Nutrient Management Workbook

Guide to Completing the Workbook – Sections A to S

This workbook is organized in sections, from A to S, with each line of the Worksheet corresponding to the detailed descriptions found here help you develop the required information.

Section C – Manure Nutrient Information

Calculate the available P₂0₅ and K₂0. (Some labs may already have done these calculations). If a manure analysis is not available, use the values in Table 3. The Nutrient Management Act requires manure nutrient testing.

The following conversions may be required:

Available P₂0₅:

Percent P________ X 0.92 =________ % available P₂0₅ (From Table 3 or Lab Analysis)

        x 10 = _______kg/1000 L
  OR x 10 = _______kg/tonne
  OR x 100 = _______ lb/1000 gal
  OR x 20 = _______ lb/ton

(Calculate only the one that you need.)
   

Available K₂0:

Percent K________ X 1.08 =________ % available K₂0 (From Table 3 or Lab Analysis)

        x 10 = ______kg/1000 L
  OR x 10 = ______kg/tonne
  OR x 100 = _____ lb/1000 gal
  OR x 20 = _____ lb/ton

(Calculate only the one that you need.)

Example:
A farmer took a liquid hog manure sample, which came back with the analysis of 0.3% N, 0.1% P, 0.2% K, and 1000 ppm. NH₄-N (0.1%). He will incorporate the manure within 3 days.
N          Availability depends on additional factors. See Method 1 or 2
P₂0₅     0.1 x 0.92 = 0.092% = 9.2 lb/1000 gal
K₂0       0.2 x 1.08 = 0.216% = 21.6 lb/1000 gal

Use Method 1 or 2 to calculate available nitrogen. Method 1 should be used where there is no manure analysis available and where manure is "Late Summer" or "Fall" applied (with Lab Analysis). Method 2 should be used for "Spring, Pre-plant or Side-dress" applied manure with Lab analysis.

Method 1: Available Nitrogen (Using Nutrient Averages or for Fall Applied Manure)

Where manure is being fall applied, use the total percent nitrogen from the analysis and determine available N (using Table 4). Where a manure analysis is not available, use the numbers in the typical analysis chart (Table 3).

Available N:

% Total N (Table 3 or Lab Analysis) ______ x Available N (Table 4) _______ = ________ %

        x 10 = ______kg/1000 L
  OR x 10 = ______kg/tonne
  OR X 100 = ______ lb/1000 gal
  OR X 20 = ______ lb/ton

Source: NMAN Databank
¹ assumes milkhouse wastes are stored with manure
² assumes some yard runoff
³ Ammonium Nitrogen (%) can be calculated by subtracting Organic N from Total N.

Source: Adapted from Barry, Beauchamp et. al., U of Guelph 2000
Available N in manure = Total Manure N applied x Available N from Table 4
¹ assumes a spring planted crop; Side-dress refers to application to a growing crop
² accounts for ammonia loss to atmosphere and mineralization of organic N
³ for manure incorporated within 3 days Use: (incorporated value + non incorporated value) / 2
Late Summer = up to Sept 20, Early Fall = Sept 21 to Nov 9, Late Fall = Nov 10 to Winter

The NMAN software uses a more detailed method of determining available nitrogen. For different incorporation periods, NMAN will provide more precise estimates of available nitrogen.

Where a cover crop (ie clover, rye, oats or barley) is utilized, and manure is applied in late Summer or fall, use the "Late Fall" column in Table 4 to determine the Available Nitrogen for the next crop.
Where manure is applied in late Summer or early fall (following the harvest of a crop), on a soil in the Hydrologic Group AA, or A or in late Summer on a soil in the B Hydrologic Group, without a cover crop, the Nitrogen Index (Section O) must be completed.

Example:
A farmer has liquid hog manure from a finishing barn. He does not have wet/dry feeders. He plans to apply the manure in late April and plans to incorporate his manure within 24 hours. Since a manure test is not available he uses a typical analysis from Table 3 and using Table 4, calculates the available N, P₂0₅ and K₂0. He finds his manure to have the following nutrients available for the next growing season.

Available N:  .49 % (Manure Analysis, Table 3) x .56 (Available N factor)  x 100 = 27.4 lb/1000 gal

Method 2: Available Nitrogen for Spring Applied Manure Using Results from a Lab Analysis

This method gives a more accurate estimate of available Ammonium-N and Organic-N from spring, pre-plant or in-crop applications of manure where an analysis is available. Determine the proportion of available organic and retained ammonium-N using Tables 5 and 6 respectively.

Available Nitrogen Using Available Organic and Ammonium-N portions (Using Lab Analysis Results):

[( percent N – percent NH4-N) x Available Organic N (Table 5)] + [(percent NH4-N x Retained Ammonium (Table 6))]

[(_________ -________ ) x____________ ] + (___________ x___________ )]

  =_____________ x 10 = ______________ kg/1000L
  =_____________ x 10 = ______________ kg/tonne
  =_____________ x 100 =______________  lb/1000 gal
  =_____________ x 20 = _______________ lb/ton 

Example:
A farmer took a liquid hog manure sample, which came back with the analysis of 0.3% N, 0.1% P, 0.2% K, and 1000 ppm NH4-N (0.1%). He will incorporate the manure within 3 days.

Available N: (0.3 – 0.1) x 0.2 (available Organic N)+ 0.1 x 0.65 (retained ammonium) = 0.105% x 100 = 10.5 lb/1000 gal.

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