Physicochemical Properties and Micromorphology of Pistachio Orchards Compared to Adjacent Non-cultivated Soils in Bayaz Area

Crop management and irrigation water quality play an important role on soil properties. The present research aimed to study physicochemical properties and micromorphology of soils under pistachio orchards compared to non-cultivated adjacent soils. Four water samples with different Mg/ca ratios were selected according to analyses of 500 irrigation water samples. Five pedons in pistachio orchards and 4 pedons in non-cultivated adjacent soils were studied. Routine physicochemical analyses and micromorphology observations performed on soil samples. Results of the study showed that electrical conductivity in non-cultivated soils (256 dS/m) was remarkably higher than cultivated soils (8. 9 dS/m). Mg/Ca ratio in cultivated soils compared to adjacent non-cultivated soils increased with increasing Mg/Ca ratio of irrigation water. On the other hand، using high quality irrigation water decreased this ratio in cultivated soils compared to blank samples. Lenticular and interlocked plates of gypsum observed in non-cultivated soils. Isolated and small size lenticular gypsum crystals were dominant in pistachio orchard soils.