Estimating Crop Yields; A Brief Guide
Note Number: AG1420
Published: November 2010
Updated: June 2013
A simple method to estimate the yield of a range of field crops for use by farmers and agribusiness is outlined.
Introduction
Accurate, early estimation of grain yield is an important skill. Farmers require accurate yield estimates for a number of reasons:
- Crop insurance purposes
- Delivery estimates
- Planning harvest and storage requirements
- Cash-flow budgeting
Extensive personal experience is essential for estimating yield at early stages of growth. As crops near maturity, it becomes easier to estimate yield with greater accuracy.
Estimation methods
There are many methods available for farmers and others to estimate yield of various crops. Some are straightforward whereas others are more complicated. The method presented in this article is one that can be undertaken relatively quickly and easily Steps are as follows:
- Select an area that is representative of the paddock. Using some type of measuring rod/tape, measure out an area 1 meter square and count the number of heads/pods.
- Do this 5 times to get an average of the crop.
- Count the number of grains in at least 20 heads/pods and average.
- Using Table 1 below determine the grain weight for the crop concerned and follow through the calculation outlined below
Accuracy of yield estimates depends upon an adequate number of counts being taken so as to get a representative average of the paddock. The yield estimate determined will only be a guide and assumptions made from the estimates contain a degree of uncertainty.
This type of yield estimation is one of the easiest and quickest to complete and should be able to be used in a number of situations on a grain growing property. Grain losses both before and during harvest can be significant and an allowance for 5-10 per cent loss should be included in your final calculations.
Table 1: Grain weights expressed as weight per 100 grains.
| Crop type | Weight of 100 grains (in grams) |
|---|---|
| Canola | 0.4 |
| Wheat | 3.4 |
| Lentils | 3.0-5.0 |
| Safflower | 3.8 |
| Oats & triticale | 4 |
| Barley | 4.2 |
| Lupin (narrow leaf) | 16 |
| Chickpea (desi) | 18 |
| Field pea | 20 |
| Lupin (broad leaf) | 30 |
| Chickpea(kabuli) | 40 |
| Faba bean | 50 |
Methodology for estimating wheat yield
| Number of heads/pods per square meter | (A) | Example | 220 |
| Average number of grains per head/pod | (B) | Example | 24 |
| Number of grains per square metre = AxB | (C) | Example | = 220 x 24 = 5280 |
| Yield per square meter = C/100 x 3.4gms | (D) | Example | = 5280/100 x 3.4 = 179.52gms |
| Yield in t/ha = D/100 | Example | = 179.52/100 = 1.79t/ha |
The same method can be used for any other grain crop as long as you choose the correct seed weight from Table 1.
The basis behind this method for estimating yields is the counting of heads or pods per square meter.
Acknowledgements
Developed by Farm Services Victoria from an article published in the Mallee Farmer Newsletter
ISSN 1329-8062
Published and Authorised by:
Department of Environment and Primary Industries
1 Spring Street
Melbourne, Victoria
This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968.
The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication
