عنوان مقاله [English]
Soil water potential was determined for three soil samples (i.e. 0-30, 30-60 and 60-90 cm depth) by the filter paper method (Hamblin, 1981) and also for four non-destructive soil samples (i.e. 0-30, 30-50, 50-75 and 75-90 cm horizon) using pressure plate method. In filter paper method, the filter paper is placed in hydraulic contact with the soil until an equilibrium state is attained in which the water potential within the filter paper is the same as that in the soil. The relationship between the matric potential of water in the filter paper and the water content of the filter paper is described by the moisture characteristic curve of the filter paper. This has been previously determined for Whatmanâ No 42 filter papers and has been shown to be consistent between batches (Hamblin, 1981). Hence, from the water content of the filter paper, the matric potential of the filter paper can be estimated, which gives the matric potential of the soil with which the filter paper is in contact.