Physical protection of mineralizable C in aggregates from long-term pasture and arable soil

Depending on agricultural management, soil aggregation can provide physical protection of organic matter against rapid decomposition. Within a given soil series, farm management affects the quality and quantity of organic inputs, soil disturbance and biological activity, and thereby the processes of aggregate formation (biogenic vs. physicogenic). We determined the physical protection of readily mineralizable organic matter against mineralization in undisturbed aggregates from a conventional arable field and a permanent pasture (>70 years). Soil samples from the two fields were incubated at constant temperature and moisture content, corresponding to field capacity. The increase in CO, evolution due to crushing (