Our study was made to determine the influence that saline water of agr
icultural quality has on microbial processes that contribute to soil s
tructure formation. Pots with Yolo fine sandy loam soil were watered f
or 6 weeks with saline water (SW) of EC = 5 ds m-1 and with regular wa
ter (RW) of EC = 1 ds m-1. Every 14 days the pots were sampled and the
following measurements were made: C and N mineralization rate; microb
ial biomass-C and -N content, carbohydrate production and soil aggrega
tion and stability. Irrigation with saline water increased the accumul
ation of C and N in microbial biomass, but decreased the rate of C and
N mineralization, carbohydrate content and aggregate stability. The p
roportion of macroaggregates (0.2-3.0 mm) in the soil was reduced due
to the effect of dry soil wetting, regardless of water type. It seems
that structure deterioration of soil under saline water irrigation, is
not solely due to chemical and physical interactions between the soil
particles and the solution salts, but also to the fact that saline wa
ter irrigation causes a reduction in carbohydrates produced by microor
ganisms, and thus a reduction in aggregate stability.