Juan Carlos Ramos Tanchez¹, Kirsten Workman¹𝄒², Carlos Irias¹, and Quirine M. Ketterings¹
Cornell University Nutrient Management Spear Program¹, PRO-DAIRY²
Introduction
Quantification of nutrients in manure is essential to ensure efficient resource management, maximize agricultural productivity, and minimize negative environmental impact. A Value of Manure Calculator cell phone app was developed to estimate the agronomic and economic fertilizer replacement value of manure. To use the app, users will need to enter (1) the percent solids, N, P, and K nutrient content from a recent manure analysis, (2) the implemented or planned manure application rate, (3) crop nutrient needs, and (4) fertilizer costs. The app will then return past and current N credits, P and K credits, the fertilizer replacement value of the manure. Once the land application cost per gallon of manure is added, the tool also calculates the land application cost per extra mile hauled and the break-even hauling distance and costs. The app uses manure N credits that are in line with Cornell’s Nitrogen Guidelines for Field Crops in New York (2023). If you are in another state, consult your local land grant university guidance for manure N credits.
Calculator Access
The Value of Manure app can be accessed at Value of Manure Calculator (https://valueofmanure-nmsp.glide.page/) with any browser or by scanning the QR code to the right. Once opened, the user will see the opening page of the calculator (Figure 1 left). The front page shows, at the bottom of the screen, seven tabs: Lab Analyses; Past Application; Current Application; Crop Needs; Fertilizer Value; Hauling; and Results (Figure 1 right).
Calculator User’s Guide
Recently a User’s Guide explaining what the app does and how to use it, was released (Figure 2). The guide walks the user through the different taps and explains in detail the following topics:
- Entering a Manure Analysis
- Calculating Nitrogen Credits from Past Applications
- Calculating Current Year Manure Nutrient Credits
- Entering Crop Needs
- Entering Fertilizer Value
- Calculating Break-Even Hauling Distances and Costs
- Understanding the Results
- Signing in to Save Results
The Value of Manure Calculator User’s Guide can be accessed at the NMSP website by clicking on the following link: http://nmsp.cals.cornell.edu/publications/extension/ValueManure2026.pdf.
Additional resources
- Value of Manure Calculator User’s Guide: http://nmsp.cals.cornell.edu/publications/extension/ValueManure2026.pdf.
- The NMSP Value of Manure Project website: http://nmsp.cals.cornell.edu/NYOnFarmResearchPartnership/Value_of_Manure.html.
- Instructional video on how to access and install the Manure Value Calculator on a cellphone: https://www.youtube.com/watch?v=DRtdWrdFeok
Acknowledgments
The original manure crediting system was developed based on many years of field research under the leadership of S.D. Klausner, with contributions by D.J. Lathwell, D.R. Bouldin, and W.S. Reid of Cornell University, Department of Crop and Soil Sciences. This app was developed with financial support from the Northern New York Agricultural Development Program, the New York Agricultural Viability Institute, and USDA-NIFA. For questions about this project, 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/.
