Author: Leslie Johnson

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Impacts of social media on public awareness and behavior related to antimicrobial resistance

Purpose

Antimicrobial resistant (AMR) infections are a significant threat to public health. That is why a nationwide coordinated effort among university outreach programs to convey science-based knowledge on AMR dynamics to stakeholders, was established using the moniker the iAMResponsible (iAMR) project in 2019. The project title, “iAMResponsible”, is intended to convey that everyone has an obligation to understand AMR and learn how they can adapt to using science-based practices to mitigate AMR and preserve the efficacy of antibiotics for future generations. The iAMR project seeks to cooperate with related efforts to leverage resources and amplify dissemination of AMR-related educational information. The objectives of the iAMR project are to: (i) increase nationwide capacity to develop AMR related educational content, (ii) facilitate the dissemination of research-based materials through a national network of project members and collaborators, (iii) effectively engage audiences of disparate backgrounds on a shared responsibility for AR, and (iv) empower behavioral change among different audience groups that preserves the efficacy of antibiotics. While the activities of the iAMR team are varied, this study assesses the network building and communication efforts of the iAMR Project on social media.

What Did We Do?

The use of social media to build communication capacity for AMR outreach was measured by the following metrics: total followers and frequency of keywords in search of follower profiles using tools from Followerwonk.com.

For this study the efficacy of social media dissemination was measured in the total impressions (number of users who saw a post) earned by outputs, and the geographical spread of follower locations. Both impressions and follower location are measured by native analytics tools available on various social media.

This study uses the engagement rate, provided by social media analytics to measure audience interest in published materials (engagement rate is the percentage of audience who saw the post and interacted with the post in some way–interactions include retweets, likes, link clicks, follows, media opens, etc.). Native (available from the social media platform) analytics data also allowed us to assess the relationship of engagement rate to specific message factors. To measure audience interest in specific topics, engagement rate was determined for tweets containing keywords and symbols.

To assess the use of social media for motivating behavioral change in the audience, the team developed a 20-question survey with questions on attitudes towards antibiotics, AMR, and the iAMR project. Beginning in the spring of 2020, the team has promoted the same survey annually on different social media platforms to determine attitude changes over time.

What Have We Learned?

Total following for iAMR social media accounts is now just over 4000 (4096 as of Feb 7, 2022). Looking at the most frequently appearing keywords appearing in follower profiles provides some insight into who the followers are (Figure 1). Preeminent among these keywords are “public health,” “antimicrobial resistance,” “infectious diseases,” and “PhD student.” Given this collection of terms we can infer that the iAMR audience likely has a strong interest in and awareness of public health threats like AMR. This would indicate that while iAMR has been effective at building a network among interested, engaged and knowledgeable people in scientific fields, but less adept in reaching audiences with little awareness of AMR or those working in agriculture or food safety fields.

Figure 1: Word cloud of terms included in the biographies of iAMResponsible’s social media followers. Created by Followerwonk.com

iAMR posts have earned roughly 1,000,000 total impressions (948,266 as of Feb 7, 2022) on 720 total posts, or roughly 1300 impressions per post. Impressions measure only the times a user has seen a post they are not a measure of audience engagement. Therefore, while impressions function as a measure of dissemination they are not a reliable measure of the communication impact. In the examination of the geographical reach of iAMR followers (Figure 2) it is evident that iAMR has a larger international than domestic audience, with a particularly large node in Great Britain.

Figure 2: iAMR’s global social network. Node colors indicate size of the nearby audience, blue (1-9), yellow (10-99), red (100-999). Total >4000 worldwide

Overall engagement by audience members with posts from iAMR activity are illustrated in (Figure 3). For the 702 (as of Feb 7, 2022) posts iAMR generated roughly 21 engagements per post, of those engagements roughly 2 were link clicks, about 5 were shares, and 9 were likes. In the context of the per tweet average for impressions (1350) these numbers seem very low but in fact the overall engagement rate of 1.53% is above average (in 2020 average engagement was 0.07% on Twitter, 0.27% on Facebook, 1.16% on Instagram).

Figure 3: Overall engagement by audience members with posts from iAMR, as of Feb 7,2022

To examine what topics were of particular interest to the audience the engagement rate data was broken down by keywords contained in the body of iAMR’s posts, the mean engagement and 95% confidence interval for posts containing the keywords are illustrated in Figure 4. In this examination of user engagement based on post characteristics, the highest engagement was associated with posts containing an “@” symbol. Whereas users were less likely to engage with posts containing the words livestock, agriculture or prescription when compared to the overall engagement with iAMR’s posts.

Figure 4: Average engagement rates for iAMR’s social media content containing keywords or symbols; error bars indicate a 95% confidence interval for mean engagement rate.

Audience engagement with AMR attitude and behavior survey has been low and because most participants respond to only some of the survey questions of the 335 total responses which have been logged during the past 3 years, many key questions have response numbers as low as 9. As a result, we do not have enough data to statistically assess our survey results and present the following as results as instructional rather than conclusive (Table 1).

Table 1: Proportion of Social Media Audience Responding Affirmatively to Selected Web Survey Questions
40% (n=40) Have a medical, doctoral or veterinary degree.
90% (n=51) Expressed concern about growing AMR
65% (n=63) Said they regularly tell others about AMR.
100% (n=23) Said they considered iAMR a reliable source for information on AMR.

Future Plans

Based on audience profiles and content engagement the iAMR account has done a poor job reaching agricultural audiences, or audiences not already engaged with AMR.  Accordingly, future work will need to identify outlets, outside of social media, for engaging new-to-AMR audiences. However, there is value in cultivating the current account audience of engaged and expert users who could join the growing network of iAMR contributors and provide some level of expertise on outreach projects going forward. Moreover, survey results indicate that the current audience has developed trust in the iAMResponsible brand and the educational materials that the team has developed, which provides additional opportunities for dissemination of content into audience communication networks that might not be picked up by the analytical approach used in this assessment.

The iAMResponsible project team will continue efforts to identify educational needs, produce and curate research-based content intended to improve public awareness about AMR, and improve access among producers, consumers, and stakeholders to research-based information about potential AMR-related food safety risks

Authors

Mara Zelt, Research Technologist, University of Nebraska

Corresponding author email address

mzelt2@unl.edu

Additional authors

Juan Carlos Ramos Tanchez, Graduate Research Assistant, University of Nebraska; Amber Patterson, Extension Assistant, University of Nebraska; Amy Schmidt, Associate Professor, University of Nebraska

Additional Information

Project website

Twitter

Acknowledgements

Funding for the iAMR Project was provided by USDA-NIFA Award Nos. 2017-68003-26497, 2018-68003-27467 and 2018-68003-27545. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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A Transportation Simulation Model for selected Concentrated Animal Feeding Facility (CAFFs) within the Maumee Watershed, Ohio

Purpose

The goal of this study was to identify areas that were prone to nutrient transport from land application of manure-based on environmental conditions including length of streams and flood hazard potential in those areas. Additionally, the study aimed at developing an economic utility for producers in transporting manure in the Maumee Watershed in North-west Ohio targeted at reducing the potential environmental impacts that may arise from over application.

What Did We Do?

The initial basic feasible solution of the Hitchcock transportation model (Derigs, U. 1988. The Hitchcock Transportation Problem. In: Programming in Networks and Graphs. Lecture Notes in Economics and Mathematical Systems, vol 300. Springer, Berlin, Heidelberg.) was used to simulate the distribution of manure from 31 dairy and swine concentrated animal feeding facilities to agricultural census block groups (soybeans and corn) in the Maumee Watershed within NW Ohio. The model considered the supply and demand capacity of nearby livestock operations (origin) and agricultural census block groups (destinations) respectively. The second objective was to identify areas that were prone to nutrient transport as determined from the model results based on environmental conditions related to floodplain and length of streams dataset using the Getis-Ord GI* statistic. Finally, using the objective function of the transportation problem, the transportation costs associated with hauling manure from the source to the destinations were calculated.

What Have We Learned?

The distribution of manure showed an unbalanced transportation problem such that available farmland that could receive manure exceeded the supply of the livestock operations. The findings suggest there is adequate agricultural land for manure distribution in the watershed. Additionally, areas indicating clustering in the distribution of manure were further examined to determine the potential for nutrient transport off the land and into nearby water bodies based on the environmental conditions used. Approximately 98% of receiving agricultural census block groups fell in the EC-1 classification, which indicates a very low potential for environmental conditions to influence nutrient movement off farmland receiving manure from the 31 CAFFs studied. Approximately 2% and 1% of total acres receiving manure had a moderate to high potential for flooding respectively and were found in Upper Maumee and St. Joseph sub-basins. The identified sub-basins are recommended target areas for best management practices in reducing nutrient runoff. In using the Getis-Ord GI* statistic in ArcMap, Auglaize, Upper Maumee, Lower Maumee, and Cedar-Portage sub-basins were identified as critical areas of concern with high total acres showing high clustering of stream length.

Future Plans

The transportation problem is a type of linear programming problem where goods and services are transported from one set of sources to one set of destination points to minimize transportation costs. There are two phases to the transportation problem – finding the initial basic feasible solution while the second phase involves optimizing the initial basic feasible solution. This study focused on finding the initial basic feasible solution for manure distribution and application in the Maumee River Watershed. Future research could include optimization of the initial basic feasible solution per the transportation problem process to test the robustness of the results from the first phase.

Secondly, the transportation model coded for this dissertation was based on the manure supply of permitted livestock facilities engaged in only swine and dairy production. The model could be refined to include the supply of all livestock operations in the watershed in addition to all destination agricultural lands. With transportation costs being a major overhead cost for producers, the model can also be calibrated based on minimal travel time as an economic utility for producers and farmers.

Furthermore, given the costs involved in the construction of manure storage facilities and the regulations surrounding manure application as identified in Ohio State Bill 1, locations for ‘manure- sheds’ can be identified for manure storage during off seasons for application. A GIS optimal model can be developed to determine the minimum cost and distance efficient for the location of the proposed ‘manure-sheds’ where both small and medium facilities with limited storage facilities can transport their manure to a centralized location for storage, while also serving as the point of distribution and utilization for farmers.

Authors

Dr. Patrick L. Lawrence, University of Toledo

Corresponding author email address

Patrick.lawrence@utoledo.edu

Additional author

Dr. Edwina Teye, University of Toledo

Acknowledgements

Ohio Sea Grant

Ohio Department of Higher Education

Ohio Pork Council

Ohio Livestock Association

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Life Cycle Assessment methodology to evaluate environmental impact of beef manure management: a comparison

Purpose

Manure from beef feedlot productions can be managed through a diversity of strategies. When choosing from the possible scenarios the main factors influencing the decision are financial, logistical or from a regulatory fulfillment focus, however it is necessary to consider the environmental impact generated from the manure management system in order to generate less burdens on behalf of meat production. One of the most reliable methodologies for this matter is Life Cycle Assessment (LCA), which considers every input and output throughout the process and will calculate environmental emissions quantitatively. In this study we compared various LCA studies of beef lot manure management processes, with the aim of understanding the different systems´ hotspots and global emissions so that these can be considered when establishing a manure management system in similar facilities.

What Did We Do?

We gathered LCA studies published from peer-reviewed scientific journals that assessed the environmental impact of beef manure management. The search terms taken into account were “LCA and beef manure” and “LCA and feedlot manure”. To enable comparison between studies the following criterion were considered for inclusion: a) manure collected from intensive feedlot facilities b) results reporting at least global warming potential.

In order to categorize emissions generated from the entire manure life cycle we established four stages of manure management: Feedlot, transport, storage/transformation and use/disposal. Next, we identified which of these stages were taken into account in each study and if emissions were reported for stages individually as well as globally. Lastly, a comparison between LCAs was conducted for which we converted the functional units reported in the references to 1 ton of manure (dry basis). With this we can visualize the emissions generated from every ton of dry manure that enters the system despite the functionality to which it´s destined.

What Have We Learned?

The final review included 14 references which resulted in 19 scenarios evaluated, ranging from 2007 to 2021. Initially we noted that the system with the greatest number of evaluations performed was the transformation of manure into an energetic resource (E), with 12 of the 19 scenarios being focused on energy generation through manure treatment processes, emphasizing that the current trends are not only leaning towards a better manure use but also cleaner energy sources. On the counter part, composting (C) and stockpiling (SP) are the two least evaluated scenarios through LCA (just once in the articles present in this review). Manure composting and stockpiling aren´t perceived as innovative solutions when aiming to mitigate emissions, but shouldn´t be left aside when performing evaluations, since they´re the most applied techniques for feedlot manure management.

The energetic evaluations represented both, the most (E3) and the least emissions (E7) through the whole process. This is because bioenergetic sources, such as the one generated from manure transformation, frequently are given environmental credits and therefore negative emission values considering the substitution of other energetic resources. In this review 10 of the 12 energetic scenarios considered emission reduction by substitution, but not because the actual process generated less amount of greenhouse gases in itself. Energy production from manure is, in many cases assessed as a life cycle for transformation and excluding other stages of the entire management system. In fact, apart from the kind of treatment only 21.4% of all the LCAs considered in this study included all four stages. Since two of them (Lansche et al, 2012; Van Stappen et al, 2016) mentioned that the best mitigation emission option was to reduce storage time, and one (Giwa et al, 2017) reported the largest emissions coming from transportation we can assume that both, storage and transport are important stages when looking at sources of emissions and should not be left aside.

The difference between emissions between different manure management systems can be as extreme as 4,000X depending on system boundaries, allocation procedures, emission factors, environmental credits, amongst others. When evaluating a manure management system, it is necessary to consider every stage and so that emission reduction can be addressed in the whole process hotspots and not only during the transformation of organic matter.

Future Plans

To conduct an attributional LCA of beef feedlot manure management system as a case study. With this we will contribute more data to contrast composting or stockpiling scenarios and address the weight of the different manure management in a feedlot facility. Also, we will report eutrophication potential and water depletion, as their importance in the environmental impacts of manure management is well known and should be considered when decisions are being made.

Authors

Andrea Wingartz, National Autonomous University of Mexico

Corresponding author email address

anwiot@gmail.com

Additional author

PhD. Rafael Olea Pérez, National Autonomous University of Mexico

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Evaluation of geospatial data for livestock operation location and estimation of manure nutrient utilization capacity in five Nebraska counties

Purpose

Livestock and poultry manure are valuable sources of organic material and nutrients for crop production and pasture growth. Nonetheless, the trend away from diversified farms has disrupted the natural nutrient recycling of manure-fertilized cropping-systems. Meanwhile, inorganic fertilizer sales in Nebraska during 2020 reached a thirty-year high. This importation of nutrients, especially nitrogen and phosphorus fertilizer to areas rich in organic fertilizer products leaves an excess of nutrients that still must be utilized and leads to higher risk for nutrient contamination of surface and groundwater sources that would reduce quality of the water.

In areas where there is a high density of livestock production, utilization of manure nutrients may require additional cropland outside the livestock operations. Moreover, the transportation and application of manure has logistical challenges that remain critical to address to motivate the local recycling of organic nutrient amendments by crop producers and livestock owners.

The present research aims to bridge this gap of knowledge by developing a clearer understanding of nutrient utilization and supply capacities through exploration of county level geospatial data.

This analysis will have two main objectives:

    1. Quantify livestock inventories, associated manure production, inorganic fertilizer imports, and potential crop nutrient utilization, and calculate nutrient surpluses or deficits in five Nebraska counties.
    2. Identify and describe the suitable land for manure applications in each of the five target counties.

What Did We Do?

The research team selected five Nebraska counties (Scottsbluff, Cuming, Custer, Nemaha, and Antelope) for their agricultural importance and diverse geographical location and characteristics. The analysis of nutrients was realized using publicly available geospatial data and governmental databases.

Objective 1. Quantify livestock inventories, associated manure production, inorganic fertilizer imports, and potential crop nutrient utilization, and calculate nutrient surpluses or deficits in five Nebraska counties.

For this research, “livestock” includes poultry, pigs, and cattle (beef and dairy). The team used data from the USDA National Agricultural Statistics Service (NASS) (Table 1) to estimate the total animal units within each category based on NASS data for sales and end-year inventory.

The scope of this assessment was limited to include only commercial production livestock operations, which were operations with at least three animal units or with more than $2,000 in sales of livestock products. To obtain an annual average number of animal units at county-level two important assumptions, based on Kellog, Lander, Moffit, & Gollehon (2000) research: (1) different cycles of confinement for each animal category (according to its spans form birth to market) ; and (2) that sales throughout the year did not have seasonal variation. Algorithms for estimating animal units, average amount of recoverable manure, and its consequent rate for nitrogen and phosphorus levels were calculated using as reference the formulas and conversion factors adapted from Kellog, Lander, Moffit, & Gollehon (2000) and Gollehon, Kellog, & Moffitt (2016).

Table 1. Input data and formulas
Data/formula Date Source
Hogs and pigs inventory and sales. 2017 USDA- NASS

 
Cattle and Calves inventory and sales. 2017 USDA-NASS
Poultry inventory and sales. 2017 USDA-NASS
Estimated nutrients from commercial fertilizers. 2016 NUGIS- The Fertilizer Institute
Crop production Layer 2020 USDA-NRCS-NASS
Balance of nutrient [Eq. 1]

 

 Balance = Farm fertilizer nutrient used + Recoverable manure nutrient use – Nutrient in harvested crops 

 

The balance of nutrients was thus determined using Eq 1 (Table 1); where farm fertilizer is estimated by fertilizer imports at county level (NuGis database, 2016). The nutrient in harvested crops is estimated with the yield report (USDA-NRCS-NASS), and average phosphorus and nitrogen uptake and fixation rate based on literature review [1].

Objective 2. Identify and describe the suitable land for manure application for each of the five target counties.

Six suitability factors were identified for manure application: land cover, potential for phosphorus uptake, proximity to road and streets, proximity to urban areas, slope, and proximity to water bodies (Table 2). Each factor class was weighted for their impact on manure application feasibility using the Analytic Hierarchy Process (AHP) and pairwise comparison method described by Doegan, Dodd, & McMaster (1994) where factors were given scores on nine objectives (A- Reducing surface water pollution, B-Reducing ground water pollution, C- Reducing soil contamination, D- Reducing runoff loss of nutrients, E- Reducing leaching loss of nutrients, F- Avoiding excessive use of manure, G-Increasing nutrient use efficiency, H-reducing cost of manure application, I- Reducing bad odor) through an objectives-oriented comparison (OOC) which values were adapted form Basnet, Apan, & Raine (2001) (Table 3).

Table 2. Input factors and constraints.
 

Input Factors

  

Data type

 Excluded land
Land cover National Land Cover Database Other land cover besides cropland
Potential uptake of cropland-P2O5 Cropland Data Layer (CDL) Grasslands, pastures, developed spaces, natural ecosystems.
Proximity to developed/urban areas National Land Cover Database Area less than 100 ft
Proximity to road and streets TIGER Primary and secondary roads and streets > 35 ft
Slope DEM of Nebraska’s County > 10%
Proximity to water bodies National Hydrography Dataset > 35 ft

 

Table 3. Weight distribution using an AHP process.
Land cover Criteria Weight
Potential uptake of cropland-P2O5 36
Proximity to developed/urban areas 6
Proximity to road and streets 6
Slope 20
Land cover 26
Proximity to water bodies, rivers and streams 6
*Consistency ratio of weight distribution= 0.00 (This range is a measure if the reliability of the comparison and should be <0.1)

[1] (Warncke, Dahl, & Zandstra, Nutrient Recommendations for Vegetable Crops in Michigan, 2004)(Kang, et al., 2020)(Meena, Kumar, Dhar, Paul, & Kumar, 2015)(Grains Research & Development Corporation, 2018)(Fertilizer Canada, 2001)(Grains Reseach & Development Research, 2018)Manitoba Government. (2009).(Barker, 2019) and ((Barker, 2017)(Warncke, Dahl, & Jacobs, 2009)(Sullivan, Peachey, Heinrich, & Brewer, 2020)(Grains Research & Development Corporation, 2018)(Sullivan, Peachey, Heinrich, & Brewer, 2020)International Plant Nutrition Institute (2013)).

What Have We Learned?

Objective 1.

The total balance of nutrients for each county showed that even though none of the counties we assessed have a surplus of nutrients at the county level, some of them are very close to meeting or surpassing the capacity of the land in the county to utilize additional nutrients. Of the five counties, Cumming county has the lowest phosphorus assimilation available at the county level, followed by Nemaha, Antelope, Custer, and Scotts Bluff. Balance nutrients showed a lower assimilation capacity on phosphorus than nitrogen. Since phosphorus is a nutrient limiting the growth of aquatic organisms and reduction on water quality, it was important to represent the potential phosphorus sinks at the geospatial level for Objective 2 (Figures 1 and 2).

Figure 1. County level nitrogen balance.

 

Figure 2. County level P2O5 balance.

Objective 2.

The area suitable for manure application in the five counties was mapped (Figure 3) with the Weighted Overlay Raster tool, on ArcGis Pro 2.9.1. This allowed the researchers to incorporate multicriteria effects with a weight for each factor. The results are summarized in Table 4 and present the proportion of land in each county that is either not suitable for manure application, has a marginal (medium) suitability, or is very suitable (high).  These classifications were determined by natural breaks (Jenks) classification which partitioned data into classes based on natural groups in the data distribution.

We recognize that land suitable for manure application is closely associated with acres in crop production, which for Custer and Scottsbluff Counties is less than 50% of the total acres. Whereas Cuming County had the highest percentage of area dedicated to crop production, which explains the high proportion of “High suitability land”. The category of “Medium suitability” has the lowest percentage for all counties because it is mainly driven by differences in low and medium potential phosphorus uptake, based on crop type and area destinated for crop production, which are regularly more spatially scarce in vegetation patches.

Figure 3. Suitable land for manure application.

 

Future Plans

    • Validate the model of suitable land for manure application by checking the available data for manure production, cropland areas and slope with other official sources, and taking random samples among the counties to compare the results under field conditions.
    • Incorporate a socio-economic analysis for manure transportation among and within different counties.
    • While the county level context and characteristics have value, it would increase the accuracy of the model if more information about individual and smaller scale farms and animal feeding operations could be geospatially available. Thus, where possible, it is the researcher’s goal to improve the current analysis with the addition of more accurate data on animal operations within each county to adjust the estimation of manure production, and the nutrients balance.
    • Promote Outreach efforts with farmers for making decisions based on a nutrient management approach that could decrease the importation of inorganic fertilizers, where possible.

Authors

Presenting author

María José Oviedo, Graduate Research Assistant, University of Nebraska-Lincoln

Corresponding author

A. Millmier Schmidt, Associate Professor & Livestock Manure Management Engineer, University of Nebraska-Lincoln

Corresponding author email address

aschmidt@unl.edu

Additional authors

A. Millmier Schmidt, Associate Professor & Livestock Manure Management Engineer, University of Nebraska-Lincoln; J. Iqbal, Assistant Professor, University of Nebraska-Lincoln; A. Yoder, Associate Professor, University of Nebraska Lincoln; and B. Maharjan, Assistant Professor, University of Nebraska Lincoln

Additional Information

Basnet, B. B., Apan, A. A., & Raine, S. R. (2001). Selecting Suitables Sites for Animal Waste Application Using Raster GIS. Environmental Management, 519-531.

Cassman, K., Dobermann, A., & Walters, D. (2002). Agroecosystems, Nitrogen-use Efficiency, and. Agronomy & orticulture– Faculty Publications, 356.

Fergunson, R. (2015). Groundwater Quality and NItrogen Use Efficiency in Nebraska’s Central Platte River Valley. Journal of Environmental Quality.

Gollehon, N., Caswell, M., Ribaudo, M., Kellog, R., Lander, C., & Letson, D. (2011). Confined Animal Production and Manure Nutrients. Washington, DC: Resource Economics Division, Economic Research Service, U.S. Department of.

Kellog, R. L., Lander, C. H., Moffit, D. C., & Gollehon, N. P. (2000, Diciembre). Manure Nutrients Relative to the Capacity of Cropland and Pastureland to Assimilate Nutrients. Retrieved from USDA: www.nhq.nrcs.usda.gov/land/index/publication.html

Nebraska Agriculture Department. (2021). Nebraska Agriculture Fact Card. Retrieved from https://nda.nebraska.gov/facts.pdf#:~:text=In%202020%2C%20Nebraska%20ranked%20second%20in%20ethanol%20production,operations%20were%20found%20on%2048%25%20of%20Nebraska%20farms.

Nebraska Department of Agriculture. (2020). Nebraska Fertilizer, Soil Conditioner and Ag Lime Tonnage and Sampling Reprot Calendar year 2020. Lincoln: nda.nebraska.gov.

Spiegal, S., Kleinman, P., Endale, D., Bryan, R., Dell, C., Goslee, S., . . . Gowda, e. a. (2020, June). Manuresheds: Advancing nutrient recycling in US agriculture. Agricultura Systems 182, 102813. doi:https://doi.org/10.1016/j.agsy.2020.102813

Doegan, H. A., Dodd, F. J., & McMaster, T. B. (1994). A Statistical Approach to Consistency in AHP. Marh.Comput.Modelling., 19-22.

Barker, B. (2017, April 4). Moderate flax response to nitrogen. Top Crop Manager. Retrieved from https://www.topcropmanager.com/moderate-flax-response-to-nitrogen-19985/#:~:text=Generally%2C%20flax%20takes%20up%202.83,sensitive%20to%20seed%2Dplaced%20fertilizer.

Barker, B. (2019, December 3). Managing phosphorus in flax. Top Crop Manager. Retrieved from https://www.topcropmanager.com/managing-phosphorus-in-flax/

Fertilizer Canada. (2001). Phosphorus Management for Pulses. Canola Council of Canada. Retrieved from https://www.canolacouncil.org/download/2042/canola-watch/14659/cfi_nutrient_uptake_for_wcanada_2001

Grains Reseach & Development Research. (2018). Grownotes: Chickpea-Section 5. Grains Reseach & Development Research. Retrieved from https://grdc.com.au/__data/assets/pdf_file/0030/369444/GrowNote-Chickpea-West-5-Nutrition.pdf

Grains Research & Development Corporation. (2018). Grownotes: Lentils- Section 7. Grains Research & Development Corporation. Retrieved from https://grdc.com.au/__data/assets/pdf_file/0028/366166/GrowNote-Lentil-West-7-Nutrition-Fertiliser.pdf

Grains Research & Development Corporation. (2018). Grownotes: Triticale-Section 5. Grains Research & Development Corporation. Retrieved from https://grdc.com.au/__data/assets/pdf_file/0025/370645/GrowNote-Triticale-South-05-Nutrition.pdf

Kang, F., Wang, Z., Xiong, H., Li, Y., Wang, Y., Fan, Z., . . . Zhang, Y. (2020). Estimation of Watermelon Nutrient Requirements based on the QUEFTS Model. Agronomy, 1776. Retrieved from file:///C:/Users/Majo/Downloads/agronomy-10-01776-v2.pdf

Manitoba Government. (2009). Calculating Manure Application Rates. Manitoba Provin. Retrieved from https://www.gov.mb.ca/agriculture/environment/nutrient-management/pubs/mmf_calcmanureapprates_factsheet.pdf

Meena, B. P., Kumar, A., Dhar, S., Paul, S., & Kumar, A. (2015). Productivity, nutrient uptake and quality of popcorn and potato in relation to organic nutrient management practices. ICAR-Indian Agricultural Research Institute, 110 012.

Sullivan, D. M., Peachey, E., Heinrich, A., & Brewer, L. J. (2020). Nutrient and Soil Health Management for Sweet Corn (Western Oregon). Oregon State University. Retrieved from https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9272.pdf

Warncke, D., Dahl, J., & Jacobs, L. (2009). Nutrient Recommendations for Field Crops in Michigan. Michigan State University. Retrieved from https://www.canr.msu.edu/fertrec/uploads/E-2904-MSU-Nutrient-recomdns-field-crops.pdf

Warncke, D., Dahl, J., & Zandstra, B. (2004). Nutrient Recommendations for Vegetable Crops in Michigan. Michigan State University.

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Pull-Plug Sedimentation Basin for Dairy Manure Management

Purpose

Many small and mid-sized dairy farms use flush systems for manure removal due to reduced chore time and increased barn cleanliness. Often, flush systems require greater attention to onsite water management and frequent lagoon maintenance. While anaerobic lagoons provide some digestion of manure solids and sludge storage, solids removal may help increase lagoon capacity and reduce costly lagoon sludge removal. A pull-plug sedimentation basin (PPSB) is a passive solids removal system that can reduce the operational time and cost of the overall manure management system by acting as both a sedimentation basin and pre-lagoon solids filter system.

Larger, denser particles accumulate on the basin floor, while buoyant particles (e.g., undigested fiber, waste forage, bedding, etc.) form a floating mat on the surface. The mat acts as a natural filter and retains some of the solids from the waste stream. The PPSB was developed as part of a collaborative effort between USDA NRCS and small dairy producers in Missouri. This abstract provides background and basic information on the PPSB, while more performance evaluation of the system based on nutrient retention, costs, and maintenance and operational considerations can be found in a University of Missouri Extension publication Eq302 (Canter et al., 2021).

What Did We Do?

Design details of a working PPSB were documented, and performance evaluation was conducted based on grab samples of the flush and PPSB locations. Critical design considerations for the PPSB including design, hydraulic loading, location of the pull-plug location, and construction details were reported in the Extension publication (Canter et al., 2021). The concrete entry ramp into the PPSB should have a maximum slope of 12:1 (or 5 degrees) (Figure 1) to minimize wheel slippage and potential for equipment overturns. The example provided in Figure 1 is of a typical PPSB design that serves a herd of ~150 milking cows with a single-flush volume of ~7,000 gallons but also represents the smallest recommended size of the system. A minimum depth of 6 feet is needed to keep settling solids out of the discharge stream.

Figure 1. Profile and plan views of typical PPSB (dimensions in feet).

Detailed discussion of the advantages and disadvantages of the PPSB system was reported in the Extension publication. Relatively little maintenance has been reported, while the pull-plug is the only moving part and may need to be replaced if damaged during cleaning or degradation, Figures 2 and 3. Details such as the management and sampling and analysis were discussed, and a case study was conducted to document the information of a PPSB system of a 120-hd dairy farm in Missouri, with a flush system and sand lane, as well as a performance evaluation.

Figure 2. A PPSB system in operation at a dairy farm.
Figure 3. PPSB with liquid discharge pipe, after manure solid was removed.

What Have We Learned?

The owners are satisfied with the performance of the PPSB, which is considered a low-maintenance, low-technology option to efficiently manage manure solids within a flush system. The primary benefit of the PPSB is a reduction in time spent agitating and removing solids/sludge in the lagoon. When less capacity in the lagoon is used for solids treatment and storage, there is more room to store water and longer intervals between repairing or unclogging pumps and the water system. There are typically three to four clean-out periods per year, depending on PPSB and herd sizes and other factors.

The primary benefit of the PPSB is the removal of manure solids using a low maintenance system, resulting in longer intervals between lagoon agitation and land applications. Approximately 23,450 cubic feet of manure solids were prevented from entering the lagoon each year, along with 6,454 pounds of nitrogen (438 pounds as ammonia-nitrogen) and 2,415 pounds of phosphorous. These represent 13 percent and 28 percent of manure-based nitrogen and phosphorous, respectively, being retained in the PPSB.

Future Plans

Additional sampling just before or during clean-out is necessary for a more accurate performance determination. PPSB installed at larger dairy farms, and those using different bedding should be evaluated for performance and documented the cost savings as compared with other popular solid separation systems.

Authors

Teng Lim, Extension Professor, Agricultural Systems Technology, University of Missouri

Corresponding author email address

Limt@missouri.edu

Additional authors

Timothy Canter, Extension Specialist, Agricultural Systems Technology, University of Missouri

Troy Chockley, Environmental Engineer, Natural Resource Conservation Service, United States Department of Agriculture

Additional Information

Canter, T., T.-T. Lim, and T. Chockley. 2021. Considerations of pull-plug sedimentation basin for dairy manure management. University of Missouri Extension. https://extension.missouri.edu/eq302

Acknowledgements

USDA NIFA, Water for Food Production Systems Program A9101, for supporting the project. It is titled “Management of Nutrients for Reuse”, a multi-faceted project that involves professionals from the University of Arkansas, University of Nebraska, Colorado School of Mines and Metallurgy, Case Western University, and University of Missouri.

Joseph Zulovich, Agricultural Systems Technology, University of Missouri

Richard Stowell, Biological Systems Engineering, University of Nebraska

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Potential soil health improvement through the integration of cover crops and manure in the upper Midwest

Purpose

Oftentimes fall manure application is associated with significant offsite transport of nitrogen and phosphorus into nearby bodies of water and the atmosphere. Mechanisms of losses include leaching, runoff, sediment transport, and volatilization processes. This is becoming more common as there has been a trend of increased wet springs that create difficult planting conditions. This prolonged period without an active root system leaves more time for nutrient loss from fall-applied manure to occur.

A strategy to offset nutrient losses in the fall and early spring is to plant a cover crop. The uptake of nutrients during this time in the field, which would otherwise be left fallow, allows for nutrients to be stored in the tissue of the cover crops, minimizing nutrient loss risk. Upon terminating the cover crops, the decomposing residues can supply nutrients to the succeeding row-crop. However, cover crop adoption is low in the upper Midwest US stemming from a short cover crop growing season due to the cold climate. This is especially the case for crops utilizing manure. A strategy to expand the cover crop growing season may be to interseed a cover crop into a maturing row-crop prior to harvest. Previous studies investigating the integration of manure and cover crops have seeded the cover crop after manure application. We wanted to measure the impacts of first planting a cover crop then applying manure once the cover crop has had ample time to get established. This may help expand the cover crop growing season and potentially limit the offsite transfer of pollutants to our water and air.

What Did We Do?

A small plot study was started in fall 2019 at the University of Minnesota West Central Research and Outreach Center near Morris, MN. We tested the effect of nitrogen source and cover crops on soil health, nutrient cycling, and agronomic responses using a randomized complete block design with split plots.

Cover crop mixtures of cereal rye and annual ryegrass were interseeded near corn’s fifth leaf collar (V5) growth stage, physiological maturity (R5 to R6 growth stage), or drilled after corn harvest. Dairy manure was sweep-injected to minimize soil disturbance in early and late fall, when soil temperatures were above and below 10°C (50°F), respectively. Non-manured plots received urea in the spring prior to corn planting. Urea applied plots (no manure) with no cover crops served as the control. Soil samples were taken throughout the cover crop and row-crop growing season from the 0-15, 15-30, and 30-60 cm (0-6, 6-12, and 12-24 in) soil layers. Cover crop biomass samples were taken in the late fall prior to the first frost event and prior to cover crop termination in the spring.

What Have We Learned?

Sweep injection is a reliable method to apply liquid manure to a field with an established stand of cover crops with minimal noticeable damage to the cover crops in the spring (Figure 1). Planting cover crops as soon as possible ensures more biomass is produced; planting after harvest consistently had lower cover crop yield than interseeding. Spring cover crop yield, right before termination, was highest when planted near physiological maturity [110 kg ha-1 (98 lb ac-1)] compared to drilling after harvest [87 kg ha-1 (78 lb ac-1)]. Nutrient source had a significant effect on silage yield. Manure, either applied in the early or late fall, had greater silage yield [58.5 and 58.7 Mg ha-1 (26.1 and 26.2 ton ac-1), respectively] than spring applied urea [53.6 Mg ha-1 (23.9 ton ac-1)]. Plots with cover crops interseeded at V5 had greater silage yield [59.5 Mg ha-1 (26.5 ton ac-1)] than all other treatments [54-56 Mg ha-1 (24-25 ton ac-1)] except no cover crops [57.8 Mg ha-1 (25.8 ton ac-1)].

Figure 1. Cover crops planted prior to late manure application. Photo was taken in the spring at cover crop termination.

Future Plans

Soil samples collected throughout the study are currently being analyzed for nutrient content and other soil health parameters. Results from this study will be used to develop best management practices for integrating cover crops and liquid injected manure in the upper Midwest.

Authors

Manuel J. Sabbagh, Graduate Research Fellow, University of Minnesota

Corresponding author email address

sabba018@umn.edu

Additional authors

Melissa L. Wilson, Assistant Professor, University of Minnesota; Paulo H. Pagliari, Associate Professor, University of Minnesota

Additional Information

Twitter: @mannyandmanure @manureprof

Lab website: https://wilsonlab.cfans.umn.edu/

Acknowledgements

This work is supported by the Conservation Innovation Grants program at the Natural Resources Conservation Service of the USDA, the Minnesota Corn Research and Promotion Council, and the Foundation for Food and Agriculture Research.

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How are Filth Flies Involved in Wasting Nitrogen?

Purpose

Filth flies are species from the Diptera order associated with animal feces and decomposing waste. Beef cattle raised on open pastures are especially susceptible to two species of filth flies: Face flies (Musca autumnalis De Geer) and Horn flies (Haematobia irritans (L.))  because these flies develop exclusively in fresh cattle manure. Filth fly impact on cattle health is related not only to the loss of body weight but also to the transmission of diseases like pink eye and mastitis (Basiel, 2020; Campbell, 1976; Hall, 1984; Nickerson et al., 1995).

Nitrogen losses from cattle’s manure has been reported for domestic flies (Musca domestica) and bottle flies (Neomyia cornicina) (Iwasa et al., 2015; Macqueen & Beirne, 1975). Despite the regular presence of face fly and horn fly in pastures, their effect on the nutrient cycles is little known. The purpose of this study is to understand the relationship between filth fly’s presence in cattle manure with the nitrogen losses caused by an increase in ammonia and nitrous oxide emissions.

What Did We Do?

The study was conducted in four pastures in the Georgia Piedmont: two near Watkinsville and two near Eatonton during June, July, and August of 2021. Ammonia volatilization and nitrous oxide emissions were measured on days 1, 4, 8, and 15 following dung deposition. Manure samples were collected on days 1 and 15. A static chamber was sealed for 24 h on each sampling date to capture manure’s ammonia and nitrous oxide emissions. In each chamber, a glass jar with boric acid was used to trap ammonia, and gas samples were collected. The gas samples were analyzed for nitrous oxide with a Varian Star 3600 CX Gas Chromatograph using an electron capture detector.

The number of filth flies was determined using a net trap covered by a black cloth that was set after 1 min of manure deposition, allowing the flies to oviposit for 10 min. On the days in which ammonia was not measured, a net trap was set to avoid additional oviposits, and record the emergence of filth flies. On the 15th day, we collected the filth flies that emerged from the eggs deposited in the manure during the first day.

What Have We Learned?

We found that cattle’s manure nitrogen loss as nitrous oxide (N2O) and ammonia (NH3) emissions have a direct relationship with the number of horn flies and face flies in the dung, Figure 1. Eighty percent of the flies trapped were horn flies. Dung with less than 5 flies can emit as little as 0.11 mg of N/kg of manure per day, while cattle manure with more than 30 flies can increase this emission by more than 10 times.

Figure 1 Nitrogen emissions such as nitrous oxide and ammonia (mg/kg of manure) and number of filth flies.

Every extra filth fly in manure can increase N emissions by 0.03 mg per kg of manure per day. According to NRCS, 59.1 lbs. of fresh manure is produced by a cow (approx. 1 000 pounds animal) every day (NRCS, 1995). Considering an average of 85 % relative humidity, 4.03 kg of dry manure can be produced per cow day. The actual economic threshold for horn fly is 200 flies per animal (Hogsette et al., 1991; Schreiber et al., 1987), considering a 1 to 1 sex ratio during emergence (Macqueen & Doube, 1988) we are assuming 100 female flies. Since the capacity of horn flies is 8-13 eggs per day (Lysyk, 1999), 100 female horn flies can generate approximately 1,000 new flies every day.  Calculating the nitrogen emissions (4.03 kg of dry manure X 0.03 mg N kg manure x 1,000 flies per day) results in 121 mg of N loss per cow per day when assuming the number of flies is just at the economic threshold. In January of 2022, USDA released the Southern Region Cattle Inventory with a total of 91.9 million head, from which 30.1 million were beef cows (USDA, 2022). Considering the earlier numbers, the horn fly presence in the beef cattle of the Southern Region could be emitting 3,639 kg of Nitrogen to the atmosphere every day.

Future Plans

We will continue the study on ammonia and nitrous oxide emissions under the same conditions during another year to confirm the trends and accuracy of the results. Also, we will implement a study to analyze the effect of the introduction of a parasitic wasp Spalangia endius as a biological control on horn fly and face fly populations and therefore on the manure’s nitrogen losses.

Authors

Presenting author

Natalia B. Espinoza, Research Assistant, Department of Crop and Soil Science, University of Georgia

Corresponding author

Dr. Dorcas H. Franklin, Professor, Department of Crop and Soil Sciences, University of Georgia

Corresponding author email address

dfrankln@uga.edu or dory.franklin@uga.edu

Additional authors

Anish Subedi, Research Assistant, Department of Crop and Soil Science, University of Georgia

Dr. Miguel Cabrera, Professor, Department of Crop and Soil Sciences, University of Georgia

Dr. Nancy Hinkle, Professor, Department of Entomology, University of Georgia

Dr. S. Lawton Stewart, Professor, Department of Animal and Dairy Science, University of Georgia

Additional Information

Basiel, B. (2020). Genomic Evaluation of Horn Fly Resistance and Phenotypes of Cholesterol Deficiency Carriers in Holstein Cattle [PennState University]. Electronic Theses and Dissertations for Graduate Students.

Campbell, J. B. (1976). Effect of Horn Fly Control on Cows as Expressed by Increased Weaning Weights of Calves. Journal of Economic Entomology, 69(6), 711-712. https://doi.org/DOI 10.1093/jee/69.6.711

Hall, R. D. (1984). Relationship of the Face Fly (Diptera, Muscidae) to Pinkeye in Cattle – a Review and Synthesis of the Relevant Literature. Journal of Medical Entomology, 21(4), 361-365. https://doi.org/DOI 10.1093/jmedent/21.4.361

Hogsette, J. A., Prichard, D. L., & Ruff, J. P. (1991). Economic-Effects of Horn Fly (Diptera, Muscidae) Populations on Beef-Cattle Exposed to 3 Pesticide Treatment Regimes. Journal of Economic Entomology, 84(4), 1270-1274. https://doi.org/DOI 10.1093/jee/84.4.1270

Iwasa, M., Moki, Y., & Takahashi, J. (2015). Effects of the Activity of Coprophagous Insects on Greenhouse Gas Emissions from Cattle Dung Pats and Changes in Amounts of Nitrogen, Carbon, and Energy. Environmental Entomology, 44(1), 106-113. https://doi.org/10.1093/ee/nvu023

Lysyk, T. J. (1999). Effect of temperature on time to eclosion and spring emergence of postdiapausing horn flies (Diptera : Muscidae). Environmental Entomology, 28(3), 387-397. https://doi.org/DOI 10.1093/ee/28.3.387

Macqueen, A., & Beirne, B. P. (1975). Influence of Some Dipterous Larvae on Nitrogen Loss from Cattle Dung. Environmental Entomology, 4(6), 868-870. https://doi.org/DOI 10.1093/ee/4.6.868

Macqueen, A., & Doube, B. M. (1988). Emergence, Host-Finding and Longevity of Adult Haematobia-Irritans-Exigua Demeijere (Diptera, Muscidae). Journal of the Australian Entomological Society, 27, 167-174. <Go to ISI>://WOS:A1988P906100002

Nickerson, S. C., Owens, W. E., & Boddie, R. L. (1995). Symposium – Mastitis in Dairy Heifers – Mastitis in Dairy Heifers – Initial Studies on Prevalence and Control. Journal of Dairy Science, 78(7), 1607-1618. https://doi.org/DOI 10.3168/jds.S0022-0302(95)76785-6

NRCS, N. R. C. S. (1995). Animal Manure Management. RCA Publication Archive(7). https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcs143_014211

Schreiber, E. T., Campbell, J. B., Kunz, S. E., Clanton, D. C., & Hudson, D. B. (1987). Effects of Horn Fly (Diptera, Muscidae) Control on Cows and Gastrointestinal Worm (Nematode, Trichostrongylidae) Treatment for Calves on Cow and Calf Weight Gains. Journal of Economic Entomology, 80(2), 451-454. https://doi.org/DOI 10.1093/jee/80.2.451

USDA. (2022). Southern Region News Release Cattle Inventory. https://www.nass.usda.gov/Statistics_by_State/Regional_Office/Southern/includes/Publications/Livestock_Releases/Cattle_Inventory/Cattle2022.pdf

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The use of cover crops and manure to retain soil moisture in Aridisols in Southern Idaho

Purpose

It is important to measure soil moisture in semi-arid regions because future models predict severe droughts and a decrease in rainfall events by up to 40%. The effects of management practices, such as reduced tillage, cover cropping, and manure application, have not been evaluated in the semi-arid and irrigated crop production area of Southern Idaho. In this study, we investigated the effects of cover crops, dairy manure, and tillage on soil physical characteristics (soil water storage, infiltration, runoff, saturated hydraulic conductivity, bulk density) and silage corn yield in silty loam soils. The objectives of this research were to: (a) determine if cover crops and dairy manure increased soil water storage, or if the cover crops were depriving the cash crop of water, (b) determine if infiltration, runoff, saturated hydraulic conductivity, and bulk density were influenced by cover crops and dairy manure, (c) determine if silage corn yield is affected by cover crops and dairy manure, and (d) determine if there are differences between tillage types.

What Did We Do?

This study was conducted at the USDA-ARS Northwest Irrigation and Soils Research Laboratory in Kimberly, Idaho. The experimental design was a split plot with four replicates and repeated measures, and the two main experiment treatments were tillage (strip till vs disk/chisel plow). The four sub-treatments were: (a) control (no cover crop or dairy manure), (b) cover crop only (CC only), (c) manure only (M only), and (d) cover crop with manure (CC + M). Treatments that did not receive manure received inorganic fertilizer to meet recommended crop needs based on spring soil tests. Inorganic fertilizer was only applied to manure treatments if spring soil tests indicated that additional nutrients were required. Stockpiled dairy manure was applied with a manure spreader at a rate of 30 ton per acre (dry weight) in the fall after corn silage harvest and incorporated by disking or left on the surface. Both the corn silage and the triticale were irrigated using handlines, as needed, during the water season, which was generally from mid-April through mid-October. Soil moisture was measured using a neutron probe throughout each growing season. Neutron probe measurements were collected every 6 inches to a maximum depth of 60 inches one to two times per month. Soil water storage (SWS) was calculated from 0 to 12 inches, 0 to 24 inches, and 0 to 60 inches using weighted depth increments. A Cornell Sprinkle Infiltrometer was used to measure infiltration and runoff rates, field saturated infiltrability, and rainfall before runoff in the middle of the growing season in 2020 prior to an irrigation event.

What Have We Learned?

From this research, we found that the use of winter cover crops and fall applied solid dairy manure did not improve soil water storage in the semi-arid and calcareous soils in Southern Idaho. Soil water storage tended to be lower in the CC + M plots (Figure 1). The CC + M plots were able to infiltrate more water prior to runoff than the control plots, suggesting that the CC + M plots are drier (Figure 2). Infiltration, runoff, and saturated hydraulic conductivity did not improve with the treatments and remained similar to the control plots. Although some research has shown improvements in soil moisture, soil physical properties, and dry biomass yield when using reduced tillage practices, there were no differences between reduced tillage and conventional tillage. Silage corn yields tended to be highest in the M only plots and lowest in the CC + M plots, however there were no treatment differences in three of the six years of the study (Figure 3). Using triticale as a winter cover crop would be beneficial to increase total dry biomass yields in dairy systems that would like to increase their forage production, however it is not advised if a producer is only looking to increase silage production.

 

Figure 1. Average soil moisture storage (SWS; inch of water) by treatment from 2016 to 2021 in the top 15, top 30, and top 60 inches. Soil moisture storage was calculated from 0 to 12 inches, 0 to 24 inches, and 0 to 60 inches using weighted depth increments. Bars represent mean plus standard error. Columns within years not connected by the same number are significantly different (p<0.05).

 

Figure 2. Average rainfall before runoff by treatment in 2020. Bars represent mean plus standard error. Columns not connected by the same number are significantly different (p<0.05).

 

Figure 3. Average dry biomass yield for silage corn by treatment from 2016 to 2021. Bars represent mean plus standard error. Columns within years not connected by the same number are significantly different (p<0.05).

Future Plans

This spring, inversion tillage will be performed prior to planting silage corn to incorporate the dairy manure into the topsoil. Dairy manure has not been applied to the field since fall of 2020. Inorganic fertilizer will be applied if needed.

Authors

Presenting author

Kevin Kruger, Research Support Scientist, University of Idaho

Corresponding author

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

Corresponding author email address

jenifer.yost@usda.gov

Additional authors

April B. Leytem, Research Soil Scientist, USDA-ARS; Robert S. Dungan, Research Microbiologist, USDA-ARS; Linda R. Schott, Nutrient and Waste Management Extension Specialist, University of Idaho

Additional Information

This research was presented at the virtual ASA, CSSA, SSSA International Annual Meeting in November of 2020. The link to the recorded presentation is found in the citation below. Although this research is not published in a scientific journal yet, we will be submitting a paper to Agricultural Water Management in early to mid 2022.

Yost, J.L., Leytem, A.B., Dungan, R.S., & Schott, L.R. (2020). The Use of Cover Crops and Manure to Retain Soil Moisture in Aridisols in Southern Idaho [Abstract]. ASA, CSSA and SSSA International Annual Meetings (2020) | Virtual, Phoenix, AZ.

https://scisoc.confex.com/scisoc/2020am/meetingapp.cgi/Paper/126244

Acknowledgements

The authors would like to thank Joy Lynn Barsotti for collecting the neutron probe measurements.

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University of Idaho Sustainable Agriculture project seeks to create a bioeconomy from dairy byproducts to increase nutrient recycling

Purpose

This Sustainable Agriculture Systems project is called “Idaho Sustainable Agriculture Initiative for Dairy (ISAID).” Its main purpose is to create a bioeconomy around dairy manure and its byproducts, generating a circular use and economy of nutrients (Figure 1). Idaho is currently the third largest milk-producing state in the USA (USDA-NASS, 2021). Idaho dairy farms typically operate as confined operations that concentrate a significant amount of manure and nutrients in relatively small areas. Over the years, this situation has increased the concentration of nutrients in farms surrounding dairies. Meanwhile, distant farms may not benefit from using those nutrients (Leytem, et al. 2021). Except for its exceptional fertilizer and soil amendment value (USEPA, 2015), dairy manure is seen as a nuisance that needs to be managed well. Manure handling and use generate expenses for the producers and may be a nuisance for the neighboring communities and a potential environmental risk for the areas surrounding dairy production (Berg, et al. 2017; Moore and Ippolito, 2009; Sheffield, et al. 2008). This multidisciplinary project aims to create bioproducts from manure to significantly change the nutrient balance and the economic impact for producers in the region. Implementing the various strategies included in the project will help export nutrients to in-need areas within the region or outside the watershed altogether. In addition, increased income from manure processing would allow for better management and reduction of overall costs associated with nutrient management in the region.  The ISAID project includes three main areas that are integrated to generate the highest impact possible. Research, Extension, and Education are the distinctive areas of work. Still, these areas don’t work as silos, having a lot of integration to get the most of everybody’s work in the project.

What Did We Do?

Figure 1. Dairy bioeconomy

A group of 25 researchers in diverse areas of expertise obtained a USDA-NIFA Sustainable Agricultural Systems grant to conduct long-term (five years or more) projects. On the research side, the multifaceted studies that are under development include: use of amendments in manure composting to increase compost quality and value, reducing air emissions; nutrients’ extraction from various fractions of manure treatment to concentrate specific nutrients for individual commercialization (including nitrogen, phosphorous, and carbon); generation of hydrochar and biochar from dairy manure; bio-plastics production; cover crops use to increase nutrient extraction and soil health; fine-tuning fertilizer guides for crops using manure, compost, and other bioproducts. Analysis of each product’s economic and social impact separately and as a multi-prong approach. The extension component includes outreach to livestock and crop producers, local authorities, and communities to communicate the applicability of researched technologies and techniques, their impacts, benefits and challenges. The development of programs to train producers, allied industry, their workforce government employees on the diverse applications resulting from the project. The education component includes the participation of graduate and undergraduate students in all facets of the project and the development of educational programs for undergraduate and graduate students on topics associated with manure and nutrient management, bioeconomy, and on-farm application and management of these technologies and techniques.

What Have We Learned?

This project just finished the first of its five years; most of the projects are in the inception phase. We are generating baseline data and linking together diverse processes to determine possible interactions and needed extension and instructional needs. The corresponding poster includes a detailed list of projects associated with the grant, their corresponding principal investigators, and any recent advances. Some examples of project outcomes include the Water Machine that extracts phosphorous from waters with high nutrient content. Ammonia extraction from dairy wastewater. Enhanced composting using zeolites, pumice, biochar, and balanced carbon. Cover crops and corn silage as dual and double cropping. Hydrochar production from dairy manure and bioplastics. We are working on obtaining stakeholders’ input through diverse methods to help assess the needs of the industry and communities and guide the evolution of the research, extension, and education processes.

Future Plans

The project will continue to gather data and evolve. Collaborations and graduate student inquiries about inclusion in some projects are welcomed. We will offer updates at various conferences, including the next Waste to Worth.

Authors

Mario E. de Haro Martí, Extension Educator, University of Idaho Extension, Central District

Corresponding author email address

mdeharo@uidaho.edu

Additional authors

Mireille Chahine, Extension Dairy Specialist, Department of Animal, Veterinary and Food Science, University of Idaho

Linda Schott, Extension Nutrient and Waste Management Specialist,  Department of Soil and Water Systems, University of Idaho

Additional Information

ISAID Website: https://www.uidaho.edu/extension/nutrient-management/isaid

Facebook: https://www.facebook.com/uofiisaid

Instagram: https://www.instagram.com/uofiisaid/

Acknowledgements

This ISAID project is supported by USDA-NIFA SAS award #2020-69012-31

References

Berg, M., Meehan, M., and Scherer T. 2017. Environmental Implications of Excess Fertilizer and Manure on Water Quality. NM1281. https://www.ag.ndsu.edu/publications/environment-natural-resources/environmental-implications-of-excess-fertilizer-and-manure-on-water-quality

Leytem, A. B., Williams, P., Zuidema, S., Martinez, A., Chong, Y. L., Vincent, A., Vincent, A., et al. 2021. Cycling Phosphorus and Nitrogen through Cropping Systems in an Intensive Dairy Production Region. Agronomy, 11(5), 1005. MDPI AG. http://dx.doi.org/10.3390/agronomy11051005

Moore, A. and Ippolito, J. 2009. Dairy Manure Field Applications—How Much is Too Much? CIS1156. http://www.extension.uidaho.edu/publishing/pdf/CIS/CIS1156.pdf

Sheffield, R. E., Ndegwa, P., Gamroth, M., and de Haro Martí, M. E. 2008. Odor Control Practices for Northwest Dairies. CIS1148. http://www.extension.uidaho.edu/publishing/pdf/CIS/CIS1148.pdf

USDA-NASS. 2021. Quick Stats. Retrieved 02 27, 2022, from National Agricultural Statistics Service: https://quickstats.nass.usda.gov

USEPA. 2015. Beneficial Uses of Manure and Environmental Protection. Fact Sheet. https://www.epa.gov/sites/default/files/2015-08/documents/beneficial_uses_of_manure_final_aug2015_1.pdf

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A mass balance approach to estimate methane and ammonia emissions from non-ruminant livestock barns

Purpose

Producers are under pressure to demonstrate and document environmental sustainability. Responding to these pressures requires measurements to demonstrate greenhouse gas (GHG) emissions and/or changes over time. Stored manure emissions are a critical piece of livestock agriculture’s contribution to GHG production. Manure sample‐based estimates show promise for estimating methane (CH4) production rates from stored manure but deserve more extensive testing and comparison to farm‐level measurements. Understanding the causes for variability offer opportunity for more realistic and farm‐specific GHG emissions. Improved GHG measurements or estimates will more accurately predict current GHG emission levels, identify mitigation techniques, and focus resources where they are needed. This project offers an innovative approach to improvement of air quality and strengthens engagement by the livestock sector in sustainability discussions.

Although CH4 and ammonia (NH3) emissions from non-ruminant livestock production systems are primarily released from stored manure, current emission inventories (models) do not account for all production and management systems. The purpose of this project was to track flows of nitrogen, volatile solids (VS), and ash into and out of several commercial livestock barns to estimate CH4 and NH3 emissions. Using a mass balance approach, volatile components like nitrogen and volatile solids are supported through simultaneous balances with ash (fixed solids). These mass-balance based estimates can be compared to national inventory emission estimates and serve as sustainability metrics, regulatory reporting, and management decisions.

What Did We Do?

In the initial step of this project, experimental data for VS, the precursor to methane, are compared to fixed estimates in methane emission estimation tools, like the EPA State Greenhouse Gas Inventory Tool (US EPA, 2017).

The litter from a commercial turkey finishing barn housing between 13,000 and 18,000 birds was sampled weekly for one month, with one additional sampling day one month later. VS concentrations were analyzed for each sample and used to estimate total VS production per year assuming six 15,000 bird flocks (Soriano et al., 2022). A range of VS percentage values for deep-pit cattle facilities were taken from Cortus et al. (2021) and converted to total VS production per year. A range of VS concentrations for deep-pit swine manure storage were taken from Andersen et al. (2015) and used to find total VS production per year of that system as well. Next, total VS productions per year were estimated for the same three systems using the State Greenhouse Gas Inventory Tool.

What Have We Learned?

Table 1 summarizes all calculated total VS values and CH4 estimates per year for both the estimation tool and the experimental data. For each of the three systems, the state inventory estimated total VS value falls within the ranges calculated with experimental data, however, the estimates cannot account for the variabilities found within each system. As seen in the experimental total VS values, there can be a large range of VS production due to differences within specific operations of each system. Total VS relates directly to CH4 emissions, so accurate estimates are important for determining greenhouse gas emission potential of a specific operation.

Table 1. All calculated total VS values and CH4 emissions estimates for each of the three systems.
Total VS production (kg/yr) Emissions*
State Inventory Experimental Values m3CH4
Feedlot Steer (500 head) 334,990 260,758 – 1,002,675 1,262**
Grower-Finisher Swine (1,200 head 160,408 107,514  – 216,669 19,050
Turkey (15,000 head) 314,594 206,838 – 359,245 1,699
*Emissions estimates found through the State Greenhouse Gas Inventory Tool
**Feedlot steer emission estimate assumes an open feedlot manure management system

Future Plans

Next steps for this study will include manure sampling at additional commercial turkey barns, deep-pit grower-finisher swine barns, and dairy cattle systems. Similar mass balances will be performed to determine total VS and nitrogen content to calculate CH4 and NH3 emissions from each system. These calculated values will again be compared to outputs of emission estimating tools.

Authors

Anna Warmka, Undergraduate Student, University of Minnesota – Twin Cities, Department of Bioproducts and Biosystems Engineering

Corresponding author email address

warmk011@umn.edu

Additional authors

Erin Cortus, Associate Professor, University of Minnesota – Twin Cities, Department of Bioproducts and Biosystems Engineering

Noelle Soriano, MS Student, University of Minnesota – Twin Cities, Department of Bioproducts and Biosystems Engineering

Melissa Wilson, Assistant Professor, University of Minnesota – Twin Cities, Department of Soil, Water, and Climate

Bo Hu, Professor, University of Minnesota – Twin Cities, Department of Bioproducts and Biosystems Engineering

Additional Information

Andersen, D.S., M.B. Van Weelden, S.L. Trabue, and L.M. Pepple. “Lab-Assay for Estimating Methane Emissions from Deep-Pit Swine Manure Storages.” Journal of Environmental Management 159 (August 2015): 18–26. https://doi.org/10.1016/j.jenvman.2015.05.003.

Cortus, E.L., B.P. Hetchler, M.J. Spiehs, and W.C. Rusche. “Environmental Conditions and Gas Concentrations in Deep-Pit Finishing Cattle Facilities: A Descriptive Study.” Transactions of the ASABE 64, no. 1 (2021): 31–48. https://doi.org/10.13031/trans.14040.

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Acknowledgements

This research was supported by the Rapid Agricultural Response Fund. We also express appreciation to farmer cooperators who allowed us to collect data on their farms and shared their observations with us.

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