Manure nutrient trends and creating dynamic “book values” through ManureDB

This webinar highlights ManureDB, a database of manure samples informing “book values”. Having current manure test numbers will assist in more accurate nutrient management planning, manure storage design, manure land application, and serve agricultural modeling purposes. This presentation was originally broadcast on June 17, 2022. Continue reading “Manure nutrient trends and creating dynamic “book values” through ManureDB”

Promoting Manure Composting for Livestock Operations

Purpose

While both raw and composted manure benefit soil health and crop production, there are benefits to creating and land-applying composted manure over raw manure. Product uniformity, volume, weed seed, pathogen and parasite reduction and nutrient stability are just a few of the benefits. However, composting manure in Minnesota and North Dakota have yet to gain popularity.

A group of compost producers, who ultimately became our producer cooperators and partnered with us for workshops, were consulted on the reason composting manure is not more common. One said, “It is lack of understanding and time management that holds most other farmers back from composting manure; they do not know how much composting can help their operation.” Another mentioned, “When I started researching composting for my farm, I took a three-day class in Illinois because there wasn’t anything available in North Dakota or Minnesota. Most farmers are not willing to travel that far. There is a need for composting education programs in the two-state area.”

What Did We Do?

NDSU Extension partnered with the University of Minnesota Extension with the original plan of holding four workshops in two years (two each in ND and MN). When implications from the COVID-19 pandemic ensued, we changed our plans to host an online workshop in 2020 and were able to continue with two in-person workshops in 2021.

The online workshop consisted of 13 videos that were sent to registrants 2 weeks before an online, live discussion was held in August 2020 with the presentation team as well as 3 producer cooperators. One of the videos consisted of on-farm interviews with each of our producer cooperators to show the registrants the ability to manage compost differently with similar results. The videos are still available and have been viewed collectively 1,845 times.

The in-person workshops were held in July and August of 2021. Each workshop covered the same material as the online workshop and all three producer cooperators attended each event. The producer cooperators were responsible for helping attendees with the compost diagnostics activity as well as answering questions during a panel discussion.

What Have We Learned?

Online Workshop

    • 180 people registered for the online workshop and 50 joined the live discussion with presenters and producer cooperators
    • 43 responded to the immediate follow-up survey where
      • 76% thought the self-paced format was excellent
      • 64% thought the amount of material was excellent
      • 62% thought the topics covered were excellent
    • 15 months after the online workshop, 21 people participated in a follow-up survey and as a result of the workshop, 58% reported they had altered their manure composting practices.
    • When asked what manure composting change(s) they made, 58% reported they improved their operations adding,
      • “I have more confidence in my ability to compost successfully and have a better understanding of the environmental impacts of composting.”
      • “I no longer have to pay someone to haul away our waste”
      • “Although not composting on a commercial level, I manage several community gardens where large volumes of biomass are accumulated. After learning additional techniques, my piles were hotter and decomposed more quickly. The key? More moisture!”

Moving the workshop online for the first year allowed us to fully engage our producer cooperators. The online workshop resulted in participant comments such as,

    • “Well organized and executed. Appreciated that videos were individual by topic area, short, and focused. That allowed me to watch what was relevant and fit it into my day more easily.”
    • “Really enjoyed the discussion and interaction between the three cooperators. Also appreciated having enough time to flesh out the information, i.e., didn’t try to squeeze it into one hour.”

Though an in-person meeting would have allowed more hands-on experience, the online version reached a broader audience with attendees from 31 states and 3 countries.

In-person Workshops

    • 31 people attended the in-person workshops in ND and MN, of which 10 participated in a 4-month follow-up survey
      • 67% of those who made changes as a result of the workshop stated they started composting manure
    • 100% of those who did not make changes were either agency or university Extension/research personnel who reported the workshops impacted them, their work, and/or their relationship with their clients by:
      • “Allowing me to be more educated about manure composting so that when producers inquire about composting I am able to give them accurate information.”
      • “Using workshop information to inform clients of another manure handling method to consider; composting.”

The workshops, both online and in-person, facilitated discussion and mutual learning among experienced and novice composters of livestock manure.

Future Plans

Questions about static composting were asked during both the online and in-person workshops. This practice is not common in North Dakota or Minnesota so there is certainly a future learning and workshop opportunity.

Authors

Mary A. Keena, Extension Specialist, North Dakota State University

Corresponding author email address

mary.keena@ndsu.edu

Additional authors

Chryseis Modderman, Extension Educator, University of Minnesota; Melissa L. Wilson, Assistant Professor and Extension Specialist, University of Minnesota; William J. Gale, Extension Agent, North Dakota State University

Additional Information

    1. Online Composting Workshop Videos YouTube playlist: https://youtube.com/playlist?list=PLnn8HanJ32l6uhwdS9m-G1z8Bq1U0aJzF
    1. Two compost-related publications for producers were created for use while at the compost rows:

Acknowledgements

This project was funded by North Central Sustainable Agriculture Research and Education (NC-SARE).

 

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.

Assessment of physical properties for cover crop and manure applied soils in Idaho’s Magic Valley

Purpose

Idaho ranks in the top 10 in the US for dairy, potato, barley, hay, sugarbeet, corn silage, and dry bean production with the highest producing area being in South Central Idaho. Crop and livestock producers in the Magic Valley depend on affordable access to clean water, healthy and productive soils, and quality grazing land to remain profitable. However, portions of the Middle Snake River, which provides irrigation and drinking water to the Magic Valley, have been impaired by high phosphorous and sediment loading for over two decades (Tetra Tech, 2014). To measure progress in producer efforts for reducing erosion and runoff, appropriate methods need identified. The soils in this region are prone to crusting, have low organic matter, and are high in calcium carbonates making these soils unique to much of the United States. Thus, the overall goal of this project was to identify management practices that enhance soil health physical properties in the Magic Valley.

What Did We Do?

Two study sites were located on the USDA-ARS Northwest Irrigation & Soils Research Laboratory farm in Kimberly, Idaho, and were established in 2013 (Long-Term Manure) and 2016 (Cover Crop). Long-Term Manure was set up as a randomized complete block design with four replicates and eight treatments. The treatments are as follows: annual application of solid dairy manure at rates of (i) 10, (ii) 20, and (iii) 30 ton per acre(dry weight), biennial application of solid dairy manure at rates of (iv) 10, (v) 20, and (vi) 30 ton per acre (dry weight), (vii) application of inorganic fertilizer (applied to match manure N and P rates; Fert), and (viii) no amendments (Control). A commercial crop rotation of wheat-potato-barley-sugarbeet was used at this study site, and sampling occurred under sugarbeet in 2020. All plots were disked immediately after manure application, and all plots were moldboard plowed prior to sugarbeet and potato planting. The Cover Crop study was set up as a split plot design with four replications and tillage as the main experimental factor (strip till vs disk/chisel plow). The four sub-treatments are as follows: (a) no cover crop or dairy manure (Control), (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 and the manure did not meet the crop needs. From 2016 to 2021, the field was cropped with continuous silage corn. Triticale was used as a winter forage cover crop and was planted directly after manure application and was harvested within one week of corn planting. Stockpiled dairy manure was applied 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.

The physical properties accessed for each study in late summer 2020 were soil aggregate stability, runoff rate and rainfall before runoff, bulk density, and compaction. Two methods were used to measure soil aggregate stability: wet sieving and a hybrid method utilizing a Cornell Sprinkle Infiltrometer (CSI). The wet sieving method incorporated four nested stainless steel wire sieves at particle diameters of 5/32, 5/64, 1/64, and 0.002 inch. The samples were submerged in 9.5 inch of water oscillating up and down 1.5 inch at 30 oscillations per minute for 10 minutes. A CSI was used to measure soil aggregate stability at the heights of 1, 3, and 5 feet. The CSI operated at a constant rainfall rate of 0.79 inch of rainfall per 10 min of operation. Runoff rate and rainfall before runoff were calculated based on the values collected from the CSI using the equations listed in van Es and Schindelbeck (2001). The CSI was placed on top of a metal ring (9.5 inch diameter), and a runoff tube was fitted in the metal ring to measure runoff. The CSI had an air entry of 3.9 inch, and data was recorded every 2 minutes once runoff started to occur until the outflow reached steady state. Because each measurement took a minimum of one hour, only one block was measured each day for a total of four days. Bulk density measurements were taken at depths of 0-2, 2-4, and 4-6 inch at each plot. Compaction was measured using a penetrometer to measure a total depth of 12 inch at increments of 1 inch.

What Have We Learned?

Two methods (wet sieving and CSI hybrid) were compared for accessing soil aggregate stability among the two studies. No differences in aggregate stability were found when the wet sieving method was used among treatments for both studies (Figure 1). However, the CSI hybrid method was found to be statistically different at an operational height of 1 foot among treatments at mean values of 0.147 ± 0.005 inch (CC + M), 0.145 ± 0.005 inch(CC only), and 0.146 ± 0.005 inch (M only) as compared to the control (0.124 ± 0.005 inch) for the Cover Crop study. It is also clear that there are large numerical differences in mean weight diameters between the operational heights for the Cover Crop study.

Figure 1. The mean weight diameter (MWD) at the Long-Term Manure (A, B) and Cover Crop (C, D) study sites. A and C represent MWD using the traditional wet sieving method, and B and D represent MWD using the Cornell Sprinkle Infiltrometer at 1, 3, and 5 foot. At the Long-Term Manure study site, 10A, 20A, and 30A represents plots that received dairy manure annually (ton per acre), and 10B, 20B, and 30B represents plots that received dairy manure biennially (ton per acre). Bars represent mean plus standard error. Columns within years not connected by the same letter are significantly different (p<0.05).

 

Significant differences in rainfall before runoff were found between treatments in the Cover Crop study, and the mean values were 2.26 ± 0.23 in (CC + M), 1.70 ± 0.23 in (CC only), and 1.53 ± 0.23 in (M only) when compared to the control (1.45 ± 0.23 in) (Figure 2). No differences were found in the Long-Term Manure study. When measuring bulk density, it was found that measurements at the 0–2-inch depth were found to be statically significant (p≤0.05) with means of 52.7 ± 3.7 pound per cubic foot (CC + M), 59.6 ± 3.7 pound per cubic foot (CC only), and 49.4 ± 3.7 pound per cubic foot (M only) when compared to the control (65.9 ± 3.7  pound per cubic foot), respectively. Compaction was found to be statistically significant at the depths of 1 through 4 inch and 10 and 12 inches. The tillage by treatment effect was also found to be statistically significant at 2 and 3 inches. Assessing physical properties among management practices can give producers a clearer insight into soil health in the Magic Valley.

Figure 2. The average runoff rate and rainfall before runoff at the Long-Term Manure (A, B) and Cover Crop (C, D) study sites. At the Long-Term Manure study site, 10A, 20A, and 30A represents plots that received dairy manure annually (ton per acre), and 10B, 20B, and 30B represents plots that received dairy manure biennially (ton per acre). Bars represent mean plus standard error. Columns within years not connected by the same letter are significantly different (p<0.05).

Future Plans

At the Long-Term Manure study site, dairy manure was applied annually or biannually from 2013-2019. The project now focuses on nutrient drawdown and manure will no longer be applied. Cover crops may be incorporated into the project. At the Cover Crop study site, inversion tillage will be performed spring of 2022 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

Linda R. Schott, Nutrient and Waste Management Extension Specialist, University of Idaho

Corresponding author email address

lschott@uidaho.edu

Additional authors

Jenifer L. Yost, Research Soil Scientist, USDA-ARS; April B. Leytem, Research Soil Scientist, USDA-ARS; Robert S. Dungan, Research Microbiologist, USDA-ARS; Amber D. Moore, Soil Fertility Specialist, Oregon State University

Additional Information

Part of 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., Kruger, K., Leytem, A.B., Dungan, R.S., & Schott, L.R. (2021). Measuring Soil Aggregate Stability Using Three Methods in Aridisols Under Continuous Corn in Southern Idaho [Abstract]. ASA, CSSA, SSSA International Annual Meeting, Salt Lake City, UT.

https://scisoc.confex.com/scisoc/2021am/meetingapp.cgi/Paper/138171

More information about the Long-Term Manure project can be found in the following scientific papers:

Leytem, A.B., Moore, A.D., & Dungan, R.S. (2019). Greenhouse gas emissions from an irrigated crop rotation utilizing dairy manure. Soil Science Society of America Journal, 83, 137-152.

https://eprints.nwisrl.ars.usda.gov/id/eprint/1693/

Bierer, A.M., Leytem, A.B., Dungan, R.S., Moore, A.D., & Bjorneberg, D.L. (2021). Soil organic carbon dynamics in semi-arid irrigated cropping systems. Agronomy, 11, 484.

https://doi.org/10.3390/agronomy11030484

The papers that were referenced in this proceedings paper are:

Reynolds, W. D., & Elrick, D. E. (1990). Ponded infiltration from a single ring: I. Analysis of steady flow. Soil Science Society of America Journal, 54, 1233–1241.

https://doi.org/10.2136/sssaj1990.03615995005400050006x.

Tetra Tech. (2014). Reevaluation of Mid Snake/Upper Snake-Rock Subbasin TMDL: Data Summary, Evaluation, and Assessment.

van Es, H. & Schindelbeck, R. (2001). Field Procedures and Data Analysis for the Cornell Sprinkler Infiltrometer. Department of Crop and Soil Science Research Series R03-01. Cornell University.

Acknowledgements

This project was funded by a USDA ARS Cooperative Agreement and USDA NIFA Project Number IDA01657. The authors would like to thank Emerson Kemper for assisting with the lab work and Peiyao Chen for assisting with field work.

 

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.

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.

Frequency of Germinable Weed Seeds in Poultry Litters of North Carolina

Purpose

With high input costs in 2022, many farmers are looking for affordable sources of nutrients.  Poultry litter is in high abundance in areas of intense poultry production, such as North Carolina. However, a common concern for farmers is whether poultry litter will carry weed seed onto their farms. With the need to better distribute nutrients throughout these areas, the transport of poultry litter is necessary.    Overcoming the concern about weed seeds is critical to improve these nutrient imbalances. Therefore, a germination study was conducted on 61 random poultry litters collected across North Carolina to determine the presence of viable weed seeds.

What Did We Do?

A series of 61 poultry litters were submitted to NC State University for testing, collected from industry representatives and Extension Agents across the state. Poultry litters were diluted with potting media to allow for germination of any existing weed seeds at a 9:1 (potting media:litter) ratio on a dry weight basis. Germination studies were then conducted using 20 g of the potting media-litter mix, replicated 5 times. Positive controls included potting media alone, and potting media mixed with poultry litter to verify there was no inhibitory effect of the poultry litter on germination. Both positive controls were spiked with one of three weed species at varying rates: 50 mustard, 50 rye, or 30 sicklepod. Additionally, three subsamples (20 g) of 10 of the poultry litters were wet sieved using three sieves with 2.8-, 1.0-, and 0.4-mm mesh sizes and dried at 35 °C. Seeds were counted under a dissecting microscope, and when located, seeds were removed and tested for viability using the imbibed seed crush test as described by Borza et al. (2007).

What Have We Learned?

Germination studies suggest small numbers of viable weed seeds, as only one seed germinated from unspiked samples. However, total weed counts suggest there can be high total seed numbers in the litters, with an average seed content of 1.17 seeds/100-g. Additionally, approximately 15% of the seeds collected were viable.

Future Plans

We intend to continue researching this topic and hope to further understand the impact of stockpiling, litter management, and handling on viable weed seeds in litter sources.

Authors

Stephanie B. Kulesza, Nutrient Management and Animal Waste Specialist, NC State University

Corresponding author email address

Sbkulesz@ncsu.edu

Additional authors

Ramon Leon, Weed Biology and Ecology Specialist, NC State University

Miguel Castillo, Forage Specialist, NC State University

Stephanie Sosinski, Forage Lab Technician, NC State University

 

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.

Groundwater Nitrate Variability at the Field Level: How to Unravel the Puzzle

Purpose

Typical groundwater monitoring for nitrate concentrations in single monitoring wells and monitoring- well networks cannot always correctly explain the nitrate distribution in groundwater at the field level. Nitrate can originate from various sources (e.g., chemical fertilizers, manure, etc.) and at various times (e.g., current practice versus legacy nitrate). Nitrate in groundwater can also vary spatially, temporally, and with groundwater flow direction. Figure 1 illustrates some of the causes of spatial and temporal nitrate variations at the field level related to water and dissolved nitrate movement. Figure 2 is one example of how complex geology (e.g., stream meanders) can affect, and complicate, groundwater and nitrate movement.

Figure 1. Factors that can contribute to spatial and temporal variations in nitrate in groundwater at the field level (with permission from the Journal of Nutrient Management).
Figure 2. Common example of a complex hydrogeology that can affect groundwater flow and nitrate concentrations at the field level.

This presentation discusses a case study where we used high resolution and advanced methods to help identify the source(s) of nitrate in groundwater at the field level. These approaches can help in permitting and other issues that center around the reporting of elevated nitrate concentrations in groundwater.

What Did We Do?

This case study involves the “upgradient” monitoring well (MW-D) in a “simple,” sandy, water table aquifer at a commercial dairy. The regulators initially considered the nitrate concentration observed at the upgradient monitoring well, MW-D in Figure 3, which was well below the drinking water criterion of 10 milligrams per liter (mg/L) to be representative of the regional groundwater (background) entering the site. However, the literature indicated the regional groundwater already contained very high nitrate concentrations that originated over many decades of chemical fertilizer applications (“legacy nitrate”). We used both high resolution and advanced approaches to unravel the cause of the anomalous nitrate concentration in groundwater at “upgradient” monitoring well MW-D so we could help negotiate an appropriate and reasonable background nitrate concentration for the dairy’s permit.

Figure 3. Case study – unraveling changes in local groundwater flow directions and nitrate concentrations using continuous groundwater level monitoring.

First, we suspected that MW-D, which is located close to the vegetative treatment area (VTA), was not a representative well for groundwater quality due to large, episodic recharge events caused by ponding on the VTA. To test this hypothesis, we installed three monitoring wells just upgradient from MW-D (MW-A, -B, and -C in Figure 3), equipped all four monitoring wells with water-level data loggers, and used these data to calculate continuous groundwater flow direction changes with time. Monitoring wells MW-A, -B, -C, and –D are screened between 28-38, 28-38, 26-36, and 22-32 feet below ground level, respectively, to monitor the water table. The groundwater elevation data and monthly nitrate monitoring (Figure 3) indicated (1) the water table fluctuated significantly and episodically in response to precipitation and ponding on the VTA, (2) the groundwater flow direction changed significantly when ponding occurred (so what is “upgradient”?), and (3)  the nitrate concentration changed at upgradient monitoring well MW-A from more than 40 mg/L when regional groundwater flowed onto the site to about 2 mg/L when ponding caused an episodic reversal of the groundwater flow direction.

Second, we tested groundwater from selected monitoring wells and ponded water on the VTA for natural isotopes in water molecules (18O and 2H). The water table monitoring wells were screened across the water table with top of screen tops ranging between 22 and 50 feet below ground level, depending on ground elevation. Two of the monitoring wells were deep wells with screen depths of 80 to 85 and 52 to 57 feet below ground level. The 18O and 2H concentrations in precipitation vary with temperature and therefore can vary from storm to storm and season to season. Groundwater acquires a “uniform” 18O and 2H signature which approximates the weighted average of the precipitation over the year(s) and therefore, can be different from that of an individual storm. Figure 4 shows that the 18O and 2H signature of groundwater at the presumptive background well (MW-D) changed from its groundwater signature before the storm to the signature of the ponded water in the VTA, due to a large spring storm that caused flooding on the VTA. The changes in 18O and 2H in groundwater at MW-D are consistent with the rapid groundwater mounding at MW-D. Furthermore, the low nitrate concentration in groundwater at MW-D was consistent with the low nitrate concentration observed in the ponded water on the VTA; the ponded water on the VTA diluted the legacy nitrate from the regional groundwater.

Figure 4. Case study – unraveling changes in groundwater nitrate concentrations due to episodic groundwater mounding using water isotopes.

Finally, we tested nitrate (NO3) ions in the groundwater for their 15N and 18O signatures. Nitrate isotopes have been used to distinguish between nitrate sources, such as chemical fertilizer and manure, for more than 20 years. Figure 5 shows the chemical and manure nitrate source fields based on nitrate isotopes. The groundwater at monitoring wells MW-A through MW-C had both isotopic signatures indicative of chemical fertilizer (legacy nitrate) and elevated nitrate concentrations consistent with those reported for the regional groundwater.

Figure 5. Case study – unraveling the source of legacy nitrate using nitrate isotopes.

What Have We Learned?

For this case study, we needed to demonstrate that the presumptive background monitoring well nitrate was not truly representative of background groundwater nitrate and explain why. Otherwise, the dairy would have been encumbered by an unfairly low background concentration in its permit. Data from typical groundwater monitoring well networks and monitoring plans may not be sufficient for either of these requirements.

High resolution and advanced monitoring approaches, such as using data loggers for continuous water level monitoring and groundwater flow maps and isotopic tracers for sourcing water and nitrate, have been around for decades. Using these approaches to unravel puzzling agricultural problems can be very helpful.

Future Plans

We will continue to use these and other high resolution and advanced investigative techniques, honed in the field of contaminant hydrogeology, to solve agricultural surface water and groundwater issues.

Authors

Michael Sklash, Ph.D., Senior Hydrogeologist, Dragun Corporation, Farmington Hills, MI. Msklash@dragun.com

Additional author

Fatemeh Vakili, Ph.D., Hydrogeologist, Dragun Corporation, Windsor, ON

Additional Information

See Journal of Nutrient Management, 2020 and 2021

 

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.

Improving Production and Minimizing Nutrient Loss in Grazing Systems through the Use of Grass-Legume Mixtures

Purpose

Feed costs are typically one of the largest costs of dairy and beef cattle production. Grazing is an option that can greatly reduce the need for, and cost of, hay production.  The addition of legumes into the pasture can reduce the need for additional fertilizer.Unfortunately, grazing can also accelerate nutrient cycling and increase nitrogen (N) leaching.  This study examines the effect of adding birdsfoot trefoil (Lotus corniculatus L.), a legume with condensed tannins (CT), to the grazing system. Condensed tannins are noted for their ability to improve nutrient utilization and shift N excretion from the urine to the feces.  Nutrient cycling under the grass-legume mixtures and grass monocultures were evaluated.  The nitrogen content in urine and feces of cattle grazing forages with, and without CT, was also examined and compared to a traditional total mixed ration (TMR) diet.

What Did We Do?

Four grasses, tall fescue (Schedonorus arundinaceus Schreb.), meadow bromegrass (Bromus biebersteinii Roem. & Schult.), orchardgrass (Dactylis glomerata L.), and perennial ryegrass (Lolium perenne L.) in monocultures, and in binary mixtures with birdsfoot trefoil (Lotus corniculatus L.) were evaluated. The study was conducted at the Utah State University Intermountain Irrigated Pasture facility in Lewiston, Utah.  Jersey dairy heifers (~450 lbs) were used to rotationally graze the paddocks with heifers being moved to a new paddock every seven days for a 35-day rotation cycle. Pastures were irrigated every two weeks.  All pastures were fertilized with Chilean nitrate (25 lbs N/acre) in April.  Grass monocultures also received Feathermeal (31 lbs N/acre) in the late spring/early summer, and an additional dose of Chilean nitrate (25 lbs N/acre) in July.  Body weight, and urine and fecal (grab) samples were collected before each grazing event, and at the end of the grazing season.  Urine samples were analyzed for urea-N on a Lachat FIA analyzer.  Fecal samples were analyzed for total N and total carbon by combustion analysis using an Elementar varioMAX CN elemental analyzer, and ammonia-N on a FIAlab 2500 instrument. Soil samples were collected at the beginning and end of each grazing season, and analyzed for available N (nitrate and ammonia) on a Lachat FIA analyzer.  Soil water (leachate) N was monitored by means of zero-tension lysimeters bi-weekly during the growing season, and as much as possible in the spring and fall.  Leachate samples were analyzed for nitrate-nitrite concentration on a Lachat FIA analyzer. The amount of leachate produced from each lysimeter was measured, and total Leachate N determined. Forage protein levels were determined using NIR. Nutrient cycling in the urine and feces were analyzed and compared to the overall protein levels in the forage.

What Have We Learned?

Average daily gains were greater with the grass-legume mixtures than the monocultures (Figure 1). This is most likely due to the higher protein content of the grass-legume mixtures versus the grass monocultures (data not shown).

Figure 1. Average Daily Gain under grass-legume mixtures versus grass monocultures versus a total mixed ration in a feedlot setting

Both the urea-N concentration in the urine (Figure 2), and the fecal N content (Figure 3) were higher in the grass-legume mixtures than the grass monocultures.  This is most likely the result of being fed a higher protein content diet in the grass-legume mixtures.

Figure 2. Urea-N content in urine when grazing grass-legume mixtures versus grass monocultures versus a total mixed ration in a feedlot setting
Figure 3. Fecal Total N content when grazing grass-legume mixtures versus grass monocultures versus a total mixed ration in a feedlot setting

Although the grass monocultures were not heavily fertilized, and the protein content of the monocultures was lower than that of the grass-legume mixtures, nitrogen leaching observed in the leachate was generally higher under the grass monocultures.

Figure 4. Total NO3 lost in leachate per zero-tension lysimeter per year

Grass-legume mixtures may be able to more effectively capture nitrogen due to the differences in the rooting structure and the microbial populations. The grass-legume mixtures were also better economically.

Future Plans

The forage type explains approximately 40% of the variability. We plan to examine the impact of breed on the rates of gain and nutrient cycling next.

Authors

Rhonda Miller, Ph.D., Agricultural Environmental Quality Extension Specialist, Utah State University

Corresponding author email address

rhonda.miller@usu.edu

Additional authors

Blair Waldron, ARS Forage & Range Research Lab; Clay Isom, Utah State University; Kara Thornton – Kurth, Utah State University; Kerry Rood, Utah State University; Earl Creech, Utah State University; Mike Peel, ARS Forage & Range Research Lab; Jacob Hadfield, Utah State University; Ryan Larson, Utah State University, and Marcus Rose, Bureau Land Management

Additional Information

Hadfield, J., B. Waldron, S. Isom, R. Feuz, R. Larsen, J. Creech, M. Rose, J. Long, M. Peel, R. Miller, K. Rood, A. Young, R. Stott, A. Sweat, and K. Thornton. 2021. The effects of organic grass and grass-birdsfoot trefoil pastures on Jersey heifer development: Heifer growth, performance, and economic impact. J. Dairy Sci. 104(10): 10863-10878. DOI: 10.3168/jds.2020-19524.

Rose, M., B. Waldron, S. Isom, M. Peel, K. Thornton, R. Miller, K. Rood, J. Hadfield, J. Long, B. Henderson, and J. Creech.  2021. The effects of organic grass and grass-birdsfoot trefoil pastures on Jersey heifer development: Herbage characteristics affecting intake.  J. Dairy Sci. 104(10): 10879-10895. DOI: 10.3168/jds.2020-19563.

Acknowledgements

Funding for this project was provided by OREI, Western SARE, and Utah State University Experiment Station.

 

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.

Using COMET Tools to Help Farms Plan for the Future

Purpose

Climate change presents real threats to U.S. agricultural production, forest resources and rural economies. Producers and land managers across the country are experiencing climate impacts on their operations through shifting weather patterns and increasingly frequent and severe storms, floods, drought and wildfire. However, producers and land managers also have an opportunity to help address climate change by mitigating greenhouse gas emissions and sequestering soil carbon.

NRCS Conservation Practice Standards have been used for decades by farmers and ranchers to enhance agricultural lands by reducing soil erosion, improving water quality, creating habitat for wildlife and a number of other benefits. In addition to these benefits, many of these practices may reduce greenhouse gas emissions and sequester carbon in woody biomass and soils. As farms look to the future, USDA’s CarbOn Management Evaluation Tools (COMET) can help estimate climate benefits of adopting certain conservation practices for cropland, pasture, rangeland, livestock operations and energy.

What Did We Do?

COMET-Farm provides a complete analysis for site-specific assessment of greenhouse gas emissions and carbon sequestration. COMET-Farm utilizes peer-reviewed greenhouse gas inventory methods sanctioned by the U.S. Department of Agriculture. Results are provided for carbon dioxide, nitrous oxide, methane and soil carbon. COMET-Planner is a web-based tool designed to provide approximate greenhouse gas mitigation potentials of implementing NRCS conservation practice standards.

The COMET tools were developed through a partnership between USDA NRCS and Colorado State University. There is more than a decade of model development experience reflected in COMET. COMET-Farm uses information on management practices on an operation together with spatially-explicit information on climate and soil conditions from USDA databases (which are provided automatically in the tool) to run a series of models that evaluate sources of greenhouse gas emissions and carbon sequestration. By integrating NRCS SSURGO database and site-specific climate data, locality-specific results are presented to COMET-Farm users. There are several modules nested within the model (i.e., Croplands, Livestock, Agroforestry, Energy), and the model relies on biogeochemical process models, IPCC methodologies, and a number of peer reviewed research results.

What Have We Learned?

Put generally, farmers, ranchers, and others can use COMET to easily estimate farm-scale GHG emissions and to explore the impacts of alternative management strategies on their net emissions. The COMET tools have a variety of additional stakeholders and users, including USDA, state governments, companies, carbon finance groups, non-governmental organization and educational institutions. There are many ways the tools can advance climate smart farming for individual farms, such as: use as part of traditional NRCS conservation planning assistance, evaluation of opportunities for farms to participate in carbon markets, as part of development of a carbon farm plan, or to quantify climate benefits for use in direct consumer marketing of farm products. Additionally, other organizations have advanced climate smart farming principles through the use of COMET, both via private industry and state government programs to incentivize conservation practices based on GHG emission reductions quantified with the tool. For examples of success stories using the COMET tools, see the links under Additional Information.

Future Plans

We look forward to continued use of the COMET tools to advance implementation of climate smart agriculture and forestry practices across the U.S.

Authors

Allison Costa, Air Quality Engineer, United States Department of Agriculture

Corresponding author email address

allison.costa@usda.gov

Additional Information

The COMET tools are available online at:  https://comet-farm.com/ and http://comet-planner.com/.

The COMET help desk, YouTube training videos, a calendar of upcoming training events and other resources can be accessed at http://comet-farm.com/HelpPage.

Example of COMET-Planner use by Ben & Jerry’s: https://www.usda.gov/media/blog/2016/12/21/climate-smart-conservation-partnership-serves-two-scoops-farm-solutions

Example of COMET-Planner use by the California Healthy Soils Program: https://www.theclimategroup.org/our-work/news/californias-healthy-soils-program-interview-dr-amrith-gunasekara

 

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.

Reporting 15 year’s of experience in WISE Aeration at manure and wastewater treatment ponds (updated)

Purpose

This presentation offers information about a low-energy high-performance manure and/or wastewater aeration technology.  Referred to as “Widespreading Induced Surface Exchange” (WISE) aeration, its performance is from 4 to 10 times more efficient per watt of energy used compared to traditional bubble blower technology for aeration.  Even though Aeration is well known to provide extensive odor reduction or elimination, its use has not been implemented because of the high energy costs associated with running blowers.  This explains why very little is published about other value offered by aeration.  The presentation discusses WISE aeration, many unexpected benefits, and unstudied results.

This presentation will quickly review the 2019 Waste to Worth presentation previously offered and will then offer additional information learned in the past 3 years, including approximately 20 key points.    For those wanting to visit an actual working site before or after the conference, equipment is installed at a regional composting facility approximately 1 hr away from the Waste to Worth facility, near Wauseon OH.

What Did We Do?

Different manufacturers have created “floating aerators” over the past decades. Some have different issues than others, but all are installed in one of the most hostile environments at any enterprise.  PondLift brand equipment has been installed at various farms, domestic wastewater treatment sites, and composting facilities to bring their ponds into full aerobic treatment, with most sites desiring odor elimination, while also allowing their effluent to be sent to growing crops through irrigation equipment, lowering their effluent handling costs while increasing the value of their effluent since it is often foliar fed, offering as much as 70% yield increase per unit of fertilizer.   The author has been at each site to maintain equipment and learn more of its performance and learn more about results, expected and unexpected.  Among the PondLift equipment installations, there are 3 pond installation sites in Ohio, and another at a dairy farm near Paw Paw MI, easily visited for those who would want to personally visit such sites.  Other sites are further distance from Ohio.

What Have We Learned?

The installations have confirmed that odor elimination is very much possible through low-energy-use WISE aeration, while also preparing the effluent to be used by irrigation equipment for foliar feeding.  Although Odor elimination is valuable, probably the most environmentally valuable result of aeration was the dramatic change in texture of the effluent (in both liquids and solids) so that when applied by traditional means, being “knifed in”, the treated manure was absorbed into the soil much faster than raw manure is absorbed into that soil.  The timeframe is hours instead of days, reducing the potential runoff timeframe significantly, potentially eliminating significant runoff events.  Given this observation at almost every site having WISE aeration, it became obvious that a method for quantifying the phenomena is needed, and this equipment needs to be defined so as to compare aerobically treated effluent to raw manure, preferably in a “side by side” process, while also being able to quantify manure runoff on different soil types, and different slopes of soils.  While the presentation will also offer other phenomena data, the final portion of the presentation defines this equipment and procedures that might be adopted so as to study and quantify runoff, and compare runoff quantities to traditional distribution methods.

And for those who are interested in performing foliar feeding through automated manure nutrient distribution through irrigation equipment, the presentation will expand on several items recently identified, including the stratification that results from WISE Aeration, allowing irrigation without plugging pivot/circle nozzles.  In addition, the presentation includes information about Struvite formation and its harvesting opportunity as well as control methods.

Future Plans

PondLift intends to offer equipment for use in studies focused on any phenomena of interest in manure or liquid waste treatment, as well as commercial use at farms.  The political climate in future years will insist that potential runoff issues be addressed, updating Best Management Practices.  In addition, it is now possible that manure odor be eliminated with a process which is financially feasible for farms.

A short discussion: Automation is valuable at farms.  Bringing WISE Aeration to dairies and other farms which store liquid manure can help automate the manure storage/handling/disposal process.  It is the opinion of the author that the small family dairy farm will continue to survive and thrive, given the advances in feeding/health/genetics at today’s farms, even though such farms offer a small percentage of milk products.

The fact that so many farms have limited potentially useable farm acres at small hilly locations, leads us to focus on improving their automation and reducing equipment and time spent on manure related work.  To this end, work is progressing through PondLift, on a low cost “drop-in-place” sand separator which can easily be placed between the barn and the manure storage pit, allowing operators to remove sand before it gets to storage, which then allows the storage pit to be converted to aerobic treatment, which then allows automated manure nutrient distribution methods to be considered.  Lastly, work continues through an associated enterprise on the SPEWPLI (self-propelled extremely-wide portable linear irrigator) which will be able to attach to a manure pumpers hose at a distant field, and distribute manure nutrients to the crop at the 1,500gpm rate often used by manure pumpers. This is important for farms which are more suited to pumping at high rates to distant fields.

Authors

John Ries, Managing Member PondLift LLC, retired professional engineer

Corresponding author email address

ries@iw.net

Additional Information

PondLift.com

 

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.

Perceptions of Agricultural Stakeholders on Manure Use, Benefits, and Barriers

Purpose

Nutrient recycling is fundamental to agricultural systems (Spiegal et al., 2020). Integration of animal and crop production represents an example of the application of a circular economy to manage nitrogen (N), phosphorus (P), and other nutrients (Figure 1) important to crop and livestock production. An integrated system recycles these critical nutrients from animal feed to manure to soils and back to animal feed. Nutrient additions to the farm, like animals, feed, and fertilizer (input arrow), are necessary to offset the nutrients leaving the farm in animal protein products (output arrow), as well as other nutrient losses in the system (Cela et al., 2014). The efficiency of this nutrient recycling process has both environmental and economic sustainability implications.

Figure 1. Recycling of nutrients is critical to an environmentally sound agricultural “circular economy”.

For many regions of the United States, such as the Corn Belt, animal agriculture remains in relatively close proximity to sufficient crop production to allow agronomic recycling of nitrogen and phosphorus (Gollehon et al., 2001, 2016). However, the sources of manure nutrients (livestock and poultry operations) and the consumers of nutrients (cropland) are often managed as independent businesses. In other regions, separation of feed and animal production by distance and business boundaries creates significant challenges for agronomic nutrient recycling (Spiegal et al., 2020).

The willingness of crop farmers to accept manure as part of their fertility program is dependent upon their perceptions of the benefits and challenges associated with using manure. Likewise, behaviors among farmers and agricultural advisors of information-seeking – “purposive acquisition of information from selected information carriers” (Johnson 1996) – must be considered as a precursor to content delivery. Thus, in early 2020, a faculty team from University of Nebraska, University of Minnesota, and Iowa State University collaborated to implement a survey of farmers and their advisors to guide multi-state outreach programming by identifying:
-Challenges that regularly prevent manure’s use in crop production and
-Perceptions of manure’s benefits that may encourage manure transfers from livestock farmers to crop producers.

What Did We Do

A draft survey was tested with three groups (a stakeholder advisory group, the national Livestock and Poultry Environmental Learning Community, and the Nebraska Animal Manure Management team) leading to the final product. The survey was delivered electronically through QualtricsXM survey application tool using a University of Nebraska-Lincoln licensed product. The survey included questions for the participants on the following subjects of interest:
1. Participant’s role in manure decision making.
2. Perceptions and knowledge of manure’s benefits. Participants were asked to rate the degree to which they considered manure to be harmful or beneficial for crop fertility, soil physical characteristics, soil biological characteristics, crop yields, and environmental quality.
3. Perceptions and knowledge of manure’s challenges. Participants were presented with a list of potential barriers which might prevent manure use in crop fertility programs and asked to identify which factors were barriers for their operations, or for their advisees.
4. The types of supporting resources which would be of most value for the participants’ decision making or advising on manure benefits and barriers.

Surveyed Participants
Responses were received from 793 individuals across the U.S. and Canada. The results are heavily weighted towards participants from the Corn Belt and the High Plains regions of the U.S. (44% and 23% of respondents, respectively). Survey participants were 87% male and 13% female. Participants’ experience were reported as 29% with less than 10 years, 22% with 11 to 20 years, and 49% with 21 years or more. Participants self-identified as a crop farmer (13%), animal feeding operation (AFO) (7%), professional advisor for crop fertility or manure management decisions (60%), or some combination of these three roles (20%). Crop farmers indicated that they were an annual user of manure (73%), user of manure within the past 3 years (9%), or user of manure within past 4 to 6 years (9%). Only 10% were not users of manure. Those identifying as advisors suggested that manure management is a primary focus of crop fertility advising (20%), frequent part of crop fertility advising (39%), or an occasional part of a crop fertility advising (36%). Only 4% of advisor responses indicated they did not include manure in their advising.

Figure 1. Region of US and Canada represented by survey participants (N= 793).

A series of five questions were presented to identify real or perceived challenges among respondents that represent potential barriers to using manure in crop fertility programs. Lists of agronomic, economic, neighbor or rural community, regulatory, and logistical challenges were presented based on outcomes of the project team’s advisory group discussions and reviews of previous surveys (Battel and Krueger, 2005; Case et al., 2017; Herrero et al., 2018; Poe et al., 2001). Lastly, respondents were asked to identify the types of supporting resources preferred for information-seeking on manure use in cropping systems.

What Have We Learned

Perceptions and Knowledge of Manure Benefits. Both private sector advisors and crop farmers shared similar positive impressions of manure’s benefits for crop fertility, yield, and soil characteristics while being less positive regarding their impressions of how manure impacts environmental quality. Crop farmers and private sector advisors recognize the complementary role of manure and fertilizer in a fertility program at 74% and 76% frequency, and at slightly higher rates than all survey responses (71%). The complementary role of manure and fertilizer was also similar across regions (Corn Belt – 70%; High Plains-69%; all other regions – 74%).

Figure 2. Perspectives of manure’s beneficial versus harmful impacts on five crop production and natural resource topics as identified by primary decision makers in crop fertility programs.

The only audience factors that significantly (p<0.05) influenced participant attitudes toward manure benefits were that participants living in the corn belt were less likely to describe manure as beneficial or slightly beneficial for environmental quality (30%, compared to 46% for high plains, and 35% for all other regions). Similarly, we found that private sector advisors were significantly (p<0.05) less likely to describe manure as beneficial to environmental quality (27%, compared with 58%, 53%, and 30% for livestock producers, crop producers, or public sector advisors respectively). No statistical differences were observed for an influence of audience factors on attitudes towards manure benefits to any of the other characteristics of cropping system benefits (crop yield, soil physical properties, soil biological properties, and crop fertility). However, across all audience sectors participants were unlikely to indicate that they thought manure could be beneficial or slightly beneficial for environmental quality (Figure 2). This data suggests that respondents do not associate improved soil physical and biological characteristics with reduced risk for nutrient transport via runoff, erosion, and leaching. Manure and inorganic fertilizer were perceived as complementary to each other by 71% of respondents, while only 17% believed these two products compete.

Figure 2. Proportion of total respondents who described manure as beneficial or slightly beneficial for different categories of cropping system characteristics. (n=793)

Barriers to Manure Use. As with perceptions of benefits of manure use, audience factors had little effect on the perceived barriers to manure use. There was an observed tendency for more advisors to include most factors as barriers to manure use; however, this tendency was only significant (p<0.05) for six potential barriers: compaction, cost of manure transportation, odors, risks posed by manure application to food crops, accessibility of custom applicators, and use of public roads (Table 1). The overall ranking of barriers to manure use can be found in Table 2. Cost of transportation (68%), odor (58%), timeliness of nutrient availability (55%), concerns related to the field conditions for manure application (50%), and access to labor for manure application (48%) were most frequently indicated as barriers for manure use. Interestingly, several of these factors correspond to those where a difference in the level of concern was observed between advisors and producers (Table 1). However, when considering barrier ranking by agronomic role, 4 of the top 5 barriers are similar between farmers and advisors (cost of transportation, odor, timeliness, and labor availability). Farmers rate concerns with weed seeds as a top 5 barrier, while advisors do not, leaving concerns with field conditions for application as the 6th most selected by crop farmers. This similarity of ranking, even where statistical differences exist, indicates that there is agreement on what are the most significant barriers, but some difference in the perceived seriousness or scale of the barrier. In general, crop farmers less frequently indicated factors as barriers to manure use than did advisors.

Table 1: The frequency survey responses identified selected barriers for manure use. Letters indicated statistical differences in how participants with different roles in agronomic decisions perceived barriers of interest at the alpha = 0.05 level.

Comparison by Role in Agronomic Decisions Animal Feeding Operator (n=66) Crop Farmer (n=120) Private Sector Advisor (n=311) Public Sector Advisors (n=196)
Compaction from application 36%a 41%a 59%b 40%a
Cost of manure application 55%a 67%ab 84%bc 85%c
Odors an air quality impairment 44%a 56%ab 75%bc 79%c
Manure application to food crop 15%ab 13%a 20%bc 22%c
Accessibility of custom applicators 20%a 19%ab 40%b 3%ab
Use of or crossing of public roads 15%a 11%a 21%b 13%a

 

Table 2: The frequency all survey responses identified specific factors as barriers for manure use (n=793)

Potential Barrier % Who perceived as a barrier Potential Barrier % Who perceived as a barrier Potential barrier % Who perceived as a barrier
Transport 68% Water Quality 35% $ of Manure 25%
Odor 58% Interference with Reduced Tillage 34% Accessibility 25%
Timeliness 55% Neighbor Concerns 34% Legal Issues 25%
Field Conditions 50% Equipment $ 34% Flies 20%
Labor 48% Regulation $ 32% Interference with Specialty Crops 19%
Low or Inaccessible Nutrients 47% Traffic 31% Risks to Food Crop 15%
Low or Inaccessible Nutrients 47% Traffic 31% Risks to Food Crop 15%
Compaction 44% Planning & Zoning 31% Road Access 14%
Imbalanced Nutrients 44% Harm to Local Infrastructure 28% Foreign Materials 9%
Uniformity 38% Stockpiles 28% Reduced Yield 5%
Setbacks 37% Presence of Applicators 27% Harmful to Soil 3%
Weed Seeds 37% Pollution 27%

Preferred Sources of Educational Materials. Among three broad groups of respondents (farmers, advisors, and educators), all identified their peers as an important source of information. Brief factsheets or news articles are identified by educators as their top resource they would use (81% of educator responses and 65% of advisor responses). Recommended research articles also ranked high among all three groups. At this point in time, social media (short videos, podcasts, and Twitter and Facebook) is a preferred resource for a smaller portion of these audiences (26% or farmers, 15% of advisors, and 47% by educators).

 

Table 3. Most valued resources for agronomic decision making

Resource Type Farmer (n=197) Advisor (n=438) Educator (n=95)
Recommended research articles 49% 53% 55%
Brief fact sheet or news articles summarizing current science 52% 65% 81%
Decision support tool 34% 39% 43%
Short videos or podcasts summarizing current science 20% 12% 36%
Scripted visuals and text for your use on Twitter, Facebook, other 6% 3% 11%
Network of farmers (or advisors or educators) with whom you interact and share experiences 62% 61% 62%
Scripted PowerPoint presentation for use in educational programs 38%

Future Plans

The intent of this survey was to help our project team and others better understand the characteristics of animal manures that are considered beneficial and barriers to future manure use. Recognition of these benefits and hurdles will be critical as the need to transfer manure nutrients from existing animal feeding operations to crop farms, many with limited previous history of using manure, expands. Matching educational and technical services to the perceptions that impede manure transfer will be necessary.

Future outreach programming should be designed to:

    • Continue to build general awareness of the agronomic and yield benefits of manure.
    • Focus on assisting AFO managers and advisors with communication of specific messages such as 1) desirable rates/plans to best meet crop N and P needs, 2) field-by-field estimation of manure’s fertilizer replacement value and nutrients contributing the greatest value, and 3) complementary manure and fertilizer recommendations for optimum yields.
    • Focus on connecting improved soil health with improved water quality.
    • Help farmers articulate among themselves and to their rural communities the water quality benefits of organic fertilizers when applied to meet agronomic needs of the crop.
    • Challenges associated with manure that frequently become barriers to manure use should be addressed through research and outreach. Specifically, the authors wish to suggest that four challenges are commonly regarded as significant barriers to manure use and require focus to overcome:
      1. Transportation Costs: Businesses providing manure hauling and land application services will be important when transferring manure to fields more distant from manure sources, and educational experiences addressing the current costs of transporting manure and the comparative economic benefit achieved by individual fields will be important.
      2. Odor: A farmers’ desire to be a good neighbor is counter to their willingness to create odors for their neighbors. Farmer and advisor education and planning for reducing odor risks is critical. Technology options to forecast, assess, and address potential nuisance odors may help alleviate odor concerns resulting from manure application.
      3. Logistical Barriers: Three logistical issues ranking highest include 1) timeliness of manure application; 2) time/labor availability; and 3) field conditions restricting manure application. Business services for transporting and land applying manure as well as manure brokering services can address many logistical challenges. Alternative application time windows, such as side dressing a crop with manure, will also be valuable.
      4. Agronomic Issues: Manure application comes with a history of agronomic concerns such as compaction, poor uniformity, and potential for weed seed and herbicide resistance concerns. Many issues are likely to be regionally and manure source specific, thus the need to adapt agronomic education to local needs. Education and business services that encourage technologies such as precision manure application and related technologies, designer manures, and manure treatment may have value based upon regional needs. A 4Rs strategy (right rate, source, time, and place) for manure, similar to what is being promoted in the fertilizer industry, may be beneficial.

Authors

Amy Millmier Schmidt, Associate Professor, University of Nebraska-Lincoln
aschmidt@unl.edu

Additional Authors

-Mara Zelt, Schmidt Lab Project Director, University of Nebraska-Lincoln;
-Daniel Andersen, Associate Professor, Iowa State University;
-Erin Cortus, Associate Professor, University of Minnesota;
-Richard Koelsch, Emeritus Professor, University of Nebraska-Lincoln;
-Leslie Johnson, University of Nebraska-Lincoln;
-Siok A. Siek, Undergraduate Student, University of Nebraska-Lincoln; and
-Melissa Wilson, Assistant Professor, University of Minnesota

Acknowledgements

Funding for this project was provided by the North Central Region Sustainable Agriculture Research and Education program. Key partners in survey deployment were the American Agronomy Society Certified Crop Advisor Program, the Fertilizer Institute and Manure Manager magazine.

 

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.