CONCLUSION
The present study focused on effects of different cropping
systems of long-term (28 yr) use of winter green
manure on the distribution of SOC and total N in soil
aggregates from the plowed soil layer. Long-term use of
winter Chinese milk vetch was the best in promoting the
formation of 2-5-mm water-stable aggregates. Winter
green manure significantly increased the SOC and total
N contents, and the proportion of organic C distributed
in water-stable aggregates was increased. The organic
C was mainly enriched in the 1-5-mm and secondly in
>5-mm water-stable aggregates. The content of total N
in all sizes of aggregates was also increased. Total N was
mainly enriched in the larger water-stable aggregates,
especially >2 mm. Long-term winter planted green
manure, especially Chinese milk vetch, increased the
storage of organic C and total N in 5-mm and