Changes in the concentration and uptake of macronutrients, fertilization economic efficiency and nitrogen use efficiency for isabgol medicinal plant production under different treatments of manure and chemical fertilizers

In order to investigate the effects of organic and inorganic fertilizer rate on the concentration and uptake of some macronutrients, nitrogen use efficiency and economic efficiency of fertilizer applications in the production of isabgol (Plantago ovata Forssk) medicinal plant, an experiment was conducted in a randomized complete block design with seven treatments and four replications at the research farm of Shahrekord University in 2011. Fertilizer treatments consisted of control (no fertilizer), three levels of available nitrogen 30, 60 and 90 kg ha-1) of cow manure and three levels of available nitrogen (30, 60 and 90 kg ha-1) of ureafertilizer. Results showed that the application of fertilizer caused a significant increase in nitrogen and potassium concentration of seed and uptake of nitrogen, phosphorus and potassium of seed (P<0,05). Seed nitrogen concentration and uptake in urea fertilizer application were significantly higher than in cow manure (P<0,05). But, the uptake of phosphorus and potassium were significantly higher in the cow manure application than the urea fertilizer application, where the concentration of 90 kg ha-1in the form of cow manure were 7,8 and 57,24 g kg-1, respectively. Generally, the highest of concentration and uptake of nutrients, nitrogen physiological and recovery efficiency were obtained in 90 kg ha-1 nitrogen as a urea and/or cow manure source. Although, the nitrogen agronomic efficiency of these two N sources have no significant difference, the nitrogen physiological efficiency, nitrogen recovery efficiency and fertilizer economic efficiency of both fertilizers have significant differences. Therefore, it is concluded that the better quality of phosphorus and potassium in seed in applications of cow manure, in addition to the equal nitrogen use efficiency of these two N sources indicate the superior ecological role of the application of manure in production of isabgol medicinal plant and the necessity of its quality validation in organic crops.