HowMuch? Relating crop yields to rainfall records.

Download HowMuch? (1.13MB)
HowMuch Factsheet (137KB)
HowMuch? Manual

The HowMuch? program is a WINDOWS based educational tool which uses rainfall records to estimate crop yields from crop Water Use Efficiency (WUE) and the Plant Available Water Capacity (PAWC) of your soil.
It is an "open box" modelling environment in which growing season rainfall is adjusted by user defined weightings to compare the influence on yield of rainfall at various crop stages.

With HowMuch? you can find...

Relationships between planting dates and rainfall patterns.
Suppose the winter planting dates for Dalby are May 22 to July 22.
With HowMuch?, you can investigate which part of the planting window coincides with the best "average" rainfall.

If it's possible to match flowering date to a period of high rainfall.
Rain at flowering of grain crops leads to greater yields. HowMuch? will show if flowering dates coincide with periods of rainfall.

Statistics associated with yields and rainfall.
Means, medians, percentiles, standard deviations and coefficients of variation.

The chance of getting rain at various (user defined) crop stages.
For instance, the chance of getting rain at harvest time.

If improving Water Use Efficiency improves yield.

or you can....

list all yields by year or size,
show and print graphs of annual yields, and rain at various crop stages.

Inputs are simple - just select from the menu:

a locality,
crop growth periods (including sowing and harvest),
Water Use Efficiency of the crop and Plant Available Water Capacity of the soil.

Over 100 years of rainfall data are generally available for each location.

Results are presented in tables and graphically.

Rainfall data are available for many localities in Australia, simply email your request to David Freebairn.

To download HowMuch? (1130KB) click here: HowMuch?