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‘Tea-bag’ test - Doncaster Ryegrass Innovation Centre

Innovation Centres

Baby grow buried to monitor the rate of breakdown in the soil

The weather last autumn and early spring has not been kind to us at the Doncaster Ryegrass Innovation Centre and Andy Cunningham, Field Technical Specialist, has struggled to get crops in the ground… but there is light at the end of the tunnel for one experiment he is carrying out with or without a crop!

Andy is looking at how healthy the soil is after two different types of cultivation, ploughing vs min-till.

Ploughing often has a negative effect on soil health as it disturbs the earthworms and soil microbes according to Andy. Whereas minimal tillage can have a positive effect by leaving the soil microbes and earthworms to do their job of being natures plough and creating healthier soils. But, due to the wet weather, the worm holes will have filled with water and therefore, in this case, the ploughed area may fair better this season.

Many people may have heard of the ‘underpant’ test, well ‘Y-fronts’ really, says Andy, but he was unable to purchase any (at a price that was low enough to justify burying them in the ground), so as a substitute is using ‘baby-grows’, which are organic (100% cotton). The rate of breakdown of these in the soil can indicate how active and healthy the soil is!

Tea bag weighing in

Andy is also carrying out the ‘Tea-bag test’, Green vs Red Tea – Green tea has a lower carbon:nitrogen ratio and so should break down whether the soil is healthy or not. The Red tea has a higher carbon:nitrogen ratio and therefore will be harder to break down, however, a healthy soil should break it down naturally. After 3 months, the bags will be weighed, a lower weight means a healthy and active soil, so let’s see…

For both of these experiments, Andy is going to bury the ‘baby-grows’ and tea bags in each of the cultivated areas and then on a monthly basis, dig them up, wash them down and weigh them to see how much degradation has occurred. By the Open Day, Andy should have a good idea of how healthy these soils are in the different cultivation situations.

To find out the results of this experiment, please join us at the Ryegrass Focus Site Innovation Centre Open Day.