The role of soil limitations on the decline of Cypress (Cupressus arizonica L.) in 20 years old forest green space of Mobarake steel complex

Understanding the capability of soils and land use limitations is a key factor in allocating the lands to the most appropriate use and also improving the growth conditions of plants in those lands. This research aimed to study the soils and recognize their limitations in cypress forest of Mobarakeh Steel Complex in order to prevent deterioration and decline of the trees. In the first step, plots were selected in the forest and a soil profiles was drilled in each plot. Soil samples were collected from the profiles. Also, soil and leaf samples were collected from the canopy of the healthy and unhealthy trees, separately. The results indicated that the soils have variety of limitations, including high gravel content (more than 50%), lack of organic matter (less than 0.5%) and nutrients, high calcium carbonate and pH coupled with soil compaction. There was a significant difference in the uptake of iron, manganese, zinc, copper, chlorine and sodium from the soil between healthy and unhealthy cypress trees. To improve the soil conditions in order to prevent the decline of cultivated trees, soil fertility and plant nutrition management program should be considered in the study area. Also, the use of organic fertilizers is recommended.