On-Farm Research and Student Engagement to Assess and Promote Manure and Mulch as Land Treatment Practices in Nebraska

In regions of intensive livestock production, like many areas in Nebraska, significant amounts of livestock manure are produced and, at times, underutilized. Manure positively impacts soil health, has been shown to reduce runoff and erosion, and is no more of a pollutant risk than commercial fertilizers when applied responsibly and at appropriate rates.

Eastern red cedar trees (Juniperus virginiana), a native tree in Nebraska and many parts of the Great Plains, can proliferate readily when not properly managed. In Nebraska, where they are often planted to create windbreaks for livestock and homesteads, red cedar trees have multiplied substantially and are now considered an invasive species in many areas. Negative ecological and economic impacts of this phenomenon include reduced forage production on rangeland, fragmented habitat for wildlife, reduced water availability due to its high water consumption and increased risk and severity of wild fires. Prescribed burning of smaller trees and mechanical removal of larger ones can effectively limit dissemination of red cedar, but the expense of mechanical removal limits the management of these trees by many landowners. Identifying value-added markets for cedar wood chips has become a priority of the Nebraska Forest Service and many Natural Resources Districts (NRDs) in the state to offset expenses for tree management. The project presented here describes on-going efforts to quantify agronomic, economic and ecological impacts of utilizing cedar wood chips alone or co-mingled with livestock manure as soil amendments in crop production systems.

In addition to investigating the impacts of this novel use for cedar wood chips, this project is contributing to a larger effort to demonstrate the value and promote the utilization of manure as a nutrient source and soil amendment in cropping systems. The overall goal of this effort is to document and demonstrate the effects of land applied manure and cedar mulch on agronomic, economic and soil health variables in cropland under different agro-climatic conditions using a novel partnership model.


A producer-driven research study was initiated in 2015 to assess the impacts of cedar woodchips alone and co-mingled with livestock manure or urea ammonium nitrate fertilizer on soil, water use efficiency and agronomic productivity. This three-year study, conducted in the Nebraska Sandhills where sandy, excessively drained soils dominate, was completed in 2018 and is now being expanded to document and demonstrate the impacts of these practices throughout Nebraska under varying soil types and climatic conditions.

An ambitious partnership model, designed to accomplish the research and outreach goals through broad collaborative efforts, encompasses an on-farm research initiative replicated in six NRDs throughout Nebraska utilizing local implementation teams. Study sites include Overton, Brule, Saint Paul, Julian, Ainsworth, and Pierce, Nebraska (Figure 1). The local implementation team for each site is composed of a crop farmer and members of the local NRD, Natural Resources Conservation Service, Nebraska Extension, the Nebraska On-farm Research Network, the Nebraska Forest Service and the University of Nebraska-Lincoln. Additionally, each local implementation team is engaged with at least one local high school agricultural program. Delivery of a curriculum to students in these programs, developed according to the research and extension objectives, and student participation in on-farm research are intended to improve their knowledge about on-farm research methods, soil health, and benefits of responsible recycling of manure and cedar mulch as soil amendments. Using their research experiences, students will develop novel outreach products intended to positively impact knowledge and behaviors related to soil health, manure and red cedar tree management among crop producers and their advisors.

Map of Nebraska: locations of on-farm research and high school agriculture program partners.
Figure 1. Statewide locations of on-farm research and high school agriculture program partners.


The current project was initiated in summer 2018 and early efforts generated broad interest among crop producers and school teachers to participate in. On-farm research sites are being established using a Complete Randomized Block Design. Plots measure 170 m (350 ft) in length and up to 12 m (40 ft) in width, depending on equipment utilized by each partnering farmer. Up to four treatments are assigned to plots within each of four blocks. Treatments include: livestock manure, manure mixed with cedar woodchips, cedar woodchips* and commercial fertilizer. (*Note: Not all sites include a woodchip-only treatment; likewise, some sites include a treatment selected by the farmer, such as biochar.) Samples collected prior to treatment applications and regularly throughout the growing season will provide agronomic, environmental and soil health data at each study site.

Curriculum implementation has begun at five high schools, each associated with a research site. Approximately 60 students will participate in the project during spring 2019. The curriculum (Figure 3) encompasses 4 modules: On-farm research (Module 1), Soil Health (Module 2), Crop Productivity (Module 3) and Outreach (Module 4). Each module is comprised of field and classroom activities. Partnering teachers and their students will use this curriculum document to complete lessons in one or more modules during each semester of engagement with the project team.

A 52-page Soil Biology Inspection Guide (Figure 4) has been developed for use by students to identify and understand the roles of soil organisms they find during hands-on soil inspections with a smart phone microscope. Along with the printed materials, each partnering teacher will receive a supply of smart phone microscopes (Figure 5) for students to use to inspect soil within the study site with which they are associated and in other soil samples.

Figure 3. Sample pages from the High School Curriculum.
Figure 3. Sample pages from the High School Curriculum.


Figure 4. Sample pages from the Soil Biology Inspection Guide.
Figure 4. Sample pages from the Soil Biology Inspection Guide.
Figure 5. Smart phone compatible microscopes to be provided to classrooms.
Figure 5. Smart phone compatible microscopes to be provided to classrooms.


On-farm research will be conducted during the 2019 and 2020 growing seasons to document short-term effects of the applied treatments. Each on-farm research site will host a field day during year three of the project to share study results and host farmer experiences with local agricultural producers and their advisors. Participating high school students will maintain an active role in research and outreach throughout the project. Assessments of knowledge gained and intended or actual behavior changes among students, their teachers, participating producers and outreach audiences will be completed to document impacts of this effort. Furthermore, an online photo sharing site is being explored to facilitate exchange of project photos among classes in all partnering high schools. Engaging students in the study near their school will be complimented by engaging classrooms from other schools participating in the project to share study statuses, data, and other information. These activities will be conducted via Zoom (online meeting platform) and facilitated by project team members to encourage students to share successes, frustrations, discoveries and outcomes from their study site with students in other schools participating in this project.


Olivo, Agustin (University of Nebraska-Lincoln) – agustinolivo@outlook.com

Schmidt, Amy (University of Nebraska-Lincoln) – aschmidt@unl.edu

Koelsch, Richard (University of Nebraska-Lincoln)

Schott, Linda (University of Nebraska-Lincoln)

Howard, Larry (University of Nebraska-Lincoln)

Ingram, Troy (University of Nebraska-Lincoln)

Lesoing, Gary (University of Nebraska-Lincoln)

Nygren, Aaron (University of Nebraska-Lincoln)

Saner, Randy (University of Nebraska-Lincoln)

Timmerman, Amy (University of Nebraska-Lincoln)

Whitney, Todd (University of Nebraska-Lincoln)





The Nebraska Environmental Trust provided funding for this project, Project 18-203: Transforming Manure and Cedar Mulch from ‘Waste’ to ‘Worth’.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

Utilization of Woody Biomass and Manure as Agricultural Soil Amendments in Nebraska

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While Eastern Redcedar are native to Nebraska and much of the Central U.S., the ability of these trees to thrive in many soils and under a broad range of climatic conditions has contributed to their designation as an invasive species. Cedar tree proliferation negatively impacts agriculture by reducing groundwater availability, compromising grazing land, impeding forage production for cattle, and altering surface water flows. Agricultural crop and livestock producers depend on affordable access to water, healthy and productive soils, and quality grazing land to remain profitable. Land treatment practices that return organic matter to soil improve soil health, which in turn positively impacts crop productivity, soil water holding capacity, soil fertility, and grazing land forage quality and productivity. This project is investigating the use of two readily available by-products in Nebraska, livestock manure and cedar tree wood chips,  as amendments on agricultural land to improve soil productivity metrics. The overall goal of this project is to demonstrate a value-added use for woody biomass to offset the cost of tree management activities and encourage landowner management of cedars.

What did we do? 

Crop year 2016 was the first year of the Woody Biomass and Manure Project. Six treatments were applied to 12-m x 10-m plots within cooperators’ fields following the 2015 harvest:

1. woody biomass (WB1), 6 ton/ac

2. woody biomass (WB2), 12 ton/ac

3. woody biomass with liquid N (WBLN), 6 ton/ac

4. woody biomass with swine manure (WBSM), 6 ton/ac

5. woody biomass with cattle manure (WBCM), 6 ton/ac

6. control (Cont), no amendments

Manure and liquid nitrogen treatments received less than 30 lbs ac-1 of N in the fall. The experiment is a completely randomized block design with four replications of each treatment, for a total of 24 plots, at each of the sites. Since the plots were established within existing crop fields, the producers were encouraged to continue their current management strategies. Both sites were irrigated, and fertilizer was applied uniformly across all plots using the pivot throughout the growing season.

Soil was sampled for chemical and biological properties in the spring and fall of 2016 and sent to a commercial lab for analyses. Rye was sampled by hand harvesting 0.25 square feet from four locations within each plot for a total of 1 square foot. Corn was sampled by hand harvesting six plants from each plot. Stand counts were also completed. WATERMARK sensors were installed at three depths (1, 2, and 3 ft) in two replications of four treatments (WBCM, WB1, WB2, Cont) at both sites. Additionally, temperature sensors were installed at a depth of 1 ft. A total of 16 plots were monitored (8 plots per site with 2 replications of 4 treatments).

What have we learned? 

Soil biological and chemical characteristics have not been affected during the first year. There were no differences in the amount or type of soil microbes due to treatment. WBCM and WBLN had greater soil nitrate than WB1 and WBSM early in the spring. Additionally, WBCM had greater soil K than the other treatments. Other than these two instances, there were no differences in organic matter, pH, and macronutrients. However, this is not surprising since measurable changes in soil properties typically occur over many years and manure application rate was relatively low. More importantly, though, is that microbial populations were not decreased by the cedar mulch.

Cedar mulch applications did not decrease biomass yield of corn and rye when applied with nitrogen. In fact, in the rye, WBLN had the greatest biomass yields followed by WBCM, WB1, WBSM, and Cont. WB2 had the lowest rye biomass, which was probably due to nitrogen tie-up by the wood chips due to the initially higher C:N ratio. There was no treatment effect for corn biomass or stand counts.

At the site planted to corn at a depth of one foot, the three woody biomass treatments monitored (WB1, WB2, and WBCM) were significantly wetter and cooler than the control from mid-June until mid-July. WBCM was also wetter at a depth of two feet than the control. Unfortunately, due to rodent activity, statistical analyses at the rye site and other times of the growing season are not possible. The differences in soil moisture and temperature are probably due to shading and the physical barrier to evaporation that the wood chips supply. The increased soil moisture under the woody biomass treatments could reduce irrigation.

Future Plans  

In order to apply for competitive funding, we need more supporting data. We are going to increase monitoring of soil moisture and temperature, so that three replications of all six treatments are monitored at both sites. Additionally, a greenhouse study will be conducted to provide water quality data and rate of decomposition of the wood chips.

Corresponding author, title, and affiliation       

Linda Schott, Extension Graduate Research Assistant, University of Nebraska-Lincoln

Corresponding author email   


Other authors   

Amy Schmidt, Assistant Professor, University of Nebraska-Lincoln; Amy Timmerman, Associate Extension Educator, University of Nebraska-Lincoln; Adam Smith, Assistant Forester, Nebraska Forest Service

Additional information               

More information can be found at: manure.unl.edu


This project is funded by the Nebraska Forest Service. We would like to thank the Middle Niobrara Natural Resource District, especially Mike Murphy, Travis Connot, and Zach Peterson, for their assistance to this project. We would also like to thank the Nebraska Forest Service, especially Richard Woollen, Adam Smith, and Heather Nobert, for their assistance to this project. Additionally, this project would not be possible without our two farmer cooperators, Leonard Danielski and Greg Wilke.

Organic Mulches in Ginseng Production

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During ginseng production, pesticides are intensively applied to the fields, creating risks to farm workers health and the environment. To reduce pest infestation, and consequently pesticide loading, organic mulches with potential disease suppressive properties were investigated as replacements for the conventional straw mulch. A four year study was initiated as ginseng is usually harvested after four years in Wisconsin. The results after one year are being presented. Anaerobic digestate solids (dairy manure feedstock) and vermicompost (grain feedstock) were applied at rates of  1/2″ or 1″ per plot, prior to planting (fall) and/ or in the spring  prior to germination. Soil samples were obtained one month following planting to determine seed damage by pest infestation; germination rates were calculated in the spring. Fewer seeds were damaged by pests in the plots with anaerobic digestate (AD) solids mulch compared to the vermicompost plots, and were similar to the controls. Germination rates for certain vermicompost and AD solids plots were equivalent to the controls. AD solids and vermicompost mulch showed beneficial results after the first year of this experiment.


Jonathan Rivin, University of Wisconsin Extension            jonathan.rivin@uwsp.edu


The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.