The field experiments of irrigation with seawater mixed with fresh water were carried out in Laizhou,Shandong Province The
results showed that high proportion of
seawater irrigated had a function of water conservation in arid and
semiarid region Characteristics of the soil moisture irrigated with seawater were as follows: (1)In semiarid region,the soil moisture content in 050 cm soil layer was affected mainly by irrigation,rainfall and evaporation etc But this effect became smaller with the depth of soil As the proportion of seawater increasing,soil water suction in 050 cm soil profile became lower while soil moisture content increased gradually,and the capacity of water conservation increased 40%60% or so (2)The soil water suction in different soil layers changed significantly with the proportions of seawater The soil water suction in 5,15 and 50 cm soil layer of different treatment was in following order: A,B,C,D,except in 30 cm soil layer,B got the highest water suction (3)All of the soil water suction decreased to the smallest in 68 hours after irrigation The soil water suction in the 515 cm of soil layer produced high increase in 7080 hours after irrigation The soil water suction in 5 cm soil layer of the treatments of A and B differed evidently from C and D in 48 hours after irrigation As the time prolonged,the difference became larger This case was also found in 15 cm of soil layer in 60 hours after irrigation The soil water suction in every treatment of 30 cm soil layer was almost identical