We are looking to do a trial working with the company Soilfixer and using their product Boichar in some of the hanging baskets to see how the product can boost the compost we are using.
At the moment what is being used is a mix of mix 50/50 compost plus Blood, Fish and Bone fertiliser/ sieved soil and this would be the control compost in the hanging baskets.
For the biochar hanging baskets it is suggested using 1/3 biochar, 1/3 spent compost with blood, fish and bone fertiliser in it and 1/3 top soil (sieved, through 10 mm mesh i.e. squirrel wire mesh) which will help water retention. Soilfixer is offering 0-8 mm sieved biochar as their suggested addition to the soil mixture.
Grower Ian would like to be able to have one polytunnel as the control tunnel and one tunnel using biochar in the hanging basket compost. This would then make it quite obvious which set of baskets is the most productive. And it would enable us to produce more over the winter from our own space for our crop shares.