From New Scientist, quoting a paper in Nature:

Soil may spoil UK’s climate efforts

'Unexpectedly vast quantities of carbon released from British soils since 1978 may be critically reducing their effectiveness as carbon sinks ( 'The scary thing is that the amount of time that we have to do something about climate change is now smaller.' )

Can anyone access the original paper, and see whether agricultural soil management techniques make any difference at all? Journal reference: Nature (DOI:10.1038/nature04038)