Abstract: Based on 184 samples taken from 27 paddy field experimental sites in the ricewheat rotation fields in lower Yangtze River， a Metaanalysis was performed to quantify the relative annual changes of soil organic carbon （SOC） content （RAC） and SOC sequestration duration in paddy fields under 4 fertilization modes （inorganic nitrogen fertilization， N; inorganic nitrogen， phosphorus， and potassium fertilization， NPK; organic fertilization， O; and inorganic combined with organic fertilization， OF）. It was shown that all fertilization treatments could significantly increase RAC in paddy fields， and the RAC under N， NPK， O and OF was 0.05， 0.19， 0.22 and 031 g·kg-1·a-1， respectively， and the highest RAC was recorded under OF treatment. RAC in topsoil under double cropping system and triple cropping system was 0.26, 0.21 g·kg-1·a-1， respectively. The topsoil organic carbon accumulation rate decreased gradually with increasing time under all 4 fertilization modes. The soil organic carbon sequestration duration of N， NPK， O and OF was 19， 36， 51 and 47 a， respectively， and it was the longest under O treatment. Accumulation enhancement rates of SOC for N， NPK， O and OF over the whole soil organic carbon sequestration period were 6.93%， 18.98%， 22.34% and 32.33%， respectively， and it was the largest under OF treatment. From the perspective of soil carbon sequestration in cropland， fertilization treatments with inorganic combined with organic fertilization was more appropriate for ricewheat rotation in the lower Yangtze River.

Key words: ricewheat rotation, fertilization, carbon sequestration, Metaanalysis