Sanjay Gami1, Juan Carlos Ramos Tanchez1, Mike Reuter2, and Quirine M. Ketterings1
Cornell University Nutrient Management Spear Program1, and Dairy One2
Introduction
The corn stalk nitrate test (CSNT) is an end-of-season evaluation tool for N management for 2nd or higher year corn fields. It allows for identification of situations where N during the growing season exceeded crop needs. Research shows that the crop had more N than needed when CSNT results exceed 2000 ppm. Results can vary across years, but where CSNT values exceed 3000 ppm for two or more years, it is highly likely that N management changes can be made without impacting yield.
Findings 2010-2025
In 2025, 37% of all tested fields had CSNT-N greater than 2000 ppm, while 28% were over 3000 ppm and 15% exceeded 5000 ppm (Table 1). In contrast, 34% of the 2025 samples were low in CSNT-N. Over the years, the percentage of samples testing excessively in CSNT-N was most correlated with the total precipitation in May-June with droughts in those months translating to a greater percentage of fields testing excessive. The year 2025 was classified as wet based on May-June rainfall but many areas experienced severe drought conditions after a wet spring, lowering yields and contributing to a higher percentage of stalks testing excessive in CSNT in 2025 compared to a more ideal rainfall year like 2024. Because crop and manure management history, soil type and growing conditions all impact CSNT results, conclusions about future N management should consider the events of the growing season. This includes weed and disease pressure, lack of moisture in the root zone in drought years, lack of oxygen in the root zone due to excessive rain in wet years, and any other stress factor that impact crop growth and N status.
Note: Data prior to 2013 reflect stalk submissions to NMSP; 2013, 2014, and 2017-2025 data include results from NMSP and Dairy One; 2015-2016 has samples from NMSP, Dairy One, and CNAL. Yield data source: USDA – National Agricultural Statistics Service. Rainfall data source: CLIMOD2, Northeast Regional Climate Center. Total number of samples: 12188. The year 2025 was an exceptionally bad year with a wet spring delaying planting followed by a drought.
Within-field spatial variability can be considerable, requiring (1) high density sampling (equivalent of 1 stalk per acre at a minimum) for accurate assessment of whole fields, or (2) targeted sampling based on yield zones, elevations, or soil management units. The 2018 expansion of adaptive management options for nutrient management now includes targeted CSNT sampling because of findings that targeted sampling generates more meaningful information while reducing the time and labor investment into sampling. Two years of CSNT data are recommended before making any management changes unless CSNT’s exceed 5000 ppm, in which case one year of data is sufficient.
Figure 1: In drought years more samples test excessive in CSNT-N. The last 16 years included six drought years (2012, 2016, 2018, and 2020 through 2023), four wet springs (2011, 2013, 2017, and 2025, which was wet followed by a severe drought), and five years labelled normal (2010, 2014, 2015, 2019, and 2024) determined by May-June rainfall (less than 7.5 inches in drought years, 10 or more inches in wet years). Weather data are state averages; local conditions may have varied from state averages.
Agronomy Factsheets #31: Corn Stalk Nitrate Test (CSNT); #63: Fine-Tuning Nitrogen Management for Corn; and #72: Taking a Corn Stalk Nitrate Test Sample after Corn Silage Harvest. http://nmsp.cals.cornell.edu/guidelines/factsheets.html.
Acknowledgments
We thank the farmers and farm consultants that sampled their fields for CSNT over the years. For questions about these results contact Quirine M. Ketterings at 607-255-3061 or qmk2@cornell.edu, and/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/.
Srinivasagan N. Subhashree1, Rahul Goel2, Manuel Marcaida III1, Juan Carlos Ramos-Tanchez1, and Quirine M. Ketterings1
1 Nutrient Management Spear Program (NMSP) and 2Department of Electrical and Computer Engineering, Cornell University
Simplifying On-Farm Research with Single-Strip Trials
On-farm research is a powerful tool to advance crop management, providing practical, field-specific insights. However, traditional designs such as the randomized complete block design, often referred to as replicated strip trials, are often difficult to implement on-farm due to time, equipment, and labor demands. With more farms collecting yield data with monitor systems, there is now an opportunity to conduct on-farm research using the Single-Strip Spatial Evaluation Approach (SSEA), which compares yield from one field-length treatment strip (at least two harvester widths) to two control strips using a spatial model. This new approach takes into account current year yield and pre-existing field variability, and reports results per yield stability zones: Q1 (high and stable), Q2 (high and variable), Q3 (low and variable), and Q4 (low and stable). As one farmer noted, “Multiple years with the SSEA has helped us tune in where we could be improving nutrient placement… The practicality and ease of use makes it a welcome trial on a busy farm.”
Until recently, SSEA analyses required support from NMSP staff. To help farmers and advisors conduct these evaluations independently, we developed a new web-based tool (https://ssea-nmsp-tool.shinyapps.io/SSEA-tool-CornellNMSP/) that automates the analysis and provides result visuals and downloadable reports (Figure 1).
Figure 1. Overview of the SSEA tool displaying the uploaded inputs such as the strip location and yield stability zone maps.
New Webtool to Support Spatial Evaluation of Single-Strip Trials
A free web-based tool was developed to automate the spatial analysis and provide interpretations of trial results without the need for statistical expertise. The tool was developed with feedback from a statewide advisory committee, who helped refine the visual outputs and ensure the tool met user’s needs. The interface includes four tabs: Inputs & Analysis, Results, Report, and About. When users first open the tool, only the Inputs & Analysis and About tabs are visible; the Results and Report tabs appear once the necessary files are uploaded, and the analysis is complete.
The Inputs & Analysis tab requires four inputs: (1) treatment and control strip locations, (2) a yield stability zone map, (3) temporal average yield layers, and (4) current-year yield data. The interface is designed to be simple and intuitive, with a satellite basemap, zoom tools, and checkboxes that allow users to view each layer individually. For farmers who share yield monitor data with the NMSP as part of the New York On-Farm Research Partnership, all tool inputs other than the strip location(s) are already prepared and shared in a ready-to-use format. Detailed instructions for creating strip shapefiles are available in the user guidelines found in the About tab.
Once the inputs are uploaded, the tool generates two key visuals: (1) a donut plot showing the distribution of yield stability zones in the field and in the strips, and (2) a confidence chart that summarizes the likelihood of yield benefit or loss as a result of the management change implemented in the treatment strip. These outputs appear in the Results tab. The tool then auto-interprets these results and compiles them into editable text boxes in the Report tab, allowing users to refine the language before downloading a polished, two-page PDF report. By delivering fast and easy-to-interpret results, the tool enables farmers to evaluate more trials and helps reduce key barriers to the adoption of on-farm research.
Case Study Results
A farm in central New York partnered with NMSP to test an agricultural product in a 23.5-acre corn silage field using the single strip approach. The treatment strip was two chopper widths wide, placed away from field edges, and positioned to allow equal-width control strips on either side. Strip locations, yield stability zone maps (derived from three years of historical yield data), temporal average yield, and current-year yield data were uploaded into the SSEA webtool.
Figure 2: Single-strip spatial evaluation approach (SSEA) analysis results show a donut plot for zone distribution in the field and in the treatment strips (center strip and the control areas on both sides).
The zone distribution donut plot (Figure 2) confirmed that the treatment and control strips captured the major yield stability zones present in the field. In this field, the consistently low-yielding zone (Q4) represented the largest large portion (43%). The placement of the treatment strip was such that all four zones were represented but with more datapoints for zone Q2 (35%) and Q1 (34%) than for Q2 (20%) and Q3 (11%).
Figure 3: Single-strip spatial evaluation approach (SSEA) analysis results show a confidence chart that lists the probability of yield response of a certain size from the treatment that was implemented in the strip.
The confidence chart produced by the SSEA webtool showed a high confidence (dark purple, 81-100% confident) of a yield benefit in lower yielding zones with increases of 0.5 to 0.75 tons/acre for Q3 and 0.75 to 1 tons/acre for Q4; however, for high yielding zones, Q1 and Q2, this yield increase was not seen. Thus, the product that was tested by the farmer helped improve yields in the lower yielding zones only. The economic value of applying the product can be assessed by combining the information from the confidence chart, the distribution of yield stability zones in the farm, and the costs involved with applying the product versus the value of a yield increase. If the yield benefits outweigh the costs for Q3 and Q4, any field with a substantial area of these two zones could be targeted for use of the product while applications to fields with mostly Q1 and Q2 where a yield benefit is not expected. If targeted use in portions of the field is an option, the product would be used for Q3 and Q4 zones within different fields as well. For results to stand the test of time, it is highly recommended to test products or management changes across years and across multiple fields. The SSEA approach can combine information for multiple fields and years.
Conclusions
The single-strip approach provides a practical way to evaluate management practices on-farm while accounting for within-field variability and minimizing disturbance of field operations. The SSEA webtool provides a platform to evaluate single-strip trials using yield monitor data and yield stability zone maps.
Full Citation
This article is summarized from: Subhashree, S.N., R. Goel, M. Marcaida III, J.C. Ramos-Tanchez, and Q.M. Ketterings (2025). Enhancing on-farm research with a web-based single-strip spatial evaluation tool: Design, features, and applications. Agronomy Journal, 56(3): e70264. DOI: 10.1002/agj2.70264
Acknowledgments
This research was supported (in part) by Cornell Atkinson’s Center for Sustainability, Northern New York Agricultural Development Program (NNYADP), New York Farm Viability Institute (NYFVI), New York State Department of Agriculture and Markets (NYSAGM), New York State Department of Environmental Conservation (NYSDEC), and by intramural research program of the U.S. Department of Agriculture, National Institute of Food and Agriculture, Hatch NYC‐127459. The findings and conclusions in this publication have not been formally disseminated by the U.S. Department of Agriculture and should not be construed to represent agency determination or policy. For questions about these results contact Quirine M. Ketterings at 607-255-3061 or qmk2@cornell.edu, and/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/.
Manuel Marcaida III1, Kirsten Workman1,2, Karl Czymmek2, and Quirine M. Ketterings1
1Cornell University Nutrient Management Spear Program (NMSP) and 2PRO-DAIRY
Introduction The New York Phosphorus Index 2.0 (NY P-Index) and the Northeast Region Phosphorus Index (NR P-Index) help farmers assess the relative risk of phosphorus (P) loss from their fields and make informed decisions about manure and fertilizer P applications. Both P-indices combine soil test phosphorus (STP) in four categories (<40, 40-100, 101-160, and >160 lbs Morgan P/acre) with a field P-Index score derived from field features such as soil type, flow distance to streams, and flooding frequency, and management practices such as incorporation or injection of manure, to derive a management implication (Figure 1).
Figure 1. With the New York and Northeast Region P-Indices, management implications are derived based on soil test P (STP) category and P-Index score, assessed using transport factors (Transport Score) and beneficial management practices (BMP Score). The management implication determines whether fields can receive manure to meet N-need of the crop (N-based), up to annual P removal (P-based), or no P allowed (Zero P). The example shown here is for the New York Phosphorus Index 2.0.
Farmers and advisors have increasingly looked at grid sampling to better management soil fertility for improved crop production. To address questions on how to use P-Index in grid sampling context where STP information are more spatially granular than traditional whole-field samples, we analyzed soil data from 20 corn fields across six New York farms. We compared P-Index results and management recommendations based on whole-field composite samples and grid-based STP data at three grid sizes (0.5, 1.0, and 2.5 acres).
Key Findings
Homogeneous field conditions lessen the need for grid sampling Most fields sampled were relatively homogeneous in terms of STP categories, with STP levels consistently classified as either A (<40 lbs Morgan P/acre) or D (>160 lbs Morgan P/acre) regardless of grid size (Figure 2). In such cases, whole-field composite sampling was sufficient for P-Index assessment and P management planning. Three fields showed noticeable variability across STP classes, with their whole-field averages in the STP range B (40-100 lbs Morgan P/acre). For these fields continued grid-based or zone sampling can help refine P management as well as address other fertility goals of the farm manager.
Figure 2. Distribution of soil test phosphorus (STP) levels within each field across different grid sampling resolutions. The bars show the fraction of each field that falls into four STP categories. Fields with more color variation indicate greater within-field differences in soil P.
Grid sampling is valuable for fields with variable STP levels For the three fields whose STP levels were predominantly in class B (40-100 lbs Morgan P/acre), grid sampling revealed meaningful within-field differences (Figure 2) that would not be apparent from a whole-field composite sample. The finer scale information can help farmers and crop advisors designate P management zones, identifying whether portions of a field may warrant more conservative manure applications, or whether lower-P areas justify continuing N-based manure rates. The value of grid sampling is not in calculating grid-level P-Index scores, but in using the spatial pattern of STP to determine whether a single field-level P-Index assessment is adequate or whether zone-based management could enhance nutrient-use efficiency and advance environmental stewardship.
Coarser grid sizes provide comparable P management insights Analysis on Fields E3, D1, and C1 showed that fields with STP levels in 40-100 lbs Morgan P/acre (class B) range gave similar management results whether sampled on 0.5-, 1.0-, or 2.5-acre grids at different P-loss risk scenarios (Figure 3). This finding suggests that coarser grids, such as 2.5 acres, can still capture the key spatial patterns needed to guide P management decisions. For farmers and crop advisors, this means sampling and testing can be streamlined without losing the detail needed to understand whether P-risk varies meaningfully across the field. While the P-Index is not intended for grid-level application, an initial grid sample can reveal where distinct P zones exist, allowing those zones to serve as the basis for future P-Index assessments.
Figure 3. Comparison of P-Index derived manure management implications using whole-field and grid-based soil sampling (0.5, 1.0, and 2.5 acres). Field maps show differences in soil test phosphorus (STP) levels, while the donut charts illustrate how the proportion of field area in each P-Index management category (N-based, P-based, or Zero P) changes across grid sizes and phosphorus loss risk scenarios.
Conclusions Grid sampling for P management is most useful in fields with 40–100 lbs/acre STP levels, where nutrient variability within the field can change management recommendations. For fields with uniformly low or excessively high STP levels, whole-field composite sampling provides adequate information for nutrient management planning. When grid sampling is beneficial, a 2.5-acre resolution captures meaningful variability without the added cost of finer grid sampling. Using the New York P-Index 2.0 or Northeast Region P-Index together with grid-based data helps farmers make informed decisions that balance productivity, nutrient efficiency, and water quality protection.
Full Citation This article is summarized from our peer-reviewed publication: Marcaida, M. III., K. Workman, K. J. Czymmek, and Q.M. Ketterings (2025). Grid-based soil sampling for Northeast Region phosphorus index assessment. Soil Science Society of America Journal, 89, e70156. https://doi.org/10.1002/saj2.70156
Acknowledgments The authors would like to thank the staff of Champlain Valley Agronomics, Western New York Crop Management Association, and participating farmers. Funding came from the Northern New York Agricultural Development Program, the New York Corn and Soybean Growers Association via the New York Farm Viability Institute, the New York State Department of Environmental Conservation, the New York State Department of Agriculture, and the intramural research program of the U.S. Department of Agriculture, National Institute of Food and Agriculture, Hatch 2021-22-210. The findings and conclusions in this publication have not been formally disseminated by the U.S. Department of Agriculture and should not be construed to represent agency determination or policy. For questions about these results contact Quirine M. Ketterings at 607-255-3061 or qmk2@cornell.edu, and/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/.
1Cornell University, School of Integrative Plant Science, Soil and Crop Sciences, Ithaca, NY; 2Cornell Cooperative Extension Northwest New York Dairy, Livestock & Field Crops, Newark, NY
Introduction
Annual ryegrass at heading stage
Annual ryegrass [Lolium perenne L. spp. multiflorum], also known as Italian rye, is commonly grown as a winter annual cover crop in New York State. Annual ryegrass was originally introduced from Europe to the United States during colonial times. About 3 million acres of annual ryegrass are currently grown as a cover crop in the United States. Annual ryegrass is often confused with perennial ryegrass (Lolium perenne L.) and rigid ryegrass (Lolium rigidum Gaud.), therefore close attention to identification characteristics between these species should be considered when distinguishing them. Annual ryegrass is generally taller than perennial ryegrass. For instance, annual ryegrass can grow 2 to 4 feet tall at full maturity, whereas perennial ryegrass can only grow 1 to 2 feet tall. Additionally, the red-tinged base of annual ryegrass also helps to distinguish annual ryegrass from perennial ryegrass, which is quite similar in growth habit and appearance. Annual ryegrass establishes quickly and grows vigorously and could become a weed if not properly managed. Annual ryegrass has been established as one of most problematic weeds in small grain cereals, row and vegetable crops as well as along roadsides in the United States. A recent survey conducted by the Weed Science Society of America (WSSA) has ranked annual ryegrass as the most troublesome and difficult to control weed in winter cereal grains. In the U.S., annual ryegrass populations have developed resistance to five different herbicide sites of action (WSSA groups: 1 2, 9, 10, and 15).
Problem of Annual Ryegrass Termination with Glyphosate
Mature annual ryegrass is generally difficult to kill with glyphosate if it is applied under suboptimal weather conditions (for instance, air temperature below 50˚ F). However, in spring of 2023, a grower in Livingston County in western New York State reported an inadequate kill during the termination of an annual ryegrass cover crop with two sequential applications of glyphosate (Roundup® or similar brands) at field-use rates (32 fl oz/a of Roundup®) (Figure 1). Similarly, in spring of 2024 and 2025, two separate field crop producers from Ontario and Genessee Counties reported termination failure of annual ryegrass cover crops with glyphosate (Figure 1). Annual ryegrass plants surviving glyphosate applications from these three fields in Livingston, Ontario, and Genesse Counties recovered, fully head out, pollinated and produced viable seeds.
Figure 1. Annual ryegrass cover crop plants surviving glyphosate applications in Livingston (A), Genesse (B), and Ontario (C) counties of western NY State (Photo credits: Mike Stanyard, CCE).
Glyphosate-Resistant Annual Ryegrass in New York
Greenhouse experiments were conducted at Cornell University Guterman Bioclimatic Laboratory in 2023 through 2024 to investigate if the annual ryegrass population from Livingston County, NY was resistant to glyphosate. Seeds of annual ryegrass plants surviving glyphosate applications from Livingston County, NY were tested along with a previously known glyphosate susceptible annual ryegrass population from Arkansas (Courtesy: Dr. Jason Norsworthy, University of Arkansas). Seedlings from both annual ryegrass populations (one from New York and the other from Arkansas) were grown separately in 4-inch plastic pots containing commercial potting mixture under greenhouse conditions. Seedlings of annual ryegrass from both populations were sprayed across a range of glyphosate doses (0, 3.3, 6.75, 13.5, 27, 54, 108, 216, and 432 fl oz/a of Durango®) along with 2% w/v ammonium sulfate (AMS) using a cabinet spray chamber when seedlings were at the 5- to- 6-leaf stage. Results indicated that Durango® applied at the field-use rate (27 fl oz/a) did not provide any control of the annual ryegrass population from Livingston County, NY at 21 days after application (DAA) (Figure 2). In contrast, plants from the Arkansas annual ryegrass population were all killed with this field-use rate of Durango® at 21 DAA. Furthermore, the annual ryegrass population from Livingston County, NY was not completely killed at the highest tested dose (432 fl oz/a) of Durango® at 21 DAA (Figure 2). Results further revealed that the annual ryegrass from Livingston, County had a 22-fold level resistance to glyphosate compared with the annual ryegrass population from Arkansas.
Figure 2. Response of annual ryegrass populations from Arkansas and New York State 21 days after treatment with Durango® (glyphosate) applied at 27 fl oz/a (field-use rate) and 432 fl oz/a (16 times the field-use rate) in greenhouse experiments at Cornell University (Photo credit: Vipan Kumar, Cornell University).
POST Herbicides for Termination of Glyphosate-Resistant Annual Ryegrass
An on-farm field study was conducted in spring of 2025 to test the effectiveness of alternative postemergence (POST) herbicides for termination of glyphosate-resistant annual ryegrass. A total of nine POST herbicide programs, including Select Max® (clethodim) at 16 fl oz/a, Assure II® (quizalofop) at 12 fl oz/a, Roundup PowerMAX® 3 (glyphosate) at 32 fl oz/a alone and in combination with Select Max® or Assure II®, Liberty® 280 SL (glufosinate) at 43 fl oz/a alone and in combination with Select Max® or Assure II®, and Gramoxone® SL 3.0 (paraquat) at 32 fl oz/a alone and in combination with Metribuzin 75 DF (metribuzin) at 4 oz/a were tested at their field-use rates for termination of glyphosate-resistant annual ryegrass. All herbicides were applied with appropriate adjuvants as recommended by each herbicide label using a CO2-operated backpack sprayer fitted with six AIXR110015 nozzles at 15 Gallons per acre, when annual ryegrass was headed out. Among all tested programs, Gramoxone® SL 3.0 alone or in combination with metribuzin, Liberty® 280 SL alone and in combination with Assure II® or Select Max® provided 92% to 100% control/kill of mature glyphosate-resistant annual ryegrass at 21 days after treatment (DAT) (Figure 3). In contrast, poor kill (10 to 25%) of glyphosate-resistant annual ryegrass was observed with Select Max or Assure II at 21 DAT.
Figure 3. Visual response of glyphosate-resistant annual ryegrass terminated with nontreated (A), Liberty® 280 SL at 43 fl oz/a (B), Gramoxone® at 32 fl oz/a (C), and Roundup PowerMAX®
Conclusions and Ongoing Research
Findings from this research confirm the first case of glyphosate resistance in annual ryegrass in New York State. Alternative POST herbicide burndown chemistries (including Liberty® 280 SL and Gramoxone® SL 3.0) can be used to terminate glyphosate-resistant annual ryegrass at or prior to planting of cash crops. We are currently investigating the status of these annual ryegrass populations for multiple herbicide resistance and underlying mechanism(s) of glyphosate resistance. We are planning to conduct on-farm field studies at multiple locations in New York State and in the northeastern region for developing cost-effective integrated strategies to manage the seedbank of glyphosate-resistant annual ryegrass in various field crops, including small grain cereals, soybean, and corn.
The Cornell Small Grains Breeding Program has announced the release of LakeEffect, the first winter malting barley released by the program in its 118-year history.
“We’re excited about LakeEffect because it couples the agronomic performance farmers want with the superior malting qualities brewers and distillers are looking for,” said Mark Sorrells, professor in Cornell’s School of Integrative Plant Science (SIPS), who led the breeding effort.
“What’s truly remarkable is that we took this from first cross to commercial release in just seven years – which is incredibly fast to move a new variety to market,” he added.
Certified seed growers are expected to harvest seed crops for commercial growers in summer 2026 for fall 2026 planting. For more information on seed availability, contact the New York Seed Improvement Program at (607) 255-9869 or nysip@cornell.edu.
Aidan Villanueva1, Juan Carlos Ramos Tanchez1, Kirsten Workman1,2, and Quirine M. Ketterings1
1Cornell University Nutrient Management Spear Program (NMSP) and 2PRO-DAIRY
Introduction
Manure contains all seventeen essential nutrients and, when properly managed, can contribute to a circular economy by offsetting fertilizer needs and building soil resiliency. Of all nutrients contained in manure, the most difficult one to manage is nitrogen (N). Manure contains N in different forms, some of which is released within the growing season following the application, while portions of the organic N can be mineralized and converted to plant-available N over multiple years.
Over the past three years, New York Farm Viability Institute (NYFVI), Northern New York Agricultural Development Program (NNYADP), USDA National Institute of Food and Agriculture, and New York State Department of Agriculture and Markets (NYSAGM) Department of Environmental Conservation (NYSDEC) co-sponsored the “Value of Manure” project, an initiative of the New York On-Farm Research Partnership of the Nutrient Management Spear Program (NMSP). The Value of Manure project now contains data for nineteen on-farm research trials collected over three seasons, and the results have been summarized each year: 2024, 2023, 2022. Here we report on the yield responses and fertilizer offsets for two trials at two different farms (Farm A and Farm B) where we collected two years of data, in the year of application, and in the year after manure application.
Trial Design
Each Value of Manure trial had three strips that received manure in 2023 and three that did not, for a total of six strips and three replications per treatment. At sidedress time, each strip was subdivided into 6 subplots and assigned varying rates of sidedress from 0 up to 200 lbs N/acre. No manure was applied in 2024 so that we could evaluate 2023 manure’s carry-over N contribution to yield in 2024 (2nd year benefits). For each trial and each year, we calculated the Most Economical Rate of Nitrogen (MERN), the point at which adding extra fertilizer stops paying for the extra yield increase. The MERN calculation assumed a fertilizer price of $0.73/lb of N, a $55 per ton silage value (at 35% DM), and a $4.2 per bushel grain value (at 85.5% DM). Farm A is in central New York and the trial field was a Lima silt loam soil (SMG2). Farm B is in northern NY and the trial field had a Grenville loam soil (SMG 4). See Table 1 for information about manure composition and application.
Findings 2023-2024
For farm A (Figure 1):
Without sidedress N, manure-treated plots yielded 101 bu/acre in 2023, compared to 69 bu/acre for plots without manure, a 32 bu/acre advantage from manure application. In 2024, without sidedress N, manure plots produced 64 bu/acre versus 57 bu/acre in non-manured plots, reflecting a 7 bu/acre benefit in the second year after application.
At the MERN (Figure 1), manured strips yielded 176 bu/acre in 2023 compared to 155 bu/acre in non-manured strips, a 21 bu/acre gain from manure application beyond what was gained from N fertilizer application. In 2024, the manured strips produced 200 bu/acre, while non-manured plots yielded 187 bu/acre, reflecting an additional 13 bu/acre benefit from manure in the second year after application.
At the MERN, manure plots required 13 lbs/acre more sidedress nitrogen than no manure plots to reach their economic optimum in 2023. In 2024, manure offset 36 lbs/acre of inorganic nitrogen, demonstrating its continued contribution in the second year after application.
Over the two years of the study, manure positively impacted yields and reduced fertilizer needs. Without sidedress nitrogen, manure provided a cumulative yield benefit of 39 bu/acre. At the MERN across both years, manure reduced fertilizer N requirements by 23 lbs N/acre and increased yields by 34 bu/acre, resulting in an economic gain of $159/acre, excluding costs of manure and sidedress application.
Figure 1. The most economic rate of N (MERN) without manure (dashed gray line) and with manure (dashed brown line) in 2023 (left) and 2024 (right) for farms A (corn grain, top) and B (corn silage, bottom).
For farm B (Figure 1):
On Farm B in 2023 (Year 1), without sidedress nitrogen, manure-treated plots yielded 24.8 tons/acre compared to 20.6 tons/acre for non-manured plots, a 4.2 ton/acre gain from manure. In 2024, without sidedressing, manure plots yielded 14.2 tons/acre versus 12.5 tons/acre in plots without manure, reflecting a 1.7 ton/acre benefit in the second year after application.
In 2023, at the MERN, manured plots yielded 24.3 tons/acre compared to 22.9 tons/acre for strips that did not receive manure, a 1.4 ton/acre increase due to manure beyond what was gained from N fertilizer application. In the second year (2024), yields were 17.3 tons/acre for manured strips versus 16.5 tons/acre without manure, resulting in a 0.8 ton/acre yield advantage due to the previous year’s manure application.
At the MERN, the plots that did not receive manure in 2023 required an additional 109 lbs N/acre of sidedress fertilizer to reach the MERN (Figure 1) compared to plots where manure had been applied. In the second year (2024), manure did not offset inorganic N fertilizer needs, as MERNs were similar for both manured and non-manured plots.
Looking at the two-year benefits from manure (Table 2), without sidedress N, the yield benefit from the manure amounted to 5.9 tons/acre. At the MERN across both years, manure reduced fertilizer nitrogen requirements by 109 lbs N/acre and increased yields by 2.2 tons/acre, resulting in an economic gain of $206/acre, excluding the costs of manure and sidedress application.
In Summary
Manure application increased yields in both 2023 and 2024, demonstrating both immediate and carryover effects at both study sites. Over the two years, when no N was sidedressed manure provided cumulative yield benefits of 39 bu/acre at Farm A and 5.9 tons/acre at Farm B. At the MERN (the point when N was optimally applied through sidedressing), total yield gains due to manure were 34 bu/acre at Farm A and 2.2 tons/acre at Farm B. Additionally, manure reduced fertilizer N needs by 23 lbs N/acre at Farm A and 106 lbs N/acre at Farm B over the two years. The combined benefits of N replacement and yield increases over both years resulted in overall economic gains of $159/acre at Farm A and $206/acre at Farm B, excluding fertilizer and manure application costs. These results highlight the significant agronomic and economic value of manure. Both trials will continue into 2025 to assess the three-year impacts on yield and fertilizer savings. Would you like to see similar data for your farm? Join the Power of Manure project!
We thank the New York Farm Viability Institute (NYFVI), Northern New York Agricultural Development Program (NNYADP), USDA National Institute of Food and Agriculture, New York State Department of Agriculture and Markets (NYSAGM) and Environmental Conservation (NYSDEC), participating farmers, consultants. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy. For questions about these results contact Quirine M. Ketterings at 607-255-3061 or qmk2@cornell.edu, and/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/.
/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/. 
