Based on the profiled soil physical/chemical and hydraulic properties measurement

the characteristics of water percolation and conservation in different aged paddy fields in the Jianghan Plain were investigated

and the paddy fields were of 17 years (new paddy field

NF) and more than 100 years (old paddy field

OF)

respectively. The results were as follows: (1) Water percolation was more likely to occur in the NF. The higher average saturated hydraulic conductivity (Ks) in the NF (32.05 cm/d) was observed than that in the OF (17.91 cm/d). The highest Ks was observed in the plow layer

followed by the subsoil layer

and the lowest Ks was in the plough pan. The Ks of plow layer was 6.3 and 5.7 times of the plough pan and subsoil layer for the NF

and 6.9 and 4.0 times for the OF

respectively. (2) Higher water capacity was observed in the OF than that in the NF. The highest water capacity was identified in the plough pan

followed by the subsoil layer

and the lowest was found in the plow layer. However

the macropore distribution showed the opposite law. (3) The available water content decreased with the decreasing soil depth in the NF and OF

with higher values observed in the OF. In addition

higher total water capacity and flooding control capacity were also observed in the OF. The water shortage stress and groundwater pollution risk were increased by the land transformation from the non-irrigated farmland to the paddy field.