Soil Your Undies group

Soil Your Undies

In a recent study field trip, Cam Barr, SFS visited the north-central and northeast NSW cropping regions and table lands surrounding the towns of Armidale, Moree and Inverell. This tour was centered around soil health and examining soil profiles across different landscapes.

Along the trip, Professor Oliver Knox, who has worked extensively in soil biology and assisting cotton growers to improve their soil productivity, introduced the group to the soil health program named ‘Soil Your Undies’, of which he has been influential in starting across Australia in conjunction with CottonInfo.

The program, which has been adapted from a similar initiative in Canada, is an engaging way of demonstrating soil microbial activity in the soil. It is a simple method that can be applied by anyone, anywhere, and has been demonstrated to more than 500 groups of Australian farmers to date.

Essentially, white pure cotton undies are buried below the soil surface for a period of 8 weeks. After this period, the undies are dug up, and varying levels of degradation can be observed depending on your soil type and microbial activity. This provides a visual representation of soil nutrient availability, organism presence and overall soil health. Professor Knox said that producers used this test alongside their soil tests as a visual marker, acting as an addition to the soil physical and chemical data detailed in their soil tests.

In further detail, the cotton fibres are made up of cellulose, which are glucose polymers pieced together. A variety of soil microbial organisms such as fungi and bacteria release cellulolytic enzymes responsible for the breakdown and cycling of these glucose polymers back into the soil system. Therefore, the more organism activity and presence in your soil system, the greater amount of breakdown of the cotton undies. The result can lead to broader considerations of your soil system, including soil pH, temperature, texture, nutrients and organic matter, which may be adjusted to influence your soil microbial population.

This is an activity you can implement on your property as well, as a visual representation of your soil health. Simply select a variety of areas across your property, with varying soil textures, colours, moisture availability, topography or crop types, and bury some 100% cotton undies in the topsoil for 8 weeks. Dig up the results and let us know how you go! Or learn more

By Cameron Barr, SFS Graduate Research & Extension

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