5.2 Supplemental Nitrogen Needed

Supplemental applications of inorganic nitrogen (N) fertilizer may be required for optimum yields. Worksheet 4 calculates the rate of supplemental N needed when manure applications are made based on crop P2O5 removal.

You will need the following information:

Soil and Manure test results:

Follow the directions of Step 4 to obtain this information.

Your Manure application rate

Results from Worksheet 3

The Nutrient Availability Factor

Nutrients are released as manure decomposes in the soil, and not at once upon application. The nutrient availability of your soil is based upon what kind of manure you are applying, and is calculated for the year of application. Use Table 4 - Estimated Total Nitrogen in Manure to determine the nutrient availability in your manure.

Use the following Worksheet (Supplimental Nitrogen Needed) which determines your need for supplimental nitrogen.

Word Excel

(*Note- Excel spreadsheets are programed to do calculations for you. On some computers you can do calculations directly on your computer. On others you must save Excel files to your computer or disk before using the spreadsheets.)

Directions for Worksheet 4 calculations:

1. Nitrogen recommendation

Enter your nitrogen recommendation - based your soil report recommendation from your soil test. See Step 4 for more information on testing your soil.

2. Manure application rate

Enter your manure application rate - obtained from Worksheet 3, line 7.

3. Total N in manure (lbs / ton)

Enter total nitrogen in manure- based your manure test. See Step 4 for more information on testing your manure.

4.Totall N applied ini manure

The Excel spreadsheet will multiply line 2 by line 3.

5. Nitrogen availability

Enter the nitrogen availability factor (see Table 4 - Estimated Total Nitrogen in Manure).

6. Available N from manure

The Excel spreadsheet will multiply line 4 by line 5.

7. Supplemental N needed

The Excel spreadsheet will subtract line 6 from line 1.

Back to Step 5