yield – Livestock and Poultry Environmental Learning Community

April 4, 2025May 11, 2025

High Clearance Robotic Irrigation Impacts on Soybeans and Corn Yield and Nutrient Application

Purpose

This collaborative project between The Ohio State University, Iowa State University, and 360YieldCenter intends to demonstrate the in-season application of commercial and animal nutrient sources and water application as a unified strategy to reduce nutrient losses while improving profitability with increased grain yields. A new and innovative high-clearance robotic irrigator (HCRI) is being used to apply liquid-phase nutrients in-season beyond all stages of row crops. Replicated strip trials of Fall, Spring, and in-season application will occur using the HCRI (e.g., 360 RAIN Robotic Irrigator, Figure 1). The in-season application consists of traditional N and P application rates as well as reduced rates to take advantage of better matching nutrient availability to crop needs during the growing season. Data were collected to verify nitrate-nitrogen leaching loss using liquid swine manure as a nutrient source in Iowa, while total and dissolved reactive phosphorus losses with both runoff and leaching using commercially available nutrients were collected in in Ohio. Secondly, as climate shifts result in water scarcity during critical crop growth stages, robotic irrigation water applications will be used to meet the crop needs. Higher crop yields are anticipated via precision water management.

What Did We Do?

OSU is conducting two field demonstrations, one with a focus on water quality, and a second for comparison of nutrient management practices. The HCRI is being utilized to apply commercial fertilizer in-season via dilution in irrigation water with up to 12 applications per growing season (effective 4.5 in. of precipitation season dependent). Nutrient injection rates (N and P) are scaled to plant nutrient uptake and irrigator pass intervals. Both sites are farmed in accordance with existing crop rotation and standard practices.

Beck’s Hybrid Site (West 1A) – The Beck’s Hybrid site (78 ac) is subdivided in accordance with the sub-watershed boundaries and managed with two treatments: 1) conventional commercial fertilizer application in accordance with the Tri-State Fertilizer recommendations, and 2) in-season nutrient management (N and P) using the HCRI and Tri-State Fertilizer Recommendations with the exception nutrient application matching with plant nutrient uptake rates as judged by growing degree days (GDD). This site is instrumented as a paired watershed for surface water and subsurface tile drainage. Further, these watersheds are monitored for precipitation, flow, and water quality (nitrate, nitrite, total phosphorus and DRP).

Molly Caren Agricultural Center (MCAC) Site 1 (Field 7) – Field demonstrations at this site (140 ac) are laid-out in a randomized complete block design (RCBD) strip trial design with treatments that include: 1) commercial fertilizer application (N and P) in accordance with the Tri-State Fertilizer recommendations, 2) in-season nutrient management (N and P) using the HCRI and Tri-State Recommendations with the exception nutrient application matched with crop nutrient uptake rates based on growth stages as determined by GDD, and 3) in-season nutrient management (N and P) using the HCRI and 67.7% Tri-State recommend application rates matched with crop nutrient uptake rates based on growth stages (GDD). Strip trials are 160 ft. in width and approximately 1,170 ft. in length (4.3 ac treatments) with eight replicates.

MCAC Site 2 (Field 8A) – Field demonstration site used to test HCRI and “sandbox” for other RCBD trials outside of NRCS CIG grant to discovery and planning for future projects. This site varies depending on studies each year, but trials are completed via RCBD strips.

Data Collection and Analysis – Demonstration sites are grid sampled each season on a 1-ac grid (Beck’s) and within treatments (MCAC site) to monitor soil fertility levels. Soil moisture and temperature in situ sensors (CropX) are placed in both study locations (three per treatment, 15 total sensors). Tissue samples are collected by treatment type to assess nutrient uptake at three stages of crop growth. Harvested crops are scaled by treatment to ensure yield monitor accuracy. Remote sensing imagery (RGB, ADVI and thermal) is collected 10 or more times during the growing season to evaluate crop growth and development. Data is analyzed using RCBD procedures in SAS.

Water Quality Assessment – Surface and subsurface (tile) monitoring capacity was established in 2016 at the Beck’s Hybrid Site. Two isolated subareas within a single production field were identified and the surface and subsurface pathways were instrumented with control volumes and automated sampling equipment. Surface runoff sites were equipped with H-flumes while compound weirs were installed at each of the subsurface (tile) outlets. Each sampling point (two surface and two subsurface) is equipped with an automated water quality sampler and programmed to collect periodic samples during discharge events. Once collected, samples will be analyzed for N and P. An on-site weather station provides weather parameters. Water samples are collected weekly from the field plots during periods of drainage and follow the same ISU protocol for NO3–N. Dissolved reactive phosphorus (DRP) and digested (total phosphorous) samples are analyzed using ascorbic acid reduction method.

What Have We Learned?

2023 Results

At the Beck’s Hybrid location field West 1A was planted to corn for the 2023 cropping season. There was an 8.0 bu/ac difference between irrigated and non-irrigated treatments. Nitrogen was injected using the rain unit and put on crop for the first application and use of the rain machine. Not having the rain unit in June made a significant difference in this study. The results of this location from 2023 should be taken lightly as complete implementation was not done until August. Location study information can be seen in Figure 2 and results in Figure 3.

Figure 2: Study information for Beck's Hybrid location in 2023 cropping season. — Figure 2: Study information for Beck’s Hybrid location in 2023 cropping season.

Figure 3: Results for Beck's Hybrid field location in 2023. — Figure 3: Results for Beck’s Hybrid field location in 2023.

In 2023, field 7 at MCAC was in soybeans and had no irrigation completed for this growing season.

Field 8A at MCAC was in corn for the 2023 cropping season. Irrigation had a statistically significant effect on yield over all treatments. Nitrogen had statistical significance from 120 versus 170 and 220 units on nitrogen treatments. The 170 units of nitrogen was the optimal amount of nitrogen for all treatments. Not having the irrigator installed in early June caused there to be less yield in irrigated treatments. The results of this location from 2023 should be taken lightly as complete implementation was not done until August. Location study information can be seen in Figure 4 and results in Figure 5.

Figure 4: Study information for MCAC 8A location in 2023 cropping season.

Figure 5: Results for MCAC 8A field location in 2023.

2024 Results

Field 7 at MCAC was in corn for the 2024 cropping season. Irrigation had a statistically significant effect on yield over all treatments. There was a 48 bu/ac between irrigated two-thirds nutrients and non-irrigated and 44 bu/ac between irrigated and non-irrigated for the 2024 growing season. A total of 773 gallons of diesel was used to run the irrigator for this trial for 2024 cropping season across 71 acres. A total of 25,739 kWh was used to run the electric pumps, base station, and well for 2024 growing season across 71 acres. These are the initial results that were published in efields and further results will continue to be analyzed to meet all project objectives. This data will be used to help in evaluating HCRI versus traditional crop production and management practices to meet project objectives. Location study information can be seen in Figure 6 and results in Figure 8. In Figure 7, aerial imagery can be seen from the 2024 cropping season.

Figure 6: Study information for MCAC 7 location in 2024 cropping season.

Figure 7: Aerial imagery of field 7 (Top l) and field 8A (Bottom left) from 2024 cropping season.

Figure 8: Results for MCAC 7 field location in 2024.

Field 8A at MCAC was in soybeans for the 2024 cropping season. Irrigation had a statistically significant effect on yield over non-irrigated. A total of 211 gallons of diesel was used to run the irrigator for this trial for 2024 cropping season across 11 acres. A total of 3,475 kWh was used to run the electric pumps, base station, and well for 2024 growing season across 11 acres. Location study information can be seen in Figure 9 and results in Figure 10. In Figure 7, aerial imagery can be seen from the 2024 cropping season.

Figure 9: Study information for MCAC 8A location in 2024 cropping season.

Figure 10: Results for MCAC 8A field location in 2024.

Future Plans

During the next 12 months, we are planning for the HCRI operation at the two sites for cropping practices and irrigation for 2025 growing season. We will be aggregating weather data, agronomic data, plant samples, surface and ground water quality samples, and machine performance data for all years of the project with the current end date as spring of 2026. We are hoping to continue to perform testing with this technology and implementing the dry product skid for field operations for the 2025 growing and full-scale implementation across all studies in 2026. The results from the Iowa State portion of this funded project will also be reported in the future as well. There is a significant need to further develop programs for injecting macro and micronutrients in liquid and granular form for growers. The potential to significantly cut application rates exists with this technology. Also, implementing this technology with liquid livestock manure producers will change the paradigm of how manure is managed in the future.

Authors

Presenting & corresponding author

Andrew Klopfenstein, Senior Research Engineer, The Ohio State University, Klopfenstein.34@osu.edu

Additional authors

Justin Koch, Innovation Engineer, 360YieldCenter; Kapil Arora, Field Agricultural Engineer, Iowa State University; Daniel Anderson, Associate Professor, Iowa State University; Matthew Helmers, Professor, Iowa State University; Kelvin Leibold, Farm Management Specialist, Iowa State University; Alex Parsio, Research Engineer, The Ohio State University; Chris Tkach, Lecturer, The Ohio State University; Christopher Dean, Graduate Research Associate, The Ohio State University; Ramareo Venkatesh, Research Associate, The Ohio State University; Elizabeth Hawkins, Agronomics Systems Field Specialist, The Ohio State University; John Fulton, Professor, The Ohio State University; Scott Shearer, Professor and Chair, The Ohio State University

Additional Information

eFields On-Farm Research Publication 2023 and 2024 Editions – https://digitalag.osu.edu/efields

Acknowledgements

Natural Resources Conservation Service – Conservation Innovation Grant (NR223A750013G037)

Ohio Department of Agriculture – H2Ohio Grant

USDA, NRCS, 360YieldCenter, Beck’s Hybrids, Molly Caren Agricultural Center, Rooted Agri Services, Iowa State University, The Ohio 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. 2025. Title of presentation. Waste to Worth. Boise, ID. April 7-11, 2025. URL of this page. Accessed on: today’s date.

April 3, 2025May 11, 2025

Leveraging Carbon Intensity Scoring for Sustainable Livestock Feed Supply Chains

Purpose

As market demands, consumer expectations, and environmental regulations evolve, agricultural producers increasingly focus on improving profitability while minimizing environmental impact. Carbon Intensity (CI) scoring is a tool that quantifies the greenhouse gas emissions associated with crop production, thereby helping producers understand their ecological footprint. CI scores may influence crop sales for biofuel production for corn and soybean producers and may eventually affect livestock feed markets as companies seek carbon-neutral supply chains. Furthermore, renewable fuel producers may become eligible for Low Carbon Fuel Standard (LCFS) credits, where revenue is contingent on the lifecycle CI score of the fuel, and similar economic approaches may be required to drive livestock feeds toward carbon neutrality. Biofuels and animal feed share a strong relationship; ethanol plants generate distiller grains, a key component of livestock diets, and soybean processing plants generate soybean meal and soybean oil. Distiller grains represent a large portion of livestock feed, and soybean oil is a common biodiesel feedstock. We evaluate the emissions associated with corn and soybean production for each county in Iowa, assessing how their yield, crop rotation, tillage practices, cover crop implementation, and manure application affect their CI scores.

What Did We Do?

This study used the Department of Energy’s Feedstock Carbon Intensity Calculator (FD-CIC) and published literature to estimate corn and soybean production emissions throughout Iowa counties. Manure nutrient volumes were found using animal feeding operation data from Iowa DNR and manure production characteristics from ASAE D384.2. Data for yield, acres of corn, acres of soybean, acres of cover crop, acres of no-tillage, acres of reduced tillage, and acres of intensive tillage by county in Iowa were found using the USDA Quick Stats Database. Diesel emissions and grain drying emissions were calculated using Iowa State University Extension resources. The nitrogen fertilizer application rate was calculated using the yield goal method (manure) and Iowa State University Extension resources (commercial fertilizers). Limestone emissions were directly correlated to the amount of CaCO3 necessary to neutralize the H+ added to the soil from manure nitrogen and anhydrous ammonia. Embedded fertilizer emissions, biomass degradation emissions, leguminous N fixation emissions, and specific fuel emission factors were pulled from FD-CIC. Corn and soybean CI scores were calculated in g CO2e/bu units. Through this work, we provide actionable insights for corn and soybean supply chain stakeholders interested in improving sustainability and expanding revenue opportunities.

What Have We Learned?

Key emission sources from corn and soybean production are nitrous oxide (N2O) from fertilizer and manure application, biomass residue degradation, embedded emissions from fertilizer production, and tractor diesel emissions. Reducing CI in corn production can be achieved through increased yield, reduced tillage, increased cover crop, and manure application. Reduced tillage and increased cover cropping increase soil organic carbon (SOC). Depending on the location and its existing soil characteristics, reduced tillage, and cover crops can sequester soil carbon, decreasing the overall CI score of the corn and soybeans. On average, SOC reduced CI scores by 6% and 18% for corn and soybeans, respectively.

Yield significantly impacted CI scores; counties with greater yield featured reduced CI scores. The CI score dropped by 33 g CO2e/bu for corn as yield increased by bu/acre with an R2 of 0.53. For soybeans, the CI score dropped by 72 g CO2e/bu as yield increased by bu/acre with an R2 value of 0.19.

Manure also significantly impacted CI scores. Although manure has increased diesel emissions compared to anhydrous ammonia application, manure lacks the embedded emissions of anhydrous ammonia, P2O5, and K2O fertilizers. As the percentage of manure-derived nitrogen increased by 1%, the CI score for corn reduced by 14 g CO2e/bu, featuring an R2 of 0.25. As the percentage of manure-derived P2O5 increased by 1%, the CI score for soybeans reduced by 25 g CO2e/bu, featuring an R2 of 0.68.

Crop rotation had a less intuitive effect on the CI score. Corn-soybean (CS) rotations typically have higher yields, reduced nitrogen fertilizer inputs, and reduced tillage. Nonetheless, continuous corn (CC) rotations facilitate greater build-up of SOC (assuming county tillage practices are evenly distributed among corn and soybean acres). Also, CC rotations occurred more frequently in high-yielding counties. For these reasons, the CS rotation was not associated with a reduced CI score.

Figure 1 and Figure 2 show carbon intensity scores of corn and soybean, respectively, for all counties throughout Iowa. Green counties typically feature greater yields, greater manure volume, and more significant SOC accumulation, whereas red counties typically feature opposite trends. It is worth noting that while CI scores are calculated per bushel, corn production averages roughly 194 bushels per acre, whereas soybean averages approximately 57 bushels per acre.

Figure 1: Corn Carbon Intensity by County in Iowa

Figure 2: Soybean Carbon Intensity by County in Iowa

Future Plans

Future analysis includes evaluating the CI scores of biofuels and animal feed produced in Iowa counties where the corn and soybean CI scores have already been assessed. Additionally, we intend on investigating the economics of implementing emission reduction strategies, considering potential yield loss and expenses of associated field activities. Also, by applying the methods of this paper to decades of historical data, we plan on analyzing how corn and soybean CI scores have evolved throughout time. Lastly, we will project future emission reduction strategy adoption and predict how CI scores of feed and fuel will change throughout the next decade.

Authors

Presenting author

Luke Soko, Graduate Student, Iowa State University

Corresponding author

Dan Andersen, Associate Professor, Iowa State University, dsa@iastate.edu

March 30, 2025April 3, 2025

Integrated Best Management Practices to Minimize Nitrate Leaching in Corn

Purpose

In Nebraska, approximately 117 out of nearly 550 groundwater-based community public water systems are required to conduct quarterly sampling due to elevated nitrate-N levels, with ten systems having already implemented costly treatment measures such as reverse osmosis to mitigate this issue. The intensive production of row crops under irrigation in the state are a primary reason for elevated nitrate concentrations in groundwater. However, the environmental impact of nitrate leaching from agricultural fields is not confined to Nebraska; it is a widespread issue across the US Midwest, where intensive crop production is prevalent.

Despite advances in N management stemming from studies comparing nitrogen fate and transport under synthetic versus manure fertilizers, cover crops versus no cover crops, and other practices, research indicates that when manure is applied following research-based best management practices (BMPs), the risk of nitrate leaching is significantly lower compared to when synthetic fertilizers are applied following BMPs. While individual practices such as cover cropping or manure application have been shown to reduce nitrate leaching, their combined effects on both nitrate leaching potential and crop productivity, particularly in corn (Zea mays L.) systems, have not been thoroughly studied. There remains a critical need to comprehensively evaluate implementation of BMPs that can reduce nitrogen losses to groundwater in Nebraska and utilize evidence-based research to motivate the implementation of BMPs.

This study was conducted to evaluate the effects of the integrated use of beef manure, woodchips, and cover crops on corn (Zea mays L.) productivity and nitrate leaching.

What Did We Do?

A two-year study was conducted on drip-irrigated land with a loamy sand soil having 0 to 2% slopes at UNL’s Haskell Agricultural Laboratory research site near Concord, Nebraska from 2022 to 2023. A total of 24 plots were established, each measuring 6.1 m x 30.48 m, and six treatments were randomly assigned to plots in a factorial combination of two fertilizer sources (manure and inorganic fertilizer), two cover crops (rye cover crop and no cover crop), and two carbon amendment treatments (woodchips of mixed species and no woodchips). Each year, all the plots received the same total N rate, equating to 30% of the total N application broadcasted at planting in the form of Agrotain coated urea, which was calculated using University of Nebraska’s N rate algorithm. The manure plots received the remaining N (70% of the total) in the form of beef manure at planting using a manure spreader. The inorganic plots received the remaining N in the form of UAN side-dressed at the V6 corn growth stage. Each year, inorganic fertilizer plots received additional P, S, and Zn at the time of planting to balance the amount of these nutrients supplied by the manure.

Data collected included:

Soil. Deep core soil samples up to 120 cm were collected before planting in the spring and after harvest each fall, divided into four depths of 30 cm increment, composited by depth within each plot, and stored in a cooler before being transported to the lab for analysis.

Crop. Plant growth parameters assessed at V10 (±1) stage included plant height, leaf chlorophyll, and canopy fullness. Grain yield, harvest index, nitrogen harvest index and partial factor productivity were determined at harvest.

Water. Concentration of NO₃-N and NH₄-N in the pore water below the root zone was measured one to two times each week throughout the growing season with the help of suction cup lysimeters, two of which were installed 6 m apart between the center two rows of each plot at a depth of 1.2 m.

Cover crop failed to establish in 2023 spring due to dry conditions, therefore, cover crop data and its effects are not reported in this paper.

What Have We Learned?

Key results of this study include:

- Manure significantly reduced nitrate leaching by providing a slower, more synchronized N release compared to inorganic fertilizers.

- Woodchip mulch initially delayed N availability and biomass N uptake but ultimately helped reduce nitrate leaching by improving soil moisture retention and temperature moderation.

- Aboveground biomass N uptake was significantly affected by fertilizer source with manure improving biomass N uptake by 11% compared to inorganic fertilizer.

- Inorganic fertilizers boosted corn yields by 9% compared to manure treatments, but increased the risk of nitrate leaching, highlighting a trade-off between productivity and environmental impact.

- Integrated management of manure and mulch was deemed crucial for optimizing N use efficiency and minimizing environmental risks in irrigated corn systems.

Future Plans

Identifying nutrient and land management practices that support sustainable agricultural practices by safeguarding groundwater quality while maintaining farm productivity are critical to the future of agriculture. Future research is expected to focus on refining the practices used in this study to maximize their benefits, including other practices such as in-season nitrogen management, and assessing outcomes under varying environmental conditions and soil types. Nitrogen availability from manure is heavily influenced by environmental and soil conditions, so multi-year data from this site and others should help determine when in-season nitrogen supplementation with inorganic fertilizer is needed to offset nitrogen deficits caused by slow conversion of organic nitrogen.

Because of the failure of cover crops to thrive in this study, future research to assess multiple practices in combination should include a cover crop versus no cover crop treatment.

Combining crop productivity and nitrogen fate and transport data with measures of soil biological conditions may also help identify trends in biological characteristics that contribute significantly to factors like nitrogen conversion and plant nitrogen uptake.

Authors

Presenting & corresponding author

Amy Millmier Schmidt, Professor and Livestock Bioenvironmental Engineering Specialist, University of Nebraska-Lincoln, aschmidt@unl.edu

Additional authors

Swetabh Patel, Assistant Professor, University of Minnesota; Michael Kurtzhals, Graduate Research Assistant, University of Nebraska-Lincoln; Arshdeep Singh, Graduate Research Assistant, University of Nebraska-Lincoln; Leslie Johnson, Extension Educator, University of Nebraska-Lincoln; Javed Iqbal, Assistant Professor, University of Nebraska-Lincoln

Additional Information

https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/156921

Acknowledgements

This research was funded by USDA-NIFA Award No. 2022-68008-36509.

The authors extend their sincere gratitude to Logan Dana, Operations Manager at the UNL Haskell Ag Lab, for his role in supporting this project.

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

March 5, 2019March 20, 2019

Improving Pasture Utilization by Optimizing Horse Preference

Purpose

Differences in preference, defined as the behavioral response of an animal to plants when a choice is given, affects not only animal utilization of forage species, but forage persistence and yield if preferred species are repeatedly grazed. Horses are known to be selective grazers, when compared to other livestock. Forage yield is an important criteria when selecting grasses for productive pastures, especially for highly selective livestock like horses. The objectives of this research were to evaluate preference and yield of cool-season perennial and annual cool-season grasses while grazed by horses.

What did we do?

Research was conducted in 2010 through 2014 in St. Paul, Minnesota. Four adult stock-type horses rotationally grazed two separate experiments. Cool-season perennial grasses were planted in replicated monocultures and grazed each month during the growing season (April through October). Cool-season perennial grasses inlcuded tall fescue, meadow fescue, quackgrass, smooth bromegrass, meadow bromegrass, reed canarygrass, perennial ryegrass, timothy, Kentucky bluegrass, creeping foxtail, and orchardgrass. Cool-season annual grasses were planted each spring and fall in replicated monocultures and grazed in May and June (spring planting) and September and October (fall planting). Cool-season annual grases included winter wheat, annual ryegrass, spring barley, spring wheat, and spring oat.

Prior to grazing, grasses were measured for yield. Immediately after grazing, horse preference was determined by visually assessing percentage of forage removal on a scale of 0 (no grazing activity) to 100 (100% of vegetation grazed). Following grazing, manure was removed, and remaining forage was mowed to 3 inches and allowed to re-grow. Plots were hand-weeded, fertilized according to soil analysis and irrigated if necessary.

What have we learned?

Figures 1 and 2. Kentucky bluegrass, timothy (photos 1 and 2) Left: pre-grazed timothy and right: post-grazed timothy), and meadow fescue were the most preferred perennial cool-season grasses with most grazing events removing > 60% of the forage, while meadow bromegrass, creeping foxtail, reed canarygrass, and orchardgrass were less preferred, with removals of < 50% of the forage (P ≤ 0.0027).

Kentucky bluegrass, timothy (Figures 1 and 2), and meadow fescue were the most preferred perennial cool-season grasses with most grazing events removing > 60% of the forage, while meadow bromegrass, creeping foxtail, reed canarygrass, and orchardgrass were less preferred, with removals of < 50% of the forage (P ≤ 0.0027). Quackgrass, tall fescue, perennial ryegrass, and smooth bromegrass were moderately preferred by horses. Orchardgrass produced the highest yield with ≥10.1 t/ha, while creeping foxtail, smooth bromegrass, and timothy produced the lowest yield with ≤ 8.7 t/ha (P = 0.0001). Quackgrass, perennial ryegrass, reed canarygrass and meadow bromegrass yielded moderately well.

Figures 3 and 4. Winter wheat (photos 3 and 4) Left: pre-grazed winter wheat and right: post-grazed winter wheat) was the most preferred annual cool-season grass with a removal of 93%, while oat was least preferred with a removal of 22% (P < 0.001).

Winter wheat (Figures 3 and 4) was the most preferred annual cool-season grass with a removal of 93%, while oat was least preferred with a removal of 22% (P < 0.001). Oat and spring wheat yielded the highest with ≥ 3.91 t/ha while winter wheat yielded the least at 1.91 t/ha (P < 0.001). This information will aid owners and professionals when choosing pasture species that maximize horse preference and forage yield.

Future Plans

Future equine grazing research should focus on evaluating horse preference and yield of cool-season grass mixtures. Research should also focus on evaluating horse preference and yield of alternative forages.

Authors

Krishona Martinson, Associate Professor, University of Minnesota krishona@umn.edu

Amanda Grev, Graduate Research Assistant, University of Minnesota; Deavan Catalano Graduate Research Assistant, University of Minnesota; Michelle Schultz, Graduate Research Assistant, University of Minnesota; and Craig Sheaffer, Professor, University of Minnesota

Additional information

Allen, E., C. Sheaffer, K. Martinson. 2013. Forage Nutritive Value and Preference of Cool-Season Grasses Under Horse Grazing. Agronomy Journal. 105: 679-684.

Allen, E., C. Sheaffer, K. Martinson. 2012. Yield and Persistence of Cool-Season Grasses Under Horse Grazing. Agronomy Journal. 104: 1741–1746.

Grev, A.M., K.L. Martinson, and C.C. Sheaffer. 2014. Yield, forage nutritive value, and preferences of spring planted annual grasses under horse grazing. Journal of Animal Science. 92; pg. 34.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2015. Title of presentation. Waste to Worth: Spreading Science and Solutions. Seattle, WA. March 31-April 3, 2015. URL of this page. Accessed on: today’s date.