Estimating Manure N App Rates
Purpose
Manure nitrogen application rates must be estimated annually based upon the most recently available information for manure nutrient concentration (manure sample) and the Section 7 estimate of crop nutrient needs. Since this information is not typically available at the time of a permit application, estimating manure nitrogen application rates as part of a permit is, at best, an educated guess made without essential information. However, the underlying principles and assumptions that will be used to estimate manure nitrogen application rates can be defined in a permit application. In addition, an example of the use of these calculations is shared in Section 12 - Annual Plan.
This section describes the calculations and assumptions that will be used to annually estimate individual field manure nitrogen application rates.
Example
Reference Materials
Please download (Save) the forms and software files to your local computer.
Nebraska CNMP – Land Application Workbook Form 17 - Crop Available Manure Nitrogen. PDF version (1 page, 93KB); MS Word Form (1 page).
Determining Crop Available Nutrients from Manure, NebGuide G1335 pdf version (4 pages, 946KB)
Discusses the availability and use of manure nutrients for field crop production and allows calculations to estimate crop-available nutrients from manure.
Software
Manure Use Plan for Nebraska: .xls Spreadsheet; Instructions
Estimates the nutrient value of manure and accurately credits those nutrients against the nutrient requirements of a crop. Maintains an 11-year record for 25 fields for manure and fertilizer application rate plans. This spreadsheet can be used for creating and maintaining an annual nutrient plan.
The Manure Management Planner and Plan Generator (MMP) is a program developed and located at Purdue University for making nutrient management plans for crop and animal feeding operations.