After reading a blog by Medwyn (of Anglesey) about the use of Charge soil conditioner, by exhibition growers. I happened upon it half price and with free p&p (dtbrown I think) late last year, and have been adding it to the mpc, when potting on this spring.
So far the results have been great, IMO it's certainly worth it, even better if you can get it at half price
charge soil conditionerThe research does seem to point to lack of humus and soil-life leading to soil erosion and reducing yields. Perhaps farming needs to look at less chemical fertilisers and more at soil improvement. I saw a case being made for returning to mixed farming (animal & agricultural) in order to improve soil fertility - perhaps that is the answer?