10 Research in Ecology | Volume 01 | Issue 01 | March 2019 Distributed under creative commons license 4.0 DOI: https://doi.org/10.30564/re.v1i1.596 Research in Ecology https://ojs.bilpublishing.com/index.php/re REVIEW Effect of Nitrogen and Potassium on Yield, Yield Components and Es- sential Oil of Black Caraway (Bunium Persicum L.) Hamid Reza Zabihi 1* Mojtaba Nourihoseini 2 1. Soil and Water Department, Khorasan-Razavi Agricultural and Natural Resources Research Centre, Agricultural Re- search, Education & Extension organization(AREEO), Mashhad, Iran 2. Post PhD student of Soil Science Department, Ferdowsi University of Mashhad and Soil and Water Department, Khorasan-Razavi Agricultural and Natural Resources Research Centre, Agricultural Research, Education & Extension organization, Mashhad, Iran Dept. of Soil and Water, Khorasan-Razavi Agricultural and Natural Resources Research Centre, Mashhad(AREEO), Iran. ARTICLE INFO ABSTRACT Article history Received: 19 March 2019 Accepted: 3 April 2019 Published Online: 30 April 2019 Fertilization is the main factor stimulating yield of plants, nitrogen and potassium are among must important essential nutrients. An experiment was conducted to investigate the effect of different rates of nitrogen and potassium on yield and yield components of Black caraway (Bunium persicum L.). The experiment was on the base of randomized complete block design with three replications for 3 years in Torogh agriculture and natural resources research station, iran. Plow, disc, leveling, creating planted rows and making plots was performed in mid-September. All potassium fertilizer and half of the nitrogen were applied at planting. The rest of the nitrogen was applied in the form of top-dressing at fowering stage in the second week of April. The size of each experimental plot was 4 × 3 meters in 6 rows and 12 lines. Treatments were 4 levels of nitrogen (0,40,80and120 kgN/ha in the form of urea), and three levels of potassium (0, 40 and 80 kg k2O/ha in the form of sop). The results showed that the effect of nitrogen and potassium on grain yield, yield components, straw yield and essential oil content was signifcant (P<0.05). Nitrogen rate of 40 kg/ha increased grain yield and some yield compo- nents and essential oil. Whereas the higher rate decreases grain yield and yield components, and increases straw yield. Interaction of nitrogen and potassium on grain yield, straw yield and number of umbels per plant, was signifcant(P<0.05). Keywords: Macronutrients Medicinal plant Potash Seed yield *Corresponding Author: Hamid Reza Zabihi, Soil and Water Department, Khorasan-Razavi Agricultural and Natural Resources Research Centre, Agricultural Research, Education & Extension organization(AREEO), Mashhad, Iran; Email: Zabihi_hamidreza@yahoo.com. 1. Introduction B lack caraway (Bunium persicum L.) Perennial plant, herbs with corm, from the Umbelliferae (Apiaceae), is endemic restricted area of West Asia which also includes the eastern half of Iran [1] . The black cumin seed has been widely used in folk medicine for the treatment of a number of diseases such as diarrhea, jaundice, amenorrhea, helminthiasis, oph- thalmic, paralysis and osthema [4] . Black caraway is a wild