Harvest Loss Calculator

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Use this tool to calculate harvest loss. This calculator is designed to measure grain loss at harvest. It can be used with trays that are thrown / placed.

A GRDC project managed by Peter Newman - Planfarm 0427 984 010

  • Schergain drop pan

  • Harvest loss calculator using drop tray

    This calculator is designed to measure grain loss at harvest using a drop tray that is mounted underneath the harvester. It can also be used with trays that are thrown / placed.

    This Schergain drop pan is 0.295m x 1.6m = 0.5m2

    (If you are using a different tray, download the spreadsheet and add your own tray dimensions)

    Open harvest loss calculator

    Download Harvest loss calculator (XLSX 17kb)

How to measure harvest loss with drop pan

There are two ways to use this drop pan to measure harvest loss:

1. Chop and spread mode

This option involves leaving your harvester in normal chop and spread mode. There will be variation in losses across the width of the machine so you may want to compare losses between the centre of the machine and just outside of the wheels
(you can attach the drop pan to the harvester front to do this)

When operating in normal chop and spread harvest mode, weigh the grain in the tray and use the formula below to calculate losses.

For a 0.5m2 tray the equation is:
Weight of grain (g) X 20 = harvest loss in kg/ha

2. Windrow mode

This option involves setting your harvester up into windrowing mode and catching everything.  This has the benefit of measuring all losses but keep in mind that switching to windrowing mode can change air flow through the harvester and can affect losses, often increasing losses.

To calculate losses using this technique measure grain loss in the drop pan in grams and multiply by the “multiplication factor” in the right hand column to estimate grain loss in kg/ha.

For a 29.5cm wide drop pan the equation is:
Weight of grain (g) X multiplication factor = harvest loss in kg/ha

Harvester width

(feet)

Harvester width

(m)

Cut width*

(m)

Area of crop **

(m2)

Multiplication factor

(multiply harvest loss in grams by the number below to calculate harvest loss in kg/ha)

30

9.1

8.9

2.63

3.81

36

11.25

11

3.25

3.08

41

12.62

12.4

3.66

2.73

42

12.92

12.7

3.75

2.67

45

13.68

13.5

3.98

2.51

50

15.21

15

4.43

2.26

60

18.41

18.2

5.37

1.86

* we removed about 200mm from front width to allow for wiggle

** area of crop calculated as harvester width multiplied by width of drop pan (0.295m)