Temporal stability of spatial distribution pattern of soil water tension at different scales

The temporal stability of soil water tension in an area of 32 km2 (Pandian Village, PDV) and in an experimental field of 0.05 km2 (Fengqiu experimental station, FQS) were analyzed. 39 and 44 measuring stations were set up in PDV and FQS, respectively. At each station, soil water tension was measured using two tensiometers at 20 cm and 40 cm depths. The soil water tension in PDV was measured 19 times from March 2004 to May 2004, and the soil water tension in FQS was measured 27 times from March 2004 to July 2004. The results show that temporal stability is existed in two scales, and FQS is priori to PDV. There is large influence of irrigation on the temporal stability of soil water tension, and the low temporal stability occurs as the transition from dry to wet. For PDV, temporal stability persists in an irrigation cycle, while for FQS, temporal stability was persists in the whole measuring period and different types of crops.