Response of Mung Bean [Vigna radiata (L.) Wilczek] to Levels of Nitrogen and Phosphorus Fertilizer under Irrigation in Central Ethiopia

Abstract

Mung bean has become an important cash and food crop in dry land areas of Ethiopia. However, there is no sufficient research information on the nitrogen (N) and phosphorus (P) fertilizers rates for the crop in the study area. Thus, field experiment was conducted to determine the effects of N and P fertilizer rates on growth, yield components and yield of mung bean under irrigation at Nura-Era, central Ethiopia. The treatments consisted of factorial combinations of three N fertilizer rates (0, 23 and 46 kg N ha-1) in the form of Urea (46% N) and five P fertilizer rates (0, 10, 20, 30 and 40 kg P ha-1) in the form of Triple Superphosphate (20% P)  laid out in randomized complete block design (RCBD) with three replications. Result of the main effect of nitrogen rate showed significantly highest number of primary branches per plant (4.25), number of  pods per plant (17.7), and 100 seed weight (4.94 g) at 23 kg N ha-1. Similarly, the main effect of P fertilizer rate showed that the application of 40 kg P ha-1 produced significantly the highest number of primary branches per plant (4.79), highest number of pods per plant (20.85), the highest number of seeds per pod (6.24), the highest aboveground dry biomass (6838.83 kg ha-1), the highest 100 seed weight (5.21 g) and the highest harvest index (25.96%). The interaction of N and P rates showed that the combination of 23 kg N ha-1 and 40 kg P ha-1 gave the highest grain yield (1902.78 kg ha-1). Thus, the combination of 23 kg N ha-1 and 40 kg P ha-1 can be used to increase the productivity of mung bean in the study area.