Influence of Blended NPSB Fertilizer Rates and Cattle Manure on Growth, Yield and Yield Components of Black Cumin <i>(Nigella Sativum</i> L.<i>) </i>in Guder, Ethiopia

Abstract

Black cumin is a seed spice cultivated in Ethiopia for a long period of time. It is also cultivated in the Toke Kutaye district of West Shewa Zone by small-holder farmers. However, the expected benefit of this crop is not being obtained by farmers since they are using in-appropriate agronomic practices including in-appropriate fertilizer applications. A field experiment was conducted at Gudar campus, Toke Kutaye district to determine the influence of different rates of NPSB fertilizer and cattle manure on growth, yield, and yield components of black cumin. The treatments consisted of factorial combinations of four NPSB blended fertilizer levels (0, 50, 100, and 150 kg ha^-1) and four CM levels (0, 2.5, 5, and 7.5 t ha^-1). The experiment was laid out as a Randomized Complete Block Design in a factorial arrangement and replicated three times. The results indicated that interaction of NPSB and CM highly significantly (P<0.01) influenced yield parameters except for growth and phenological parameters such as days to 50% flowering, days to 90% maturity, primary branches, and secondary branches. However, Days to 50% emergence was not affected by the combined application of NPSB blended fertilizer and cattle manure. The tallest plants (49.20 cm), the highest number of capsules per plant (25.00), the highest numbers of seeds per capsule (99.40) and, the highest harvest index (47.42%) was obtained from the treatment that received 100 kg NPSB ha^-1 and 7.5 t CM ha^-1. The highest seed yield (1113.33 kg ha^-1) was also obtained from the application of 100 kg NPSB ha^-1 and 7.5 t CM ha^-1. Similarly, the highest MRR (%) was obtained from the interaction effect of 100 kg NPSB ha^-1 and 7.5 t CM ha^-1 with a marginal rate of revenue (20576%) and net benefit of 86579.7 birr. Thus, the application of 100 kg NPSB ha^-1 and 7.5 t CM ha^-1 can be promoted for increased productivity of black cumin and economically feasible in the study area. Since the experiment was conducted at one place and one cropping season, the further trial will be needed for the final recommendation.