar sidedress bar.

Soil data collection methods

Soil nitrate and ammonium samples were taken 5 times through the growing season, approximately every 4 weeks, to track nitrogen in the soil profile. Soil sample depths were 0-6, 6-12, and 12-24 inches from the soil surface. Soil

Two foot soil sampling with tractor probe.
Two foot soil sampling with tractor probe.

samples were taken from the middle of the interrow, 7.5 inches from both sides of the middle of the inter row and in the middle of the row. This sample method assured soil samples would be representative of the soil profile since banded fertilizer can skew results.

Yield data collection methods

Yield was harvested October 6th by a combine with a 6-row head. The combine took the middle 12 rows of the 24-row treatment reducing the side effects from neighboring treatments. A calibrated weigh wagon measured the weight of each combine pass which was calculated to find yield in bushels per acre for every sample.

What we have learned

First year data revealed all sidedressed nitrogen sources significantly increased corn yields over the control but were otherwise statistically similar (Figure 1).

Figure 1. Yield data from 2018 manure sidedress trial in bushels per acre. AA=anhydrous ammonia, UAN=urea ammonium nitrate, Control=received no additional N at sidedress, and Dragline=swine manure slurry applied via dragline hose.
Figure 1. Yield data from 2018 manure sidedress trial in bushels per acre. AA=anhydrous ammonia, UAN=urea ammonium nitrate, Control=received no additional N at sidedress, and Dragline=swine manure slurry applied via dragline hose.

When we analyzed the soil inorganic nitrogen by each date differently, nitrogen concentrations between treatments were only statistically different on the soil sample date of June 15th (Figure 2) This soil sample date was ten days after the sidedress application on June 4th.  All other soil nitrogen sample dates are not statistically different between treatments and even the control.  

Figure 2. Total soil inorganic N (ammonium and nitrate) by treatment and sample date.
Figure 2. Total soil inorganic N (ammonium and nitrate) by treatment and sample date.

Statistics have not yet been run on the whole plant nitrogen content data in the graph below but numerically there doesn’t seem to be a difference in nitrogen content between the three sidedress treatments but a difference from the control (Figure 3).

Figure 3. Percent nitrogen in harvest grain, R6 cobbs, and R6 stover between treatments.
Figure 3. Percent nitrogen in harvest grain, R6 cobbs, and R6 stover between treatments.

Future plans

The first year of data was collected during the 2018 growing season and a second year of data will be collected in the summer of 2019. This study aims to evaluate the effectiveness of sidedressed swine manure slurry compared to traditionally used synthetic fertilizers. Since we have seen promising results this first year an additional study that could follow this experiment would be a direct comparison of fall applied swine manure and sidedressed swine manure. This information would help us understand the efficiency of sidedressing compared to fall application. Soil samples from this study would also illustrate the difference in mineralization and nitrogen movement between fall-applied and sidedressed swine manure slurry.    

Authors

  • Chris Pfarr, M.S. student in the Land and Atmospheric Sciences Program, University of Minnesota, pfarr025@umn.edu
  • Melissa Wilson, Ph.D., Assistant Professor and Extension Specialist, Department of Soil, Water, and Climate, University of Minnesota, mlw@umn.edu

Additional information

Acknowledgements  

This project was partially funded by the Minnesota Soybean Research and Promotion Council and the Minnesota Pork Board.

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. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

Early Stage Economic Modeling of Gas-permeable Membrane Technology Applied to Swine Manure after Anaerobic Digestion

 

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Purpose

The objective of this study was to conduct cost versus design analysis for a gas-permeable membrane system using data from a small pilot scale experiment and projection of cost versus design to farm scale.

What did we do?

This reported work includes two major steps. First, the design of a small pilot scale batch gas-permeable membrane system was scaled to process effluent volumes from a commercial pig farm. The scaling design maintained critical process operating parameters of the experimental membrane system and introduced assumed features to characterize effluent flows from a working pig farm with an anaerobic digester. The scaled up design was characterized in a spreadsheet model. The second step was economic analysis of the scaled-up model of the membrane system. The objective of the economic analysis was to create information to guide subsequent experiments towards commercial development of the technology. The economic analysis was performed by introducing market prices for components, inputs, and products and then calculating effects on costs and on performance of changes in design parameters.

What have we learned?

First, baseline costs and revenues were calculated for the scaled up experimental design. The commercial scale design of a modular gas-permeable membrane system was modeled to treat 6 days accumulation of digester effluent at 16,300 gallons per day resulting in a batch capacity of 97,800 gallons. The modeled large scale system is 19,485 times the capacity of the 5.02 gallon experimental pilot system. The installation cost of the commercial scale system was estimated to be $903,333 for a system treating 97,800 gallon batches over a 6 day period.

At $1/linear ft. and 7.9 ft./gallon of batch capacity, membrane material makes up 86% of the estimated installation cost. Other installation costs include PVC pipes, pumps, aerators, tanks, and other parts and equipment used to assemble the system, as well as water to dilute the concentrated acid prior to initiating circulation. The annual operating cost of the system includes concentrated sulfuric acid consumed in the process. Using limited experimental data on this point, we assume a rate of 0.009 gallons (0.133 pounds) of acid per gallon of digester effluent treated. At a price of $1.11 per gallon ($0.073/lb) of acid, acid cost per gallon of effluent treated is $0.010. Other operating costs include electric power, labor, and repairs and maintenance of the membrane and other parts of the system estimated at 2% of investment cost for non-moving parts and 6% of investment for moving parts. Potential annual revenue from the system includes the value of ammonium sulfate produced. Over the 6 day treatment period, if 85% of the TAN-N in the digester effluent is removed by the process, and if 100% of the TAN-N removed is recovered as ammonium sulfate, and given the TAN-N concentration in digester effluent was 0.012 pounds per gallon (1401 mg/l), then 0.01 pounds of TAN-N are captured per gallon of effluent treated. At an ammonium sulfate fertilizer price of $588/ton or $0.294/pound and ammonium sulfate production of 0.047 pounds (0.01 pounds TAN-N equivalent), potential revenue is $0.014 per gallon of effluent treated. No price is attached here for the elimination of internal and external costs associated with potential release to the environment of 0.01 pounds TAN-N per gallon of digester effluent or 59,073 pounds TAN-N per year from the system modeled here.

Several findings and questions, reported here, are relevant to next steps in experimental evaluation and commercial development of this technology.

1. Membrane price and/or performance can be improved to substantially reduce installation cost. Membrane material makes up 86% of the current estimated installation cost. Each 10% reduction in the product of membrane price and length of membrane tube required per gallon capacity reduces estimated installation cost per gallon capacity by 8.6%.

2. The longevity and maintenance requirements of the membrane in this system were not examined in the experiment. Installation cost recovery per gallon of effluent decreases at a declining rate with longevity. For example, Cost Recovery Factors (percentage of initial investment charged as an annual cost) at 6% annual interest rate vary with economic life of the investment as follows: 1 year life CRF = 106%, 5 year life CRF = 24%, 10 year life CRF = 14% . Repair costs are often estimated as 2% of initial investment in non-moving parts. In the case of the membrane, annual repair and maintenance costs may increase with increased longevity. Longevity and maintenance requirements of membranes are important factors in determining total cost per gallon treated.

3. Based on experimental performance data (TAN removal in Table 1) and projected installation cost for various design treatment periods ( HRT = 2, 3, 4, 5, or 6 days), installation cost per unit mass of TAN removal decreases and then increases with the length of treatment period. The minimum occurs at HRT = 4 days when 68% reduction of TAN-N in the effluent has been achieved.

Table 1. Comparison of installation cost and days of treatment capacity

4. Cost of acid relative to TAN removal from the effluent and relative to fertilizer value of ammonium sulfate produced per gallon of effluent treated are important to operating cost of the membrane system. These coefficients were beyond the scope of the experiment although some pertinent data were generated. Questions are raised about the fate of acid in circulation. What fraction of acid remains in circulation after a batch is completed? What fraction of acid reacts with other constituents of the effluent to create other products in the circulating acid solution? What fraction of acid escapes through the membrane into the effluent? Increased efficiency of TAN removal from the effluent per unit of acid consumed will reduce the cost per unit TAN removed. Increased efficiency of converting acid to ammonium sulfate will reduce the net cost of acid per gallon treated.

5. Several operating parameters that remain to be explored affect costs and revenues per unit of effluent treated. Among those are parameters that potentially affect TAN movement through the membrane such as: a) pH of the effluent and pH of the acid solution in circulation, b) velocity of liquids on both sides of the membrane, and c) surface area of the membrane per volume of liquids; effluent and acid solution, in the reactor. Similarly, the most profitable or cost effective method of raising pH of the digester effluent remains to be determined, as it was beyond the scope of the current study. Aeration was used in this experiment and in the cost modeling. Aeration may or may not be the optimum method of raising pH and the optimum is contingent on relative prices of alternatives as well as their effect on overall system performance. Optimization of design to maximize profit or minimize cost requires knowledge of these performance response functions and associated cost functions.

6. Management of ammonium sulfate is a question to be addressed in future development of this technology. Questions that arise include: a) how does ammonium sulfate concentration in the acid solution affect rates of TAN removal and additional ammonia sulfate production, b) how can ammonium sulfate be removed from, or further concentrated in, the acid solution, c) can the acid solution containing ammonium sulfate be used without further modification and in which processes, d) what are possible uses for the acid solution after removal of ammonium sulfate, e) what are the possible uses for the effluent after removal of some TAN, and f) what are the costs and revenues associated with each of the alternatives. Answers to these questions are important to designing the membrane system and associated logistics and markets for used acid solution and ammonium sulfate. The realized value of ammonium sulfate and the cost (and revenue) of used acid solution are derived from optimization of this p art of the system.

7. LCA work on various configurations and operating parameters of the membrane system remains to be done. Concurrent with measurement of performance response functions for various parts of the membrane system, LCA work will quantify associated use of resources and emissions to the environment. Revenues may arise where external benefits are created and markets for those benefits exist. Where revenues are not available, marginal costs per unit of emission reduction or resource extraction reduction can be calculated to enable optimization of design across both profit and external factors.

Future Plans

A series of subsequent experiments and analyses are suggested in the previous section. Suggested work is aimed at improving knowledge of performance response to marginal changes in operating parameters and improving knowledge of the performance of various membranes. Profit maximization, cost minimization, and design optimization across both financial and external criteria require knowledge of performance response functions over a substantial number of variables. The economic analysis presented here addresses the challenge of projecting commercial scale costs and returns with data from an early stage experimental small pilot; and illustrates use of such preliminary costs and returns projections to inform subsequent experimentation and development of the technology. We will continue to refine this economic approach and describe it in future publications.

Corresponding author, title, and affiliation

Kelly Zering, Professor, Agricultural and Resource Economics, North Carolina State University

Corresponding author email

kzering@ncsu.edu

Other authors

Yijia Zhao, Graduate Student at BAE, NCSU; Shannon Banner, Graduate Student at BAE, NCSU; Mark Rice, Extension Specialist at BAE, NCSU; John Classen, Associate Professor and Director of Graduate Programs at BAE, NCSU

Acknowledgements

This project was supported by NRCS CIG Award 69-3A75-12-183.

Talking Climate with Animal Agriculture Advisers


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Purpose             

The Animal Agriculture in a Changing Climate (AACC) project was established to leverage limited Extension expertise across the country in climate change mitigation and adaptation, with the goal of building capacity among Extension professionals and other livestock advisers to address climate change issues.

What did we do? 

The Animal Agriculture in a Changing Climate project team created a suite of educational programs and products to build capacity across the United States. Key products of the project:

  • Online courses: 363 participants registered with a 35% completion rate (Whitefield et al., JOE, 2016)
  • National and regional symposia and workshops: 11 face-to-face conferences with approximately 1,350 attendees.
  • Website: Over 5,900 users with over 21,100 total views. Project videos have received nearly 8,900 views.
  • Social media: AACC weekly blog (990 subscribers); daily Southeast Climate Blog (38,506 site visits); regional newsletters (627 subscribers); Facebook & Twitter (280 followers)
  • Ready-to-use videos, slide sets, and fact sheets
  • Educational programming: 390 presentations at local, regional, and international meetings
  • Collaboration with 14 related research and education projects

What have we learned? 

A survey was sent out to participants in any of the project efforts, in the third year of the project and again in year five. Overall, participants found the project resources valuable, particularly the project website, the online course, and regional meetings. We surveyed two key measures: abilities and motivations. Overall, 60% or more of respondents report being able or very able to address all eight capabilities after their participation in the AACC program. A sizeable increase in respondent motivation (motivated or very motivated) existed after participation in the program, particularly for helping producers take steps to address climate change, informing others about greenhouse gases emitted by agriculture, answering client questions, and adding new information to programs or curriculum.

The first challenge in building capacity in Extension professionals was finding key communication methods to engage them. Two key strategies identified were to: 1) start programming with a discussion of historical trends and agricultural impacts, as locally relevant as available, and 2) start the discussion around adaptation rather than mitigation. Seeing the changes that are already apparent in the climatic record and how agriculture has adapted in the past and is adapting to more recent weather variability and climatic changes often were excellent discussion starters.

Another challenge was that many were comfortable with the science, but were unsure how to effectively communicate that science with the sometimes controversial discussions that surround climate change. This prompted us to include climate science communication in most of the professional development opportunities, which were then consistently rated as one of the most valuable topics.

Future Plans    

The project funding ended on March 31, 2017. All project materials will continue to be available on the LPELC webpage.

Corresponding author, title, and affiliation        

Crystal Powers, Extension Engineer, University of Nebraska – Lincoln

Corresponding author email    

cpowers2@unl.edu

Other authors   

Rick Stowell, University of Nebraska – Lincoln

Additional information

lpelc.org/animal-agriculture-and-climate-change

Acknowledgements

Thank you to the project team:

Rick Stowell, Crystal Powers, and Jill Heemstra, University of Nebraska – Lincoln

Mark Risse, Pam Knox, and Gary Hawkins, University of Georgia

Larry Jacobson and David Schmidt, University of Minnesota

Saqib Mukhtar, University of Florida

David Smith, Texas A&M University

Joe Harrison and Liz Whitefield, Washington State University

Curt Gooch and Jennifer Pronto, Cornell University

This project was supported by Agricultural and Food Research Initiative Competitive Grant No. 2011-67003-30206 from the USDA National Institute of Food and Agriculture.

 

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. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

EPA’s Nutrient Recycling Challenge


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Purpose 

Come to this session to learn about the Nutrient Recycling Challenge and meet some of the involved partners and experts, as well as some innovators who are competing to develop nutrient recovery technologies that meet the needs of pork and dairy farmers. This session will begin with an overview of the challenge. Next, innovators will provide snapshot presentations about the technology ideas they are working on, followed by live feedback/Q&A sessions on each technology where we can harness the buzzing brainpower at Waste to Worth. Finally, we will move into a “workshop” designed to support innovators participating in the Nutrient Recycling Challenge as they refine their designs before they build prototypes.

What did we do?

Background on the Nutrient Recycling Challenge

At Waste to Worth 2015, the U.S. Environmental Protection Agency (EPA) hosted a brainstorm session about developing technologies that livestock farmers want to help manage manure nutrients. That session sowed the seeds for the Nutrient Recycling Challenge—a global competition to find affordable and effective nutrient recovery technologies that create valuable products farmers can use, transport, or sell to where nutrients are in demand. Pork and dairy producers, USDA, and environmental and scientific experts saw the tremendous opportunity to generate environmental and economic benefits, and partnered with EPA to launch the challenge in November 2015 (www.nutrientrecyclingchallenge.org).

What have we learned? 

There is a tremendous opportunity to generate environmental and economic benefits from manure by-products, but further innovation is needed to develop more effective and affordable technologies that can extract nutrients and create products that farmers can use, transport, or sell more easily to where nutrients are in demand.

In the Nutrient Recycling Challenge, innovators have proposed a range of technology systems to recover nitrogen and phosphorus from dairy and swine manure, including physical, chemical, biological, and thermal treatment systems. Some such systems may also be compatible with manure-to-energy technologies, such as anaerobic digesters. Farms of all sizes are interested in nutrient recovery, and there is demand for diverse types of technologies due to a diversity in end users. To improve the adoptability of nutrient recovery systems, it is critical that innovators are mindful of the affordability of technologies, and work to lower capital and operations and maintenance costs, and improve the potential for returns on investment. A key factor for offsetting the costs of a technology and improving its marketability will be in its ability to generate valuable nutrient-containing products that are competitive in the market.

Future Plans 

The challenge has four phases, in which innovators are turning concepts into designs, and eventually to pilot these working technologies on livestock farms. Thirty-four innovator teams whose concepts were selected from Phase I are refining technology designs in Phase II.  Design prototypes will be built in Phase III. This workshop is designed to help innovators maximize their potential for developing nutrient recovery technologies that meet farmer needs.

Corresponding author, title, and affiliation 

Joseph Ziobro, Physical Scientist, U.S. Environmental Protection Agency; Hema Subramanian, Environmental Protection Specialist, U.S. Environmental Protection Agency

Corresponding author email 

ziobro.joseph@epa.gov; subramanian.hema@epa.gov

Session Agenda

  1. Overview of the Nutrient Recycling Challenge, Hema Subramanian and Joseph Ziobro of EPA
  2. Nutrient Recycling Challenge Partner Introductions, Nutrient Recycling Challenge Partners (including National Milk Producers Federation, Newtrient, Smithfield Foods, U.S. Department of Agriculture Agricultural Research Service and Natural Resources Conservation Service, U.S. Department of Energy, and Water Environment & Reuse Foundation)
  3. Showcase of Innovators’ Technology Ideas
    • Decanter Centrifuge and Struvite Recovery for Manure Nutrient Management, Hiroko Yoshida
    • Manure Solids Separation BioFertilizer Produccion Drinking Water Efluente, Aicardo Roa Espinosa
    • Nutrient Recovery from Anaerobic Digestates, Rakesh Govind
    • Organic Waste Digestion and Nutrient Recycling, Steven Dvorak
    • Manure Treatment with the Black Solder Fly, Simon Gregg
  4. Nutrient Recycling Challenge Workshop for Innovators
    • Developing technologies: From concept to pilot (to full-scale), Matias Vanotti
    • Waste Systems Overview for Dairy and Swine and Innovative Technologies: What Steps Should be Taken (Lessons Learned), Jeff Porter

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. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

Exploring Interactions Betwen Agricultural Decisions and Greenhouse Gas Emissions Using Swine Production

green stylized pig logoThe materials on this page are an interactive lab designed to introduce students (high school level) to pig farming and the connections between management decisions  and the greenhouse gas emissions. It also includes information on the economic implications of those decisions. Background information and activities are provided in a graphical (visual) format. Part one can be a stand-alone activity or prepare students for part two.

You can download each of the files individually using the links below or download the entire lab (134 pages – PDF format). The information contains references to Arkansas agriculture and swine production in some areas, but the information is still applicable in other states.

What do you know about swine and greenhouse gases?

This one page (PDF format) fact sheet (including a fun short quiz) can be utilized as part of this lab or as a stand-alone handout to stimulate discussion. Download factsheet

Part One Activity  – The Basics

This section includes five files that introduce the basic concepts of greenhouse gases, swine production systems, and glossary of swine production terms. This activity utilizes both text and graphical presentation of concepts and emphasizes information comprehension. Download Part One

  • Resource information – lesson plan and background information. This includes three aspects of swine management systems including feed management, housing management, and manure management.
  • Farm management system graphics – a visual aid to depict how each individual practice/component contributes to the building of a given pig farm system.
  • Farm flashcards – brief description and graphical rendering of various swine farm components
  • Lab report form – several structured questions designed to
  • Farm management option guide (FMOG)*

*The FMOG also doubles as a scenario key for the completion of Part 2.

Part Two Activity – Challenging

This section provides more in-depth information on swine production systems and greenhouse gases. It provides insight into management obstacles faced by pig farmers in balancing carbon footprints, available resources, producer goals, and legal compliance. This critical-thinking activity is meant to be completed in small groups. Download Part Two

  • Resource information – lesson plan and background information.
  • Farm management option guide FMOG
  • Three scenarios – each covers manure, feed, and housing
  • Flashcards – including health and feed, housing, manure

Acknowledgements

Authors: Rick Fields and Karl Vandevender, University of Arkansas. For questions about these materials, contact Rick at rfields@uaex.edu

This information is part of the program “Integrated Resource Management Tool to Mitigate the Carbon Footprint of Swine Produced In the U.S.,” and is supported by Agriculture and Food Research Initiative Competitive Grant no. 2011-68002-30208 from the USDA National Institute of Food and Agriculture. Project website.

Low-Power Aerators Combined with Center Pivot Manure Application at a Northeast Nebraska Hog Finishing Facility Created an Easy to Manage, Turn-Key System

trnkey animal waste management systemApplying livestock manure from lagoon storage through center pivot irrigation has long been considered a low-labor, uniform method of application that can deliver nutrients in-season to a growing crop. Three challenges with this system have been odor, pivot nozzle clogging and loss of nitrogen. A new innovation in lagoon treatment addresses these challenges. Low-power circulators were installed at a Northeast Nebraska commercial hog finishing facility and used to aerate the lagoon by moving oxygen-rich water and beneficial microbes to the bottom of the lagoon, reducing odor and potent greenhouse gases while lowering disease pathogen risk. This process preserved nitrogen and made it 40-60% more available in the first year of application. Circulation also reduced lagoon solids and bottom sludge, resulting in reduced agitation and dredging expense. Having a continuously well-mixed lagoon facilitated accurate manure nutrient sampling and consistent nutrient concentration delivery to the irrigation system. Combined with the ease of calibration of the center pivots, precision uniform nutrient application was achieved. Center pivot application had several additional advantages over tractor-based systems: less soil compaction, optimal nutrient timing during plant growth, higher uniformity, lower labor and energy costs, and eliminating impact on public roads. The circulators combined with flush barns and center pivot irrigation creates a complete turn-key manure management system.

Do Circulators Make a Difference in Liquid Manure Storage?

pumping nutrients from lagoon on korus pig siteThe purpose of the project was to evaluate the effectiveness of low powered circulators to treat livestock waste in lagoons. The objective was to evaluate how the addition of circulators to a livestock pond would change: 1. Odor levels, 2. Pivot nozzle clogging problems, and 3. Nitrogen loss.

What did we do?

A demonstration was conducted by installing five circulators on a lagoon receiving manure from a 3000 pig finisher facility. The lagoon is owned by a Lindsay customer that was already pumping the top water from the pond through pivots, but was having difficulty with plugging nozzles and was hiring a commercial pumper to agitate and pump solids. The circulators were installed in May of 2013. Starting with the day of installation and each month after through November 2013, effluent lab samples were collected, photos of the pond and effluent were taken, and odor level estimated.

comparison of manure application systems

report from Korus farm
table of report from Korus farms

The effluent was pumped through pivots where odor and nozzle clogging problems were evaluated on August 15th and December 2nd of 2013. The pond was refilled with fresh water, circulated for a few days, and re-pumped right after the August 15th event so more of the nutrients could be utilized by the crops.

What have we learned?

The benefits of using aerobic lagoons with livestock waste have been known for many years. The challenge has been finding a cost effective and reliable method to facilitate the process. The cost to run all five circulators was about $3300 per year figuring $0.10 per kWh.

The circulators facilitated the following changes in the pond:

  • Reduced dry matter in effluent to <0.4%-starting at 0.57% and ending at 0.37%
  • Greatly reduced hog hair and soybean hulls caught in the filter resulting in virtually eliminating nozzle and pressure regulator clogging on the pivot
  • Reduced solids and bottom sludge-sonar indicated a 5+ ft reduction in bottom solids in 5 months
  • Doubled 1st year availability of nitrogen-%NH4 to total N was >80% compared to average book values of 40%
  • Greatly reduced offensive manure odor-downwind from pivot applying effluent, very little odor was observed
  • Reduced disease pathogens-Total Coliform went 11,000 to 30 CFU/g & Escherichia coli went from 460 to <10 CFU/g
  • Reduced flies-virtually eliminated floating solids and fly habitat on the pond
  • Reduced severe greenhouse gasses (GHGs)
  • Generated safer and lower odor water to recycled back through the barn for manure removal

Future Plans

We would like to continue evaluating the system for more precise odor reduction ratings, nitrogen preservation during pond storage, and affect on disease pathogens.

Author

Steve Melvin, Irrigation Applications Specialist, Lindsay steve.melvin@lindsay.com

Additional information

Call Steve Melvin at 402-829 6815 for additional information.

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. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.