More than 50 people crowded into Rob and Trish McCosker’s shed for the Border Landcare Organic Group (BLOG) meeting on Saturday to see David Hardwick demonstrate the art and science of soil chromatography.
Soil chromatography is an inexpensive means of soil testing, first invented 70 years ago and now increasingly used in South American countries.
Those attending found out how to do their own tests at home using a few basic ingredients and kitchen utensils.
David and Rob gave a cooking demonstration and showed how a sample of soil is ground up in an alkaline solution and then absorbed onto a filter paper previously treated with silver nitrate. The finished tests literally give a picture of how much mineral, organic matter and microbial life is contained in the soil sample and the interaction between the components.
The pictures are very decorative, looking like the iris of an eye, but are extremely informative.
David showed how the tests can be carried out within a few hours and then how to easily interpret the results.
A succession of tests over time will indicate the effectiveness of fertilisers, composts and other soil inputs. There was a lot of interest in running an additional workshop where members could bring along their own soils to be tested.
Next month BLOG will be visiting the vegetable gardens of Rex Maddocks, one of the founders of BLOG, as part of their 10th birthday celebrations.
