Page 198 - Nutrient Management Planning Guide

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Calibrating Manure Application Equipment

Flow Rate (L/min) × 60 min/h × 10,000 m 2 /ha Speed (km/h) × 1,000 m/km × Width of application (m)

Application Rate (L/ha)

Application Rate (L/min) x Speed (km/h) x 1,000 m/km x Width of application (m)

60 min/h x 10,000 m 2 /ha

Flow Rate (L/min)

13,000 L/ha x 6 km/h x 1,000 m/km x 4.9 m

60 min/h x 10,000 m 2 /ha

382,200,000 600,000

= 637 L/min is the flow rate

Achieving Target Application Rate in a Dragline System

The example below only shows the values for each of the known factors, since the units in this equation (particularly those of the conversion factors) can become confusing.

The target application rate for a field is approximately 13,000 L/ha. The field conditions dictate that ground speed should not exceed 6 km/h. The application width of the dragline system is approximately 4.9 m. The flow rate that would be required to achieve an application rate of 13,000 L/ha would be:

Weight-Area Calibration

The weight-area calibration technique directly measures the weight of manure delivered to a known area at a given speed and setting. This is then used to determine the application rate in t/ha (or tn/ac).

This technique requires one or more plastic sheets, tarps or collection trays; means for securing these in place (e.g., pegs, weights); a suitable scale to weigh the manure collected; a tape measure; a notepad and a calculator. Weighing can be made easier by having a large plastic pail or garbage can on hand.

Follow the steps below to use the weight-area technique to calibrate application equipment.

Prepare the Collection Sheets or Pans 1.

Use either a single large sheet, or several smaller sheets installed side by side, spanning the equivalent of twice the spreader width to collect solid manure. If using a single long sheet, divide the sheet evenly into sections using paint, tape or another suitable method. Ensure that the total area covered by the collection sheets or pans is at least 9 m 2 (100 ft 2 ). For liquid manure use a series of strategically placed shallow pans (Figure 4.6.2). For best results, use a minimum of 8 to 10 pans for the calibration.

If sheets or pans are used for several runs, the tare weight must be

determined before each run to account for any residual manure remaining.

s i d e b a r

tip

Tarps are convenient for the purposes of collecting solid manure since they are easily secured to the ground, inexpensive, easy to clean, and typically come in standard dimensions. Long, shallow, plastic home organization boxes, though somewhat more costly, are equally convenient for liquid manure calibrations.