بررسي وضعيت تغذيه اي درختان ملج Ulmus glabra Huds و ارتباط آن با ضعف و خشكيدگي آنها در باغ گياه شناسي ملي ايران

Nutritional status of Elm (Ulmus glabra Huds.) trees in National Botanical Garden of Iran

The National Botanical Garden of Iran (NBGI) with an area of 145 hectares contains various plants with different ecological requirements, including trees, shrubs, herbs and ornamentals. Weakness and decline of some tree speeies including Elm trees of botanical garden is one of the problems, which considered as the main priorities to be investigated by the garden authorities. Soil productivity and plant nutrient were concerned to be studied. For this reason, soil samples were taken from three layers of each profile (0-10,10-30 and 30-100 em) around Elm trees, after studying the soil profile morphology. Leaf sampling was made at appropriate time in order to test N, P, K at first year and N, P, K, Ca, Fe, Mn and Zn at second year. Results showed that the soil texture was sandy, organic mater was low and pH was alkaline. The mineral elements were lower than the optimum range in soil and tree leaves. 1t can be concluded that increasing soil organic matter, adding adequate amount of manure and chemical fertilizers to soil and applying appropriate irrigation regime might improve the plants health and growth and prevent their decline.