Nutritional responses of Thymus exposed leaf spraying under soil nitrogen deficiency

Thyme is a valuable plant used in medicine, perfumery and food industry. Mineral deficiencies often limit the growth of plants. Nitrogen deficiency in agricultural soils is a problem throughout the world. The present study evaluated effects of applying Fe and Zn in absorption of some important nutrients of Thymus vulgaris L. under nitrogen deficiency. Potted experiments were designed to study effect of spraying some micronutrients on nutrient contents of thyme. Nitrogen deficiency applied whereas application of N decreased to half, 1/4 and zero. At the same time, foliar spraying of Fe2+ and Zn2+ in concentration of 1% and 2% was replicated each 15 days. Results showed that application of Zn 2% cause increase in NO3- content of thymus root and in shoots of deficient plants. Also foliar spraying of Zn and Fe cause increase in P and NO3- content of thymus plants under nitrogen deficiency conditions. There was significant correlation (P<0.05, r>0.9) among micronutrients, P and NO3- content under N deficiency. Analysis of variance showed that the difference in all nutrients content between nitrogen treatments, among spray of different micronutrients and nitrogen treatments × spray was significant in roots and shoots of plants and soil. Foliar application of iron and zinc significantly enhanced the absorption of other nutrients in thymus plants under deficiency conditions, but influence of zinc was higher. It seems that foliar fertilizer improves nutrition of plant in nitrogen deficiency conditions and decrease environmental hazard by decreasing the applying of chemical fertilizers in soils.