Page 222 - Nutrient Management Planning Guide

214

Calculating Manure Application Rates and Fertilizer Requirements

Crop Available N Liquid manure source:

Organic N (g/L) = 3.8 g/L – 1.9 g/L Organic N (g/L) = 1.9 g/L

Available Organic N, year 1 (g/L) = 1.9 g/L × 0.25 Available Organic N, year 1 (g/L) = 0.5 g/L Since the intention is to inject manure during wet/ cool spring conditions: Retained NH

4

-N (g/L) = 1.9 g/L × 1.00 (from Table 4.3.4) Retained NH

4

-N (g/L) = 1.9 g/L

Crop Available N (g/L) = 0.5 g/L + 1.9 g/L Crop Available N (g/L) = 2.4 g/L

Solid manure source:

Organic N (g/kg) = 8.3 kg/t – 2.0 kg/t Organic N (g/kg) = 6.3 kg/t

Available Organic N, year 1 (kg/t) = 6.3 kg/t × 0.25 Available Organic N, year 1 (kg/t) = 1.6 kg/t Since the intention is to surface apply during wet/cool spring conditions and incorporate within 2 days: Retained NH

4

-N (g/kg) = 2.0 kg/t × 0.87 (from Table 4.3.4) Retained NH

4

-N (g/kg) = 1.7 kg/t

Crop Available N (g/kg) = 1.6 kg/t + 1.7 kg/t Crop Available N (g/kg) = 3.3 kg/t

Crop Available P Liquid manure source:

Crop Available P (year 1) (g/L) = 1.0 g/L × 0.7 Crop Available P (year 1) (g/L) = 0.7 g/L

Solid manure source:

Crop Available P (year 1) (g/kg) = 2.3 kg/t × 0.7 Crop Available P (year 1) (g/kg) = 1.6 kg/t

Crop Available K Liquid manure source:

Crop Available K (g/L) = 4.3 g/L × 0.9 Crop Available K (g/L) = 3.9 g/L

Solid manure source:

Crop Available K (kg/t) = 6.9 kg/t × 0.9 Crop Available K (kg/t) = 6.2 kg/t

Estimating Crop Available Nutrient Content

Lab analysis of liquid and solid manure sources yielded the following nutrient content information:

Source Moisture

Total N (wet basis)

NH

4

-N 1

(wet basis)

Total P (wet basis)

Total K (wet basis)

Liquid 92 % 3.8 g/L 1.9 g/L 1.0 g/L 4.3 g/L Solid 50 % 8.3 kg/t 2.0 kg/t 2.3 kg/t 6.9 kg/t

1 NH

4

-N is Ammonium-Nitrogen