EFFECT OF BLENDED NPSB FERTILIZER RATES AND INTRA ROW SPACING ON GROWTH, YIELD AND YIELD COMPONENTS OF FABA BEAN (Vicia faba L.) AT LOMA DISTRICT, SOUTH WESTERN ETHIOPIA

Abstract

Faba bean (Vicia faba L.) is a legume crop in the fabaceae family. It is cultivated by farmers for consumption and commercial purposes in Dawuro zone particularly in Loma. However, the yield of the crop is low in the area due to low soil fertility, lack of information regarding optimum planting density and the actual rate of the newly recommended blended NPSB. Therefore, current study was conducted to determine approprite intra-row spacing and blended NPSB fertilizer rates for growth, yield and yield component of faba bean in Loma District. The experiment was laid out in a randomized complete block design (RCBD) with three replications in a 3x5 factorial arrangement.There were 15 treatment combinations consisting of three intra-row spacing( 5, 10, and 15 cm) and five rates of blended NPSB fertilizer (0, 50, 100, 150, and 200 kg ha-1).Result showed that NPSB fertilizer rates and intra-row spacing had significant effect on branch number per plant, total nodule number per plant, seed number per pod, thousand seed weight, and harvest index. Thus, highest branch number per plant (3.3) and total nodule number per plant (153.7) were recorded from application of 200 kg NPSB ha-1. Whereas, highest seed number per pod (2.9), thousand seed weight (567.7g) and harvest index (35.2%) were recorded from application of 150 kg NPSB ha-1. Regarding intra-row spacing, the highest branch number (2.9) and total nodule number (121.5) were recorded from 15cm intra-row spacing. Similarly, highest seed number per pod (2.75), thousand seed weight (533.3g) and harvest index (33.7%) were recorded from 15cm intra-row spacing. The highest plant height (147.7cm), and pod number per plant (24.26) were recorded from the interaction of 200kg NPSB fertilizer ha-1 with 5 and 15cm intra-row spacing respectively. The highest above ground biomass yield (11600kg ha-1) and highest grain yield (4006.8kg ha-1) were recorded from interaction of 150kgNPSB fertilizer ha-1 with 5cm intra-row spacing. With regard to partial budget analysis, the highest net benefit (112,507ETB ha-1) with marginal rate of return (1380%) was obtained from interaction of 150 kg NPSB fertilizer per ha combined with 5cm intra-row spacing. Based on the results of this study, it can be concluded that application of 150 kg NPSB ha-1 combined with 5cm intra-row spacing could be used for faba bean production in the study area.