Investigation of Selcote Ultra Fertilizer Different Rates on Selenium Concentration in Alfalfa (Medicago sativa L.) in order to Satisfy Selenium Requirement

BACKGROUND: Selenium is now recognized as essential trace element for ruminants. OBJECTIVES: Studying the effect of different levels of selcote ultra fertilizer and farm yard manure on the concentration of selenium in alfalfa in order to achieve optimum concentration of selenium in this plant. METHODS: The experiment was factorial based on randomized complete block design with three replications. Experimental factors consisted of Se levels (0, 5, 10, 20 and 40 g ha-1) and farm yard manure (zero and 100 tons per hectare). Plant was harvested at the height of 20 cm in three turns and after preparation the plant samples, their selenium concentration was measured. RESULT: The result of means comparison showed that the concentration of selenium during three harvests was affected by different levels of selenium fertilizer and farm yard manure. With increasing selenium rates, selenium concentration in the plant aerial parts in all three harvests raised significantly (p<0.05). Selenium concentration for the cattle in all treatments except for the control treatment in all three harvests was in the optimal range. CONCLUSION: The treatment of 5 g ha-1 selenium could be used as a suitable treatment for providing cattle and human demands with selenium, because its application is more economical in comparison to treatments of 10, 20, and 40 g.ha-1.