Journal of Plant Process and Function

Today, due to positive effect of nitrogenous fertilizers on growth, yield and quality of agricultural crops, irregular use of fertilizers is increased. In order to evaluate the effects of different sources and quantities of nitrogen fertilizers on some of physiological properties of Fenugreek (Trigonella foenum- graecum L.) medicinal plant, an experiment was carried out as a randomized block design with four replications at research farm, department of horticulture, Ilam University during summer 2015. Treatments included different levels of (0, 25, 50 and 100 kg/h) from Urea and Calcium Nitrate fertilizer sources and Amino Acid with four concentrations: 0, 1,2 and 4 g/l. Studies traits were including photosynthetic pigments content (Chlorophyll a &b, total chlorophyll and carotenoids) fiber percentage, Carbohydrates content, proteins percentage and essential oil yield of leaves. Results showed that sources and quantities of nitrogen significantly affected all studied parameters. The highest pigments’ content, protein and essential oil yield of leaves obtained from 4 g/l amino acid treatment; the highest leaf fiber from 100 kg/h calcium nitrate and the highest leaf carbohydrate content obtained from control plants and increasing in nitrogen from all three sources led to decrease in carbohydrates content. The research revealed that using different sources and quantities of nitrogen fertilizers (especially amino acids) have positive effects on improvement of physiological traits of fenugreek and application of nitrogen can be advised for increasing quality of the leafy vegetable and medicinal plant.