Page 170 - Nutrient Management Planning Guide

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Manure Test Interpretation

Estimating Crop Available N

Swine manure (1.8 kg/1000 L of NH

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-N) is to be surface applied using a splash plate application system on a soil under conventional tillage. This situation is assumed to be similar to surface application and incorporation within one day. Since application is planned over a period of several days, and the weather conditions during this period are expected to be quite variable, an average retention factor of 0.75 is used.

Retained NH

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-N = NH

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-N × Retention Factor (Table 4.6.3) = 1.8 kg/1000 L × 0.75 = 1.35 kg/1000 L

Available organic N content for the year of application is: Available Organic N = Organic N × 0.25 = 1.7 kg/1000 L × 0.25 = 0.425 kg/1000 L

The total amount of crop available N in this manure then is:

Estimated Crop Available N = Available Organic N (year 1) + Retained NH

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-N = 0.425 kg/1000 L + 1.35 kg/1000 L = 1.78 kg/1000 L